South San Francisco City Council
December 10, 2025

Table 1: Sample Summary
Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves
Property Location Sample
ID(s)
Depth
Interval
(feet bgs)
Matrix Latitude
(ɿN)
Longitude
(ɿW)
Analyses
Performed
616
Linden
SG-1 616-SG-1-
03042021 5 Soil Gas 37° 39'

31.910”
122° 24'

30.803”
VOCs
(BTEX, MTBE,
naphthalene,

EDB, EDC)
Oxygen,
Helium
SG-2 616-SG-2-
03042021 5 Soil Gas 37° 39' 31.545”
122° 24'

30.906”
VOCs
(BTEX, MTBE,
naphthalene,

EDB, EDC)
Oxygen,
Helium
SG-3 616-SG-3-
03042021 5 Soil Gas 37° 39'

31.497”
122° 24'

30.383”
VOCs
(BTEX, MTBE,
naphthalene,

EDB, EDC)
Oxygen,
Helium
SG-4 616-SG-4-
03042021 5 Soil Gas 37° 39'

31.203”
122° 24'

31.121”
VOCs
(BTEX, MTBE,
naphthalene,

EDB, EDC)
Oxygen,
Helium
SB-4
(collocated
with SG-4)
616-SB-4-
03022021
616-SB-4-
03022021-
D
4 – 5 Subsurface
Soil
37° 39'

31.203”
122° 24'

31.121”
VOCs (BTEX,
MTBE,
naphthalene,
t-Butyl alcohol,
chlorinated
VOCs),
16 priority
pollutant PAHs,
Wear metals,
TPH (TPH-g,
TPH-d,
TPH-mo)
SG-6 616-SG-6-
03042021 5 Soil Gas 37° 39'

30.598”
122° 24'

31.256”
VOCs
(BTEX, MTBE,
naphthalene,

EDB, EDC)
Oxygen,
Helium

DCE, PCE,
TCE, vinyl
chloride
Table 1: Sample Summary
Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves

Property Location Sample
ID(s)
Depth
Interval
(feet bgs)
Matrix Latitude
(ɿN)
Longitude
(ɿW)
Analyses
Performed
616
Linden
Temporary
Stockpile
(Soil within
Concrete
Structure)
616-EC03012021 0.5 -3.8 Soil 37° 39'

30.725”
122° 24'

31.466”
Title 22 Metals,

STLC CA WET
with Citrate
Buffer
(Chromium and
lead), , STLC
CA WET with
DI water (Lead
ony), TCLP
(Lead only)
Immediately
below
concrete
structure
616-SB-7-
03012021 3 – 3.4 Soil 37° 39'

30.725”
122° 24'

31.466”
Title 22 Metals,

STLC CA WET
with DI water
(Chromium and
lead)
700
Linden
SS-1 700-SS-1-
03042021 0 – 0.5 Surface Soil
37° 39'

33.628”
122° 24'

30.537”
Lead
(composite
sample)
37° 39'

33.376”
122° 24'

30.457”
37° 39'

33.438”
122° 24'

30.760”
37° 39'

33.817”
122° 24'

30.314”
37° 39'

33.880”
122° 24'

30.617”
SS-2 700-SS-2-
03042021 0 – 0.5 Surface Soil
37° 39'

33.503”
122° 24'

29.931”
Lead
(composite
sample)
37° 39'

33.251”
122° 24'

29.851”
37° 39'

33.313”
122° 24'

30.154”
37° 39'

33.755”
122° 24'

30.011”
37° 39'

33.693”
122° 24'

29.708”
SS-3 700-SS-3-
03042021 0 – 0.5 Surface Soil
37° 39'

32.921”
122° 24'

30.767”
Lead
(composite
sample)
37° 39'

33.173”
122° 24'

30.847”
37° 39'

33.111”
122° 24'

30.544”
37° 39'

32.732”
122° 24'

30.990”
37° 39'

32.669”
122° 24'

30.687”
Table 1: Sample Summary
Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves

Property Location Sample
ID(s)
Depth
Interval
(feet bgs)
Matrix Latitude
(ɿN)
Longitude
(ɿW)
Analyses
Performed
700
Linden SS-4 700-SS-4-
03042021 0 – 0.5 Surface Soil
37° 39'

32.797”
122° 24'

30.161”
Lead
(composite
sample)
37° 39'

32.607”
122° 24'

30.384”
37° 39'

32.545”
122° 24'

30.081”
37° 39'

33.049”
122° 24'

30.241”
37° 39'

32.986”
122° 24'

29.938”
905
Linden
GW-1 905-GW-1-
03032021 5 Groundwater 37° 39' 43.864”
122° 24'

27.863”
VOCs (BTEX,
MTBE,
naphthalene, tButyl alcohol,
chlorinated
VOCs), TPH
(TPH-g,
TPH-d,
TPH-mo)
GW-2 905-GW-2-
03152021 5 Groundwater 37° 39'

43.480”
122° 24'

27.495”
VOCs (BTEX,
MTBE,
naphthalene, tButyl alcohol,
chlorinated
VOCs), TPH-g
GW-3
905-GW-3-
03032021
905-GW-3-
03032021-
D
5 Groundwater 37° 39'

43.549”
122° 24'

28.573”
VOCs (BTEX,
MTBE,
naphthalene, tButyl alcohol,
chlorinated
VOCs), TPH
(TPH-g,
TPH-d,
TPH-mo)
GW-4 905-GW-4-
03032021 5 Groundwater 37° 39'

43.171”
122° 24'

28.005”
VOCs (BTEX,
MTBE,
naphthalene, tButyl alcohol,
chlorinated
VOCs) TPH-g
Table 1: Sample Summary
Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves

Property Location Sample
ID(s)
Depth
Interval
(feet bgs)
Matrix Latitude
(ɿN)
Longitude
(ɿW)
Analyses
Performed
905
Linden
GW-4 905-GW-4-
S-03032021 4 – 5 Subsurface
Soil
37° 39'

43.171”
122° 24'

28.005”
VOCs (BTEX,
MTBE,
naphthalene, tButyl alcohol,
chlorinated
VOCs), 16
priority
pollutant PAHs,
Wear metals,
TPH (TPH-g,
TPH-d,
TPH-mo)
GW-5
905-SG-5-
03042021
905-SG-5-
03122021-
D
5 Soil Gas 37° 39'

42.773”
122° 24'

28.631”
VOCs (BTEX,
MTBE,
naphthalene,

EDB, EDC)
Oxygen,
Helium
705
Cypress
S-1 705-SS-1-
03052021 0 – 0.5 Surface Soil 37° 39' 32.483”
122° 24'

24.349” Pesticide, Lead
S-2 705-SS-2-
03052021 0 – 0.5 Surface Soil 37° 39' 32.446”
122° 24'

23.989” Pesticide, Lead
S-3 705-SS-3-
03052021 0 – 0.5 Surface Soil 37° 39'

31.680”
122° 24'

24.967” Pesticide, Lead
S-4 705-SS-4-
03052021 0 – 0.5 Surface Soil 37° 39'

31.382”
122° 24'

24.654” Pesticide, Lead
S-5
705-SS-5-
03052021
705-SS-5-
03042021-
D
0 – 0.5 Surface Soil
37° 39'

31.231”
122° 24'

24.577”
Pesticide, Lead
(Composite
Sample)
37° 39'

31.305”
122° 24'

24.215”
37° 39'

31.657”
122° 24'

24.031”
37° 39'

32.009”
122° 24'

23.848”
37° 39'

32.361”
122° 24'

23.664”
Notes:
ɿ Decimal degrees
bgs Below ground surface
BTEX Benzene, toluene,
ethylbenzene, and xylene
D Duplicate sample
DCE 1,2-Dichloroethene
EDB 1,2-Dibromoethane
EDC 1,2-Dichloroethane
GW Groundwater Sample
MTBE Methyl tert-butyl ether
N North
PAH Polycyclic aromatic
hydrocarbon
PCE Tetrachloroethene
SB Soil Boring/Subsurface
Soil Sample
SG Soil Gas Sample
SS Surface Soil Sample
TCE Trichloroethene
TPH Total petroleum
hydrocarbons
TPH-d Total petroleum
hydrocarbons as diesel
TPH-g Total petroleum
hydrocarbons as gasoline
TPH-mo Total petroleum
hydrocarbons as motor oil
VOC Volatile organic compound
W West
Table 2: Summary of Analytical Data - Soil Gas - VOCs
Phase I/II ESA TBA Report
South San Francisco - Linden and Cypress Aves
(Residential
Soil Gas)
(Commercial
Soil Gas)
(Residential
Soil Gas)
(Commercia
l Soil Gas)
Result
(ƬJ/m3) Qual Result
(ƬJ/m3
) Qual Result
(ƬJ/m3
) Qual Result
(ƬJ/m3
) Qual Result
(ƬJ/m3
) Qual Result
(ƬJ/m3
) Qual Result
(ƬJ/m3
) Qual
695 2,920 2,400 10,000 -- -- -- -- 0.17 U -- --

0.16 0.68 3.6* 16* 360 U 470 U 0.08 U 1,000 U 0.33 U 0.097 U 0.09 U

3.6 16 3.6* 16* 1,400 3,000 0.042 U 540 U 0.17 U 0.051 U 0.047 U 12 52 3.2 14 9,500 68,000 1.2 4,400 16 0.47 J 0.037 UJ
NC NC 280 1,200 -- -- -- -- 0.17 U -- --
37 164 37 160 19,000 46,000 1.3 580 U 23 1 J 0.051 UJ
3,480 14,600 3,500 15,000 64,000 200,000 3.8 580 U 110 3.5 J 0.051 UJ 360 1,570 360* 1,600* 170 U 220 U 0.037 U 480 U 0.15 U 0.046 U 0.042 U

2.75 12 2.8* 12* 790 U 1,000 U 0.26 U 2,200 U 1.1 U 0.32 U 0.29 U 3,480 14,600 3,500 15,000 320 29,000 1.4 580 U 32 0.33 J 0.051 UJ 360 1,570 15 67 -- -- -- -- 1.8 -- --
174,000 730,000 10,000 44,000 660 83,000 10 500 U 98 1.2 J 0.044 UJ 139 584 2,800 12,000 -- -- -- -- 0.17 U -- --
16 100 16* 100* -- -- -- -- 0.23 U -- --
6 93 0.32* 5.2* -- -- -- -- 0.11 U -- --
Notes:

All results have been validated.
* Indicates use of most stringent value between cancer and noncancer endpoints. a EPA VISLs for Target Sub-Slab and Near-source Soil Gas Concentration (THQ = 1) from May 2021 EPA VISL Calculator (see Appendix H). b RWQCB Vapor ESLs (Subslab/Soil Gas) (Table SG-1) Rev. 2 (RWQCB 2019) and not available online; they can be requested from [email protected].

Highlighted cells indicate values exceed screening levels. -- No data
Ƭg/m3 Micrograms per cubic meter
D Duplicate
DTSC California Department of Toxic Substances Control
EPA U.S. Environmental Protection Agency
ESL Environmental screening level
J Estimated value
NC No criteria
Qual Qualifier
RSL Regional screening level
RWQCB San Francisco Bay Regional Water Quality Control Board SL Screening level
U Not detected at concentration at or above reporting limit UJ The analyte was analyzed for, but was not detected at or above the associated value (reporting limit), which is considered approximate dueto deficiencies in one or more quality control criteria.

VISL Vapor intrusion screening level
VOC Volatile organic compound
905-SG-5-03122021-
D
616 Linden Avenue 905 Linden Avenue
616-SG-1-03122021
616-SG-2-
03042021
616-SG-3-
03122021
616-SG-4-
03042021 616-SG-6-03042021 905-SG-5-03122021 RWQCB ESLs b EPA VISLs a Screening Level (Ƭg/m3)
Analyte
1,2-DIBROMOETHANE
1,1-DICHLOROETHENE

VINYL CHLORIDE

TRICHLOROETHENE
TRANS-1,2-DICHLOROETHENE

TOLUENE

TETRACHLOROETHENE
CIS-1,2-DICHLOROETHENE

BENZENE
1,2-DICHLOROETHANE (EDC)

O-XYLENE

NAPHTHALENE

METHYL TERT-BUTYL ETHER

M,P-XYLENE

ETHYLBENZENE

Table 3: Summary of Analytical Data - Soil Gas - Additional Analytes Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
Result
(%) Qual Result (%) Qual Result (%) Qual Result (%) Qual Result (%) Qual Result (%) Qual Result (%) Qual

0.0037 U 0.0047 U 0.004 U 0.0051 U 0.005 U 0.0049 U 0.0045 U

1.4 2.6 15 1.2 7.8 13 13
Notes:

All results have been validated
% Percent
D Duplicate
Qual Qualifier
U Not detected at concentration at or above reporting limit 616-SG-3-
03122021
616 Linden Avenue
905-SG-5-03122021-
D
905 Linden Avenue
616-SG-4-03042021 905-SG-5-03122021 616-SG-6-
03042021
Analyte
OXYGEN
HELIUM
616-SG-1-03122021 616-SG-2-03042021

Table 4: Summary of Analytical Data - Groundwater - VOCs Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
(Residential
Groundwater)
(Commercial
Groundwater)
(Residential
Groundwater)
(Commercial
Groundwater)
Result
(Ƭg/L) Qual Result
(Ƭg/L) Qual Result
(Ƭg/L) Qual Result
(Ƭg/L) Qual Result
(Ƭg/L) Qual

3.71 16.2 3.8* 17* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U
7,420 31,100 1,500 6,300 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

3.23 14.1 3.2* 14* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

5.21 22.8 5.2* 23* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

7.64 33.4 7.6* 33* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U
195 821 66 280 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

22.3 93.7 22 94 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U

0.176 0.769 0.17* 0.76* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U
2,660 11,200 2,700 11,000 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

2.24 9.78 2.2* 9.8* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

6.58 28.7 2.3* 10* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

2.59 11.3 2.6* 11* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

1.59 6.93 0.42* 1.8* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

0.415 1.81 0.43* 1.9 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U
410 1,720 400 1,700 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U
23,000 96,500 23,000 97,000 0.15 U 0.15 U 0.15 U 0.15 U 0.15 U

0.814 3.55 0.81* 3.6* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U
260 1,090 260 1,100 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U
242 1,020 NC NC 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U

3.49 15.2 3.5* 15* 0.1 U 0.1 U 0.1 U 0.53 J 0.1 U
355 1,490 390 1,600 0.36 J 0.21 U 0.21 U 0.96 J 0.21 U
450 1,970 450 2,000 4.5 1.1 0.15 U 0.15 U 0.15 U
763 9,230 7.8* 94* 0.25 U 0.25 U 0.25 U 0.25 U 0.25 U

4.59 20.1 4.6* 20* 0.25 U 0.25 U 0.25 U 0.92 J 0.25 U
492 2,070 390 1,600 0.14 J 0.1 U 0.1 U 0.42 J 0.1 U

14.9 65.2 0.64* 2.8* 0.15 U 0.15 U 0.15 U 0.15 U 0.15 U 19,200 80,700 1,200 4,900 0.1 U 0.1 U 0.1 U 0.43 J 0.1 U 109 457 220 920 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

1.19 7.43 1.2* 7.5* 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U

0.147 2.45 0.0086* 0.14* 0.11 U 0.11 U 0.11 U 0.11 U 0.11 U Notes:

All results have been validated. DTSC California Department of Toxic Substances Control SL Screening Level All samples are grab groundwater samples. EPA U.S. Environmental Protection Agency U Not detected at concentration at or * Indicates use of most stringent value between cancer and noncancer endpoints. ESL Environmental screening level above reporting limit a EPA VISLs for Target Groundwater Concentration (THQ = 1) from May 2021 EPA VISL Calculator (see Appendix H). J Estimated value VISL Vapor intrusion screening level b RWQCB Groundwater ESLs (Groundwater Vapor Intrusion Human Health Risk Levels) (Table GW-3) Rev. 2 NC No criteria VOC Volatile organic compound (RWQCB 2019) and not available online; they can be requested from [email protected]. Qual Qualifier Ƭg/L Micrograms per liter RSL Regional screening level
D Duplicate RWQCB San Francisco Bay Regional Water Quality Control Board 905-GW-3-03032021

BENZENE

VINYL CHLORIDE

TRICHLOROETHENE
TRANS-1,2-DICHLOROETHENE

TOLUENE

TETRACHLOROETHENE

O-XYLENE

NAPHTHALENE

CHLOROBENZENE

CARBON TETRACHLORIDE
EPA VISLs a RWQCB ESLs b 905-GW-1-03032021 905-GW-2-03152021

METHYLENE CHLORIDE
905-GW-3-03032021-D
905 Linden Avenue
Analyte
1,4-DICHLOROBENZENE
1,2-DICHLOROPROPANE
1,2-DICHLOROETHANE (EDC)
1,2-DICHLOROBENZENE
1,2-DIBROMOETHANE
1,2,3-TRICHLOROPROPANE
1,1-DICHLOROETHENE
1,1-DICHLOROETHANE
1,1,2-TRICHLOROETHANE
1,1,2,2-TETRACHLOROETHANE
1,1,1-TRICHLOROETHANE
Screening Level (mg/kg)
905-GW-4-03032021

CHLOROFORM

CHLOROETHANE
1,1,1,2-TETRACHLOROETHANE

METHYL TERT-BUTYL ETHER

M,P-XYLENE

ETHYLBENZENE

DICHLORODIFLUOROMETHANE

CHLOROMETHANE

Table 5: Summary of Analytical Data - Groundwater - TPH Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
(Residential
Groundwater)
(Commercial
Groundwater)
Result
(Ƭg/L) Qual Result
(Ƭg/Lg) Qual Result
(Ƭg/L) Qual Result
(Ƭg/L) Qual Result
(Ƭg/L) Qual

0.75 3.15 100 51 U -- 55 U -- 50 U

10.4 43.7 100 13 J 10 U 12 J 480 11 J
NC NC NC 51 U -- 55 U -- 50 U
Notes:

All results have been validated.

All samples are grab groundwater samples.
a
aliphatic and aromatic high, TPH-d corresponds with aliphatic and aromatic medium, and TPH-g corresponds with aliphatic and aromatic low. b RWQCB Tier 1 ESLs Rev. 2 (RWQCB 2019) and not available online; they can be requested from [email protected]. c The Tier 1 ESL is based on the generic conceptual site model for a residential receptor where groundwater is a drinking water resource. d TPH-d and TPH-mo samples could not be collected from GW-2 and GW-4 because of insufficient water.

Highlighted cells indicate values exceed screening levels. -- No data
Ƭg/L Micrograms per liter
D Duplicate
EPA U.S. Environmental Protection Agency
ESL Environmental screening level
J Estimated value
NC No criteria
Qual Qualifier
RWQCB San Francisco Bay Regional Water Quality Control Board TPH-D Total petroleum hydrocarbons as diesel
TPH-G Total petroleum hydrocarbons as gasoline
TPH-MO Total petroleum hydrocarbons as motor oil
U Not detected at concentration at or above reporting limit VISL Vapor intrusion screening level
Analyte 905-GW-1-03032021
TPH-MO
TPH-G
TPH-D
Screening Level (Ƭg/L)
RWQCB Tier 1
ESLs b,c
EPA VISLs a 905-GW-2-03152021 d 905-GW-3-03032021 905-GW-4-03152021 d 905 Linden Avenue
905-GW-3-03032021-D
EPA VISLs for Target Groundwater Concentration (THQ = 1) from May 2021 EPA VISL Calculator (see Appendix H). The lower of the target groundwater concentrations for TPH aliphatic and aromatic values were used. TPH-mo corresponds with

Table 6: Summary of Analytical Data - Soil - VOCs
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
EPA RSLa
(Residential Soil)
EPA RSLa
(Commercial Soil)
DTSC SLb
(Residential Soil)
DTSC SLb
(Commercial Soil) Result (mg/kg) Qual
2 8.8 2* 8.8* 0.0004 U
8,100 36,000 1,700 7,200 0.0004 U

0.6 2.7 0.6* 2.7* 0.0004 U

1.1 5 NC NC 0.0004 U

3.6 16 3.6* 16* 0.0004 U
230 1,000 83 350 0.0004 U

0.0051 0.11 0.0015* 0.021* 0.00081 U

0.036 0.16 NC NC 0.0004 U
1,800 9,300 NC NC 0.0004 U

0.46 2 NC NC 0.0004 U

2.5 11 NC NC 0.0004 U

2.6 11 NC NC 0.0004 U

1.2 5.1 0.33 1.4* 0.00081 J

0.65 2.9 0.65* 2.9* 0.0004 U
280 1,300 NC NC 0.0004 U
14,000 57,000 NC NC 0.00081 U

0.32 14 NC NC 0.0004 U
110 460 NC NC 0.00081 U
6,700 28,000 NC NC 0.0016 U

5.8 25 NC NC 0.0021 J
550 2400 NC NC 0.0054 J
47 210 NC NC 0.0004 U
57 1,000 2.2* 26* 0.0016 U
650 2,800 NC NC 0.0011 J
24 100 0.59 2.7 0.00081 U
4,900 47,000 1,100 5,300 0.0025 J
NC NC NC NC 0.0004 U

0.94 6 NC NC 0.0004 U

0.059 1.7 0.082* 0.15* 0.00081 U
Analyte
1,2-DICHLOROETHANE
1,2-DICHLOROBENZENE
1,2-DIBROMOETHANE
1,2,3-TRICHLOROPROPANE
1,1-DICHLOROETHENE
1,1-DICHLOROETHANE
1,1,2,2-TETRACHLOROETHANE
1,1,1-TRICHLOROETHANE
1,1,1,2-TETRACHLOROETHANE
1,1,2-TRICHLOROETHANE
Screening Level (mg/kg)
905 Linden Avenue
905-GW-4-S-03032021

VINYL CHLORIDE

TRICHLOROETHENE
TRANS-1,2-DICHLOROETHENE

TOLUENE

TETRACHLOROETHENE

O-XYLENE

METHYLENE CHLORIDE

METHYL TERT-BUTYL ETHER

M,P-XYLENE

ETHYLBENZENE
1,4-DICHLOROBENZENE
1,2-DICHLOROPROPANE

DICHLORODIFLUOROMETHANE

CARBON TETRACHLORIDE

BENZENE

CHLOROMETHANE

CHLOROFORM

CHLOROETHANE

CHLOROBENZENE

Table 6: Summary of Analytical Data - Soil - VOCs
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
Notes:

All results have been validated.
* Indicates use of most stringent value between cancer and noncancer endpoints. a EPA RSLs from November 2020 are available at https://www.epa.gov/risk/regional-screening-levels-rsls. b DTSC SLs from June 2020 are available at https://dtsc.ca.gov/wp-content/uploads/sites/31/2019/04/HHRA-Note-3-June-2020-A.pdf. -- No data
D Duplicate
DTSC California Department of Toxic Substances Control
EPA U.S. Environmental Protection Agency
J Estimated value
mg/kg Milligrams per kilogram
NC No criteria
Qual Qualifier
RSL Regional screening level
SL Screening level
U Not detected at concentration at or above reporting limit VOC Volatile organic compound

Table 7: Summary of Analytical Data - Soil - PAHs
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
EPA RSLa
(Residential Soil)
EPA RSLa
(Commercial Soil)
DTSC SLb
(Residential Soil)
DTSC SLb
(Commercial Soil) Result (mg/kg) Qual Result (mg/kg) Qual Result (mg/kg) Qual 3,600 45,000 3,300 23,000 0.0086 U 0.0059 U 0.017 U
NC NC NC NC 0.0086 U 0.0059 U 0.017 U
18,000 230,000 17,000 130,000 0.0086 U 0.0059 U 0.017 U

1.1 21 1.1* 12* 0.012 J 0.007 J 0.017 U

0.11 2.1 0.11* 1.3* 0.0086 U 0.0059 U 0.017 U

1.1 21 1.1* 13* 0.0086 U 0.0059 U 0.017 U
NC NC NC NC 0.0086 U 0.0059 U 0.017 U
11 210 11* 130* 0.0086 U 0.0059 U 0.017 U
110 2,100 110* 1,300* 0.0086 U 0.0059 U 0.017 U

0.11 2.1 0.028* 0.31* 0.0086 U 0.0059 U 0.017 U
2,400 30,000 2,400 18,000 0.0086 U 0.0059 U 0.017 U
2,400 30,000 2,300 17,000 0.0086 U 0.0059 U 0.017 U

1.1 21 1.1* 13* 0.0086 U 0.0059 U 0.017 U
2 8.6 2* 6.5* 0.0086 U 0.0059 U 0.017 U
2,400 30,000 NC NC 0.013 J 0.0075 J 0.017 U
1,800 23,000 1,800 13,000 0.01 J 0.007 J 0.017 U
Notes:

All results have been validated.
* Indicates use of most stringent value between cancer and noncancer endpoints. a EPA RSLs from November 2020 are available at https://www.epa.gov/risk/regional-screening-levels-rsls. b DTSC SLs from June 2020 are available at https://dtsc.ca.gov/wp-content/uploads/sites/31/2019/04/HHRA-Note-3-June-2020-A.pdf.

D Duplicate
DTSC SL California Department of Toxic Substances Control EPA U.S. Environmental Protection Agency
J Estimated value
mg/kg Milligrams per kilogram
NC No criteria
PAH Polycyclic aromatic hydrocarbon
PAL Project action limit
Qual Qualifier
RSL Regional screening level
SL Screening level
U Not detected at concentration at or above reporting limit

FLUORANTHENE
PYRENE

PHENANTHRENE

NAPHTHALENE
INDENO(1,2,3-CD)PYRENE

FLUORENE
905 Linden Avenue
905-GW-4-S-03032021 Screening Level (mg/kg) 616-SB-4-03022021 616-SB-4-03022021-D

BENZO(A)PYRENE

BENZO(A)ANTHRACENE

DIBENZ(A,H)ANTHRACENE

CHRYSENE

BENZO(K)FLUORANTHENE

BENZO(G,H,I)PERYLENE

BENZO(B)FLUORANTHENE

ANTHRACENE

ACENAPHTHYLENE

ACENAPHTHENE
616 Linden Avenue
Analyte

Table 8: Summary of Analytical Data - Soil - Metals
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
700-SS-1-
03042021
700-SS-2-
03042021
700-SS-3-
03042021
700-SS-4-
03042021
705-SS-1-
03052021
705-SS-2-
03052021
705-SS-3-
03052021
705-SS-4-
03052021
705-SS-5-
03052021
705-SS-5-
03042021-D
Result
(mg/kg) Qual Result (mg/kg) Qual Result (mg/kg)
Result
(mg/kg)
Result
(mg/kg)
Result
(mg/kg)
Result
(mg/kg) Qual Result (mg/kg)
Result
(mg/kg)
Result
(mg/kg)
Result
(mg/kg)
Result
(mg/kg)
Result
(mg/kg)
CADMIUM 71 980 NC NC 0.582 0.52 J NS NS NS NS 0.177 J -- -- -- -- -- -- CHROMIUM NC NC NC NC 95.1 93.8 NS NS NS NS 49 -- -- -- -- -- -- LEAD 400 800 80 320 47.4 43.8 38 52 33 24 11.8 55 54 41 76 60 59 NICKEL 1,500 22,000 820 11,000 88.7 87.9 NS NS NS NS 35.4 -- -- -- -- -- -- ZINC 23,000 350,000 NC NC 308 266 NS NS NS NS 49.4 -- -- -- -- -- -- Notes:

Wear metals are presented in bold font.

Results for the 616 Linden Avenue soil boring and 905 Linden Avenue have been validated. Results for 616 Linden Avenue soil associated with the concrete structure have not been validated. a EPA RSLs from November 2020 are available at https://www.epa.gov/risk/regional-screening-levels-rsls. b DTSC SLs from June 2020 are available at https://dtsc.ca.gov/wp-content/uploads/sites/31/2019/04/HHRA-Note-3-June-2020-A.pdf. -- Not analyzed
D Duplicate
DTSC SL California Department of Toxic Substances Control - Screening Level EPA U.S. Environmental Protection Agency
J Estimated value
mg/kg Milligrams per kilogram
NC No criteria
NS Not Sampled
Qual Qualifier
RSL Regional screening level
U Not detected at concentration at or above reporting limit wear metals Cadmium, chromium, lead, nickel, and zinc
Screening Level (mg/kg) 700 Linden Avenue 705 Cypress Avenue 905 Linden Avenue 616-SB-4-03022021 616-SB-4-03022021-
D
905-GW-4-S03032021 Analyte EPA RSLa
(Residential
Soil)
EPA RSLa
(Commercial
Soil)
DTSC SLb
(Residential
Soil)
DTSC SLb
(Commercial
Soil)
616 Linden Avenue Soil Boring

Table 9: Waste Characterization - Soil - Metals
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
Result
(mg/kg) Qual Result (mg/kg) Qual
ANTIMONY 31 470 NC NC 500 150 NC 3.16 J 2.44
ARSENIC 0.68 3 0.11 4.2 500 50 100 8.29 8.56
BARIUM 15,000 220,000 NC NC 10,000 1,000 2,000 218 132
BERYLLIUM 160 2300 16 230 75 8 NC 0.582 0.705
CADMIUM 71 980 NC NC 100 10 20 0.991 J 0.11 U
CHROMIUM NC NC NC NC 2,500 50 100 80 87.4
COBALT 23 350 NC NC 8,000 800 NC 11.3 10.3
COPPER 3,100 47,000 NC NC 2,500 250 NC 35.3 23.6
LEAD 400 800 80 320 1,000 50 100 239* 67.6
MOLYBDENUM NC NC NC NC 3,500 3,500 NC 0.598 J 0.445 J
NICKEL 1,500 22,000 820 11,000 2,000 200 NC 52.6 67.6
SELENIUM 390 5800 NC NC 100 10 20 0.566 U 0.562 J
SILVER 390 5800 NC NC 500 50 100 0.113 U 0.11 U
THALLIUM 0.78 12 NC NC 700 70 NC 0.52 0.687 J
VANADIUM 390 5800 NC NC 2,400 240 NC 61.5 68.2
ZINC 23,000 350,000 NC NC 5,000 2,500 NC 397 J 330
MERCURY 20 2 4 0.12 0.06 J
Notes:

All results have been validated.

Highlighted cells indicate values exceed screening levels. # California WET is required to assess leachable metals; concentration exceeds STLC limit using a dilution factor of 10. *
a Total concentrations cannot equal or exceed the TTLC value, which identifies a California hazardous waste. b Source: California Code of Regulations, Title 22, Chapter 11, Article 3. c If total concentrations equal or exceed 10x STLC limit, a California WET leachable metal analysis is required. d Source: Kettleman Hills Class I Landfill Waste Classification Criteria e If total concentrations equal or exceed 20x TCLP limit, TCLP leachable metals analysis is required.

J Estimated value
Both California WET extraction (exceed STLC trigger) and TCLP extraction is required to assess leachable RCRA metals; concentration exceeds TCLP limit using a dilution factor of 20.
616-EC-03012021
(Temporary
Stockpile)
616-SB-7-03012021
(Discrete)
Waste Characterization Criteria (mg/kg)
Analyte
616 Linden Avenue - Soil Associated with
Concrete Structure
TTLC
(mg/kg) a,b
STLC Trigger
(STLC Threshold)
(10x STLC)
(mg/kg) b,c
TCLP Trigger
(TCLP Threshold)
(20x TCLP)
(mg/kg) d
Screening Level (mg/kg)
EPA RSLa
(Residential
Soil)
EPA RSLa
(Commercial
Soil)
DTSC SLb
(Residential
Soil)
DTSC SLb
(Commercial
Soil)

Table 9: Waste Characterization - Soil - Metals
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
DTSC SL California Department of Toxic Substances Control - Screening Level EPA U.S. Environmental Protection Agency
J Estimated value
mg/kg Milligrams per kilogram
mg/L Milligram per liter
NC No criteria
Qual Qualifier
RCRA Resource Conservation and Recovery Act
RSL Regional screening level
STLC Soluble threshold limit concentration
TCLP Toxicity characteristic leaching procedure
TTLC Total threshold limit concentration
U Not detected at concentration at or above reporting limit WET Waste extraction test

Table 10: Waste Characterization - Leachate - Metals
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
WET using
Citrate Buffer TCLP
Result (mg/L) Result
(mg/L) Qual Result
(mg/L)
Result
(mg/L) Qual
CHROMIUM 55 0.357 -- -- -- 0.25 U
LEAD 55 8.24 0.198 J 0.0557 0.25 U
Notes:

All results have been validated.
a Source: California Code of Regulations, Title 22, Chapter 11, Article 3. b Source: RCRA toxicity characteristic list at 40 Code of Federal Regulations 261.24 -- Not analyzed
J Estimated value
mg/L Milligrams per liter
RCRA Resource, Conservation, and Recovery Act
STLC Soluble threshold limit concentration
TCLP Toxicity characteristic leaching procedure
TTLC Total threshold limit concentration
U Not detected at concentration at or above reporting limit WET Waste Extraction Test
Highlighted cell indicates the STLC limit is exceeded when using a citrate buffer. If soil is excavated and removed from the site, it must be disposed of as non-RCRA Class I California Hazardous Waste.

Chromium is a California Class III inert waste and may be disposed of at a Class II or III landfill. Disposal at a Class III landfill would depend on the waste acceptance criteria of the landfill, which are permit based.

Waste Characterization Criteria
(mg/L) 616 Linden Avenue - Soil Associated with Concrete Structure WET using
Deionized Water
616-SB-7-03012021
(Discrete Sample) 616-EC-03012021 (Composite Sample)
STLC Limit
(Applies to
WET) a
TCLP Limit b
Analyte WET using
Deionized Water
Based on WET results using deionized water as a buffer, chromium and lead would not leach from soil and threaten water quality and may be left on site without a cap. However, a cap would be required to prevent direct exposure.

Table 11: Summary of Analytical Data - Soil - TPH
Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
RWQCB Tier 1
ESLsa Result (mg/kg) Qual Result (mg/kg) Qual Result (mg/kg) Qual 260 560 300 70
100 43 J- 14 800
1,600 930 510 22 J
Notes:

All results have been validated.

The Tier 1 ESL is based on the generic conceptual site model for a residential receptor where groundwater is a drinking water resource. a RWQCB Tier 1 ESLs Rev. 2 (RWQCB 2019) and not available online; they can be requested from [email protected].

D Duplicate
ESL Environmental screening level
J Estimated value
J- Estimated value; may be biased low.
mg/kg Milligrams per kilogram
PAL Project action limit
Qual Qualifier
RWQCB San Francisco Bay Regional Water Quality Control Board TPH-D Total petroleum hydrocarbons as diesel
TPH-G Total petroleum hydrocarbons as gasoline
TPH-MO Total petroleum hydrocarbons as motor oil
Highlighted cells indicate values exceed screening levels. 905 Linden Avenue
616-SB-4-03022021 616-SB-4-03022021-D 905-GW-4-S-03032021 616 Linden Avenue
TPH-D
TPH-G
TPH-MO
Analyte
Screening Level
(mg/kg)

Table 12: Summary of Analytical Data - Soil - Pesticides Phase I/Phase II ESA TBA Report
South San Francisco - Linden and Cypress Aves
(Residential
Soil)
(Commercial
Soil)
(Residential
Soil)
(Commercial
Soil)
Result
(mg/kg) Qual Result (mg/kg) Qual Result (mg/kg) Qual Result (mg/kg) Qual Result (mg/kg) Qual Result (mg/kg) Qual

1.9 9.6 1.9 6.2* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U 2 9.3 23 9.3* 0.0016 J 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

1.9 8.5 1.9 7.1* 0.0035 0.0043 J 0.0095 J 0.0034 U 0.0044 J 0.0093 J

0.039 0.18 0.039* 1.8* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

0.086 0.36 0.086* 0.24* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

0.3 1.3 0.3* 0.82* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

1.7 7.7 NC NC 0.00091 J 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U NC NC NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

0.034 0.14 0.034* 0.093* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U NC NC NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U NC NC NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U NC NC NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U 19 250 19 160 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U NC NC NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U NC NC NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

0.57 2.5 0.57* 2* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

0.13 0.63 0.13* 0.63* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U

0.07 0.33 0.07* 0.33* 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U 320 4,100 320 2,600 0.0022 U 0.011 U 0.022 U 0.023 U 0.012 U 0.024 U

0.49 2.1 0.45* 1.2* 0.017 U 0.084 U 0.17 U 0.17 U 0.088 U 0.18 U

1.7 7.7 NC NC 0.00033 U 0.0017 U 0.0033 U 0.0034 U 0.0018 U 0.0036 U Notes:

All results have been validated.
* Indicates use of most stringent value between cancer and noncancer endpoints. a EPA RSLs from November 2020 are available at https://www.epa.gov/risk/regional-screening-levels-rsls b DTSC SLs from June 2020 are available at https://dtsc.ca.gov/wp-content/uploads/sites/31/2019/04/HHRA-Note-3-June-2020-A.pdf.

D Duplicate mg/kg Milligrams per kilogram
DDD Dichlorodiphenyldichloroethane NC No criteria
DDE Dichlorodiphenyldichloroethylene PAL Project action limit DDT Dichlorodiphenyltiichloroethylene Qual Qualifier
DTSC California Department of Toxic Substances Control RSL Regional screening level EPA U.S. Environmental Protection Agency SL Screening Level J Estimated value U Not detected at concentration at or above reporting limit Analyte

DELTA-BHC

CIS-CHLORDANE

BETA-BHC

ALPHA-BHC
ALDRIN
4,4'-DDT
4,4'-DDE
4,4'-DDD
Screening Level (mg/kg) 705 Cypress Avenue
EPA RSLa DTSC SLb 705-SS-1-03052021 705-SS-2-03052021 705-SS-3-03052021 705-SS-4-03052021 705-SS-5-03042021 705-SS-5-03042021-D

ENDOSULFAN SULFATE

ENDOSULFAN II

ENDOSULFAN I

DIELDRIN

GAMMA-BHC (LINDANE)

ENDRIN KETONE

ENDRIN ALDEHYDE
ENDRIN

TRANS-CHLORDANE

TOXAPHENE

METHOXYCHLOR

HEPTACHLOR EPOXIDE

HEPTACHLOR

Table 13: Soil Gas VOC Exceedances Summary at 616 Linden Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves
Sample
Information EDC Benzene Ethylbenzene m,p-Xylene o-Xylene Toluene # of Samples 7 7 7 7 7 7
# of
Exceedances 2 4 2 2 1 1
Concentratio
n Range
Nondetect -
3,000 μg/m3
Nondetect –
68,000 μg/m3
Nondetect –
46,000 μg/m3
Nondetect –
200,000
μg/m3
Nondetect –
29,000 μg/m3
Nondetect –
83,000 μg/m3
Screening
Level 3.6 μg/m3 a 3.2 μg/m3 b 37 μg/m3 b 3,480 μg/m3 c 3,480 μg/m3 c 10,000 μg/m3 b
Exceedances
(μg/m3)
616-SG-1-
03122021:
1,400 μg/m3
616-SG-2-
03042021:
3,000 μg/m3
616-SG-1-
03122021:
9,500 μg/m3
616-SG-2-
03042021:
68,000 μg/m3
616-SG-4-
03042021:
4,400 μg/m3
616-SG-6-
03042021:
16 μg/m3
616-SG-1-
03122021:
19,000 μg/m3
616-SG-2-
03042021:
46,000 μg/m3
616-SG-1-
03122021:
64,000
μg/m3
616-SG-2-
03042021:
200,000
μg/m3
616-SG-2-
03042021:
29,000 μg/m3
616-SG-2-
03042021:
83,000 μg/m3
Notes:
a EPA VISL and RWQCB ESL for residential soil gas.
b RWQCB ESL for residential soil gas.
c EPA VISL for residential soil gas.
μg/m3 Micrograms per cubic meter of air
EPA U.S. Environmental Protection Agency
ESL Environmental screening level
RWQCB San Francisco Bay Regional Water Quality Control Board VISL Vapor intrusion screening level

Table 14: Groundwater TPH Exceedances Summary at 905 Linden Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves
Sample Information TPH-g
# of Samples 5
# of Exceedances 4 (including one duplicate)
Concentration Range Nondetect - 480 μg/L
Screening Levela,b 10.4 μg/L a
Exceedances (μg/L)
905-GW-1-03032021:
13 J μg/L
905-GW-3-03032021:
12 J μg/L
905-GW-4-03152021:
480 μg/L
905-GW-4-03152021-D:
11 J μg/L
Notes:
a EPA VISLs for Target Groundwater Concentration (THQ = 1) from May 2021 EPA VISL Calculator (see Appendix H)
μg/L Micrograms per liter
EPA U.S. Environmental Protection Agency
TPH-g Total petroleum hydrocarbons as gasoline
VISL Vapor intrusion screening level

Table 15: Soil TPH Exceedances Summary at 616 Linden and 905 Linden Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves
Sample Information TPH-d TPH-g
# of Samples 3 3
# of Exceedances 2 1
Concentration Range 70 - 560 mg/kg 14 – 800 mg/kg
Screening Level a 260 mg/kg 100 mg/kg
Exceedances (mg/kg)
616-SB-4-03022021:
560 mg/kg
616-SB-4-03022021-D:
300 mg/kg
905-GW-4-S-03032021:
800 mg/kg
Notes:
a RWQCB Tier 1 ESLs.

D Duplicate
ESL Environmental screening level
mg/kg Milligrams per kilogram
RWQCB San Francisco Bay Regional Water Quality Control Board TPH-d Total petroleum hydrocarbons as diesel
TPH-g Total petroleum hydrocarbons as gasoline

Table 16: Summary of Approximate Minimum Search Distances Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves
Area of Concern
Approximate Minimum Search Distances Surrounding the Site (miles)
Standard Environmental Record Sources
(where available) Chemicals of Concern Petroleum Hydrocarbon Chemicals of Concern
Federal NPL 0.33 0.10
Federal CERCLIS 0.33 0.10
Federal RCRA CORRACTS 0.33 0.10
Federal RCRA non-CORRACTS TSD 0.33 0.10
Federal RCRA Generators Site Only Site Only
Federal Institutional Control/Engineering Control Site Only Site Only Federal ERNS Site Only Site Only
State and Tribal-equivalent NPL 0.33 0.10
State and Tribal-equivalent CERCLIS 0.33 0.10
State and Tribal Landfill or Solid Waste Disposal Sites 0.33 0.10 State and Tribal LUST 0.33 0.10
State and Tribal UST Site Only Site Only
State and Tribal Institutional Control/Engineering Control Site Only Site Only State and Tribal Voluntary Cleanup 0.33 0.10
State and Tribal Brownfield 0.33 0.10
Notes:

CERCLIS Comprehensive Environmental Response, Compensation, and Liability Information System CORRACTS RCRA Corrective Action Activity
ERNS Emergency Response Notification System
LUST Leaking underground storage tank
NPL National Priorities List
RCRA Resource Conservation and Recovery Act
TSD RCRA Treatment, Storage, and Disposal
UST Underground storage tank

Table 17: Summary of Analyses and Findings
Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves
Property Location Sample ID(s) Matrix Analyses Performed Finding 616
Linden
SG-1 616-SG-1-03122021 Soil Gas
VOCs
(BTEX, MTBE,
naphthalene, EDB, EDC)
Oxygen, Helium
EDC, Benzene,
Ethylbenzene,
and m,p-Xylene
exceed screening
levels.

SG-1 616-SG-2-03042021 Soil Gas
VOCs
(BTEX, MTBE,
naphthalene, EDB, EDC)
Oxygen, Helium
EDC, Benzene,
Ethylbenzene,
m,p-Xylene, oXylene, and
Toluene exceed
screening levels.

SG-3 616-SG-3-03122021 Soil Gas
VOCs
(BTEX, MTBE,
naphthalene, EDB, EDC)
Oxygen, Helium
No issues noted.

SG-4 616-SG-4-03042021 Soil Gas
VOCs
(BTEX, MTBE,
naphthalene, EDB, EDC)
Oxygen, Helium
Benzene exceeds
screening levels.

SB-4 (same
location as
SG-4)
616-SB-4-03022021
616-SB-4-03022021-D Soil
VOCs (BTEX, MTBE,
naphthalene, t-Butyl
alcohol, chlorinated
VOCs) 16 priority
pollutant PAHs, Wear
metals, TPH (TPH-g,
TPH-d, TPH-mo)
TPH-d exceeds
screening levels.

SG-6 616-SG-6-03042021 Soil Gas
VOCs
(BTEX, MTBE,
naphthalene, EDB, EDC)
Oxygen, Helium, DCE,
PCE, TCE, vinyl chloride
Benzene exceeds
screening levels.

Temporary
Stockpile
(Soil within
Concrete
Structure)
616-EC-03012021 Soil
Title 22 Metals, STLC CA
WET using citrate buffer
(Chromium and lead),
STLC CA WET using DI
buffer (Lead only), TCLP
(Lead only)
Soil may remain
on site without a
cap; if disposed
off-site, soil is
non-RCRA Class
I California
hazardous waste
(for lead)
Immediately
below
concrete
structure
616-SB-7-03012021 Soil
Title 22 Metals, STLC CA
WET using DI buffer
(Chromium and lead)
Soil may remain
on site without a
cap.
700
Linden
SS-1 700-SS-1-03042021 Soil Lead (composite sample) No issues noted.

SS-2 700-SS-2-03042021 Soil Lead (composite sample) No issues noted.

SS-3 700-SS-3-03042021 Soil Lead (composite sample) No issues noted.

SS-4 700-SS-4-03042021 Soil Lead (composite sample) No issues noted.

Table 17: Summary of Analyses and Findings
Phase I/Phase II ESA TBA Report
South San Francisco - Linden & Cypress Aves

Property Location Sample ID(s) Matrix Analyses Performed Finding 905
Linden
GW-1 905-GW-1-03032021 Groundwater
VOCs (BTEX, MTBE,
naphthalene, t-Butyl
alcohol, chlorinated
VOCs) TPH (TPH-g,
TPH-d, TPH-mo)
TPH-g exceeds
screening levels.

GW-2 905-GW-2-03152021 Groundwater
VOCs (BTEX, MTBE,
naphthalene, t-Butyl
alcohol, chlorinated
VOCs), TPH-g
No issues noted.

GW-3 905-GW-3-03032021
905-GW-3-03032021-D Groundwater
VOCs (BTEX, MTBE,
naphthalene, t-Butyl
alcohol, chlorinated
VOCs) TPH (TPH-g,
TPH-d, TPH-mo)
TPH-g exceeds
screening levels.

GW-3 905-GW-4-03152021 Groundwater
VOCs (BTEX, MTBE,
naphthalene, t-Butyl
alcohol, chlorinated
VOCs), TPH-g
TPH-g exceeds
screening levels.

GW-4 905-GW-4-S-03032021 Soil
VOCs (BTEX, MTBE,
naphthalene, t-Butyl
alcohol, chlorinated
VOCs) 16 priority
pollutant PAHs, Wear
metals, TPH-g
TPH-g exceeds
screening levels.

GW-5 905-SG-5-03122021
905-SG-5-03122021-D Soil Gas
VOCs (BTEX, MTBE,
naphthalene, EDB, EDC)
Oxygen, Helium
No issues noted.
705
Cypress
S-1 705-SS-1-03052021 Soil Pesticides & Lead No issues noted.

S-2 705-SS-2-03042021 Soil Pesticides & Lead No issues noted.

S-3 705-SS-3-03052021 Soil Pesticides & Lead No issues noted.

S-4 705-SS-4-03052021 Soil Pesticides & Lead No issues noted.

S-5 705-SS-5-03042021
705-SS-5-03042021-D Soil Pesticides & Lead (composite sample) No issues noted.

Notes:

BTEX Benzene, toluene, ethylbenzene, and xylene
D Duplicate Sample
DCE 1,2-Dichloroethene
EDB 1,2-Dibromoethane
EDC 1,2-Dichloroethane
GW Groundwater Sample
MTBE Methyl tert-butyl ether
PAH Polycyclic aromatic hydrocarbon
PCE Tetrachloroethene
RCRA Resource Conservation and Recovery Act
SB Soil Boring
SG Soil Gas Sample
SS Surface Soil Sample
STLC Soluble threshold limit concentration
TBD To be determined
TCE Trichloroethene
TPH Total petroleum hydrocarbon
TPH-d Total petroleum hydrocarbons as diesel
TPH-g Total petroleum hydrocarbons as gasoline
TPH-mo Total petroleum hydrocarbons as motor oil
TCLP Toxicity characteristic leaching procedure
VOCs Volatile organic compound
WET Waste extraction test

APPENDIX A

PHASE I ENVIRONMENTAL SITE ASSESSMENT REPORT
B2. Analysis of Brownfields Cleanup Alternatives
(Toeroek Associates and Tetra Tech Inc. 2021)
New Park at Linden and Pine Project
Initial Study/Mitigated Negative Declaration
August , 2021
Dr. Kelly Garbach
EPA TBA Project Manager
U.S. Environmental Protection Agency, Region 9
75 Hawthorne Street
San Francisco, CA 94105
Subject: Final Analysis of Brownfields Cleanup Alternatives Report South San Francisco – Linden & Cypress Aves, South San Francisco, California, U.S. EPA Region 9, Resource Conservation and Recovery Act (RCRA) Enforcement, Permitting, and Assistance (REPA) Contract No. 68HERH19D0018, Task Order No. 68HE0920F0007
Dear Dr. Garbach:

Toeroek Associates, Inc. (Toeroek) and Tetra Tech, Inc. (Tetra Tech) (hereinafter “Toeroek Team”) submit the attached Final Analysis of Brownfields Cleanup Alternatives Report regarding a TBA at the South San Francisco – Linden & Cypress Aves site.

This deliverable has been revised to reflect U.S. Environmental Protection Agency and City of South San Francisco comments on the draft report of the same name. Responses to comments are enclosed as a separate attachment. After revision, this final report was reviewed internally as part of Tech Tech’s quality assurance program, as well as Toeroek’s quality assurance program, and is consistent with Toeroek’s Quality Management Plan for the REPA contract. Documentation of this review is retained in the Toeroek Team’s project files.

If you have any questions or comments, please contact Greg Hanna at (720) 898-4102 or Dayna Aragon at (510) 302-6242.

Sincerely,
Greg Hanna Dayna Aragon
Toeroek Team Program Manager Toeroek Team Project Manager Enclosure: Final Analysis of Brownfields Cleanup Alternatives Report Responses to Comments, Analysis of Brownfields Cleanup Alternatives cc: Lisa Hanusiak, EPA Region 9 TOCOR
Jinky Callado, EPA Region 9 Alternate TOCOR
Toeroek Team files
W~ nn T;:i:T amProgramM anager

ANALYSIS OF BROWNFIELDS CLEANUP ALTERNATIVES

SOUTH SAN FRANCISCO - LINDEN & CYPRESS AVES

SOUTH SAN FRANCISCO, CALIFORNIA

TARGETED BROWNFIELDS ASSESSMENT (TBA)

RESOURCE CONSERVATION AND RECOVERY ACT (RCRA)

ENFORCEMENT, PERMITTING, AND ASSISTANCE (REPA)

CONTRACT
CONTRACT NO. 68HERH19D0018; TASK ORDER NO. 68HE0920F0007 Prepared for:

EPA REGION 9

TBA SUPPORT PROGRAM
75 HAWTHORNE STREET
SAN FRANCISCO, CALIFORNIA 94105
AUGUST 24, 2021
Final
Prepared by:

Toeroek Associates, Inc.
300 Union Blvd., Suite 520
Lakewood, Colorado 80228
303-420-7735
and
Tetra Tech, Inc.
1999 Harrison Street, Suite 500
Oakland, California 94612
510-302-6300
i

ANALYSIS OF BROWNFIELDS CLEANUP ALTERNATIVES

SOUTH SAN FRANCISCO - LINDEN & CYPRESS AVES

SOUTH SAN FRANCISCO, CALIFORNIA
CONTRACT NO. 68HERH19D0018;
TASK ORDER NO. 68HE0920F0007

APPROVAL PAGE
Prepared by:

Dayna Aragon, Project Manager
Tetra Tech, Inc.

Date: _08/24/2021_______
Reviewed by:

Bradley K. Martin, P.E., Senior Engineer
Toeroek Associates, Inc.

Date: _08/24/2021______
Approved by:

Lisa Hanusiak, Contracting Officer’s Representative
U. S. Environmental Protection Agency, Region 9
Han US Date: __________________
·1 a k L"1 sa Digitally signed by Hanusiak, Lisa
, Date: 2021.08.25 12:43:40 -07'00' -------
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TABLE OF CONTENTS
APPROVAL PAGE ................................................................................................................................. i TABLE OF CONTENTS ..................................................................................................................... ii ACRONYMS AND ABBREVIATIONS .............................................................................................. iv EXECUTIVE SUMMARY .................................................................................................................... 1

1.0 INTRODUCTION AND BACKGROUND ............................................................................. 1

1.1 SITE LOCATION ............................................................................................................................... 1

1.2 OWNERSHIP AND PREVIOUS USE .......................................................................................... 2

1.3 PREVIOUS INVESTIGATIONS .................................................................................................... 2

1.3.1 Previous Investigations and Remediation Activities at 616 Linden ................................................ 2

1.3.2 Previous Investigations and Remediation Activities at 905 Linden ................................................ 3

1.3.3 Phase II ESA ............................................................................................................................. 4

1.4 PROJECT GOAL ................................................................................................................................ 6

2.0 APPLICABLE REGULATIONS AND ASSUMED CLEANUP LEVELS ............................. 8

2.1 CLEANUP OVERSIGHT RESPONSIBILITY ............................................................................ 8

2.2 ASSUMED CLEANUP LEVELS FOR MAJOR CONTAMINANTS ..................................... 8

2.3 LAWS AND REGULATIONS APPLICABLE TO THE CLEANUP ..................................... 8

3.0 EVALUATION OF BROWNFIELDS CLEANUP ALTERNATIVES ................................. 10

3.1 CLEANUP ACTION OBJECTIVES ............................................................................................ 10

3.2 IDENTIFICATION OF CLEANUP ALTERNATIVES ......................................................... 10

3.2.1 616 Linden ................................................................................................................................ 11

3.2.2 905 Linden ................................................................................................................................ 17

3.2.3 Alternatives Considered and Dismissed....................................................................................... 23

3.3 COMPARISON OF ALTERNATIVES ....................................................................................... 24

3.3.1 616 Linden ................................................................................................................................ 24

3.3.2 905 Linden ................................................................................................................................ 25

3.4 CONSIDERATION OF CLIMATE CHANGE IMPACTS .................................................... 26

3.5 GREEN AND SUSTAINABLE REMEDIATION GUIDANCE .......................................... 28

3.5.1 Administrative Suggestions ......................................................................................................... 29

3.5.2 Operations Suggestions ................................................................................................................ 30

4.0 LIMITATIONS AND ADDITIONAL ASSESSMENT NEEDS ........................................... 31

5.0 REFERENCES ....................................................................................................................... 32 Analysis of Brownfields Cleanup Alternatives
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iii

LIST OF FIGURES
Figure 1: Site Locations
Figure 2: Current Site Features – 616 Linden Avenue
Figure 3: Current Site Features – 905 Linden Avenue
Figure 4: Sampling Locations and Results Exceeding Screening Levels – 616 Linden Avenue Figure 5: Sampling Locations and Results Exceeding Screening Levels – 905 Linden Avenue Figure 6: Alternatives 3 and 4: Approximate Areas to Be Excavated – 616 Linden Avenue Figure 7: Alternatives 3 and 4: Approximate Area to Be Excavated – 905 Linden Avenue

LIST OF TABLES
Table ES-1: Summary of Cleanup Alternatives
Table 1: Summary of Assumed Cleanup Levels for Soil Gas Table 2: Summary of Assumed Cleanup Levels for Soil
Table 3: Summary of Assumed Cleanup Levels for Groundwater Table 4: Summary of Cost Estimates
Table 5: Summary of Alternatives Considered and Dismissed Table 6: Summary of Alternatives

LIST OF APPENDICES
Appendix A: Environmental Footprint Evaluation

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ACRONYMS AND ABBREVIATIONS
ABCA Analysis of Brownfields Cleanup Alternatives
amsl Above mean sea level
Applicants City of South San Francisco and Friends of Parks ASTM ASTM International
bgs Below ground surface
BTEX Benzene, toluene, ethylbenzene, and xylenes
COC Contaminant of concern
CY Cubic yard
DI Deionized
DPT Direct-push technology
DTSC California Department of Toxic Substances Control
EDR Environmental Data Resources, Inc.

EPA U.S. Environmental Protection Agency
ESA Environmental Site Assessment
ESL Environmental screening level
HAZWOPER Hazardous Waste Operations and Emergency Response IC Institutional control
LUST Leaking underground storage tank
O&M Operation and maintenance
PAH Polycyclic aromatic hydrocarbon
PID Photoionization detector
RACER Remedial Action Cost Engineering and Requirements System RBSL Risk-based screening level
RCRA Resource Conservation and Recovery Act
REC Recognized environmental condition
RWQCB San Francisco Bay Regional Water Quality Control Board SEFA Spreadsheets for Environmental Footprint Analysis
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SL Screening level
SMCGPP San Mateo County Groundwater Protection Program
SMP Soil Management Plan
STLC Soluble threshold limit concentration
SVE Soil vapor extraction
SWRCB California State Water Resources Control Board
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ACRONYMS AND ABBREVIATIONS (CONTINUED)
TBA Targeted Brownfields Assessment
TCE Trichloroethene
Toeroek Team Toeroek Associates, Inc., and its subcontractor, Tetra Tech, Inc.

TPH Total petroleum hydrocarbons
TPH-d Total petroleum hydrocarbons as diesel
TPH-g Total petroleum hydrocarbons as gasoline
TPH-mo Total petroleum hydrocarbons as motor oil
USGS U.S. Geological Survey
UST Underground storage tank
VEC Vapor encroachment concern
VISL Vapor intrusion screening level
VOC Volatile organic compound
WET Waste extraction test
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ES-1

EXECUTIVE SUMMARY
The U.S. Environmental Protection Agency (EPA) Region 9 tasked Toeroek Associates, Inc., and its subcontractor, Tetra Tech, Inc., (hereinafter the Toeroek Team) to conduct an Analysis of Brownfields Cleanup Alternatives (ABCA) for the South San Francisco – Linden & Cypress Aves site (the Site) comprising two locations: 616 Linden Avenue (hereinafter 616 Linden) and 905 Linden Avenue (hereinafter 905 Linden) in South San Francisco, San Mateo County, California (Figure 1). For Site features, see Figure 2 and Figure 3. The City of South San Francisco and Friends of Parks (the Applicants) have an interest in redeveloping the Site for a neighborhood park, a cultural center, affordable housing, mixed-use ground-floor commercial buildings, or some combination of these. The purpose of this ABCA is to evaluate potential cleanup alternatives to address environmental conditions preventing or impeding the preferred type of Site redevelopment and to do so in a manner protective of human health. The cleanup alternatives considered were evaluated based on effectiveness, implementability, and cost.

A Phase II Environmental Site Assessment (ESA) was performed by the Toeroek Team in 2021 for the Site (Toeroek Team 2021). The Toeroek Team conducted soil gas, groundwater, and soil sampling at the Site (Figure 4 and Figure 5). Additionally, geophysical surveys were conducted to locate any remaining underground storage tanks (USTs) at 616 Linden and 905 Linden. The geophysical survey results identified an electromagnetic anomaly at 616 Linden as an additional potential environmental concern. The anomaly was investigated during the Phase II ESA and was determined to be two pieces of metal within a subsurface concrete structure filled with soil. At 616 Linden, volatile organic compounds in soil gas and lead and petroleum hydrocarbons in soil exceeded screening levels (Figure 4). At 905 Linden, petroleum hydrocarbons in soil and groundwater exceeded screening levels (Figure 5). A vapor encroachment concern (VEC) remains at both 616 and 905 Linden. The Phase II ESA also included properties at 700 Linden Avenue and 705 Cypress Avenue. No exceedances of screening levels were observed at these properties, and they are not discussed further.

Based on the planned future use of the Site, the following cleanup alternatives were considered for 616 Linden and 905 Linden, respectively.
616 Linden • Alternative 1: No Action (Baseline)
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ES-2
• Alternative 2: Passive Vapor Mitigation, Soil Management Plan (SMP), Operation and Maintenance (O&M) and Institutional Controls (ICs) • Alternative 3: Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M and ICs • Alternative 4: Soil Excavation with Off-Site Disposal and ICs (neighborhood park reuse only) Alternative 1 for 616 Linden is included as a baseline for comparison to the other proposed alternatives. This alternative would involve no containment, treatment, removal, or monitoring of contaminants.

Alternative 2 for 616 Linden would involve installation of a passive vapor mitigation system for a new structure to be built on the property and implementation of a SMP for contaminated soil left in place.

Alternative 3 for 616 Linden would involve installation of an active vapor mitigation system for a new structure to be built on the property and excavation of contaminated soil.

Alternative 4 for 616 Linden would involve excavation of contaminated soil to allow for redevelopment of the Site as a neighborhood park.
905 Linden • Alternative 1: No Action (Baseline) • Alternative 2: Passive Vapor Mitigation, SMP, O&M and ICs • Alternative 3: Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M and ICs • Alternative 4: Soil Excavation with Off-Site Disposal and ICs (neighborhood park reuse only) Alternative 1 for 905 Linden is included as a baseline for comparison to the other proposed alternatives. This alternative would involve no containment, treatment, removal, or monitoring of contaminants.

Alternative 2 for 905 Linden would involve installation of a passive vapor mitigation system for a new structure to be built on the property and implementation of a SMP for contaminated soil left in place.

Alternative 3 for 905 Linden would involve installation of an active vapor mitigation system for a new structure to be built on the property and excavation of contaminated soil.

Alternative 4 for 905 Linden would involve excavation of contaminated soil to allow for redevelopment of the Site as a neighborhood park.

Table ES-1 summarizes the effectiveness, implementability, and cost for each cleanup alternative evaluated to address environmental conditions preventing or impeding the preferred type of Site redevelopment. The cost Analysis of Brownfields Cleanup Alternatives
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ES-3
estimates presented in the table are order-of-magnitude estimates intended only for the relative comparison of the alternatives; they should not be used as budget- or design-level estimates.

Analysis of Brownfields Cleanup Alternatives
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1 1.0 INTRODUCTION AND BACKGROUND
The U.S. Environmental Protection Agency (EPA) Region 9 tasked Toeroek Associates, Inc., and its subcontractor, Tetra Tech, Inc., (hereinafter the Toeroek Team) to conduct an Analysis of Brownfields Cleanup Alternatives (ABCA) for the South San Francisco – Linden & Cypress Aves site (the Site) located at 616 Linden Avenue (hereinafter 616 Linden) and 905 Linden Avenue (hereinafter 905 Linden) in South San Francisco, San Mateo County, California (Figure 1). The City of South San Francisco and Friends of Parks (the Applicants) have an interest in redeveloping the Site for a neighborhood park, a cultural center, affordable housing, mixed-use ground-floor commercial buildings, or some combination of these.

This ABCA considers cleanup alternatives based on EPA (2020a) vapor intrusion screening levels (VISLs) or San Francisco Bay Regional Water Quality Control Board (RWQCB) (2019) environmental screening levels (ESLs), whichever is more conservative, for soil gas. For soil, this ABCA considers alternatives based on RWQCB (2019) Tier 1 ESLs for total petroleum hydrocarbons (TPH) and the California Department of Toxic Substances Control (DTSC) (2020) screening level (SL) for lead. For groundwater, this ABCA considers alternatives based on the EPA VISLs (2020a) for residential groundwater. Although groundwater in the vicinity of the Site is not known to be a source of drinking water and there are no future plans to use groundwater for this purpose at the Site, this ABCA considers cleanup alternatives to address the potential for vapor intrusion from groundwater contamination. Furthermore, this ABCA includes rough order-ofmagnitude cost estimates (accuracy range of -25 to +75 percent based on the Project Management Institute’s [2017] A Guide to the Project Management Body of Knowledge) of evaluated cleanup alternatives intended for comparison purposes only; they should not be used as budget- or design-level estimates.

1.1 SITE LOCATION
The property at 616 Linden is a 0.32-acre commercial property covered by an asphalt parking lot approximately 40 feet above mean sea level (amsl) in an urban area of South San Francisco, California. Depth to groundwater at 616 Linden is unknown as groundwater was not encountered during Phase II Environmental Site Assessment (ESA) activities at this property (Toeroek Team 2021). However, during a groundwater sampling event conducted in January 2001, groundwater was measured at 24 to 24.53 feet below top of casing (Atlas Engineering Services, Inc. 2001). The property is bounded to the northeast, east, southeast, and west by residential developments; north by a vacant vegetated lot; and south, southwest, and northwest by small businesses. Uses of surrounding properties include residential, commercial, and vacant land. Figure 2 illustrates the location and boundaries of 616 Linden.

Analysis of Brownfields Cleanup Alternatives
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2 The property at 905 Linden is a 0.27-acre vegetated lot with sod, a sprinkler system, and fence approximately 40 feet amsl in an urban area of South San Francisco, California. During the Phase II ESA investigation, shallow groundwater was encountered between 3.65 and 5 feet below ground surface (bgs) at 905 Linden (Toeroek Team 2021). Groundwater flow direction is generally east. The property is bounded to the north, east, and west by commercial and industrial buildings, and south and partially west by residential developments. Uses of surrounding properties include residential and commercial. Figure 3 illustrates the location and boundaries of 905 Linden.

1.2 OWNERSHIP AND PREVIOUS USE
The Site is owned by the City of South San Francisco, one of the Applicants.

Based on a review of aerial photographs, Sanborn maps, and previous investigation reports, 616 Linden was undeveloped until between 1910 and 1925 when a single-family home and garage were built on the southern end of the property. Between 1943 and 1946, the home and garage were torn down and an automotive shop (Volante Automotive) was built along with a used car lot and a parking lot. Volante Automotive ceased operations in the early 2000s. The current parking lot on the property was built between 1998 and 2006 (Environmental Data Resources, Inc. [EDR] 2020a, 2020b, 2020c; San Mateo County Groundwater Protection Program [SMCGPP] 2001).

Based on a review of aerial photographs and previous investigation reports, 905 Linden was undeveloped until a gas station was built between 1946 and 1956. Four underground storage tanks (USTs) formerly present at 905 Linden were removed by November 1998, at which time the property became a vegetated lot. The property currently hosts a vegetated lot with sod, a sprinkler system, a sign, a fence to the south and west, ornamental vegetation to the south and west, and ornamental boulders to the north and east (EDR 2020a, 2020b, 2020c; SMCGPP 2003).

1.3 PREVIOUS INVESTIGATIONS
Investigations and remediation activities have been completed at both 616 Linden and 905 Linden. In 2021, the Toeroek Team performed a Phase II ESA to evaluate the previous investigations and remediation activities, which provides a basis for this ABCA.

At 616 Linden, environmental investigations and remediation activities associated with Volante Automotive were conducted between July 1993 and February 2001. On July 13, 1993, one 1,000-gallon gasoline UST and

13.1 Previous Investigations and Remediation Activities at 616 Linden Analysis of Brownfields Cleanup Alternatives
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3 one 250-gallon waste oil UST were excavated from the property following detection of a leak. Soil samples were collected at the time of the UST excavations within excavation pits and soil stockpiles. Because elevated concentrations of hydrocarbons were present in the former UST pits, the pits were excavated again on August 25 and October 21, 1993 and additional confirmation samples were collected. Monitoring wells were installed in 1994 and 1996 to facilitate groundwater monitoring, which occurred until January 2001. The case closure memorandum states that 616 Linden qualified for closure under the RWQCB (1996) “1995 Interim Guidance on Required Cleanup at Low Risk Fuel Sites.” However, the qualification for closure did not include the requirement to assess the potential for vapor intrusion. In 2021, the Toeroek Team performed a Phase I ESA to evaluate any remaining recognized environmental conditions (RECs) from previous investigations and remediation activities.

At 905 Linden, environmental investigations, remediation activities, and monitoring were conducted between December 1985, when a leaking underground storage tank (LUST) was discovered, and October 2003. A monitoring well was installed and sampled from 1990 through 1998 (California State Water Resources Control Board [SWRCB] 2020). Multiple site features were removed, over-excavated, and investigated, including a 4,000-gallon diesel UST, a 8,000-gallon gasoline UST, a 6,000-gallon gasoline UST, a 1,000-gallon waste oil tank, a dispenser island, a pipeline from the USTs to the dispenser island, inlets from the service bays to the waste oil tank, hoists, a water collection sump, and an oil-water separator. Six additional monitoring wells were established, and groundwater sampling occurred from February 1999 through November 2003. The well locations were surveyed in April 2002, and a well survey and conduit study (preferential pathway investigation) occurred on January 30, 2003 (EDR 2020b). The wells were destroyed on August 7, 2003. The property was deemed clean by the County of San Mateo Health Services Agency through the SMCGPP, and the case was closed on November 17, 2003 (SWRCB 2020; County of San Mateo Health Services Agency 2003). Overall, 720.93 tons of soil and two truckloads with an unknown quantity of soil were removed from the property and sent for disposal between 1998 and 1999 (County of San Mateo Health Services Agency 2003). The case closure memorandum concluded that 905 Linden qualified for closure despite exceedances of soil Tier 2 risk-based screening levels (RBSLs) for TPH as gasoline (TPH-g) and benzene in soil samples collected between 5 and 8 feet bgs. According to the case closure memorandum, because groundwater at the property is shallow and most of the soil samples appeared to be either from the capillary fringe or the saturated zone, the presence of TPH-g and benzene above their RBSLs for ceiling value and indoor air exposure criteria in a sandy clayed silt soil was not a concern for potential health impacts (SMCGPP 2003). Furthermore, the TPH-g exceedances were also not deemed a concern because the

1.3.2 Previous Investigations and Remediation Activities at 905 Linden Analysis of Brownfields Cleanup Alternatives
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4 groundwater RBSLs for TPH-g and TPH as diesel (TPH-d) were based on a general nuisance and odor threshold for TPH. However, the vapor intrusion pathway was not evaluated (SMCGPP 2003).

The Toeroek Team conducted a Phase II ESA in 2021 to (1) confirm the presence or absence of RECs identified during the Phase I ESA completed by the Toeroek Team in 2021; (2) acquire information regarding the nature of contamination (if present) and risks posed by that contamination that would inform business decisions about the property; and (3), where applicable, satisfy the innocent purchaser defense under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (ASTM International [ASTM] 2019). In addition to the 616 Linden and 905 Linden properties, the Phase II ESA also included properties at 700 Linden Avenue and 705 Cypress Avenue. No exceedances of screening levels were observed at these latter properties, and they are not discussed further.

During the Phase II ESA, the Toeroek Team conducted soil gas, groundwater, and soil sampling. Soils at the properties were observed to be a mixture of silts, clays, sand, and loam with varying colors of brown, orange, and grey. Soil samples were collected at depths ranging from 0 to 5 feet bgs. Additionally, geophysical surveys were conducted to locate any remaining USTs at 616 Linden and 905 Linden. The geophysical survey results identified an electromagnetic anomaly at 616 Linden as an additional potential environmental concern. The anomaly was determined to be two pieces of metal within a subsurface concrete structure filled with soil.

Review of analytical data from the Phase II ESA led to the following noteworthy findings summarized below, shown on Figure 4 and Figure 5 and presented in the Phase I/II ESA Targeted Brownfields Assessment (TBA) Report (Toeroek Team 2021): • The following exceedances were noted in soil gas and soil at 616 Linden: o 1,2-Dichloroethane soil gas concentrations exceeded all four SLs at sampling locations SG-1 and SG-2.
o Benzene soil gas concentrations exceeded all four SLs at sampling locations SG-1, SG-2, and SG-4; whereas at sampling location SG-6, benzene concentrations exceeded the EPA VISL for residential soil gas and RWQCB ESLs for both residential and commercial soil gas. o Ethylbenzene soil gas concentrations exceeded all four SLs at sampling locations SG-1 and SG-2.
o M,p-xylene concentrations exceeded all four SLs at sampling locations SG-1 and SG-2. o O-xylene soil gas concentrations exceeded all four SLs at sampling location SG-2.

1.3.3 Phase II BSA
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5 o Toluene soil gas concentrations exceeded RWQCB ESLs for both residential and commercial soil gas at sampling location SG-2.
o The TPH-d soil concentration exceeded the RWQCB Tier 1 ESL at sampling location SB-4 (colocated with sampling location SG-4).
o Lead was detected at a concentration above the residential DTSC SL at the five-point composite location associated with soil within the subsurface concrete structure (616-EC-03012021).

Although the lead concentration is within the USGS San Mateo County background range, it was substantially higher than lead concentrations detected in soil at the other sample locations at 616 Linden and the other Site properties and is likely not representative of background concentrations in South San Francisco. The lead concentration within the stockpiled soil was likely impacted by debris discovered within the soil in the concrete structure. At the same location, leachable lead in soil is above the California soluble threshold limit concentration (STLC) limit based on the California waste extraction test (WET) using the citrate buffer, which indicates that if soil is excavated for off-Site disposal in the future, the soil should be treated or disposed of as a non-Resource Conservation and Recovery Act (RCRA) Class I California hazardous waste because of the potential for lead to leach under typically acidic landfill conditions. However, the WET result using deionized (DI) water buffer indicates that lead would not leach from in situ soil and threaten water quality and that soil may be left on site without a cap. A cap (such as the pavement currently in place) would be necessary to address direct exposure to in situ soil based on exceedance of the residential DTSC SL. • The following exceedances were noted in groundwater and soil at 905 Linden: o The TPH-g groundwater concentrations exceeded the EPA VISL for residential groundwater at sampling locations GW-1, GW-3, and GW-4.
o The TPH-g soil concentration at sampling location GW-4 exceeded the RWQCB Tier 1 ESL.

The Phase II ESA concluded that a vapor encroachment concern (VEC) remains at 616 Linden. Subsurface soil gas sample locations at this property contained 1,2-dichloroethane and benzene, toluene, ethylbenzene, and xylenes (BTEX) at concentrations above SLs (Figure 4). Use of the Site for residential or commercial purposes could require installing a vapor mitigation system(s) in any future buildings or land use controls to prevent exposure or release and to mitigate potential impacts on human health.

At 616 Linden, subsurface soil contains TPH at concentrations above the Tier 1 ESL, which is based on a generic site model of residential use where groundwater is used as drinking water (Figure 4). Soil could Analysis of Brownfields Cleanup Alternatives
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6 require treatment, removal, or capping to prevent exposure or release and to mitigate potential impacts on human health if the Site is used for residential purposes where groundwater is used as drinking water. Because of its shallow depth, location in an urban environment, and proximity to the San Francisco Bay, groundwater is unlikely to be used as potable water at the Site.

At 616 Linden, soil within the subsurface concrete structure uncovered during the anomaly investigation contains lead above the residential DTSC SL (Figure 4). The WET results using the DI water buffer indicate that lead would not leach from soil or threaten water quality and that soil may be left on site without a cap.

However, a cap (such as the pavement currently in place) would be necessary to address direct exposure to in situ soil. If soil within the subsurface concrete structure is excavated for off-Site disposal in the future, the soil would likely require treatment or disposal as a non-RCRA Class I California hazardous waste because of the potential for leachable lead in landfill conditions.

A VEC remains at 905 Linden. Groundwater at sampling locations GW-1, GW-3, and GW-4 contains TPH-g at a concentration above SLs (Figure 5). Use of the Site for residential or commercial purposes may require treatment to prevent exposure or release and to mitigate potential impacts on human health. No VOCs in groundwater were detected above residential or commercial SLs at 905 Linden.

At 905 Linden, subsurface soil at sampling location GW-4 contains TPH-g at a concentration above the Tier 1 ESL, which is based on a generic site model of residential use where groundwater is used as drinking water (Figure 5). Soil could require treatment, removal, or capping to prevent exposure or release and to mitigate potential impacts on human health if the Site is used for residential purposes where groundwater is used as drinking water. However, groundwater is unlikely to be used as potable water at the Site.

The Phase II ESA indicated that an ABCA should be prepared to evaluate cleanup alternatives required to address the constituents reported above SLs in subsurface soil gas at 616 Linden, soil within the subsurface concrete structure at 616 Linden, and in groundwater and subsurface soil at 905 Linden.

No other prior environmental investigations have occurred at the Site.

1.4 PROJECT GOAL
The overall goal of any brownfields cleanup action is to address environmental conditions preventing or impeding the preferred type of Site redevelopment and to do so in a manner protective of human health. The Applicants have interest in redeveloping the Site for a neighborhood park, a cultural center, affordable housing, mixed-use ground-floor commercial buildings, or some combination of these. This ABCA considers cleanup alternatives based on applicable federal and state screening levels. For soil gas, this ABCA considers Analysis of Brownfields Cleanup Alternatives
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7 EPA VISLs or RWQCB ESLs, whichever is more conservative (see Table 1). For subsurface soil, the ABCA considers alternatives based on the RWQCB Tier 1 ESL for TPH and the DTSC SL for lead (see Table 2).

For groundwater, the ABCA considers alternatives based on the EPA VISL for residential groundwater (see Table 3). Although groundwater in the vicinity of the Site is not known to be a source of drinking water and there are no future plans to use groundwater for this purpose at the Site, this ABCA considers cleanup alternatives to address the potential for vapor intrusion from groundwater contamination. This ABCA does not present cleanup alternatives to address any potential ecological risks. The Phase II ESA investigation did not include an ecological risk assessment or collection of data associated with evaluating ecological risks as these are outside the scope of work for this TBA and the Site is within an urban setting with minimal potential ecological habitat.

This ABCA addresses COCs as identified in the Phase II ESA, which are BTEX and 1,2-dichloroethane in soil gas; TPH-d, TPH-g, and lead in soil; and TPH-g in groundwater.

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8 2.0 APPLICABLE REGULATIONS AND ASSUMED CLEANUP LEVELS This section discusses oversight responsibility for cleanup, assumed cleanup levels, and applicable laws and regulations.

2.1 CLEANUP OVERSIGHT RESPONSIBILITY
Cleanup and redevelopment of the Site must be completed in compliance with applicable laws and regulations. RWQCB, DTSC, and EPA regulate and oversee cleanup of contaminated sites in California. The lead agency for oversight of remedial activities is assumed to be RWQCB or DTSC.

2.2 ASSUMED CLEANUP LEVELS FOR MAJOR CONTAMINANTS
For the purpose of this ABCA, screening levels are used as the assumed cleanup levels. The Applicant or organization undertaking cleanup actions at the Site will need to work with the oversight agency to establish appropriate cleanup levels specific to the Site. For the purpose of the ABCA, assumed cleanup levels for soil gas are the most conservative EPA VISL (2020a) or RWQCB ESL (2019). Assumed cleanup levels for soil are the RWQCB Tier 1 ESL (2019) for TPH and the DTSC SL (2020) for lead. The assumed cleanup level for groundwater for TPH-g is the EPA VISL (2020a). Although groundwater in the vicinity of the Site is not known to be a source of drinking water and there are no future plans to use groundwater for this purpose at the Site, this ABCA considers cleanup alternatives to address the potential for vapor intrusion from groundwater contamination. Assumed cleanup levels for soil gas, soil, and groundwater are presented in Table 1, Table 2, and Table 3, respectively. The Toeroek Team screened the analytical data collected during previous investigations against the assumed cleanup levels identified above to determine the areas where remediation is needed. The data are presented in the Phase I/II ESA TBA Report (Toeroek Team 2021). Figure 4 and Figure 5 depict the exceedances of the screening criteria at 616 Linden and 905 Linden; Figure 6 and, Figure 7 show the approximate areas where remediation is needed in soil based on these data. These areas are a rough approximation, and actual Site conditions may vary.

2.3 LAWS AND REGULATIONS APPLICABLE TO THE CLEANUP
Site cleanup must be completed in compliance with applicable cleanup laws and regulations. General environmental laws and regulations that may be applicable to the cleanup activities are identified and briefly Analysis of Brownfields Cleanup Alternatives
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9 summarized below. This subsection is for informational purposes only. It is the responsibility of the party or parties conducting remedial activities to ensure compliance with all applicable laws and regulations.

Activities that generate waste would be subject to the waste management requirements in the California Code of Regulations, Title 22, Division 4.5 or California Code of Regulations, Title 23, Division 3, both of which regulate hazardous waste, and California Code of Regulations, Title 27, Division 2, which regulate certain solid wastes. These regulations contain requirement on the proper handling, management, and disposal of waste depending on the determination of whether the waste is hazardous, designated, or non-hazardous solid waste.

The Bay Area Air Quality Management District that has promulgated rules for stockpiling VOCcontaminated soil and discharges of VOCs into the air from soil vapor extraction operations.

California Health and Safety Code Division 20, Chapter 6.5, California Civil Code Division 3, and California Code of Regulations Title 22, Division 4.5, Chapter 39 contain requirements for developing institutional controls and land use covenants for property where hazardous substances remain at levels unacceptable for unrestricted use.

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10 3.0 EVALUATION OF BROWNFIELDS CLEANUP ALTERNATIVES
The evaluation of cleanup alternatives in this ABCA is based on the anticipated future use scenario for the Site—redeveloping the Site for a neighborhood park, a cultural center, affordable housing, mixed-use ground-floor commercial buildings, or some combination of these. Because a human health risk assessment of the Site has not been completed, screening levels are used as the assumed cleanup levels. The Applicant or organization undertaking cleanup actions at the Site will need to work with the oversight agency to establish appropriate cleanup levels specific to the Site. For the purpose of the ABCA, assumed cleanup levels for soil gas are the most conservative EPA VISL (2020a) or RWQCB ESL (2019). Assumed cleanup levels for soil are the RWQCB Tier 1 ESL (2019) for TPH and the DTSC SL (2020) for lead. The assumed cleanup level for groundwater for TPH-g is the EPA VISL (2020a).

3.1 CLEANUP ACTION OBJECTIVES
The cleanup action objectives for the Site are to mitigate potential human exposure to contaminants identified in soil gas, soil, and groundwater at the Site at levels exceeding the assumed cleanup levels presented in Section 2.2. Future redevelopment of the Site is intended to include residential exposure scenarios. The cleanup alternatives and costs presented in this ABCA may change if different exposure scenarios are identified, additional data becomes available, or a human health risk assessment is performed.

3.2 IDENTIFICATION OF CLEANUP ALTERNATIVES
The cleanup alternatives selected for evaluation were initially assessed to determine technical feasibility and if the alternative is capable of achieving the project goal to address environmental conditions preventing or impeding the preferred type of Site redevelopment in a manner protective of human health. EPA (2020b) provides guidance for the various technologies available to ensure contamination is either removed from a site or treated so it no longer poses a threat to human health.

Those alternatives deemed potentially capable of achieving the overall project goal were further evaluated for effectiveness, implementability, and cost. The cost estimates presented in this ABCA are rough order-ofmagnitude estimates (accuracy range of -25 to +75 percent) and are intended for comparison purposes only; they should not be used as budget- or design-level estimates.

Section 3.2.3, Alternatives Considered and Dismissed, and Table 5 discusses alternatives considered but not selected for further evaluation as a part of alternatives at the Site.

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11 Based on the planned future use of the Site, the following cleanup alternatives were considered for 616 Linden and 905 Linden:
616 Linden • Alternative 1: No Action (Baseline) • Alternative 2: Passive Vapor Mitigation, Soil Management Plan (SMP), Operation and Maintenance (O&M) and Institutional Controls (ICs) • Alternative 3: Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M and ICs • Alternative 4: Soil Excavation with Off-Site Disposal and ICs (neighborhood park reuse only) 905 Linden • Alternative 1: No Action (Baseline) • Alternative 2: Passive Vapor Mitigation, SMP, O&M and ICs • Alternative 3: Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M and ICs • Alternative 4: Soil Excavation with Off-Site Disposal and ICs (neighborhood park reuse only) Detailed descriptions of each alternative for 616 Linden and 905 Linden and the results of a comparative analysis of alternatives are presented in the subsections below.

Detailed descriptions of each alternative evaluated for 616 Linden are included in the subsections below.

3.2.1.1 616 Linden - Alternative 1 – No Action (Baseline) The no action alternative is included as a baseline for comparison to the other proposed alternatives. This alternative would involve no containment, treatment, removal, or monitoring of contaminants. All contaminated soil would be left in place, soil gas would be left unmitigated, and no restrictions on future land use would be imposed.

Effectiveness
The no action alternative is not considered effective because it would not be protective of human health for the proposed reuse of the Site.

3.2.1 616 Linden
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12 Implementation
Implementation of this alternative would require no effort because no containment, treatment, removal, or monitoring of contaminants would occur.

Cost
No costs are associated with this alternative because no activities would occur.

3.2.1.2 616 Linden - Alternative 2 – Passive Vapor Mitigation, SMP, O&M and ICs This alternative would involve construction of a passive vapor mitigation system for new structures built at 616 Linden. A passive vapor mitigation system would create a small negative pressure underneath the slab of the structure, providing a preferential flow pathway for vapor, thus allowing the vapors to move through the perforated piping and outside rather than into the occupied structure. The passive vapor mitigation system would include a gravel layer with perforated piping and a vapor barrier consisting of metalized film sheet, nitrile-modified asphalt, and protection fabric layers. Vent risers would extend through the roof of the structure. The soil gas collected would be vented outside to the atmosphere through these risers. Regular inspections and potential repairs and maintenance of the vapor mitigation system would be needed as long as the structure is occupied and contamination remains in soil gas above the cleanup levels.

Contaminated soil would be left in place in the area of sampling location SB-4, where TPH-d was detected at a concentration exceeding the assumed cleanup level, and in the area of the subsurface concrete structure, where lead was detected at a concentration above the assumed cleanup level. Potential Site receptors are currently protected from exposure by the layer of soil and pavement over these contaminated areas.

However, a SMP would be necessary to guide proper handling of soil at 616 Linden if the soil is disturbed (for example, during new structure construction). The SMP would present a tiered approach to soil management, regulatory approval, documentation, and record keeping to minimize administrative requirements.

ICs would be necessary to ensure (1) new structures built at 616 Linden are designed with a vapor mitigation system, (2) the continued integrity of the vapor mitigation system, and (3) that a SMP is in place to manage contaminated soils and maintain the existing asphalt cover.

For cost estimating purposes, the Toeroek Team made the following assumption: • The location, size, and number of structures to be built at 616 Linden is unknown. Therefore, a three-story structure with a slab foundation encompassing 14,000 SF of first-floor space was assumed.

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13 Alternative 2 would allow for residential and commercial/industrial use of the Site.

Effectiveness
Alternative 2 rates moderate for effectiveness as this method would limit exposure of potential vapors and contaminated soils to Site receptors. However, soil contamination around sampling location SB-4 and the subsurface concrete structure would remain in place. This alternative would allow for redevelopment of 616 Linden as proposed; however, ICs would also be required to ensure new structures built at 616 Linden are designed with a vapor mitigation system, the continued integrity of vapor mitigation system, and that a SMP is in place to manage contaminated soils and maintain the existing asphalt cover.

Implementation
Alternative 2 rates moderate for implementation as passive vapor mitigation is a common remediation practice and the materials, services, and equipment necessary for implementation are readily available; however, the passive vapor mitigation system would require routine inspections and potential repairs and maintenance until vapor concentrations are below cleanup levels. A SMP and ICs would also be easy to implement as no physical remediation would be required. Implementation of ICs would include a restrictive covenant that would be filed with the Register of Deeds to ensure new structures built at 616 Linden are designed with a vapor mitigation system. The SMP would be prepared to guide proper handling of soil potentially impacted by lead and TPH-d.

Cost
The total cost of Alternative 2 in 2021 dollars is estimated at $298,000, which includes a capital cost of $228,000, $53,000 for ICs, and $17,000 for O&M over 30 years. For cost estimating purposes, O&M is assumed to be required for 30 years; however, O&M will be needed in perpetuity for the life of the vapor mitigation system and ICs as long as contamination remains at 616 Linden above cleanup levels. Costs were estimated by applying selected functions of RACER Version 11.2.16.0, contractor quotes, and professional judgment, and include a 30 percent contingency to account for unknown costs associated with changes in scope that may occur during the design phase and unknown costs associated with the construction and implementation of the alternative. Cost details are presented in Table 4. 3.2.1.3 616 Linden - Alternative 3 – Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M and ICs
Alternative 3 would involve construction of an active vapor mitigation for new structures built at 616 Linden.

The active vapor mitigation system would consist of a sub-slab depressurization system that would mechanically create a vacuum to collect soil gas from beneath the structure and vent the vapors outside. The Analysis of Brownfields Cleanup Alternatives
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Date: August 24, 2021
14 components of the active vapor mitigation system would be similar to the passive vapor mitigation system described in Alternative 2; however, the system would be an active system with the addition of blowers to mechanically create a vacuum.

Long-term O&M would be needed as long as a structure is occupied at 616 Linden and contamination remains in soil gas above cleanup levels. Electricity would be required to operate the blowers, and occasional maintenance or replacement of the blowers may be needed. ICs would be necessary to ensure (1) new structures built at the property are designed with a vapor mitigation system and (2) the continued integrity of the vapor mitigation system.

Soil would also be excavated in the area of sampling location SB-4, where TPH-d was detected at a concentration exceeding the assumed cleanup level, and in the area of the subsurface concrete structure, where lead was detected at a concentration above the assumed cleanup level.

For cost estimating purposes, the Toeroek Team made the following assumptions: • The size, number, and location of structures to be built at 616 Linden is unknown. Therefore, a three-story structure with a slab foundation encompassing 14,000 SF of first-floor space was assumed. • Soil Excavation around Sampling Location SB-4: The volume of soil to be excavated to the assumed cleanup levels is approximately 145 CY, assuming an area of 150 SF and a depth of 26 feet bgs.

Shoring would be needed because of the excavation depth. The area requiring excavation is depicted on Figure 6. • Soil Excavation around Subsurface Concrete Structure: The volume of soil to be excavated to the assumed cleanup levels is approximately 6 CY, assuming an area of 54 SF and a depth of 3 feet bgs.

In addition, the concrete walls and floor of the structure would be demolished. Approximately 0.6 ton of concrete is assumed to require demolition and off-Site disposal. The area requiring excavation is depicted on Figure 6. • Confirmation Sampling: Confirmation soil sampling will require collection of 10 five-point composite samples, five from the walls and floor of each excavated area. • Backfill: Excavated areas will be backfilled with clean off-Site material, graded, and seeded as needed for redevelopment. • Waste Disposal: Soil around the subsurface concrete structure is assumed to require disposal at a non-RCRA Class I California hazardous waste facility based on the WET results using the citrate Analysis of Brownfields Cleanup Alternatives
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15 buffer that indicated that leachable lead in soil is above the California STLC. Soil around sampling location SB-4 is assumed to be accepted at a Class III landfill as non-hazardous waste.

Alternative 3 would allow for residential and commercial/industrial use of the Site.

Effectiveness
Alternative 3 rates moderate to high for effectiveness as this method would limit exposure of potential vapors to Site receptors by pushing air into the venting layer below the slab with the use of electric blowers.

In addition, contaminated soil in the area of sampling location SB-4 and the subsurface concrete structure would be permanently removed from the Site. However, long-term O&M would be required for the active vapor mitigation system to ensure (1) new structures built at the property are designed with a vapor mitigation system and (2) the continued integrity of the vapor mitigation system.

Implementation
Alternative 3 rates difficult to moderate for implementation as the active vapor mitigation system would require electricity usage and long-term O&M until vapor concentrations are below cleanup levels. For the purpose of this ABCA, O&M is assumed to be required for 30 years. Any structure to be built at 616 Linden would be designed with an active vapor mitigation system, including a vapor barrier, gravel layer, perforated piping, and blowers. Implementation of ICs would include a restrictive covenant that would be filed with the Register of Deeds to ensure new structures built at 616 Linden are designed with a vapor mitigation system.

Excavation is a common remediation practice and equipment and contractors are readily available.

Excavation preparation would involve obtaining buried utility clearances, securing the area, and constructing runoff controls for surface drainage. The work area would be secured to prevent unauthorized access. During construction, a stormwater pollution prevention plan would be required to meet the requirements of the State of California. Soil excavation by qualified equipment operators would comply with applicable state and federal regulations. In total, excavation of approximately 151 CY of soil is assumed. All waste soil excavated during this process would be transported to and disposed of at a Class I-, II-, or III-permitted facility, depending on results on hazardous and leaching characteristics. However, vapor mitigation is a common remediation practice and the materials, services, and equipment necessary for implementation are readily available.

Cost
The total cost of Alternative 3 in 2021 dollars is estimated at $531,000, which includes a capital cost of $275,000, $53,000 for ICs, and $203,000 for O&M over 30 years. For cost estimating purposes, O&M is Analysis of Brownfields Cleanup Alternatives
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16 assumed to be required for 30 years; however, O&M will be needed in perpetuity for the life of the vapor mitigation system and ICs as long as contamination remains at 616 Linden above cleanup levels. Costs were estimated by applying selected functions of RACER Version 11.2.16.0, contractor quotes, and professional judgment, and include a 30 percent contingency to account for unknown costs associated with changes in scope that may occur during the design phase and unknown costs associated with the construction and implementation of the alternative. Cost details are presented in Table 4. 3.2.1.4 616 Linden - Alternative 4 – Soil Excavation with Off-Site Disposal and ICs (neighborhood park reuse only)
Alternative 4 assumes 616 Linden will be redeveloped as a neighborhood park and will not include the construction of any structures that would be occupied by people on a regular basis for any length of time.

This alternative would involve excavation of soil in the area of sampling location SB-4, where TPH-d was detected at a concentration exceeding the assumed cleanup level, and in the area of the subsurface concrete structure, where lead was detected at a concentration above the assumed cleanup level. ICs would be necessary to ensure that if a structure is built on the property, a vapor mitigation system would be required.

For cost estimating purposes, the Toeroek Team made the following assumptions: • Soil Excavation around Sampling Location SB-4: The volume of soil to be excavated to the assumed cleanup level is approximately 145 CY, assuming an area of 150 SF and a depth of 26 feet bgs.

Shoring would be needed because of the excavation depth. The area requiring excavation is depicted on Figure 6. • Soil Excavation around Subsurface Concrete Structure: The volume of soil to be excavated to the assumed cleanup level is approximately 6 CY, assuming an area of 54 SF and a depth of 3 feet bgs. In addition, the concrete walls and floor of the structure would be demolished. Approximately 0.6 ton of concrete is assumed to require demolition and off-Site disposal. The area requiring excavation is depicted on Figure 6. • Confirmation Sampling: Confirmation soil sampling will require collection of 10 five-point composite samples, five from the walls and floor of each excavated area. • Backfill: Excavated areas will be backfilled with clean off-Site material, graded, and seeded as needed for redevelopment. • Waste Disposal: Soil around the subsurface concrete structure is assumed to require disposal at a non-RCRA Class I California hazardous waste facility based on the WET results using the citrate Analysis of Brownfields Cleanup Alternatives
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Date: August 24, 2021
17 buffer that indicated that leachable lead in soil is above the California STLC. Soil around sampling location SB-4 is assumed to be accepted at a Class III landfill as non-hazardous waste.

Effectiveness
Alternative 4 rates moderate to high for effectiveness as contaminated soil in the area of sampling location SB-4 and the subsurface concrete structure would be permanently removed from the Site. However, this alternative would limit redevelopment of 616 Linden to a neighborhood park. If any structures are to be built that would be occupied by people on a regular basis for any length of time, vapor mitigation systems would be required as included in Alternatives 2 and 3.

Implementation
Alternative 4 rates easy to moderate for implementation as excavation is a common remediation practice and equipment and contractors are readily available. Excavation preparation would involve obtaining buried utility clearances, securing the area, and constructing runoff controls for surface drainage. The work area would be secured to prevent unauthorized access. During construction, a stormwater pollution prevention plan would be required to meet the requirements of the State of California. Soil excavation by qualified equipment operators would comply with applicable state and federal regulations. All waste soil excavated during this process would be transported to and disposed of at a Class I-, II-, or III-permitted facility, depending on results on hazardous and leaching characteristics. Planning these processes would require careful consideration of precautions concerning worker health and safety.

Implementation of ICs would include a restrictive covenant that would be filed with the Register of Deeds to ensure that if structures are built at 616 Linden, vapor mitigation systems would be required.

Cost
The total cost of Alternative 4 in 2021 dollars is estimated at $124,000, which includes a capital cost of $71,000 and $53,000 for ICs. Costs were estimated by applying selected functions of RACER Version

11.2.16.0, contractor quotes, and professional judgment, and include a 30 percent contingency to account for unknown costs associated with changes in scope that may occur during the design phase and unknown costs associated with the construction and implementation of the alternative. Cost details are presented in Table 4. Based on the results from the Phase II ESA, concentrations of TPH-g exceed the EPA VISL in groundwater and exceed the RWQCB Tier 1 ESL in soil. These present a potential vapor intrusion concern. However,

3.2.2 905 Linden
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18 before redevelopment of the property, soil gas sampling for volatile petroleum hydrocarbons is recommended to confirm the potential for vapor intrusion.

Detailed descriptions of each alternative evaluated for 905 Linden are included in the subsections below.

3.2.2.1 905 Linden - Alternative 1 – No Action (Baseline) The no action alternative is included as a baseline for comparison to the other proposed alternatives. This alternative would involve no containment, treatment, removal, or monitoring of contaminants. All contaminated soil and groundwater would be left in place, potential for vapor intrusion would be left unmitigated, and no restrictions on future land use would be imposed.

Effectiveness
Because the no action alternative would not be protective of human health for the proposed reuse of the Site, it is not considered effective.

Implementation
Implementation of this alternative would require no effort because no containment, treatment, removal, or monitoring of contaminants would occur.

Cost
No costs are associated with this alternative because no activities would occur.

3.2.2.2 905 Linden - Alternative 2 - Passive Vapor Mitigation, SMP, O&M and ICs This alternative would involve construction of a passive vapor mitigation system for new structures built on the property at 905 Linden. A passive vapor mitigation system would create a small negative pressure underneath the slab of the structure, providing a preferential flow pathway for vapor, thus allowing the vapors to move through the perforated piping and outside rather than into the occupied structure. The passive vapor mitigation system would include a gravel layer with perforated piping and a vapor barrier consisting of metalized film sheet, nitrile-modified asphalt, and protection fabric layers. Vent risers would extend through the roof of the structure. The soil gas collected would be vented outside to the atmosphere through these risers. Regular inspections and potential repairs or maintenance of the passive vapor mitigation system would be needed as long as the structure is occupied and contamination remains in soil gas above cleanup levels.

Contaminated soil would be left in place in the area of sampling location GW-4, where TPH-g was detected at 4 to 5 feet bgs at a concentration exceeding the assumed cleanup level. Potential Site receptors are currently Analysis of Brownfields Cleanup Alternatives
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Date: August 24, 2021
19 protected from exposure by the layer of soil over this contaminated area. However, a SMP would be necessary to guide proper handling of soil at 905 Linden if the soil is disturbed (for example, during new structure construction). The SMP would present a tiered approach to soil management, regulatory approval, documentation, and record keeping to minimize administrative requirements.

ICs would be necessary to ensure (1) new structures built at 905 Linden are designed with a vapor mitigation system, (2) the continued integrity of the vapor mitigation system, (3) that a SMP is in place to manage contaminated soils and the existing soil cover, and (4) use of untreated groundwater for drinking water is prohibited.

For cost estimating purposes, the Toeroek Team made the following assumption: • The size, location, and number of structures to be built at 905 Linden is unknown. Therefore, a three-story structure with a slab foundation encompassing 12,000 SF of first-floor space was assumed.

Alternative 2 would allow for residential and commercial/industrial use of the Site.

Effectiveness
Alternative 2 rates moderate for effectiveness as this method would limit exposure of potential vapors and contaminated soils to Site receptors. However, groundwater contamination and known soil contamination around sampling location GW-4 would remain in place untreated. This alternative would allow for redevelopment of 905 Linden as proposed; however, ICs would also be required to ensure new structures built at 905 Linden are designed with a vapor mitigation system, the continued integrity of vapor mitigation system, that a SMP is in place to manage contaminated soils and the existing soil cover, and to prohibit use of untreated groundwater for drinking water.

Implementation
Alternative 2 rates moderate for implementation as passive vapor mitigation is a common remediation practice and the materials, services, and equipment necessary for implementation are readily available; however, the vapor mitigation system would require routine inspections and potential repairs and maintenance until vapor concentrations are below cleanup levels. A SMP and ICs would be easy to implement as no physical remediation would be required. Implementation of ICs would include a restrictive covenant that would be filed with the Register of Deeds to ensure new structures built at 905 Linden are designed with a vapor mitigation system and use of untreated groundwater for drinking water is prohibited.

The SMP would be prepared to guide proper handling of soil potentially impacted by TPH-g.

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20 Cost
The total cost of Alternative 2 in 2021 dollars is estimated at $271,000, which includes a capital cost of $201,000, $53,000 for ICs, and $17,000 for O&M over 30 years. For cost estimating purposes, O&M is assumed to be required for 30 years; however, O&M will be needed in perpetuity as long as contamination remains in groundwater above cleanup levels posing a potential vapor intrusion issue. Costs were estimated by applying selected functions of RACER Version 11.2.16.0, contractor quotes, and professional judgment, and include a 30 percent contingency to account for unknown costs associated with changes in scope that may occur during the design phase and unknown costs associated with the construction and implementation of the alternative. Cost details are presented in Table 4. 3.2.2.3 905 Linden - Alternative 3 - Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M and ICs
Alternative 3 would involve construction of an active vapor mitigation for new structures built at 905 Linden.

The active vapor mitigation system would consist of a sub-slab depressurization system that would mechanically create a vacuum to collect soil gas from beneath the structure and vent the vapors outside. The components of the active vapor mitigation system would be similar to the passive vapor mitigation system described in Alternative 2; however, the system would be an active system with the addition of blowers to mechanically create a vacuum.

Long-term O&M would be needed as long as a structure is occupied at 905 Linden and contamination remains in groundwater above cleanup levels posing a potential vapor intrusion issue. Electricity would be required to operate the blowers and occasional maintenance, or replacement of the blowers may be needed.

ICs would be necessary to ensure (1) new structures built at the property are designed with a vapor mitigation system, (2) the continued integrity of the vapor mitigation system, and (3) use of untreated groundwater for drinking water is prohibited.

Soil would also be excavated in the area of sampling location GW-4, where TPH-g was detected at a concentration exceeding the assumed cleanup level.

For cost estimating purposes, the Toeroek Team made the following assumptions: • The size, location, and number of structures to be built at 905 Linden is unknown. Therefore, a three-story structure with a slab foundation encompassing 12,000 SF of first floor space was assumed.

Analysis of Brownfields Cleanup Alternatives
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Final
Date: August 24, 2021
21 • Soil Excavation around Sampling Location GW-4: The volume of soil to be excavated to cleanup levels is approximately 65 CY, assuming an area of 290 SF and a depth of 6 feet bgs. The area requiring excavation is depicted on Figure 7. • Confirmation Sampling: Confirmation soil sampling will require collection of five five-point composite samples from the walls and floor of the excavated area. • Backfill: Excavated areas will be backfilled with clean off-Site material, graded, and seeded as needed for redevelopment. • Waste Disposal: Soil around sampling location GW-4 is assumed to be accepted at a Class III landfill as non-hazardous waste.

Alternative 3 would allow for residential and commercial/industrial use of the Site.

Effectiveness
Alternative 3 rates moderate to high for effectiveness as this method would limit exposure of potential vapors to Site receptors by pushing air into the venting layer below the slab with the use of electric blowers.

In addition, contaminated soil in the immediate area of sampling location GW-4 would be permanently removed from the Site. However, long-term O&M would be required for the active vapor mitigation system to ensure (1) new structures built at the property are designed with a vapor mitigation system, (2) the continued integrity of the vapor mitigation system, and (3) use of untreated groundwater for drinking water is prohibited.

Implementation
Alternative 3 rates difficult to moderate for implementation as the active vapor mitigation system would require electricity usage and long-term O&M until vapor concentrations are below cleanup levels. However, vapor mitigation is a common remediation practice and the materials, services, and equipment necessary for implementation are readily available. For the purpose of this ABCA, O&M is assumed to be required for 30 years. Any structure to be built at 905 Linden would be designed with an active vapor mitigation system, including a vapor barrier, gravel layer, perforated piping, and blowers. Implementation of ICs would include a restrictive covenant that would be filed with the Register of Deeds to ensure new structures built at 905 Linden are designed with a vapor mitigation system and use of untreated groundwater for drinking water is prohibited.

Excavation is a common remediation practice and equipment and contractors are readily available.

Excavation preparation would involve obtaining buried utility clearances, securing the area, and constructing Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
22 runoff controls for surface drainage. The work area would be secured to prevent unauthorized access. During construction, a stormwater pollution prevention plan would be required to meet the requirements of the State of California. Soil excavation by qualified equipment operators would comply with applicable state and federal regulations. In total, excavation of approximately 65 CY of soil is assumed. All waste soil excavated during this process would be transported to and disposed of at a Class I-, II-, or III-permitted facility, depending on results on hazardous and leaching characteristics.

Cost
The total cost of Alternative 3 in 2021 dollars is estimated at $460,000, which includes a capital cost of $204,000, $53,000 for ICs, and $203,000 for O&M over 30 years. For cost estimating purposes, O&M is assumed to be required for 30 years; however, O&M will be needed in perpetuity for the life of the vapor mitigation system and ICs as long as contamination remains at 616 Linden above cleanup levels. Costs were estimated by applying selected functions of RACER Version 11.2.16.0, contractor quotes, and professional judgment, and include a 30 percent contingency to account for unknown costs associated with changes in scope that may occur during the design phase and unknown costs associated with the construction and implementation of the alternative. Cost details are presented in Table 4. 3.2.2.4 905 Linden - Alternative 4 - Soil Excavation with Off-Site Disposal and ICs (neighborhood park reuse only)
Alternative 4 assumes 905 Linden will be redeveloped as a neighborhood park and will not include the construction of any structures that would be occupied by people on a regular basis for any length of time.

This alternative would involve excavation of soil in the area of sampling location GW-4, where TPH-g was detected at a concentration exceeding the assumed cleanup level. ICs would be necessary to ensure that if a structure is built on the property, a vapor mitigation system would be required and to prohibit use of untreated groundwater for drinking water.

For cost estimating purposes, the Toeroek Team made the following assumptions: • Soil Excavation around Sampling Location GW-4: The volume of soil to be excavated to cleanup levels is approximately 65 CY, assuming an area of 290 SF and a depth of 6 feet bgs. The area requiring excavation is depicted on Figure 7. • Confirmation Sampling: Confirmation soil sampling will require collection of five five-point composite samples from the walls and floor of the excavated area. • Backfill: Excavated areas will be backfilled with clean off-Site material, graded, and seeded as needed for redevelopment.

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23 • Waste Disposal: Soil around sampling location GW-4 is assumed to be accepted at a Class III landfill as non-hazardous waste.

Effectiveness
Alternative 4 rates moderate to high for effectiveness as contaminated soil in the area of sampling location GW-4 would be permanently removed from the Site. However, this alternative would limit redevelopment of 905 Linden to a neighborhood park. If any structures are to be built that would be occupied by people on a regular basis for any length of time, vapor mitigation systems would be required as included in Alternatives 2 and 3 as well as prohibiting use of untreated groundwater for drinking water.

Implementation
Alternative 4 rates easy to moderate for implementation as excavation is a common remediation practice and equipment and contractors are readily available. Excavation preparation would involve obtaining buried utility clearances, securing the area, and constructing runoff controls for surface drainage. The work area would be secured to prevent unauthorized access. During construction, a stormwater pollution prevention plan would be required to meet the requirements of the State of California. Soil excavation by qualified equipment operators would comply with applicable state and federal regulations. All waste soil excavated during this process would be transported to and disposed of at a Class I-, II-, or III-permitted facility, depending on results on hazardous and leaching characteristics. Planning these processes would require careful consideration of precautions concerning worker health and safety.

Implementation of ICs would include a restrictive covenant that would be filed with the Register of Deeds to ensure that if structures are built at 905 Linden, vapor mitigation systems would be required and to prohibit use of untreated groundwater for drinking water.

Cost
The total cost of Alternative 4 in 2021 dollars is estimated at $80,000, which includes a capital cost of $27,000 and $53,000 for ICs. Costs were estimated by applying selected functions of RACER Version 11.2.16.0, contractor quotes, and professional judgment, and include a 30 percent contingency to account for unknown costs associated with changes in scope that may occur during the design phase and unknown costs associated with the construction and implementation of the alternative. Cost details are presented in Table 4. A wide variety of alternatives are available for the remediation of soil and groundwater. Table 5 identifies alternatives considered but not selected for further evaluation as a part of alternatives at the Site.

3.2.3 Alternatives Considered and Dismissed
Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
24 3.3 COMPARISON OF ALTERNATIVES
The Toeroek Team assessed each cleanup alternative selected for evaluation to determine its effectiveness, implementability, and cost in Section 3.2. A comparative analysis of alternatives based on the same criteria is provided in this subsection.

Effectiveness
Alternative 1, the no action alternative, would not be protective of human health and would not meet the project goal for the Site.

Alternative 2 is rated moderate for effectiveness as the passive vapor mitigation system would limit exposure of potential vapors to Site receptors and the SMP would guide proper handling of soil if the soil is disturbed.

Alternative 3 is rated slightly higher than Alternative 2 with a rating of moderate to high for effectiveness as the active vapor mitigation system would be more effective at pushing air into the venting layer below the slab with the use of electric blowers. ICs would also be required for both Alternatives 2 and 3 to ensure (1) new structures built at 616 Linden are designed with a vapor mitigation system and (2) the continued integrity of vapor mitigation system.

Alternative 4 is rated moderate to high for effectiveness as contaminated soil in the area of sampling location SB-4 and the subsurface concrete structure would be permanently removed from the Site. However, this alternative would limit redevelopment of 616 Linden to a neighborhood park. If any structures are to be built that would be occupied by people on a regular basis for any length of time, vapor mitigation systems would be required as included in Alternatives 2 and 3.

Implementability
Alternative 2 is rated moderate for implementation as vapor mitigation is a common remediation practice and materials, services, and equipment are readily available; however, the vapor mitigation system would require routine inspections and potential repairs and maintenance in perpetuity. In addition, a SMP would need to be implemented to guide proper handling of contaminated soils. Alternative 3 is rated slightly lower than Alternative 2 with a rating of difficult to moderate. Alternative 3 would also involve the installation of a vapor mitigation system and soil excavation with off-Site disposal. However, electric blowers would be required for the vapor mitigation system, along with long-term O&M. Both Alternatives 2 and 3 would require implementation of ICs, which would include a restrictive covenant that would be filed with the Register of Deeds to ensure new structures built at 616 Linden are designed with a vapor mitigation system.

3.3.1 616 Linden
Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
25 Alternative 4 is rated easy to moderate for implementation as excavation is a common remediation practice and equipment and contractors are readily available. However, as with Alternatives 2 and 3, this alternative would require implementation of ICs, which would include a restrictive covenant that would be filed with the Register of Deeds to ensure that if structures are built at 616 Linden, vapor mitigation systems would be required.

Cost
Estimated costs for Alternatives 2 and 3 are similar in magnitude; however, Alternative 3 is expected to cost slightly more because of the addition of blowers and long-term O&M, including electricity usage of the blowers. Alternative 4 is expected to cost the least as this alternative assumes that the property will be redeveloped as a neighborhood park and that, therefore, vapor intrusion into structures would not need to be addressed.

Table 6 summarizes each alternative based on effectiveness, implementability, and cost.

Effectiveness
Alternative 1, the no action alternative, would not be protective of human health and would not meet the project goal for the Site.

Alternative 2 rates moderate for effectiveness as the passive vapor mitigation system would limit exposure of potential vapors to Site receptors and the SMP would guide proper handling of soil if soil is disturbed.

However, contaminated soil and groundwater would remain in place at the Site.

Alternative 3 rates slightly higher than Alternative 2 at moderate to high for effectiveness as contaminated soil in the immediate area of sampling location GW-4 would be permanently removed from the Site. In addition, the vapor mitigation system would actively push air into the venting layer below the slab with the use of electric blowers. However, long-term O&M of the vapor mitigation system would be required.

Alternative 4 rates similar to Alternative 3 as moderate to high for effectiveness as contaminated soil in the area of sampling location GW-4 would be permanently removed from the Site. However, this alternative would limit redevelopment of 905 Linden to a neighborhood park. If any structures are to be built that would be occupied by people on a regular basis for any length of time, vapor mitigation systems would be required as included in Alternatives 2 and 3 as well as prohibiting use of untreated groundwater for drinking water.

3.3.2 905 Linden
Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
26 Implementability
Alternative 2 is rated moderate for implementation as vapor mitigation is a common remediation practice and materials, services, and equipment are readily available; however, the vapor mitigation system would require routine inspections and potential repairs and maintenance in perpetuity. In addition, a SMP would need to be implemented to guide proper handling of contaminated soils. Alternative 3 is rated slightly lower than Alternative 2 with a rating of difficult to moderate. Alternative 3 would also involve the installation of a vapor mitigation system and soil excavation with off-Site disposal. However, electric blowers would be required for the vapor mitigation system, along with long-term O&M. Both Alternatives 2 and 3 would require implementation of ICs, which would include a restrictive covenant that would be filed with the Register of Deeds to ensure new structures built at 905 Linden are designed with a vapor mitigation system and use of untreated groundwater for drinking water is prohibited.

Alternative 4 is rated easy to moderate for implementation as excavation is a common remediation practice and equipment and contractors are readily available. However, as with Alternatives 2 and 3, this alternative would require implementation of ICs, which would include a restrictive covenant that would be filed with the Register of Deeds to ensure that if structures are built at 905 Linden, vapor mitigation systems would be required and use of untreated groundwater for drinking water is prohibited.

Cost
Alternatives 2 and 3 are relatively comparable; however, Alternative 3 is expected to cost slightly more because of the addition of blowers and long-term O&M, including electricity usage of the blowers.

Alternative 4 is expected to cost the least as this alternative assumes that the property will be redeveloped as a neighborhood park and that, therefore, vapor intrusion into structures would not need to be addressed.

Table 6 summarizes each alternative based on effectiveness, implementability, and cost. Both Alternatives 2 and 3 were ranked equally against these three criteria as they would apply similar technologies. Alternative 4 would not address vapor intrusion and would limit redevelopment of the property to a neighborhood park only. Before redevelopment of the Site, soil gas sampling for volatile petroleum hydrocarbons is recommended to confirm the potential for vapor intrusion.

3.4 CONSIDERATION OF CLIMATE CHANGE IMPACTS
Scientific evidence demonstrates that the climate is changing at an increasingly rapid rate, beyond the range to which society has previously adapted, posing a challenge to EPA in its ability to fulfill its mission to protect human health and the environment. EPA must adapt to climate change to continue to fulfill its statutory, Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
27 regulatory, and programmatic requirements. In January 2014, EPA (2014a) published a Climate Change Adaptation Plan, which described priority actions for EPA to integrate into its programs, policies, rules, and operations.

EPA Region 9’s Climate Change Adaptation Implementation Plan identifies the adverse impacts of climate change as air temperature increase, precipitation decrease, storm intensity increase, ocean acidification and warming, and sea level rise. Vulnerabilities specific to the southwest geographic region, where the Site is located, include (EPA 2014b): • Warmer temperatures, resulting in reduced mountain snowpacks and shifting of peak spring runoff from snow melt to earlier in the season, leading to a shortage of fresh water during the summer • Magnitude of projected temperature increases represent significant stresses to health, energy, and water supply in an area that is already experiencing high summer temperatures • Reduced groundwater supply because of a lack of recharge • Warmer ocean temperatures decreasing productivity and impacting fisheries and aquatic life • Increased frequency and altered timing of flooding increasing risks to people, ecosystems, and infrastructure • Sea level rise contributing to the loss of wetlands and infrastructure along coastal corridors • Magnitude and frequency of wildfires, which has increased over the last 30 years, impacting water quality in streams, creeks, rivers, lakes, and estuaries The Site is located within the southwest region of EPA Region 9 and is, therefore, directly susceptible to many of the vulnerabilities identified above. The Site is located 4.8 miles east of the Pacific Ocean coast and

2.25 miles west of San Francisco Bay at an elevation of 40 feet amsl and is unlikely to be affected by sea level rise.

In June 2021, EPA (2021) published a Climate Smart Brownfields Manual that provides guidance to communities related to climate mitigation, adaptation, and resilience in the content of brownfield cleanup and redevelopment. As the Applicant moves toward cleanup of the Site, this manual may be useful in identifying ways to reduce climate impacts through greener demolition or implementing greener cleanups.

Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
28 3.5 GREEN AND SUSTAINABLE REMEDIATION GUIDANCE
The cleanup of a site can be seen as “green” in that the cleanup improves the environmental and public health conditions of a site. However, these remediation efforts require energy, water, and other material resources to achieve cleanup objectives. Therefore, the process of remediation creates its own environmental footprint. EPA provides guidance on how to optimize environmental performance and implement protective cleanups that are greener. In Principles for Greener Cleanups, which serves as the foundation for the greener cleanup policy, EPA (2020c) identifies the following elements of a green cleanup assessment that may assist in selecting and implementing protective cleanup activities: • Total energy use and renewable energy use • Air pollutants and greenhouse gas emissions • Water use and impacts to water resources • Materials management and waste reduction • Land management and ecosystem protection The Toeroek Team conducted an analysis on the environmental footprints of the removal actions for 616 Linden and 905 Linden using the Spreadsheets for Environmental Footprint Analysis (SEFA) (EPA 2019). The analysis looks at the first two bullets stated above and determines the total energy usage and the mass of different emissions generated by different construction activities, including greenhouse gases, nitrogen oxides, sulfur oxides, particulate matter, and listed air pollutants. Results of the SEFA are summarized below and presented in Appendix A. 616 Linden The impacts for Alternative 3 (Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M, and ICs) are rated high for total energy usage and all emissions, relative to other alternatives considered. The impacts for Alternative 2 (Passive Vapor Mitigation, SMP, O&M, and ICs) and Alternative 4 (Soil Excavation with Off-Site Disposal and ICs) are low for most emissions and total energy usage, relative to Alternative 3.

Alternatives 2 and 3 are similar in the technologies used; however, Alternative 3 would require more total energy usage and would produce more emissions compared with Alternative 2, as electricity would be required to continually operate the blowers for an assumed period of 30 years. Alternative 4 assumes that the property would be redeveloped as a neighborhood park and that, therefore, vapor intrusion would not need to be mitigated. The emissions and total energy usage would be less compared with Alternatives 3. For Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
29 Alternative 3, a portion of the electricity usage could also be offset by installing solar panels if allowed by the property owner and adequate space is available. A portion of the electricity usage could also be offset by installing solar panels on the Site if allowed by the property owner and adequate space is available. However, the treatment system itself would require direct connection to the main power grid because of heavy start up and continuous amperage loading.
905 Linden
The impacts for Alternative 3 (Active Vapor Mitigation, Soil Excavation with Off-Site Disposal, O&M, and ICs) are rated high for total energy usage and all emissions, relative to other alternatives considered.

Alternative 2 (Passive Vapor Mitigation, SMP, O&M, and ICs), on the other hand, is rated low to medium for total energy usage and emissions. Impacts for Alternative 4 (Soil Excavation with Off-Site Disposal and ICs) are comparable to Alternative 2. Alternative 4 has a rating of low for total energy usage and all emissions except particulate matter. Particulate matter for Alternative 4 has a medium rating, relative to Alternatives 2 and 3, primarily because of the transportation of excavated soils off the Site. In total, expected particulate matter emissions for Alternative 4 are 40 pounds, while Alternative 2 are 10 pounds. The greatest energy usage for Alternative 3 is from O&M as this alternative requires blowers operating continuously for an assumed period of 30 years. The environmental footprint for both these alternatives could be reduced if groundwater contamination posing a potential vapor intrusion concern is mitigated. Before redevelopment of the property, soil gas sampling for volatile petroleum hydrocarbons is recommended to confirm the potential for vapor intrusion. Mitigation of groundwater would create a greater short-term environmental footprint, but long-term O&M may not be needed depending on the length of time it takes to treat or remove groundwater.

For Alternative 3, a portion of the electricity usage could also be offset by installing solar panels if allowed by the property owner and adequate space is available.

When selecting remediation contractors, emphasis should be placed on those who follow green remediation best management practices and take into consideration the five elements identified above. Redevelopment plans and planned future use of the Site should direct the type of remediation necessary to ensure that efficient and sustainable methods are used. Renewable energy should be considered for future redevelopment.

Reporting efforts should use digital format as opposed to hard copy when feasible.

3.5.1 Administrative Suggestions
Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
30 The following operations suggestions should be considered to achieve green and sustainable remediation at the Site: • Use of non-renewable energy should be minimized to the extent feasible by use of energy efficient equipment and vehicles, renewable energy supplies, and renewable energy generation systems on the Site. • Sustainable practices that may reduce the use of fossil fuels, such as performing on-Site capping as opposed to off-Site disposal, and the use of native vegetation should be utilized when possible. • Wastes should be minimized as much as possible by use of recycling and reuse efforts. • Transport and disposal operations should function as efficiently as possible to reduce the number of trips needed. • Drilling and excavation activities should include clean fuel and emission controls, such as idle reduction devises, use of ultra-low sulfur diesel and fuel-grade biodiesel, EPA- or California Air Resources Board-verified emission control technology, and routine engine maintenance.

3.5.2 Operations Suggestions
Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
31 4.0 LIMITATIONS AND ADDITIONAL ASSESSMENT NEEDS
The volumes and areas presented in this ABCA are estimates based on available information or lack thereof; actual Site conditions may vary. For instance, the vertical extent of TPH in soils may not be fully characterized and contamination may extend beyond the depths identified by the Toeroek Team. Therefore, additional excavation may be required beyond the depths and volumes presented in this ABCA to meet cleanup goals. Concentrations of contaminants may extend outside the boundaries defined in this ABCA, requiring additional excavation.

This ABCA provides mitigation guidance but is not intended to be used as a removal characterization report or design document. This ABCA presents only the Site-specific RECs and opinion of the Toeroek Team environmental professional who prepared this document. The cost estimates presented are rough order-ofmagnitude estimates solely for comparison purposes and should not be used as budget- or design-level estimates. In addition, other technologies may be available for remediation of the Site that were not considered in this ABCA.

While the exact areas to be redeveloped for each of the scenarios is undetermined at this time, the alternatives presented in this ABCA present options for residential land uses; with the exception of alternative 4, which presents options for recreational use as a park only. Following the completion of a development plan for the Site, the alternatives and cost estimates presented in this ABCA should be reevaluated and adjusted as appropriate.

Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
32 5.0 REFERENCES
ASTM International (ASTM). 2019. Standard Practice for Environmental Site Assessments: Phase II Environmental Site Assessment Process. ASTM E1903-19. October.

Atlas Engineering Services, Inc. 2001. Quarterly Monitor Well Sampling, Winter 2001, 616 Linden Avenue, South San Francisco, California. January.

California Department of Toxic Substances Control (DTSC). 2020. Updated Human Health Risk Assessment Note 3 – DTSC-Modified Screening Levels. June. https://dtsc.ca.gov/wpcontent/uploads/sites/31/2019/04/HHRA-Note-3-June-2020-A.pdf. California State Water Resources Control Board (SWRCB). 2020. GeoTracker Case Summary for South City Texaco, 905 Linden, South San Francisco, CA 94080, San Mateo County, LUST Cleanup Site.

August 5.

County of San Mateo Health Services Agency. 2003. Letter Regarding Case Closure for Petroleum Hydrocarbon UST Removed at 905 Linden Avenue, South San Francisco, California. From Dean D.

Peterson, Director of Environmental Health, County of San Mateo Health Services Agency. To Jose Montes, City Mobile Services. November 17.

Environmental Data Resources, Inc. (EDR). 2020a. EDR Aerial Photo Decade Package. July 23.

Environmental Data Resources, Inc. (EDR). 2020b. EDR Radius Map Report with GeoCheck. July 30.

Environmental Data Resources, Inc. (EDR). 2020c. EDR Sanborn Map Report. July 27.

Project Management Institute. 2017. A Guide to the Project Management Body of Knowledge. Sixth edition. Project Management Institute. Newtown Square, PA.

San Francisco Bay Regional Water Quality Control Board (RWQCB). 1996. Supplemental Instructions to State Water Board December 8, 1995, Interim Guidance on Required Cleanup at Low Risk Fuel Sites. January 5. https://ustlowriskpolicy.org/wp-content/uploads/2012/04/1995-01_ClosureCriteria-for-Region-2_Low-Risk.pdf. San Francisco Bay Regional Water Quality Control Board (RWQCB). 2017. Water Quality Control Plan (Basin Plan) for the San Francisco Bay Basin. May 4.
https://www.waterboards.ca.gov/sanfranciscobay/basin_planning.html San Francisco Bay Regional Water Quality Control Board (RWQCB). 2019. Environmental Screening Levels. https://www.waterboards.ca.gov/sanfranciscobay/water_issues/programs/esl.html.

Analysis of Brownfields Cleanup Alternatives
South San Francisco - Linden & Cypress Aves TBA
Final
Date: August 24, 2021
33 San Mateo County Groundwater Protection Program (SMCGPP). 2001. Case Closure Memorandum, SMCo.

Site No. 550097, APN: 012-174-300, Volante Automotive, 616 Linden, South San Francisco, California. February 16.

San Mateo County Groundwater Protection Program (SMCGPP). 2003. Case Closure Memorandum, SMCo.

Site No. 550027, APN: 012-101-100, Independent Texaco, 905 Linden, South San Francisco, California. From Charles Ice, Haz-Mat Specialist II. To File. May 30.

Toeroek Associates, Inc., and its subcontractor, Tetra Tech, Inc. (Toeroek Team). 2021. Draft Phase I/II Environmental Site Assessment Targeted Brownfields Assessment Report, South San Francisco – Linden & Cypress Aves, South San Francisco, California. June.

U.S. Environmental Protection Agency (EPA). 2014a. “Climate Change Adaptation Plan.” EPA 100-K-14- 001. January.

U.S. Environmental Protection Agency (EPA). 2014b. “EPA Region 9 Climate Change Adaptation Implementation Plan.” EPA-100-K-14-001P. May.

U.S. Environmental Protection Agency (EPA). 2019. “EPA Spreadsheets for Environmental Footprint Analysis (SEFA).” Office of Superfund Remediation and Technology Innovation. https://cluin.org/greenremediation/SEFA/. U.S. Environmental Protection Agency (EPA). 2020a. Vapor Intrusion Screening Level Calculator. https://www.epa.gov/vaporintrusion/vapor-intrusion-screening-level-calculator. U.S. Environmental Protection Agency (EPA). 2020b. “Technologies for Cleaning Up Contaminated Sites.” https://www.epa.gov/remedytech. U.S. Environmental Protection Agency (EPA). 2020c. “EPA Principles for Greener Cleanups.” https://www.epa.gov/greenercleanups/epa-principles-greener-cleanups. U.S. Environmental Protection Agency (EPA). 2021. “Climate Smart Brownfields Manual .” EPA 560-F-21- 002. June.

U.S. Geological Survey (USGS). 2021. Average Concentrations of Elements in San Mateo County, California.

Accessed May 7.
https://mrdata.usgs.gov/geochem/county.php?place=f06081&el=Pb&rf=southwestern.

FIGURES
616 Linden Ave
905 Linden Ave
Source: ESRI, ArcGIS Online, Open Streets Map Basemap, 2019 Figure 1
South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
Site Locations Date: 8/18/2020 Drawn By: Elaia McDonald Project No: 103Z65210007M Legend
Approximate Site Boundary
0 1,000 2,000
Feet
Site Vicinity Scale: 1 inch = 10 miles
N
A
Linden Cleaners
(former dry cleaners and potential REC)
Source: ESRI, ArcGIS Online, World Imagery, 2018
Figure 2
Current Site Features - 616 Linden Avenue Date: 9/3/2020 Drawn By: Elaia McDonald Project No: 103Z65210007M Legend
Approximate Site Boundary
0 25 50
Feet
South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
Notes:

REC Recognized environmental condition
-t
m
-t
;:a
)>
-t
m
n
:I
D
>z
Rollin J Lobaugh
(machine shop and potential REC)
Source: ESRI, ArcGIS Online, World Imagery, 2018
Figure 3
Current Site Features - 905 Linden Avenue Date: 12/18/2020 Drawn By: Elaia McDonald Project No: 103Z65210007M Legend
Approximate Site Boundary
0 40 80
Feet
South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
P:\EPA_REPA6_Brownfields\PROJECT MANAGEMENT\GIS'GIS\MapFiles\T013_Fig3_SouthSF _905_SiteFeatures.mxd (1)
-I
m
-I
;ICI
J>
-I
m
n
:I
D
:>,-z
3 2
1 Former 250-Gallon
Waste Oil UST
Excavation
Former 1,000-Gallon
Gasoline UST
Excavation
616-SB-7-03012021
Lead: 239 mg/kg
Former
Building
Former
Auto
Repair
Shop
Former
Residences
616-SG-6-03042021
Benzene: 16 ug/m3
616-SG-2-03042021
1,2-Dichloroethane: 3,000 ug/m3
Benzene: 68,000 ug/m3
Ethylbenzene: 46,000 ug/m3
m,p-Xylene: 200,000 ug/m3
o-Xylene: 29,000 ug/m3
Toluene: 83,000 ug/m3
616-SG-1-03122021
1,2-Dichloroethane: 1,400 ug/m3
Benzene: 9,500 ug/m3
Ethylbenzene: 19,000 ug/m3
m,p-Xylene: 64,000 ug/m3
616-SG-4-03042021
Benzene: 4,400 ug/m3
616-SB-4-03022021
TPH-d: 560 mg/kg
616-SB-4-03022021-D
TPH-d: 300 mg/kg
SG-3
EC5
Source: ESRI, ArcGIS Online, World Imagery, 2018
Figure 4 Sampling Locations and Results Exceeding
Screening Levels – 616 Linden Avenue Date: 8/2/2021 Drawn By: Elaia McDonald Project No: 103Z65210007M Legend
Soil Gas Sample
Soil and Soil Gas Sample
Soil Sample
?@ Former Monitoring Well1
?@ Former Piezometer1 Unidentified Utility Lines2 Groundwater Flow Direction3 Concrete Subsurface Structure 4 Apparent Backfilled Excavation Detected with GPR2 EM61- GPR Anomaly
Former Buildings
Approximate Site Boundary
South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
SSFO-EPA VISLs (Residential Soil Gas) SSFO-EPA VISLs (Commercial Soil Gas)
SSFO-WQCB ESLs (Residential Soil
Gas)
SSFO-RWQCB ESLs (Commercial
Soil Gas) SSFO-Selected Project
Screening Level
1,2,-Dichloroethane 3.6 15.7 3.6 16 3.6 Benzene 12 52.4 3.2 14 3.2 Ethylbenzene 37.4 164 37 160 37 m,p-Xylene 3,480 14,600 3,500 15,000 3,480 o-Xylene 3,480 14,600 3,500 15,000 3,480 Toluene 174,000 730,000 10,000 44,000 10,000 Soil Gas ug/m3 Analyte
RWQCB Tier 1 ESLs EPA RSL(Residential
Soil) EPA RSL
(Commercial
Soil) DTSC SL (Residential Soil) DTSC SL (Commercial Soil) Lead -- 400 800 80 320 TPH-d 260 -- -- -- -- Soil Analyte mg/kg
0 15 30
Feet
Micrograms per cubic meter
California Department of Toxic Substances
Control - Screening Level
Electromagnetic 61
U.S. Environmental Protection Agency
Environmental screening level
Ground-penetrating radar
Milligrams per kilogram
Regional Screening Level
San Francisco Bay Regional Water
Quality Control Board South San Francisco Total petroleum hydrocarbons - diesel range Underground storage tank
Vapor intrusion screening level
Notes: 1Removed
2 Identified during the geophysical survey
conducted on October 14, 2020. 3Based on historical groundwater investigation data. 4 Identified during Phase II anomaly investigation.

Formerly known as Anomaly 4. 5Soil sample was collected from a temporary stockpile during the anomaly investigation; soil was placed back into the subsurface concrete structure and surface was restored. ug/m3 DTSC SL EM61 EPA ESL GPR mg/kg RSL RWQCB
SSFO
TPH-d UST VISL
• [ZZJ
~ 0
a 0 -
CJ I
i CJ
[ "11:] TETRA TECH
~ C i
~ • ~
Groundwater
Flow Direction
Former
Service
Bays
Former
Office
905-GW-4-S-03032021
TPH-g: 800 mg/kg
905-GW-4-03152021
TPH-g: 480 ug/L
905-GW-3-03032021
TPH-g: 12 ug/L
905-GW-1-03032021
TPH-g: 13 ug/L
GW-2
GW-5
Source: ESRI, ArcGIS Online, World Imagery, 2018
Figure 5
Sampling Locations and Results Exceeding
Screening Levels – 905 Linden Avenue Date: 8/2/2021 Drawn By: Elaia McDonald Project No: 103Z65210007M South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
TPH-g 100
Analyte
Soil (mg/kg)
RWQCB Tier 1
ESLs
TPH-g 100 10.4 43.7
Analyte RWQCB Tier 1
ESLs
EPA VISLs
(Residential)
EPA VISLs
(Commercial)
Groundwater (ug/L)
0 20 40
Feet
Notes:

Site locations are approximate except for monitoring wells MW-1 through MW-6 and the backfilled excavation, which
were surveyed. 1Removed
2Based on historical groundwater investigation data.
ug/L
EPA
ESL
ft bgs
GPR
mg/kg
RWQCB
TPH-g
UST
VISL
Micrograms per liter
U.S. Environmental Protection Agency
Environmental screening level
Feet below ground surface
Ground-penetrating radar
Milligrams per kilogram
San Francisco Bay Regional Water
Quality Control Board
Total petroleum hydrocarbons - gasoline range
Underground storage tank
Vapor intrusion screening level
Legend
Grab Groundwater Sample
Soil Gas Sample
Soil and Grab Groundwater
Sample
Former Hoist
Former UST Fill Covers
Electric Vault
?@ Former Groundwater Wells1 Former Inlet Pipe
Groundwater Flow Direction2 Apparent Backfilled Excavation Detected with GPR
Former Oil Water Separator
Excavation (Depth 8 ft bgs)
Former Buildings
Former Piping Location and
Pump Island Excavation (1998)
(Depth 7 ft bgs)
UST Excavation (1998) (Depth
12 ft bgs)
Former Hoist Excavation (Depth
8 ft bgs)
Former Waste Oil UST
Excavation (Depth 6 ft bgs)
Former 4,000-Gallon UST -
Diesel
Former 6,000-Gallon UST -
Leaded Gasoline
Former 8,000-Gallon UST -
Unleaded Gasoline
Approximate Site Boundary
P:\EPA_REPA6_Brownfields\PROJECT MANAGEMENT\GIS'GIS\MapFiles\T013_Fig9_SouthSF _905_ExceedancesABCA.mxd D 8
I t I [,> 0 • •
(1)
-I m -I
;ICI
J>
-I m
n
:I
3 2
1 Former 250-Gallon
Waste Oil UST
Excavation
Former 1,000-Gallon
Gasoline UST
Excavation
4 Former
Building
Former
Auto
Repair
Shop
Former Dry Cleaner
(612 Linden Avenue)
Former
Residences
SG-6
SG-3
SG-2
SG-1
SB-4
and
SG-4
SB-7
EC5
Source: ESRI, ArcGIS Online, World Imagery, 2018
Figure 6
Alternatives 3 and 4: Approximate Areas to Be
Excavated – 616 Linden Date: 8/16/2021 Drawn By: Elaia McDonald Project No: 103Z65210007M Legend
Soil Gas Sample
Soil and Soil Gas Sample
Soil Sample
?@ Former Monitoring Well1
?@ Former Piezometer1 Unidentified Utility Lines2 Groundwater Flow Direction3 Approximate Area to be Excavated Concrete Subsurface Structure 4 Apparent Backfilled Excavation Detected with GPR2 EM61- GPR Anomaly2 Approximate Site Boundary Former Buildings
South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
Notes: 1Removed
2 Identified during the geophysical survey
conducted on October 14, 2020. Anomalies were
assigned numbers to aid in discussion. 3Based on historical groundwater investigation data. 4 Identified during Phase II anomaly investigation.

Formerly known as Anomaly 4. 5Soil sample was collected from a temporary stockpile during the anomaly investigation; soil was
placed back into the subsurface concrete structure
and surface was restored.

Electromagnetic 61
Ground-penetrating radar
Underground storage tank
EM61
GPR
UST
0 15 30
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Groundwater
Flow Direction
Former
Service
Bays
Former
Office
GW-2
GW-5
GW-3
GW-1
GW-4
Source: ESRI, ArcGIS Online, World Imagery, 2018
Figure 7
Alternatives 3 and 4: Approximate Area to Be
Excavated – 905 Linden Date: 8/16/2021 Drawn By: Elaia McDonald Project No: 103Z65210007M South San Francisco- Linden & Cypress Aves
Targeted Brownfields Assessment
South San Francisco, California
Notes: 1Removed
2Based on historical groundwater investigation data.

Site locations are approximate except for monitoring wells MW-1 through MW-6 and the backfilled excavation, which
were surveyed.
ft bgs Feet below ground surface
GPR Ground-penetrating radar
UST Underground storage tank
0 20 40
Feet
Legend
Grab Groundwater Sample
Soil Gas Sample
Soil and Grab Groundwater Sample
?@ Former Groundwater Wells1 Former Hoist
Former UST Fill Covers
Electric Vault
Former Inlet Pipe
Groundwater Flow Direction2 Approximate Area to be Excavated Former Oil Water Separator Excavation (Depth 8 ft bgs)
Former Piping Location and Pump Island Excavation (1998) (Depth 7 ft bgs) UST Excavation (1998) (Depth 12 ft bgs)
Former Hoist Excavation (Depth 8 ft bgs)
Apparent Backfilled Excavation Detected with GPR
Former Waste Oil UST Excavation (Depth 6 ft bgs)
Former 4,000-Gallon UST - Diesel
Former 6,000-Gallon UST - Leaded Gasoline
Former 8,000-Gallon UST - Unleaded Gasoline
Former Buildings
Approximate Site Boundary
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TABLES
Table ES-1
Summary of Cleanup Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

CY Cubic yard
IC Institutional control
NA Not applicable
O&M Operation and maintenance
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SMP Soil Management Plan

616 Linden
Alternative Actions Effectiveness Implementation Cost Considerations 1 No Action • None NA NA $0
This alternative would not be
protective of human health and the
environment and would not meet
the project goal for the Site.
2 Passive Vapor Mitigation,
SMP, O&M, and ICs • Installation of a passive vapor
mitigation system for a new
structure (assumed to be 14,000
SF of first-floor space). • Implementation of a SMP to
guide proper handling of
contaminated soil if the soil is
disturbed • Implementation of ICs to ensure new structures are designed with a vapor mitigation system and to ensure
the continued integrity of the
vapor mitigation system.

Moderate Moderate $298,000
This alternative assumes a
footprint for a new structure to be
built; however, the actual footprint
may vary.

Table ES-1
Summary of Cleanup Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

CY Cubic yard
IC Institutional control
NA Not applicable
O&M Operation and maintenance
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SMP Soil Management Plan

616 Linden
Alternative Actions Effectiveness Implementation Cost Considerations 3 Active Vapor Mitigation,
Soil Excavation with OffSite Disposal, O&M, and
ICs
• Installation of an active vapor
mitigation system for a new
structure (assumed to be 14,000
SF of first-floor space). • Excavation of 151 CY of
contaminated soil. • Off-Site disposal of soil at a
permitted disposal facility. • Backfilling of excavated areas. • Implementation of ICs to ensure new structures are designed with a vapor mitigation system and to ensure
the continued integrity of the
vapor mitigation system. • Long-term O&M of the vapor
mitigation system as long as a
structure is occupied. • Electricity required for blowers and occasional maintenance or
replacement of blowers.

Moderate to
High
Difficult to
Moderate $531,000
This alternative assumes a
footprint for a new structure to be
built; however, the actual footprint
may vary.

This alternative includes an
estimated volume of soil for
excavation; however, the extent of
contamination is unknown and
actual Site conditions may vary.

This alternative assumes clean fill
material for backfilling will be
brought in from off Site.

Table ES-1
Summary of Cleanup Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

CY Cubic yard
IC Institutional control
NA Not applicable
O&M Operation and maintenance
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SMP Soil Management Plan

616 Linden
Alternative Actions Effectiveness Implementation Cost Considerations 4 Soil Excavation with OffSite Disposal and ICs • Excavation of 151 CY of contaminated soil. • Off-Site disposal of soil at a
permitted disposal facility. • Backfilling of excavated areas. • Implementation of ICs to ensure that if a structure is to
be built on the property, then a
vapor mitigation system would
be required.

Moderate to
High Easy to Moderate $124,000
This alternative assumes
redevelopment of the property will
be limited to a neighborhood park.

This alternative includes an
estimated volume of soil for
excavation; however, the extent of
contamination is unknown and
actual Site conditions may vary.

This alternative assumes clean fill
material for backfilling will be
brought in from off Site.

Table ES-1
Summary of Cleanup Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

CY Cubic yard
IC Institutional control
NA Not applicable
O&M Operation and maintenance
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SMP Soil Management Plan

905 Linden
Alternative Actions Effectiveness Implementation Cost Considerations 1 No Action • None NA NA $0
This alternative would not be
protective of human health and
the environment and would not
meet the project goal for the Site.
2 Passive Vapor Mitigation,
SMP, O&M, and ICs • Installation of a passive vapor
mitigation system for a new
structure (assumed to be 12,000
SF of first-floor space). • Implementation of a SMP to
guide proper handling of
contaminated soil in the event
that the soil would be disturbed • Implementation of ICs to ensure new structures are designed with a vapor mitigation system and to ensure
the continued integrity of the
vapor mitigation system and
prohibiting use of groundwater
as drinking water.

Moderate Moderate $271,000
This alternative assumes a
footprint for a new structure to be
built; however, the actual
footprint may vary.

Table ES-1
Summary of Cleanup Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

CY Cubic yard
IC Institutional control
NA Not applicable
O&M Operation and maintenance
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SMP Soil Management Plan

905 Linden
Alternative Actions Effectiveness Implementation Cost Considerations 3 Active Vapor Mitigation,
Soil Excavation with Offsite Disposal, O&M, and
ICs
• Installation of an active vapor
mitigation system for a new
structure (assumed to be 12,000
SF of first-floor space). • Excavation of 65 CY of
contaminated soil. • Off-Site disposal of soil at a
permitted disposal facility. • Backfilling of excavated areas. • Implementation of ICs to ensure new structures are designed with a vapor mitigation system, to ensure the
continued integrity of the vapor
mitigation system, and to
prohibit use of groundwater as
drinking water. • Long-term O&M of the vapor
mitigation system as long as a
structure is occupied. • Electricity required for blowers and occasional maintenance or
replacement of blowers.

Moderate to
High
Difficult to
Moderate $460,000
This alternative assumes a
footprint for a new structure to be
built; however, the actual
footprint may vary.

This alternative includes an
estimated volume of soil for
excavation; however, the extent of
contamination is unknown and
actual Site conditions may vary.

This alternative assumes clean fill
material for backfilling will be
brought in from off Site.

Table ES-1
Summary of Cleanup Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

CY Cubic yard
IC Institutional control
NA Not applicable
O&M Operation and maintenance
SF Square foot
Site South San Francisco – Linden & Cypress Aves site
SMP Soil Management Plan

905 Linden
Alternative Actions Effectiveness Implementation Cost Considerations 4 Soil Excavation with
Off-Site Disposal and ICs • Excavation of 65 CY of
contaminated soil. • Off-Site disposal of soil at a
permitted disposal facility. • Backfilling of excavated areas. • Implementation of ICs to ensure that if a structure is built
on the property, a vapor
mitigation system would be
required, and to prohibit use of
groundwater as drinking water..

Moderate to
High Easy to Moderate $80,000
This alternative assumes
redevelopment of the property will
be limited to a neighborhood park.

This alternative includes an
estimated volume of soil for
excavation; however, the extent of
contamination is unknown and
actual Site conditions may vary.

This alternative assumes clean fill
material for backfilling will be
brought in from off Site.

Notes:
µg/m3 Microgram per cubic meter
COC Contaminant of concern
EPA U.S. Environmental Protection Agency
ESL Environmental screening level
RWQCB San Francisco Bay Regional Water Quality Control Board VISL Vapor intrusion screening level

Table 1
Summary of Assumed Cleanup Levels for Soil Gas
ABCA Document
South San Francisco – Linden & Cypress Aves
COC Assumed Cleanup Level
(µg/m3) Reference
1,2-Dichloroethane 3.6 EPA (2020a) VISL and RWQCB (2019) ESL Benzene 3.2 RWQCB (2019) ESL
Ethylbenzene 37 EPA (2020a) VISL and RWQCB (2019) ESL
M,P-Xylene 3,480 EPA (2020a) VISL
O-Xylene 3,480 EPA (2020a) VISL
Toluene 10,000 RWQCB (2019) ESL
Notes:

COC Contaminant of concern
DTSC California Department of Toxic Substances Control
ESL Environmental screening level
mg/kg Milligram per kilogram
RWQCB San Francisco Bay Regional Water Quality Control Board SL Screening level
TPH-d Total petroleum hydrocarbons as diesel
TPH-g Total petroleum hydrocarbons as gasoline

Table 2
Summary of Assumed Cleanup Levels for Soil
ABCA Document
South San Francisco – Linden & Cypress Aves
COC Assumed Cleanup Level
(mg/kg) Reference
TPH-d 260 RWQCB (2019) Tier 1 ESL
TPH-g 100 RWQCB (2019) Tier 1 ESL
Lead 80 DTSC (2020) Residential SL
Notes:
µg/L Microgram per liter
COC Contaminant of concern
EPA U.S. Environmental Protection Agency
TPH-g Total petroleum hydrocarbons as gasoline
VISL Vapor intrusion screening level

Table 3
Summary of Assumed Cleanup Levels for Groundwater
ABCA Document
South San Francisco – Linden & Cypress Aves
COC Assumed Cleanup Level
(µg/L) Reference
TPH-g 10.4 EPA (2020a) VISL Residential Groundwater
Table 4
Summary of Cost Estimates
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:
* Assumes O&M over a 30-year time period.

IC Institutional control Site South San Francisco – Linden & Cypress Aves site NA Not applicable SMP Soil Management Plan
O&M Operation and maintenance SVE Soil vapor extraction

Alternative
Action Cost
Total
Cost Land Uses Allowed Type
of
Cost
Description Cost
616 Linden
1 No Action
Capital
Cost NA $0
$0 NA ICs NA $0
O&M NA $0
2 Passive Vapor
Mitigation,

SMP, O&M,
and ICs
Capital
Cost
Passive Vapor Mitigation $202,000
$298,000
Residential,
Commercial/Industrial,
and Recreational (i.e.
neighborhood park)
SMP $26,000
ICs Restrictive Covenant $53,000
O&M* Routine Inspections $17,000
3 Active Vapor
Mitigation, Soil
Excavation with
Off-Site
Disposal, O&M,
and ICs
Capital
Cost
Active Vapor Mitigation $204,000
$531,000
Residential,
Commercial/Industrial,
and Recreational (i.e.
neighborhood park)
Soil Excavation and OffSite Disposal $71,000
ICs Restrictive Covenant $53,000
O&M* O&M, Blower
Replacement $203,000
4 Soil Excavation
with Off-Site
Disposal and
ICs
Capital
Cost
Soil Excavation and OffSite Disposal $71,000
$124,000
Recreational (i.e.
neighborhood park)
Only
ICs Restrictive Covenant $53,000
O&M NA $0
Table 4
Summary of Cost Estimates
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:
* Assumes O&M over a 30-year time period.

IC Institutional control Site South San Francisco – Linden & Cypress Aves site NA Not applicable SMP Soil Management Plan
O&M Operation and maintenance SVE Soil vapor extraction

Alternative
Action Cost
Total
Cost Land Uses Allowed Type
of
Cost
Description Cost
905 Linden
1 No Action
Capital
Cost NA $0
$0 NA ICs NA $0
O&M NA $0
2 Passive Vapor
Mitigation,

SMP, O&M,
and ICs
Capital
Cost
Passive Vapor Mitigation $175,000
$271,000
Residential,
Commercial/Industrial,
and Recreational (i.e.
neighborhood park)
SMP $26,000
ICs Restrictive Covenant $53,000
O&M* Routine Inspections $17,000
3 Active Vapor
Mitigation, Soil
Excavation with
Off-Site
Disposal, O&M,
and ICs
Capital
Cost
Active Vapor Mitigation $177,000
$460,000
Residential,
Commercial/Industrial,
and Recreational (i.e.
neighborhood park)
Soil Excavation and OffSite Disposal $27,000
ICs Restrictive Covenant $53,000
O&M* O&M, Blower
Replacement $203,000
4 Soil Excavation
with Off-Site
Disposal and
ICs
Capital
Cost
Soil Excavation and OffSite Disposal $27,000
$80,000
Recreational (i.e.
neighborhood park)
Only
ICs Restrictive Covenant $53,000
O&M NA $0
Notes:
bgs Below ground surface
O&M Operation and maintenance

Table 5
Summary of Alternatives Considered and Dismissed
ABCA Document
South San Francisco – Linden & Cypress Aves
Alternative Description Considerations
Bioremediation
Bioremediation involves the use of
microorganisms to degrade organic
contaminants. The microorganisms
break down contaminants by using
them as a food source or
co-metabolizing, converting them
to end products such as methane
and carbon dioxide.

Although it is effective for breakdown of
organic contaminants such as gasoline, this
alternative is not effective in remediating the
inorganic contaminants (lead) present at the
Site. Bioremediation is often not uniform
and requires maintaining proper moisture,
pH, temperature, and nutrients. This
alternative may require longer treatment
times. However, bioremediation could be
used in combination with other treatment
technologies.

In Situ Thermal Treatment
In situ thermal treatment uses
temperature to increase the
volatility of the contaminants in
the soils. It may require off-gas and
residual liquid treatment.

This alternative is not effective in
remediating the inorganic contaminants
(lead) present at the Site. In addition, this
alternative requires longer treatment time
and remediation is often not uniform. This
alternative is the costliest treatment (driven
by energy and equipment costs); and is
O&M intensive.

Phytoremediation
Phytoremediation is a process that
uses plants to extract, degrade,
contain, or immobilize
contaminants in soils and
sediment.

Because of the depth of contaminated soils
at the Site (up to 5 feet bgs), this alternative
would not be effective as phytoremediation
would be limited to the treatment of shallow
soil.

Table 6
Summary of Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

Effectiveness Ratings: Cost Ratings:

Low 1 1 >$3 Million
Low to Moderate 2 2 $2.25 to $3 Million
Moderate 3 3 $1.5 to $2.25 Million
Moderate to High 4 4 $750,000 to $1.5 Million
High 5 5 $0 to $750,000
Implementation Ratings: IC Institutional control
Difficult 1 NA Not applicable
Difficult to Moderate 2 O&M Operation and maintenance
Moderate 3 Site South San Francisco – Linden & Cypress Aves site Easy to Moderate 4 SMP Soil management plan
Easy 5

Criteria
616 Linden
Alt. 2 Alt. 3 Alt. 4
Passive Vapor Mitigation, SMP, O&M,
and ICs
Active Vapor Mitigation, Soil Excavation
with Off-Site Disposal, O&M, and ICs
Soil Excavation with Off-Site Disposal
and ICs
Rating Score Rating Score Rating Score
Effectiveness Moderate 3 Moderate to High 4 Moderate to High 4 Implementation Moderate 3 Difficult to
Moderate 2 Easy to Moderate 4
Cost $298,000 5 $531,000 5 $124,000 5
Overall Score 11 11 13
Table 6
Summary of Alternatives
ABCA Document
South San Francisco – Linden & Cypress Aves
Notes:

Effectiveness Ratings: Cost Ratings:

Low 1 1 >$3 Million
Low to Moderate 2 2 $2.25 to $3 Million
Moderate 3 3 $1.5 to $2.25 Million
Moderate to High 4 4 $750,000 to $1.5 Million
High 5 5 $0 to $750,000
Implementation Ratings: IC Institutional control
Difficult 1 NA Not applicable
Difficult to Moderate 2 O&M Operation and maintenance
Moderate 3 Site South San Francisco – Linden & Cypress Aves site Easy to Moderate 4 SMP Soil management plan
Easy 5

Criteria
905 Linden
Alt. 2 Alt. 3 Alt. 4
Passive Vapor Mitigation, SMP, O&M,
and ICs
Active Vapor Mitigation, Soil Excavation
with Off-Site Disposal, O&M, and ICs
Soil Excavation with Off-Site Disposal
and ICs
Rating Score Rating Score Rating Score
Effectiveness Moderate 3 Moderate to High 4 Moderate to High 4 Implementation Moderate 3 Difficult to
Moderate 2 Easy to Moderate 4
Cost $271,000 5 $460,000 5 $80,000 5
Overall Score 11 11 13

APPENDIX A

ENVIRONMENTAL FOOTPRINT EVALUATION
B3. Supplemental Site Investigation Report
(Ninyo & Moore 2023)
New Park at Linden and Pine Project
Initial Study/Mitigated Negative Declaration
1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 | www.ninyoandmoore.com Supplemental Site Investigation Report
616 Linden Avenue
South San Francisco, California
Closed LUST Cleanup Site Case No. 550097
City of South San Francisco
33 Arroyo Drive | South San Francisco, California 94080 September 21, 2023 | Project No. 403151010
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS .........
.......
.......
.........
ninyn &/Vltmre
Geotechnical Geotechnical && Environmental Environmental Sciences Sciences Consultants Consultants 1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 | www.ninyoandmoore.com September 21, 2023
Project No. 403151010
Mr. Philip Vitale
City of South San Francisco
33 Arroyo Drive
South San Francisco, California 94080
Subject: Supplemental Site Investigation Report
616 Linden Avenue
South San Francisco, California
Closed LUST Cleanup Site Case No. 550097
Dear Mr. Vitale:

Ninyo & Moore has prepared a Supplemental Site Investigation Report (SSI Report) for the above referenced property located at the City of South San Francisco (City) property located at 616 Linden Avenue in South San Francisco, California (site). This investigation was proposed in Ninyo & Moore’s February 28, 2023 Brief Work Plan for Supplemental Site Investigation (Work Plan), which was conditionally approved in San Mateo County Groundwater Protection Program’s (GPP’s) March 31, 2023 email.

We appreciate the opportunity to be of service to the City on this project. If you have any questions or comments regarding this Report, please contact the undersigned at your convenience.

Sincerely,

NINYO & MOORE
Connor Escobar
Senior Staff Scientist
Aubrey K. Cool, PG 7659
Principal Geologist
CRE/AKC/gvr
cc: Jacob Madden, San Mateo County Groundwater Protection Program lying &/Vlnure
YEARS
Geotechnical & Environmental Sciences Consultants
\ONAL
/J,- /I
, ,
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Jo . 14 /L-4_
No. 7659
JVin9o&iy\oore
Geotechnical & Environmental Sciences Consultants
Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023 i

CONTENTS
1 INTRODUCTION 1
2 PRE-FIELD ACTIVITIES 1

2.1 Permitting 1

2.2 Health and Safety Plan 1

2.3 Utility Location 1
3 FIELD ACTIVITIES 2

3.1 Soil Sampling 2

3.2 Investigation-Derived Waste 2
4 ANALYTICAL RESULTS 3

4.1 Volatile Organic Compounds 3

4.2 Polyaromatic Hydrocarbons 3

4.3 Lead 3
5 FINDINGS AND CONCLUSIONS 3
6 LIMITATIONS 3
TABLE
1 – Soil Analytical Results

FIGURES
1 – Site Location
2 – Site Plan

APPENDICES
A – Manifest and Disposal Documentation
B – Laboratory Analytical Reports
Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023 1 1 INTRODUCTION
On behalf of the City of South San Francisco (City), Ninyo & Moore presents this Supplemental Site Investigation Report (SSI Report) for the property located at 616 Linden Avenue in South San Francisco, California (site).

The site is a 0.32-acre property, located on the southeastern corner of Linden Avenue and Pine Avenue in a mixed residential and commercial area in South San Francisco (Figure 1). It is currently an active parking lot.

Redevelopment into a City park is planned for the subject site as well as the adjacent property at 700 Linden Avenue. Park design is expected to begin soon. This SSI was warranted to assess whether current site conditions meet State Water Resources Control Board (State Water Board) Low-Threat Underground Storage Tank Case Closure Policy (Low-Threat Closure Policy) direct contact and outdoor air exposure criteria.
2 PRE-FIELD ACTIVITIES
The following activities were performed prior to initiating the subsurface investigation.

2.1 Permitting
San Mateo County Environmental Health Services did not require permits for this SSI as the borings were shallower than 10 feet below ground surface (bgs) and groundwater was not encountered.

2.2 Health and Safety Plan
Ninyo & Moore updated the site-specific health and safety plan (HASP) prior to mobilization. Ninyo & Moore reviewed the HASP with field personnel prior to the start of each day of field work, and field personnel signed the acknowledgement form attached to the HASP indicating they understood and would abide by its provisions.

2.3 Utility Location
As required by California law, Ninyo & Moore marked out the vicinity of the boring locations in white paint and notified USA North 811 (USA). USA marked locations surrounding the site. In addition, the boring locations were cleared by a private utility locating service.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023 2 3 FIELD ACTIVITIES
Ninyo & Moore field staff oversaw VTS Drilling, LLC (VTS) of Hayward, California (C-57 License No. 916085) advance seven soil borings (B1 through B7) on June 30, 2023. The borings were advanced by a direct-push drill rig to a maximum depth of 9.5 feet bgs. Equipment was decontaminated with a rinse of Alconox®
and water, followed by two rinses with distilled water, between each sampling location.

3.1 Soil Sampling
Two discrete soil samples were collected from each soil boring: one between the surface and 5 feet bgs and one between 5 feet bgs and the total depth. The samples were transferred into laboratory-supplied glass containers, labeled with sample identifications, placed in re-sealable plastic bags, and stored in a cooler containing ice. They were transported under chain-of-custody (COC) documentation to Torrent Laboratories in Milpitas, California, a California-certified analytical laboratory.

The soil samples were analyzed for benzene, ethylbenzene, and naphthalene using United States Environmental Protection Agency (US EPA) Method 8260B and polyaromatic hydrocarbons (PAHs) using US EPA Method 8270C. In addition, because the site is planned to be redeveloped as a park which may have landscaping and the potential for the public to come into contact with site soil, the shallow soil sample from each boring was also analyzed for lead using US EPA Method 6010B.

3.2 Investigation-Derived Waste
Investigation-derived waste (IDW) generated from the boring advancement consisted of soil cuttings and asphalt/concrete waste. The IDW was stored in a 55-gallon drum, which was labelled and placed in a secure location pending waste profiling and proper off-site disposal. The IDW was characterized as non-hazardous waste.. On July 27, 2023, the drum was transported off site and is pending final transportation to Soil Safe of Adelanto, California as non-hazardous waste. The preliminary manifest presented in Appendix A, and the laboratory report used to characterize the waste is included in Appendix B.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023 3 4 ANALYTICAL RESULTS
Laboratory analytical results were compared to the Low-Threat Closure Policy criteria.

Additionally, lead results were compared to residential San Francisco Bay Regional Water Quality Control Board environmental screening limits (ESLs). The data are presented on Table 1, and the laboratory analytical report, including COC, is provided in Appendix B.

4.1 Volatile Organic Compounds
Benzene, ethylbenzene, and naphthalene were not detected above laboratory reporting limits (RLs) in any samples.

4.2 Polyaromatic Hydrocarbons
PAHs were not detected above laboratory RLs in any samples.

4.3 Lead
Lead was detected in all samples analyzed for lead, at concentrations ranging from 10.9 milligrams per kilogram (mg/kg) in sample B3-3 to 71.0 mg/kg in B1-1. No detections exceeded the residential ESL of 80 mg/kg. .
5 FINDINGS AND CONCLUSIONS
Ninyo & Moore advanced seven soil borings at the site to assess whether current site conditions meet Low-Threat Closure Policy direct contact and outdoor air exposure criteria.

As discussed above, benzene, ethylbenzene, naphthalene, and PAHs were not detected above laboratory RLs in any samples, and lead detections were below residential ESLs.

Based on this information, the site soil conditions meet the Low-Threat Closure Policy criteria for unrestricted land use.
6 LIMITATIONS
The environmental services described in this report have been conducted in general accordance with current regulatory guidelines and the standard-of-care exercised by environmental consultants performing similar work in the project area. No warranty, expressed or implied, is made regarding the professional opinions presented in this report. Variations in site conditions may exist and conditions not observed or described in this report may be encountered during Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023 4 subsequent activities. Please also note that this assessment did not include an evaluation of geotechnical conditions or potential geologic hazards.

Ninyo & Moore's opinions and recommendations regarding environmental conditions, as presented in this report, are based on limited subsurface assessment and chemical analysis.

Further assessment of potential adverse environmental impacts from past on-site and/or nearby use of hazardous materials may be accomplished by a more comprehensive assessment. The samples collected and used for testing, and the observations made, are believed to be representative of the area(s) evaluated; however, conditions can vary significantly between sampling locations. Variations in soil and/or groundwater conditions will exist beyond the points explored in this evaluation.

The environmental interpretations and opinions contained in this report are based on the results of laboratory tests and analyses intended to detect the presence and concentration of specific chemical or physical constituents in samples collected from the subject site. The testing and analyses have been conducted by an independent laboratory which is certified by the State of California to conduct such tests. Ninyo & Moore has no involvement in, or control over, such testing and analysis. Ninyo & Moore, therefore, disclaims responsibility for any inaccuracy in such laboratory results.

Ninyo & Moore’s conclusions, recommendations and opinions are based on an analysis of the observed site conditions. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires any additional information, or has questions regarding content, interpretations presented, or completeness of this document.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions and/or recommendations of this report by parties other than those noted is undertaken at said parties’ sole risk.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023 Appendix A
Photographic Documentation
TABLE
-II
a e - OI na lca esu s
Sample ID Dale Collected Benzene Ethylbsnzane Naphthalene (ii bgs)
B1-1 71.0
B1.6
B22
B26
B33
B3-5
B4-4
B4-B
B51
B5-9
BB2
B66
B7-3
B7-7
6/30/2023
6/30/2023
6/30/2023
5/3012023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
6/30/2023
1 e
2 6
3 s
4 8
1 g
2 6
:s
7 ND<0.00B1
ND<0.0079
ND¢0.0093
ND<0.0090
ND<0.00B7
ND<0.0081
ND¢0.0DB8
ND<0.0092
ND<0.0083
ND<0.0D81
ND<0.00B5
ND<0.0D8B
ND<0.0080
ND¢0.0DB3
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

ND<0.0D81
ND<0.0079
nD<o.oo93
ND<0.0U9U
ND<0.00B7
no=o.ooa1
nD<o.ooaa
ND<0.0U92
nD=o.ooa3
ND<0.00B1
ND<0.0DB5
ND<0.00B8
ND<0.0080
nD<o.ooa3
.
.
.
.
.
.
.
.
.
.
.
.
.
.
nD<o.oos1
ND<0.00?9
nD<o.oo93
ND¢0.D090
nD<o.oo87
nD=o.oo81
ND¢0.00B8
nD<0.gog2
r~ID<o.oo83
ND<0.0081
ND<0.00B5
nD=o.oosa
ND<0.0080
ND<0.0083
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

40.9 10.9

17.2 52.5

34.0 42.8

1.9 2.8
14 NA
21 32
314
NA

9.7 9.7
219
NA
Residential (0 to 5 fi bgs)
Residential Volatilization Io outdoor air (5 to 10 It bgs)' Uliity Worker (0 to 10 fl boo'
Residential ESLs
ID ldenlMcallon
VOCs volatile organic compounds. analyzed :org United Stales Enwonrnenlal Protection Agency (US EPA) Method 82608 Load analyzed usng US EPA Method 601I:IB
PAHs polyuomatuc hydrocarbons. analyzed using US EPA method 8270c flbgs -lee! below found surface
mgnrg -mlrgrams per kilogrm
ND ml detected
ND<X -analvw ml deneclod at or above the laboratory reporting limt x -not aneyroea
1 LowTlveal Underground Storage To* Case Cbenn Policy. Concentrations of Petroleum Constituents in Son That Wil Hayer No Srgndicanl Rlslr d Adversely Aflechng Human Health (Table I) 2 San Francisco Bay RegionalWisNer Quality Control Board enwonmenlal screerung levels (ESLs), Deed Exposure Human Health Risk Levels (Table S1), Residenlial Shadow Soil Exposure 2019 (Rev. 2) NA weaning level not applicable
NA
NA
NA
80 ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

0.063
NA

4.5 NA
NInyo&Mooro | 616 Linden Avewe.Snutl\Sal1Flsienco.Cifonia 94080 | 403151010 | September 21,20Q3 1 81-1 6/30/2023
81-6 6/30/2023
82-2 6/30/2023
82-6 6/30/2023
83-3 6/30/2023
83-5 6/30/2023
84-4 6/30/2023
84-8 6/30/2023
85-1 6/30/2023
85-9 6/30/2023
86-2 6/30/2023
86-6 6/30/2023
87-3 6/30/2023
87-7 6/30/2023
Residential (0 to 5 ft bgs)1
Residential Volatilization to outdoor air (5 to 10 ft bgs)1 Utility Worker (0 to 1 Oft bgs) 1
Residential ESLs2
ID-identification
N0<0.0081 N0<0.0081
ND<0.0079 ND<0.0079
ND<0.0093 ND<0.0093
N0<0,0090 N0<0.0090
N0<0.0087 N0<0.0087
ND<0.0081 ND<0.0081
ND<0.0088 ND<0.0088
N0<0,0092 ND<0.0092
N0<0.0083 N0<0.0083
ND<0.0081 ND<0.0081
ND<0.0085 ND<0.0085
N0<0,0088 N0<0.0088
N0<0.0080 N0<0.0080
ND<0.0083 ND<0.0083

1.9 21

2.8 32
14 314
NA NA
voes• volatie organic compounds, analyzed using United states Envi'onmental Protection Agency (US EPA) Melhod 82608 Leed enetyzed using US EPA Method 80108
PAHs • potya-omalic hy«oeatbons, analyzed using US EPA Method 8270C ft bgs - feet below ground stmce
mg/kg- mil igrams per kilogram
ND-not detected
ND<X- enetyte not detected at~ above lhe laboratay reporting limilX - nolllfl8ylized
mg/kg
N0<0.0081 71.0
ND<0.0079
ND<0.0093 40.9
N0<0,0090
N0<0.0087 10.9
ND<0.0081
ND<0.0088 17.2
N0<0,0092
N0<0.0083 52.5
ND<0.0081
ND<0.0085 34.0
N0<0,0088
N0<0.0080 42.8
ND<0.0083

9.7 NA

9.7 NA
219 NA
NA 80
1 • Low-Threat Underr,ound Stc.n,ge Tank Case Closure Policy, Concentrations of Petroleum Constituents in Soil That Will Have No Significant Risk of Adversely Affecting Human Heallh (Table 1) ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

0.063
NA

4.5 NA
2 • San Francisco Bay Regional Water Quaity Control Boll"d environmental screening lewls (ESLs), Direct ExpOS\l'e Human Heelth Risk Lewis (Table S-1), Residentiat Shtdow Soil ExpOSW'e, 2019 {Rev. 2) NA-screeninglevelnot epplicable
Ninyo &Moore I 616 Linden Avenue, South San Francisco, California 94080 I 403151010 I September 21, 2023 Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | September 21, 2023

FIGURES
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_ FIGURE 1

SITE LOCATION
lyIng &/Vluure
Geotechnical & Environmental Sciences Consultants

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 07/23
NOTE: DIMENSIONS, DIRECTIONS, AND LOCATIONS ARE APPROXIMATE I REFERENCE: USGS, 2018 Geotechnical & Environmental Sciences Consultants

SCALE (FEET)
0 2,000
0 Oyst
P.oin
4,000
FIGURE 1

SITE LOCATION

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 07/23
LEGEND

SITE BOUNDARY
p//v5,4 VE
B1 O SOIL BORING
(N&M, 2023)
lx:
cz:

FORMER MONITORING WELL

FORMER PIEZOMETER
SB-7 GO SOIL SAMPLE
(TETRATECH, 2021)
SG-1 .

SB-4/ e

SOIL GAS SAMPLE
(TETRATECH, 2021)
SOIL AND SOIL GAS SAMPLE Fu'
I
.|
(TETRATECH, 2021)

UNKNOWN UTILITY LINE

CONCRETE SUBSURFACE

STRUCTURE

APPARENT BACKFILLED

EXCAVATION DETECTED

WITH GPR
EM61-GPR

ANAMOLY
FORMER
BUILDING B4

I FORMER AUTO

REPAIR SHOP /
O
NOTES
ELECTROMAGNETIC 61

GROUND PENETRATING RADAR

UNDERGROUND STORAGE TANK
FORMER

BUILDING
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I
0 SCALE(FEET)
25 I
50 Nl'I1§0 8z/Vltmre
Geotechnical & Environmental Sciences Consultants

SITE PLAN

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 07/23
~
~
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~
~ "'
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(TETRATECH, 2021)
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SG-4 (TETRATECH, 2021)
- · - · - · - · - UNKNOWN UTILITY LINE
l'ZZI
NOTES:

CONCRETE SUBSURFACE

STRUCTURE

APPARENT BACKFILLED

EXCAVATION DETECTED

WITH GPR
EM61-GPR

ANAMOLY
FORMER

BUILDING
EM61 = ELECTROMAGNETIC 61
GPR = GROUND PENETRATING RADAR
UST= UNDERGROUND STORAGE TANK
---, - ,
-- , I ........ ~ u --
1 ............ I .............
'° NOTE: DIMENSIONS, DIRECTIONS, AND LOCATIONS ARE APPROXIMATE ~ REFERENCES: GOOGLE EARTH, 2023; TETRA TECH 2021 .., ,__ __ _ Geotechnical & Environmental Sciences Consultants
0 B6
0 I
I
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SCALE (FEET)
25 50
FIGURE 2

SITE PLAN

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 07/23
B4. Supplemental Site Investigation No. 2 Report
(Ninyo & Moore 2024)
New Park at Linden and Pine Project
Initial Study/Mitigated Negative Declaration
1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 | www.ninyoandmoore.com Supplemental Site Investigation Report
616 Linden Avenue
South San Francisco, California
Closed LUST Cleanup Site Case No. 550097
City of South San Francisco
33 Arroyo Drive | South San Francisco, California 94080 March 27, 2024 | Project No. 403151010
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS No. 2
.........
.......
.......
.........
ninyn &/Vltmre
Geotechnical & Environmental Sciences Consultants
No.2
Geotechnical & Environmental Sciences Consultants
Nl'I'IHO &/Vlunre
YEARS
Geotechnical & Environmental Sciences Consultants
March 27, 2024
Project No. 403151010
Mr. Philip Vitale
City of South San Francisco
33 Arroyo Drive
South San Francisco, California 94080
Subject: Supplemental Site Investigation No. 2 Report
616 Linden Avenue
South San Francisco, California
Closed LUST Cleanup Site Case No. 550097
Dear Mr. Vitale:

Ninyo & Moore has prepared this Supplemental Site Investigation (SSI) No. 2 Report for the above referenced City of South San Francisco (City) property located at 616 Linden Avenue in South San Francisco, California (site). This investigation was proposed in Ninyo& Moore's January 25, 2024 Proposal for Soil Characterization Investigation.

We appreciate the opportunity to be of service to the City on this project. If you have any questions or comments regarding this Report, please contact the undersigned at your convenience.

Sincerely,

NINYO & MOORE
Connor Escobar
Senior Staff Scientist
¥~~
Aubrey K. PG 7659
Principal Geologist
-i5\QNAL GE
56° go! K _01
No. 7659
,l.

CRE/AKC/gvr
1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 | www.ninyoandmoore.com Geotechnical & Environmental Sciences Consultants
March 27, 2024
Project No. 40315101 0
Mr. Philip Vitale
City of South San Francisco
33 Arroyo Drive
South San Francisco, California 94080
Subject: Supplemental Site Investigation No. 2 Report
616 Linden Avenue
South San Francisco, California
Closed LUST Cleanup Site Case No. 550097
Dear Mr. Vitale:

Ninyo & Moore has prepared this Supplemental Site Investigation (SSI) No. 2 Report for the above referenced City of South San Francisco (City) property located at 616 Linden Avenue in South San Francisco, California (site). This investigation was proposed in Ninyo & Moore's January 25, 2024 Proposal for Soil Characterization Investigation.

We appreciate the opportunity to be of service to the City on this project. If you have any questions or comments regarding this Report, please contact the undersigned at your convenience.

Sincerely,

NINYO & MOORE
Connor Escobar
Senior Staff Scientist
CRE/AKC/gvr
~~K~L Aubrey K. Cool, PG 7659
Principal Geologist o. 765
1301 Marina Village Parkway, Suite 110 I Alameda, California 94501 I p. 510.343.3000 I www.ninyoandmoore.com

CONTENTS

INTRODUCTION

PRE-FIELD ACTIVITIES
Permitting
Health and Safety Plan
Utility Location

FIELD ACTIVITIES
Soil Sampling
Investigation-Derived Waste

ANALYTICAL RESULTS
Volatile Organic Compounds
Total Petroleum Hydrocarbons as Diesel and Gasoline
Lead

CONCLUSIONS AND RECOMMENDATIONS

LIMITATIONS
1 1
1 1
2 2
2 2
3 3
3 3
4 4
TABLE
1 - Soil Analytical Results

FIGURES
1 - Site Location
2 - Site Plan

APPENDIX
A - Laboratory Analytical Reports
Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 I March 27, 2024 i

CONTENTS
1 2

2.1 2.2

2.3 3

3.1 3.2
4 4.1

4.2 4.3
5 6
TABLE

INTRODUCTION

PRE-FIELD ACTIVITIES
Permitting
Health and Safety Plan
Utility Location

FIELD ACTIVITIES
Soil Sampling
Investigation-Derived Waste

ANALYTICAL RESULTS
Volatile Organic Compounds
Total Petroleum Hydrocarbons as Diesel and Gasoline
Lead

CONCLUSIONS AND RECOMMENDATIONS

LIMITATIONS
1 - Soil Analytical Results

FIGURES
1 - Site Location
2-Site Plan

APPENDIX
A - Laboratory Analytical Reports
Ninyo & Moore I 616 Linden Avenue, South San Francisco, California 94080 I 403151010 I March 27, 2024 1 1
1 1
2 2
2 2
3 3
3 3
4 4
Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024 1 1 INTRODUCTION
On behalf of the City of South San Francisco (City), Ninyo & Moore presents this Supplemental Site Investigation (SSI) No. 2 Report for the property located at 616 Linden Avenue in South San Francisco, California (site).

The site is a 0.32-acre property, located on the southeastern corner of Linden Avenue and Pine Avenue in a mixed residential and commercial area in South San Francisco (Figure 1). It is currently an active parking lot.

Redevelopment into a City park is planned for the subject site as well as the adjacent property at 700 Linden Avenue. Park design is expected to begin soon, and the City is exploring whether voluntary soil excavation to remove soil impacted by residual total petroleum hydrocarbons (TPHs) is warranted. This SSI was conducted to determine the extent of TPH in soil that exceeds State Water Resources Control Board (State Water Board) Low-Threat Underground Storage Tank Case Closure Policy (Low-Threat Closure Policy) petroleum vapor intrusion to indoor air criteria for a bioattenuation zone. In the event that excavation would be warranted, samples were also collected to pre-classify the soil for disposal.
2 PRE-FIELD ACTIVITIES
The following activities were performed prior to initiating the subsurface investigation.

2.1 Permitting
San Mateo County Environmental Health Services did not require permits for this work as the borings were shallower than 10 feet below ground surface (bgs) and groundwater was not encountered.

2.2 Health and Safety Plan
Ninyo & Moore updated the site-specific health and safety plan (HASP) prior to mobilization. Ninyo & Moore reviewed the HASP with field personnel prior to the start of each day of field work, and field personnel signed the acknowledgement form attached to the HASP indicating they understood and would abide by its provisions.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024 2

2.3 Utility Location
As required by California law, Ninyo & Moore marked out the vicinity of the boring locations in white paint and notified USA North 811 (USA). USA marked locations surrounding the site. In addition, the boring locations were cleared by a private utility locating service. 3 FIELD ACTIVITIES
Ninyo & Moore field staff oversaw VTS Drilling, LLC (VTS) of Hayward, California (C-57 License No. 916085) advance eight soil borings (B8 through B15) on February 22, 2024. The borings were advanced by a direct-push drill rig to a maximum depth of approximately 5.5 feet bgs. Equipment was decontaminated with a rinse of Alconox®
and water, followed by two rinses with distilled water, between each sampling location.

3.1 Soil Sampling
Two discrete soil samples were collected from each soil boring: one between the surface and 2.5 feet bgs and one between 2.5 and 5 feet bgs. The samples were transferred into clean laboratorysupplied containers, labeled with sample identifications, placed in re-sealable plastic bags, and stored in a cooler containing ice. They were transported under chain-of-custody documentation to Torrent Laboratories in Milpitas, California, a California-certified analytical laboratory.

The soil samples were analyzed for TPH as motor oil and TPH as diesel (TPHd) using United States Environmental Protection Agency (US EPA) Method 8015, TPH as gasoline (TPHg) and volatile organic compounds using US EPA Method 8260B, and metals using US EPA Method 6010B.

3.2 Investigation-Derived Waste
Investigation-derived waste (IDW) generated from the boring advancement consisted of soil cuttings and asphalt/concrete waste. The IDW was stored in a 55-gallon drum, which was labelled and placed in a secure location pending waste profiling and proper off-site disposal. The IDW was classified as non-hazardous waste. On March 22, 2024, the drum was transported off site and is pending final transportation to Soil Safe of Adelanto, California. The manifest is pending, and the laboratory report used to characterize the waste is included in Appendix A.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024 3 4 ANALYTICAL RESULTS
The laboratory analytical reports, presenting all requested analyses, are provided in Appendix A.

Select results are discussed in detail below.

TPHd and TPHg analytical results were compared to the Low-Threat Closure Policy petroleum vapor intrusion to indoor air criteria for a bioattenuation zone. Additionally, lead results were compared to residential San Francisco Bay Regional Water Quality Control Board environmental screening levels (ESLs). The TPHd, TPHg, and lead data are presented on Table 1.

4.1 Volatile Organic Compounds
Volatile organic compounds (VOCs) were not detected above laboratory reporting limits (RLs) in any samples.

4.2 Total Petroleum Hydrocarbons as Diesel and Gasoline TPHd was detected in all samples at concentrations ranging from 3.23 milligrams per kilogram (mg/kg) in sample B8-3 to 29.2 mg/kg in B9-4. TPHg was not detected above laboratory RLs in any samples.

According to the Low-Threat Closure Policy vapor intrusion scenario for direct measurement of soil gas concentrations (Appendix 4, Scenario 4 [2 of 2]), TPH concentrations (defined as TPHd + TPHg) must be less than 100 mg/kg measured in at least 2 depths within the 5-foot zone. None of the sample TPH totals exceeded 100 mg/kg (Table 1). Additionally, no TPHd detections exceeded the residential ESL of 260 mg/kg.

4.3 Lead
Lead was detected in all samples, at concentrations ranging from 12.6 mg/kg in sample B13-5 to

80.0 mg/kg in B9-2. The detection in B9-2, equaled the residential ESL of 80 mg/kg, but no detections exceeded it.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024 4 5 CONCLUSIONS AND RECOMMENDATIONS
Ninyo & Moore advanced eight soil borings to further evaluate TPH impacts to site soil and to characterize soil for potential disposal.

The analytical results show that existing soil conditions satisfy Low-Threat Closure Policy criteria for a bioattenuation zone, and TPH concentrations are below residential ESLs. Therefore, additional soil excavation is not warranted to remove TPHs.

Ninyo & Moore recommends removing the lead-impacted soil located in a subsurface concrete structure that was identified during the Phase II Environmental Site Assessment. If the City concurs, this work can be proposed in a Site Management Plan to be submitted to San Mateo County Groundwater Protection Program for review.
6 LIMITATIONS
The environmental services described in this report have been conducted in general accordance with current regulatory guidelines and the standard-of-care exercised by environmental consultants performing similar work in the project area. No warranty, expressed or implied, is made regarding the professional opinions presented in this report. Variations in site conditions may exist and conditions not observed or described in this report may be encountered during subsequent activities. Please also note that this assessment did not include an evaluation of geotechnical conditions or potential geologic hazards.

Ninyo & Moore's opinions and recommendations regarding environmental conditions, as presented in this report, are based on limited subsurface assessment and chemical analysis.

Further assessment of potential adverse environmental impacts from past on-site and/or nearby use of hazardous materials may be accomplished by a more comprehensive assessment. The samples collected and used for testing, and the observations made, are believed to be representative of the area(s) evaluated; however, conditions can vary significantly between sampling locations. Variations in soil and/or groundwater conditions will exist beyond the points explored in this evaluation.

The environmental interpretations and opinions contained in this report are based on the results of laboratory tests and analyses intended to detect the presence and concentration of specific chemical or physical constituents in samples collected from the subject site. The testing and analyses have been conducted by an independent laboratory which is certified by the State of California to conduct such tests. Ninyo & Moore has no involvement in, or control over, such Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024 5 testing and analysis. Ninyo & Moore, therefore, disclaims responsibility for any inaccuracy in such laboratory results.

Ninyo & Moore’s conclusions, recommendations and opinions are based on an analysis of the observed site conditions. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires any additional information, or has questions regarding content, interpretations presented, or completeness of this document.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions and/or recommendations of this report by parties other than those noted is undertaken at said parties’ sole risk.

Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024 Appendix A
Photographic Documentation
TABLE
-II
DleCollected TPHd TPHg LTCP TPH
fmglkgj
81 1
B1 6
B22
B26
B33
B35
B44
Baa
B51
B59
B62
B66
B73
B7T
B81
883
B92
B94
BIG2
8106
B1 10.5
B114
8121
8123
B132
B135
8141
B143
B152
8155
araofzoza
&3€U2023
waorzozs
esraorzozs
B302023
&30!2023
waorzoza
arsorzoza
w30f2oza
arawzozs
sraorzoza
araomza
arswzoza
wacvzoza
22210024
2222024
2222024
2/22!2024
2n2:2024
232212024
23222024
212212024
222J2004
232212024
232212tJ24
21222024
22212024
22212024
212212024
2212024
I
6 2
6 3
s
4 s
1 9
2 5
3 7
I
3 2
4 2
5 0,5
4 1
3 2
s
1 3
2 5

10.8 x

3.23 x

15.2 x

29.2 x

4.6B x

3.51 x

17.B x

5.90 x
B.32 x

4.32 x

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9.7 9.7
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NA
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71.0 40.9

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52.5 24.0

42.8 58.5

46.4 80.0

53.0 80.5

35.2 46.9

26.6 23.6

29.6 35,6

12.6 39.8

31.6 at.5

44.1 NA
NA
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4.5 NA
NA
Nlnyo a Moon I 616 Undsn Avenue. Snug\ San Flsicrsco. Cifofnia 91080 I 403151010 I March 27. 2024 1 BM 6/30/2023
B1-6 6/30/2023
B2-2 6/30/2023
B2-6 6/30/2023
B3-3 6/30/2023
B3-5 6/30/2023
B4-4 6/30/2023
B4-6 6/30/2023
BS-1 6/30/2023
BS-9 6/30/2023
B6-2 6/30/2023
BB-6 6/30/2023
B7-3 6/30/2023
B7-7 6/30/2023
B3-1 2/22/2024 10.8x
B3-3 2/22/2024 3.23x
B9-2 2/22/2024 15.2x
B9-4 2122/2024 29.2x
810-2 2/22f2024 4.56x
810-5 2/22f2024 3.51 X
811-0.5 2122/2024 0.5 17.6x
811-4 2122'2024 5.90x
812-1 2/2212004 8.32x
812-3 2/22f2024 4.32x
813-2 2/22f2024 3.58x
813-5 2/22f2024 9.65x
814-1 2/22f2024 8.90x
B14-3 2/22f2024 3.45x
815-2 2122'2024 6.94x
815-5 2/22f2024 3.24x
Residential(0to5ftbgs)1 NA
ResidentialVolatilizationtooutdoorair(Sto 10ftbgs) 1 NA Utility Worker (0 to 10 ft bgs) 1 NA
8ioattenuationZone2 NA
Residential ESLs~ 260
Naln :
ll - identiicatioo
TPHs-mlalpetroleumhydl'OClllboos
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ND<0.10 3.3
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ND<0.090 4.7
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ND<0.096 6.0
ND<0.10 8.4
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ND<0.062 9.0
ND<0.092 3.5
ND<0.079 7.0
ND<0.075 3.3
NA NA
NA NA
NA NA
NA 100
100 NA
1-Low-Th!M!Llndervotl'ldSrng&Tlnl QiseCilaJrePoicy, Calcartratia'lsclf'mllaum OJnslituents i'I Soil lhlllWil H-NoSiglilcsr!Ritkcl AdverwlyAlkdngHulllSI Healti(Tabh1) 2-Low-Three1LlndeflJOllldSrngeTenkC-Cl>wrePoicy SDi GesSemping-.-ritlBioettenue1ooZOtl8(~dix ,SoenllriD -0JIIC1~re ofSai Ge Crincenb'etian l2of2D 3- Ssi FrendllCO Bey RegionalWallrQ.Jaity O:inlrolBoa-denvillllmenlal &ereeni'lglavels(ESl.s), llred Expoue Human Ha8'h Riall8V81s(TSJla S-1), Residenht Shalbw Soi l Elpo&tn, 2019 (Rev, 2) NA-screeninglevel no111!'Plcable
Ninyo &Moore I 616 Linden Avenue, South San Francisco, California 94080 I 403151010 I M.-ch 27, 2024 voes
ND<0.0081 ND<0.0081
ND<0.0079 ND<0.0079
ND<0.0093 ND<0.0093
ND<0.0090 ND<0.0090
ND<0.0087 ND<0.0087
ND<0.0081 ND<0.0081
ND<0.0088 ND<0.0088
ND<0.0092 ND<0.0092
ND<0.0083 ND<0.0083
ND<0.0081 ND<0.0081
ND<0.0085 ND<0.0085
ND<0.0088 ND<0.0088
ND<0.0080 ND<0.0080
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ND<0.0098 ND<0.0098
ND<0.010 ND<0.010
ND<0.0097 ND<0.0097
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ND<0.0090 ND<0.0090
ND<0.0074 ND<0.0074
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ND<0.010 ND<0.010
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ND<0.0062 ND<0.0062
ND<0.0092 ND<0.0092
ND<0.0079 ND<0.0079
ND<0.0075 ND<0.0075

1.9 21

2.8 32
14 314
NA NA
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9.7 9.7
219
NA
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71.0 40.9

10.9 17.2

52.5 34.0

42.8 58.5

46.4 90.0

53.0 60.5

35.2 46.9

26.6 23.6

29.6 35.6

12.6 39.8

31.6 61.5

44.1 NA
NA
NA
NA
80 ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
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0.063
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4.5 NA
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Ninyo & Moore | 616 Linden Avenue, South San Francisco, California 94080 | 403151010 | March 27, 2024

FIGURES
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_ FIGURE 1

SITE LOCATION
lyIng &/Vluure
Geotechnical & Environmental Sciences Consultants

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 03/24
~
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SCALE (FEET)
0 2,000
0 Oyst
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4,000
FIGURE 1

SITE LOCATION

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 03/24
LEGEND

SITE BOUNDARY
B8 . SOIL BORING
(N&M, 2024)
B1 O SOIL BORING
(N&M, 2023)
m
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FORMER MONITORING WELL

FORMER PIEZOMETER
SB-7 GO SOIL SAMPLE
(TETRATECH, 2021)
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UNKNOWN UTILITY LINE

CONCRETE SUBSURFACE

STRUCTURE

APPARENT BACKFILLED

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WITH GPR
EM61-GPR

ANAMOLY
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Geotechnical & Environmental Sciences Consultants

SITE PLAN

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 03/24
I
0 0
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EM61 = ELECTROMAGNETIC 61
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'° NOTE: DIMENSIONS, DIRECTIONS, AND LOCATIONS ARE APPROXIMATE ~ REFERENCES: GOOGLE EARTH, 2023; TETRA TECH 2021 .., ,__ __ _ Geotechnical & Environmental Sciences Consultants
B14 •
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SCALE (FEET)
25 50
FIGURE 2

SITE PLAN

SUPPLEMENTAL SITE INVESTIGATION REPORT
616 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 03/24
B5. Environmental Summary Report
(Ninyo & Moore 2024)
New Park at Linden and Pine Project
Initial Study/Mitigated Negative Declaration
1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 | www.ninyoandmoore.com Environmental Summary Report
616 and 700 Linden Avenue
South San Francisco, California
City of South San Francisco
33 Arroyo Drive | South San Francisco, California 94080 August 30, 2024 | Project No. 403151010
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS ......
...............
&
Geotechnical & Environmental Sciences Consultants
n/°nga Moore
Geotechnical & Environmental Sciences Consultants
1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 | www.ninyoandmoore.com August 30, 2024
Project No. 403151010
Mr. Philip Vitale
City of South San Francisco
33 Arroyo Drive
South San Francisco, California 94080
Subject: Environmental Summary Report
616 and 700 Linden Avenue
South San Francisco, California
Dear Mr. Vitale:

Ninyo & Moore prepared this Environmental Summary Report (Report) for the above referenced City of South San Francisco (City) properties located at 616 and 700 Linden Avenue in South San Francisco, California (site). This Report summarizes the historical investigations completed at both properties, and evaluates the investigation findings in the context of the site’s planned use as a City park.

We appreciate the opportunity to be of service to the City on this project. If you have any questions or comments regarding this Report, please contact the undersigned at your convenience.

Sincerely,

NINYO & MOORE
August 30, 2024
August 30, 2024
Aubrey K. Cool, PG 7659
Principal Geologist
Scott Bittinger, PG 7477
Senior Geologist
SGB/AKC/gvr
ninyu &maule YEARS
Geotechnical & Environmental Sciences Consultants
"
A
Scott G. Bittinger
No. 7477
i 44 Fr " 6
QF CAD*
No. 7659
Geotechnical & Environmental Sciences Consultants
~~KC-r-L ~~~
o. 765
Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 i

CONTENTS
1 EXECUTIVE SUMMARY 1
2 INTRODUCTION 2
3 HISTORICAL ENVIRONMENTAL INVESTIGATIONS 2

3.1 Closed Underground Storage Tank Case – 616 Linden Avenue 2

3.2 Targeted Brownfields Assessment – 616 and 700 Linden Avenue 2

3.3 Supplemental Site Investigations – 616 Linden Avenue 4 4 FINDINGS 4

4.1 616 Linden Avenue 4

4.1.1 Soil Conditions 4

4.1.2 Soil Vapor Conditions 5

4.2 700 Linden Avenue 5
5 CONCLUSIONS 6
6 LIMITATIONS 7
7 REFERENCES 9
TABLES
1 – Soil Analytical Results
2 – Soil Vapor Analytical Results

FIGURES
1 – Site Location
2 – Site Plan
Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 1 1 EXECUTIVE SUMMARY
The City of South San Francisco (City) intends to redevelop two adjoining properties of land, located at 616 and 700 Linden Avenue and totaling 0.66 acre, into a park.

Extensive environmental investigation work has been performed at 616 Linden Avenue, where motor vehicle fuels had been historically stored and dispensed. Some of the work was performed to meet regulatory requirements, and some of the work was performed out of an abundance of caution. During removal of fuel underground storage tanks (USTs) at 616 Linden Avenue, petroleum hydrocarbons were detected in soil. With oversight from representatives of San Mateo County Groundwater Protection Program (GPP), in the late 1990s and early 2000s, 440 cubic yards of soil were excavated and hauled off site to a landfill, removing most of the petroleum hydrocarbon contamination from the property. The area was then backfilled with imported fill material, and after follow up testing, the County GPP closed the environmental case in 2001.

Prior to redevelopment, historical property uses were evaluated using the Phase I and II Environmental Site Assessment process on both properties in 2021, which is common when changes in property use or ownership occurs or as an initial investigation step.

With the new property use as a park considered, supplemental site investigations were completed at 616 Linden Avenue in June 2023 and February 2024. Shallow soil samples were collected and analyzed for petroleum hydrocarbons and lead. The State of California has established risk-based screening levels specifically for former UST cases. Lead is commonly detected in soil, and State regulatory agencies have established toxicologically-based screening levels to assess safe lead concentrations for different property uses. The supplemental testing and evaluation of the soil data confirms that 616 Linden Avenue is acceptable for use as a park.

At 700 Linden Avenue, shallow soil samples were collected in 2021, composited, and tested for the presence of lead as review of historical site use identified lead as the only likely potential contaminant on that property. Based on the lead data, the property is safe for use as a park.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 2 2 INTRODUCTION
Ninyo & Moore prepared this Environmental Summary Report (Report) on behalf of the City of South San Francisco (City) for the properties located at 616 and 700 Linden Avenue in South San Francisco, California (site).

The 616 Linden Avenue property is a 0.32-acre lot, located on the southeastern corner of Linden Avenue and Pine Avenue, South San Francisco (Figure 1). It is currently used as a parking lot.

The 700 Linden Avenue property is a 0.34-acre vacant, vegetated lot, located on the northeastern corner of Linden Avenue and Pine Avenue, South San Francisco (Figure 1). The surrounding area is mixed residential and commercial land use.

Redevelopment into a City park is planned for the subject site, and park design is underway. This Report was prepared to summarize the historical environmental data collected at both properties and assess whether residual contamination affects the planned use as a City park. 3 HISTORICAL ENVIRONMENTAL INVESTIGATIONS

3.1 Closed Underground Storage Tank Case – 616 Linden Avenue Volonte Automotive, a repair shop, operated at the 616 Linden Avenue property from the 1940s through the early 2000s. The layout of the property is depicted on Figure 2. A leaking underground storage tank cleanup case was opened under San Mateo County Groundwater Protection Program (GPP) oversight following removal of one gasoline UST and one waste oil UST in 1993, and the detection of petroleum hydrocarbons in soil below the USTs. According to the case closure summary (GPP, 2001), approximately 440 tons of soil were excavated and disposed of off site following the UST removals, to remove the petroleum hydrocarbon impacted soil from the property. Groundwater monitoring and sampling was then conducted through January 2001 to assess the shallow groundwater for the presence of petroleum hydrocarbons. GPP confirmed that the investigation and remedial action were satisfactorily completed and closed the case in September 2001.

3.2 Targeted Brownfields Assessment – 616 and 700 Linden Avenue Working under a United States Environmental Protection Agency (EPA) Targeted Brownfields Assessment (TBA) grant, consultants retained by the EPA conducted Phase I and Phase II Environmental Site Assessments (ESAs) for several sites in South San Francisco in 2021, including the subject sites.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 3 The Phase I ESA, which is a record search, identified the following recognized environmental conditions (RECs) at the site:
• Vapor intrusion potential from residual petroleum hydrocarbons (616 Linden Avenue); • Possible presence of additional USTs (616 Linden Avenue); • Possible contamination from a former dry cleaner at 612 Linden Avenue (616 Linden Avenue); and
• Potential historical aerially deposited lead (700 Linden Avenue).

According to the Final Phase I/Phase II ESA TBA Report, the Phase II ESA did not identify any additional USTs at 616 Linden Avenue, but it did identify a buried concrete structure containing metal and elevated lead concentrations in soil.

During the Phase II ESA, which consisted of soil and soil vapor sample collection, the EPA consultant collected three soil samples and five soil gas samples at 616 Linden Avenue. The soil sample analyzed for petroleum hydrocarbons contained up to 930 milligrams per kilogram (mg/kg) total petroleum hydrocarbons (TPH) as motor oil, 560 mg/kg TPH as diesel (TPHd) and 43 mg/kg TPH as gasoline (TPHg). Lead was detected in soil at concentrations ranging from 43.8 to 239 mg/kg. Low concentrations of polyaromatic hydrocarbons (PAHs; benzo(a)anthracene, phenanthrene, and pyrene) were also detected in soil. Of these, only the TPHd detections and one lead detection (from the buried concrete structure) exceeded San Francisco Bay Regional Water Quality Control Board (Regional Water Board) environmental screening levels (ESLs) for direct contact with soil under residential land use. In soil vapor, the following volatile organic compounds (VOCs) were detected: 1.2 to 68,000 micrograms per cubic meter (µg/m3 ) benzene,

1.3 to 46,000 µg/m3 ethylbenzene, 10 to 83,000 µg/m3 toluene, 5.2 to 230,000 µg/m3 total xylenes, 1,400 to 3,000 µg/m3 1,2-dichloroethane (1,2-DCA), and 1.8 µg/m3 tetrachloroethene. Some of the benzene, ethylbenzene, toluene, total xylenes (BTEX) and 1,2-DCA concentrations exceeded Regional Water Board ESLs for vapor intrusion to residential indoor air.

Four composite soil samples were collected at 700 Linden Avenue and analyzed for lead, which was detected at concentrations ranging from 24 to 52 mg/kg. These concentrations are below Regional Water Board ESLs for direct contact with soil under residential land use, thus confirming suitability for use as a park.

Analytical results and regulatory screening levels are presented on Tables 1 and 2, and sample locations are shown on Figure 2.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 4

3.3 Supplemental Site Investigations – 616 Linden Avenue With the objective of evaluating risk to future receptors under the scenario of redeveloping the subject site into a park, Ninyo & Moore consulted with the GPP and conducted a Supplemental Site Investigation (SSI) at the 616 Linden Avenue property in June 2023 to collect additional soil data. Ninyo & Moore advanced seven borings (B1 through B7) to assess whether current site soil conditions meet State Water Resources Control Board’s (State Water Board’s) Low-Threat Underground Storage Tank Case Closure Policy (Low-Threat Closure Policy) direct contact and outdoor air exposure criteria (which requires testing for benzene, ethylbenzene, naphthalene, and PAHs in the upper 10 feet of the subsurface). Additionally, soil samples were analyzed for lead and results were compared to residential Regional Water Board ESLs. Benzene, ethylbenzene, naphthalene, and PAHs were not detected in any samples. Lead was detected in all samples analyzed for lead, at concentrations ranging from 10.9 mg/kg in sample B3-3 to 71.0 mg/kg in B1-

1. None of these detections exceeded the residential ESL of 80 mg/kg for direct soil contact.

To determine if TPH remained in soil at levels that warranted excavation and removal from the property, and to characterize soil for potential disposal, Ninyo & Moore conducted another SSI and advanced eight soil borings (B8 through B15) in February 2024. TPHd was detected in all samples at concentrations ranging from 3.23 mg/kg in sample B8-3 to 29.2 mg/kg in B9-4; these detections are below the residential ESL of 260 mg/kg for direct soil contact. TPHg was not detected in any of the samples. Lead was detected in all samples, at concentrations ranging from

12.6 mg/kg in sample B13-5 to 80.0 mg/kg in B9-2. The detection in B9-2, equaled the residential ESL of 80 mg/kg, but no detections exceeded it.

The analytical data and regulatory screening levels are shown on Table 1, and sample locations are shown on Figure 2.
4 FINDINGS

4.1 616 Linden Avenue

4.1.1 Soil Conditions
Total petroleum hydrocarbons (TPHs) were detected in soil samples collected during the EPA and Ninyo & Moore investigations. Total petroleum hydrocarbons as diesel (TPHd) detections in one sample location only (616-SB-4) collected in 2021 exceeded the Regional Water Board environmental screening level (ESL) for direct soil contact with residential land use.

Subsequent samples collected across the 616 Linden Avenue property showed significantly lower concentrations. Additionally, the TPH analytical results show that existing soil Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 5 conditions satisfy Low-Threat Closure Policy criteria for a bioattenuation zone, which would support biodegradation of petroleum hydrocarbon vapors.

Volatile organic compounds (VOCs) were not detected in any samples collected during the EPA or Ninyo & Moore investigations.

PAHs were detected at low concentrations in one sample location during the EPA investigation in 2021. They were not detected in samples collected across the 616 Linden Avenue property during Ninyo & Moore’s investigation in 2023, and no detections exceeded regulatory screening levels.

Lead was detected in soil samples collected at the 616 Linden Avenue property at concentrations ranging from 10.9 to 239 mg/kg. The only concentration that exceeded the Regional Water Board ESL for direct soil contact with residential land use of 80 mg/kg was from soil within the buried concrete structure.

4.1.2 Soil Vapor Conditions
As discussed above, volatile organic compounds (VOCs); specifically benzene, ethylbenzene, toluene, total xylenes and 1,2-dichloroethane; were detected in soil vapor samples at concentrations that exceeded Regional Water Board ESLs for vapor intrusion to residential indoor air. The benzene and ethylbenzene detections also exceeded State Water Board Low-Threat Closure Policy criteria for residential soil gas concentrations with no bioattenuation zone. Note that these regulatory screening levels only apply to scenarios with residential indoor air.

4.2 700 Linden Avenue
The Phase I Environmental Site Assessment records search, which reviewed historical site use, identified lead as the only contaminant of potential concern as this property, because there were no USTs or other known sources of contamination. Lead was detected in soil samples collected at 700 Linden Avenue at concentrations ranging from 24 to 52 mg/kg. These concentrations are below Regional Water Board ESLs for direct contact with soil under residential land use.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 6 5 CONCLUSIONS
Multiple investigations have been conducted on the site properties, soil and soil vapor samples have been collected, and the analytical results have been compared to applicable regulatory screening levels.

The analytical results for 616 Linden Avenue show that existing soil conditions satisfy the State Water Board Low-Threat Closure Policy criteria for residential direct contact and outdoor air, and lead concentrations in shallow soil are equal to or below residential ESLs. Therefore, there is not significant risk posed by site soils, and additional excavation and off-hauling of soil is not necessary to allow for property redevelopment as a park to proceed.

Prior to park construction, a Site Management Plan (SMP) will be prepared and submitted to San Mateo County Groundwater Protection Program (GPP) for review. This Plan will describe recommended steps necessary to ensure safety of workers, residents and park users during construction. It will also describe procedures that will be followed if petroleum hydrocarbon impacted soils are encountered during construction, although this is not expected. Further, any soils planned for off-haul to a landfill will be tested and disposed of accordingly.

The City plans to remove the lead-impacted soil located within the buried concrete structure at 616 Linden Avenue that was identified during the Phase II Environmental Site Assessment. This work will be proposed in the SMP described above and submitted to the San Mateo County Groundwater Protection Program for review.

The soil vapor contamination identified at 616 Linden Avenue does not affect redevelopment into a park, because the screening levels apply to residential indoor air. If any buildings are planned, they can be placed on the 700 Linden Avenue property without restrictions. If buildings are proposed at the 616 Linden Avenue property, additional investigation can be conducted or mitigation measures, such as a vapor intrusion mitigation system (VIMS) can be implemented.

There are no known environmental issues or restrictions for redevelopment at the 700 Linden Avenue property.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 7 6 LIMITATIONS
The environmental services described in this report have been conducted in general accordance with current regulatory guidelines and the standard-of-care exercised by environmental consultants performing similar work in the project area. No warranty, expressed or implied, is made regarding the professional opinions presented in this report. Variations in site conditions may exist and conditions not observed or described in this report may be encountered during subsequent activities. Please also note that this assessment did not include an evaluation of geotechnical conditions or potential geologic hazards.

Ninyo & Moore's opinions and recommendations regarding environmental conditions, as presented in this report, are based on limited subsurface assessment and chemical analysis.

Further assessment of potential adverse environmental impacts from past on-site and/or nearby use of hazardous materials may be accomplished by a more comprehensive assessment. The samples collected and used for testing, and the observations made, are believed to be representative of the area(s) evaluated; however, conditions can vary significantly between sampling locations. Variations in soil and/or groundwater conditions will exist beyond the points explored in this evaluation.

The environmental interpretations and opinions contained in this report are based on the results of laboratory tests and analyses intended to detect the presence and concentration of specific chemical or physical constituents in samples collected from the subject site. The testing and analyses have been conducted by an independent laboratory which is certified by the State of California to conduct such tests. Ninyo & Moore has no involvement in, or control over, such testing and analysis. Ninyo & Moore, therefore, disclaims responsibility for any inaccuracy in such laboratory results.

Ninyo & Moore’s conclusions, recommendations and opinions are based on an analysis of the observed site conditions. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 8 This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires any additional information, or has questions regarding content, interpretations presented, or completeness of this document. This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions and/or recommendations of this report by parties other than those noted is undertaken at said parties’ sole risk.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 9 7 REFERENCES
Ninyo and Moore, 2023. Supplemental Site Investigation Report; 616 Linden Avenue, South San Francisco, California. September 21.

Ninyo and Moore, 2024. Supplemental Site Investigation No. 2 Report; 616 Linden Avenue, South San Francisco, California. March 27.

San Francisco Bay Regional Water Quality Control Board, 2019. Environmental Screening Levels. Rev. 2.

San Mateo County Groundwater Protection Agency (GPP), 2001. Case Closure of One 1,000 Gallon Gasoline UST and One 250 Gallon Waste Oil UST Formerly Located at Volonte Automotive, 616 Linden Avenue, South San Francisco, California, SMCo Site #550097.

September 27.

State Water Resources Control Board, 2012. Low-Threat UST Case Closure Policy. August 17.

Toeroek Associates, Inc. and Tetra Tech, Inc., 2021. Final Phase I/Phase II Environmental Site Assessment Targeted Brownfields Assessment Report, South San Francisco, CA. July 2.

Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 Appendix A
Photographic Documentation
TABLES
II
Table 1 – Soil Analytical Results
TPHmo TPHd TPHg Benzene Ethylbenzene Naphthalene Cadmium Chromium Lead Nickel Zinc (ft bgs)
616-SB-4-03022021 3/2/2021 4-5 930 560 43 J -- -- ND<0.0086 0.582 95.1 47.4 88.7 308 a 616-SB-4-03022021-D 3/2/2021 4-5 510 300 14 -- -- ND<0.0059 0.520 J 93.8 43.8 87.9 266 b 616-EC-03012021 3/1/2021 temp stockpile -- -- -- -- -- -- 0.991 J 80.0 239 52.6 397 J -- 616-SB-7-03012021 3/1/2021 3-3.4 -- -- -- -- -- -- ND<0.110 87.4 67.6 67.6 330 -- B1-1 6/30/2023 1 -- -- -- ND<0.0081 ND<0.0081 ND<0.0081 -- -- 71.0 -- -- ND B1-6 6/30/2023 6 -- -- -- ND<0.0079 ND<0.0079 ND<0.0079 -- -- -- -- -- ND B2-2 6/30/2023 2 -- -- -- ND<0.0093 ND<0.0093 ND<0.0093 -- -- 40.9 -- -- ND B2-6 6/30/2023 6 -- -- -- ND<0.0090 ND<0.0090 ND<0.0090 -- -- -- -- -- ND B3-3 6/30/2023 3 -- -- -- ND<0.0087 ND<0.0087 ND<0.0087 -- -- 10.9 -- -- ND B3-5 6/30/2023 5 -- -- -- ND<0.0081 ND<0.0081 ND<0.0081 -- -- -- -- -- ND B4-4 6/30/2023 4 -- -- -- ND<0.0088 ND<0.0088 ND<0.0088 -- -- 17.2 -- -- ND B4-8 6/30/2023 8 -- -- -- ND<0.0092 ND<0.0092 ND<0.0092 -- -- -- -- -- ND B5-1 6/30/2023 1 -- -- -- ND<0.0083 ND<0.0083 ND<0.0083 -- -- 52.5 -- -- ND B5-9 6/30/2023 9 -- -- -- ND<0.0081 ND<0.0081 ND<0.0081 -- -- -- -- -- ND B6-2 6/30/2023 2 -- -- -- ND<0.0085 ND<0.0085 ND<0.0085 -- -- 34.0 -- -- ND B6-6 6/30/2023 6 -- -- -- ND<0.0088 ND<0.0088 ND<0.0088 -- -- -- -- -- ND B7-3 6/30/2023 3 -- -- -- ND<0.0080 ND<0.0080 ND<0.0080 -- -- 42.8 -- -- ND B7-7 6/30/2023 7 -- -- -- ND<0.0083 ND<0.0083 ND<0.0083 -- -- -- -- -- ND B8-1 2/22/2024 1 -- 10.8 x ND<0.098 ND<0.0098 ND<0.0098 ND<0.0098 -- -- 58.5 -- -- -- B8-3 2/22/2024 3 -- 3.23 x ND<0.10 ND<0.010 ND<0.010 ND<0.010 -- -- 46.4 -- -- -- B9-2 2/22/2024 2 -- 15.2 x ND<0.083 ND<0.0097 ND<0.0097 ND<0.0097 -- -- 80.0 -- -- -- B9-4 2/22/2024 4 -- 29.2 x ND<0.095 ND<0.0095 ND<0.0095 ND<0.0095 -- -- 53.0 -- -- -- B10-2 2/22/2024 2 -- 4.56 x ND<0.090 ND<0.0090 ND<0.0090 ND<0.0090 -- -- 60.5 -- -- -- B10-5 2/22/2024 5 -- 3.51 x ND<0.074 ND<0.0074 ND<0.0074 ND<0.0074 -- -- 35.2 -- -- -- B11-0.5 2/22/2024 0.5 -- 17.6 x ND<0.088 ND<0.0088 ND<0.0088 ND<0.0088 -- -- 46.9 -- -- -- B11-4 2/22/2024 4 -- 5.90 x ND<0.096 ND<0.0096 ND<0.0096 ND<0.0096 -- -- 26.6 -- -- -- B12-1 2/22/2004 1 -- 8.32 x ND<0.10 ND<0.010 ND<0.010 ND<0.010 -- -- 23.6 -- -- -- B12-3 2/22/2024 3 -- 4.32 x ND<0.10 ND<0.010 ND<0.010 ND<0.010 -- -- 29.6 -- -- -- B13-2 2/22/2024 2 -- 3.58 x ND<0.065 ND<0.0065 ND<0.0065 ND<0.0065 -- -- 35.6 -- -- -- B13-5 2/22/2024 5 -- 9.65 x ND<0.095 ND<0.0095 ND<0.0095 ND<0.0095 -- -- 12.6 -- -- -- B14-1 2/22/2024 1 -- 8.90 x ND<0.062 ND<0.0062 ND<0.0062 ND<0.0062 -- -- 39.8 -- -- -- B14-3 2/22/2024 3 -- 3.45 x ND<0.092 ND<0.0092 ND<0.0092 ND<0.0092 -- -- 31.6 -- -- -- B15-2 2/22/2024 2 -- 6.94 x ND<0.079 ND<0.0079 ND<0.0079 ND<0.0079 -- -- 61.5 -- -- -- B15-5 2/22/2024 5 -- 3.24 x ND<0.075 ND<0.0075 ND<0.0075 ND<0.0075 -- -- 44.1 -- -- -- 700-SS-1-03042021 3/4/2021 0-0.5 -- -- -- -- -- -- -- -- 38 -- -- -- 700-SS-2-03042021 3/4/2021 0-0.5 -- -- -- -- -- -- -- -- 52 -- -- -- 700-SS-3-03042021 3/4/2021 0-0.5 -- -- -- -- -- -- -- -- 33 -- -- -- 700-SS-4-03042021 3/4/2021 0-0.5 -- -- -- -- -- -- -- -- 24 -- -- -- Screening Levels
NE NE NE 1.9 21 9.7 NE NE NE NE NE 0.063
NE NE NE 2.8 32 9.7 NE NE NE NE NE NE
12,000 260 430 NA NA NA 78 NE 80 320 23,000 NA
Notes:

ID - identification
TPHs - total petroleum hydrocarbons
VOCs - volatile organic compounds, analyzed using United States Environmental Protection Agency (US EPA) Method 8260B Metals analyzed using US EPA Method 6010B
PAHs - polyaromatic hydrocarbons, analyzed using US EPA Method 8270C TPHmo - TPH as motor oil analyzed using US EPA Method 8015B TPHd - TPH as diesel analyzed using US EPA Method 8015B TPHg - TPH as gasoline analyzed using US EPA Method 8260B ft bgs – feet below ground surface
mg/kg – milligrams per kilogram
-- not anaylized
ND<X – analyte not detected at or above the laboratory reporting limit X ND - not detected; see laboratory report for specific chemicals and reporting limits a - 0.012 mg/kg benzo(a)anthracene, 0.013 mg/kg phenanthrene, and 0.01 mg/kg pyrene (estimated values) b - 0.007 mg/kg benzo(a)anthracene, 0.0075 mg/kg phenanthrene, and 0.007 mg/kg pyrene (estimated values) J - estimated value
x - diesel value the result of overlap of oil range into diesel range 2 - San Francisco Bay Regional Water Quality Control Board environmental screening levels (ESLs), Direct Exposure Human Health Risk Levels (Table S-1), Residential: Shallow Soil Exposure, 2019 (Rev. 2) NE - screening level not established
NA - screening level not applicable
Bold indicates concentration exceeds screening level
1 - Low-Threat Underground Storage Tank Case Closure Policy, Concentrations of Petroleum Constituents in Soil That Will Have No Significant Risk of Adversely Affecting Human Health (Table 1) PAHs
Sample ID Date Collected
Residential ESLs2
Depth
LTCP Volatilization to outdoor air (5 to 10 ft bgs)1
VOCs
LTCP Residential (0 to 5 ft bgs)1
(mg/kg)
TPHs Metals
616 Linden Avenue
700 Linden Avenue
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II
Table 2 – Soil Vapor Analytical Results
Helium Oxygen 1,2-Dichloroethane Benzene Ethylbenzene Total Xylenes Naphthalene Tetrachloroethene Toluene (ft bgs)
616-SG-1-03122021 3/12/2021 5 <0.0037 1.4 1,400 9,500 19,000 64,000 ND<790 -- 660 616-SG-2-03042021 3/4/2021 5 <0.0047 2.6 3,000 68,000 46,000 230,000 ND<1,000 -- 83,000 616-SG-3-03122021 3/12/2021 5 <0.0040 15 ND<0.042 1.2 1.3 5.2 ND<0.26 -- 10 616-SG-4-03042021 3/4/2021 5 <0.0051 1.2 ND<540 4,400 ND<580 ND<580 ND<2,200 -- ND<500 616-SG-6-03042021 3/4/2021 5 <0.0050 7.8 ND<0.17 16 23 140 ND<1.1 1.8 98 Screening Levels
NE NE NE 85 1,100 NE 93 NE NE
NE NE 3.6 3.2 37 3,500 2.8 15 10,000
Notes:

ID - identification
Fixed Gases analyzed using ASTM D-1946
VOCs - volatile organic compounds, analyzed using United States Environmental Protection Agency (US EPA) Method TO-15 ft bgs – feet below ground surface
% - percent
mg/m3
– microrams per cubic meter
-- not anaylized
ND<X – analyte not detected at or above the laboratory reporting limit X 2 - San Francisco Bay Regional Water Quality Control Board environmental screening levels (ESLs), Subslab/Soil Gas, Vapor Intrusion: Human Health Risk Levels (Table SG-1), Residential, 2019 (Rev. 2) NE - screening level not established
NA - screening level not applicable
Bold indicates concentration exceeds screening level
Detected VOCs tabulated
VOCs
mg/m3
616 Linden Avenue
1 - Low-Threat Underground Storage Tank Case Closure Policy, Soil Gas Sampling - No Bioattenuation Zone (Appendix 4, Scenario 4 - Direct Measure of Soil Gas Concentrations [1 of 2]) Fixed Gases
%
LTCP Residential1
Residential ESLs2
Sample ID Date Collected
Depth
Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 1 _

II II II II II II II
Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024

3. Description
Appendix A
Photographic Documentation

FIGURES
SITE
(616 LINDEN)
SITE
(700 LINDEN)

SITE LOCATION
Geotechnical & Environmental Sciences Consultants
FIGURE 1
NOTE: DIMENSIONS, DIRECTIONS, AND LOCATIONS ARE APPROXIMATE I REFERENCE: USGS, 2018 0

SCALE (FEET)
2,000 4,000
N 403151010.dwg 07/23/2024 AEK
616 AND 700 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 07/24
KINGS
Sierra Point
atOyster
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FORMER

BUILDING

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REPAIR SHOP
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B2
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B3
B5 B6
B7
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B12
B10
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B15
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B13
8th LN
SS-2
SS-1
SS-3
SS-4
700 LINDEN AVE
616 LINDEN AVE

SITE PLAN
Geotechnical & Environmental Sciences Consultants
FIGURE 2
0 SCALE (FEET)
25 50
N 403151010.dwg 07/23/2024 AEK
LEGEND

SITE BOUNDARY
616 AND 700 LINDEN AVENUE

SOUTH SAN FRANCISCO, CALIFORNIA
403151010 I 07/24

SOIL AND SOIL GAS SAMPLE
(TETRATECH, 2021)
SB-4/
SG-4

SOIL GAS SAMPLE
(TETRATECH, 2021)
SG-1

U U U U UNKNOWN UTILITY LINE

FORMER MONITORING WELL

SOIL SAMPLE
(TETRATECH, 2021)
SB-7

SOIL BORING
(N&M, 2023)
B1
NOTE: DIMENSIONS, DIRECTIONS, AND LOCATIONS ARE APPROXIMATE REFERENCES: GOOGLE EARTH, 2023; TETRA TECH 2021

FORMER PIEZOMETER

CONCRETE SUBSURFACE

STRUCTURE

APPARENT BACKFILLED

EXCAVATION DETECTED

WITH GPR
EM61-GPR

ANAMOLY
FORMER

BUILDING
NOTES:

EM61 = ELECTROMAGNETIC 61
GPR = GROUND PENETRATING RADAR
UST = UNDERGROUND STORAGE TANK

SOIL BORING
(N&M, 2024)
B8

COMPOSITED SOIL SAMPLE
(TETRATECH, 2021)
SS-1
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Ninyo & Moore | 616 and 700 Linden Avenue, South San Francisco, California 94080 | 403151010 | August 30, 2024 1301 Marina Village Parkway, Suite 110 | Alameda, California 94501 | p. 510.343.3000 ARIZONA | CALIFORNIA | COLORADO | NEVADA | TEXAS | UTAH ninyoandmoore.com
Geotechnical & Environmental Sciences Consultants
n/°nga oore
Geotechnical & Environmental Sciences Consultants

APPENDIX C
CalEEMod Output Results
New Park at Linden and Pine Project
Initial Study/Mitigated Negative Declaration
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 South San Francisco Linden and Pine Aves Project v2 Custom Report Table of Contents
1 . Basic Project Information
1 . 1 . Basic Project Information

1.2. Land Use Types

1.3. User-Selected Emission Reduction Measures by Emissions Sector

2. Emissions Summary

2.1. Construction Emissions Compared Against Thresholds

2.2. Construction Emissions by Year, Unmitigated

2.3. Construction Emissions by Year, Mitigated

2.4. Operations Emissions Compared Against Thresholds

2.5. Operations Emissions by Sector, Unmitigated

2.6. Operations Emissions by Sector, Mitigated

3. Construction Emissions Details

3.1. Demolition (2026) - Unmitigated

3.2. Demolition (2026) - Mitigated

3.3. Site Preparation (2026) - Unmitigated
1 /70

3.4. Site Preparation (2026) - Mitigated

3.5. Grading (2026) - Unmitigated

3.6. Grading (2026) - Mitigated

3.7. Building Construction (2026) - Unmitigated

3.8. Building Construction (2026) - Mitigated

3.9. Paving (2026) - Unmitigated

3.10. Paving (2026) - Mitigated

3.11. Architectural Coating (2026) - Unmitigated

3.12. Architectural Coating (2026) - Mitigated

4. Operations Emissions Details

4.1. Mobile Emissions by Land Use

4.1.1. Unmitigated

4.1.2. Mitigated

4.2. Energy

4.2.1. Electricity Emissions By Land Use - Unmitigated

4.2.2. Electricity Emissions By Land Use - Mitigated

4.2.3. Natural Gas Emissions By Land Use - Unmitigated

4.2.4. Natural Gas Emissions By Land Use - Mitigated
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 2/70

4.3. Area Emissions by Source

4.3.1. Unmitigated

4.3.2. Mitigated

4.4. Water Emissions by Land Use

4.4.1. Unmitigated

4.4.2. Mitigated

4.5. Waste Emissions by Land Use

4.5.1. Unmitigated

4.5.2. Mitigated

4.6. Refrigerant Emissions by Land Use

4.6.1. Unmitigated

4.6.2. Mitigated

4.7. Offroad Emissions By Equipment Type

4.7.1. Unmitigated

4.7.2. Mitigated

4.8. Stationary Emissions By Equipment Type

4.8.1. Unmitigated

4.8.2. Mitigated
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 3170

4.9. User Defined Emissions By Equipment Type

4.9.1. Unmitigated

4.9.2. Mitigated

4.10. Soil Carbon Accumulation By Vegetation Type
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

4.10.1. Soil Carbon Accumulation By Vegetation Type - Unmitigated

4.10.2. Above and Belowground Carbon Accumulation by Land Use Type - Unmitigated

4.10.3. Avoided and Sequestered Emissions by Species - Unmitigated

4.10.4. Soil Carbon Accumulation By Vegetation Type - Mitigated

4.10.5. Above and Belowground Carbon Accumulation by Land Use Type - Mitigated

4.10.6. Avoided and Sequestered Emissions by Species - Mitigated

5. Activity Data

5.1. Construction Schedule

5.2. Off-Road Equipment

5.2.1. Unmitigated

5.2.2. Mitigated

5.3. Construction Vehicles

5.3.1. Unmitigated

5.3.2. Mitigated
4170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

5.4. Vehicles

5.4.1. Construction Vehicle Control Strategies

5.5. Architectural Coatings

5.6. Dust Mitigation

5.6.1. Construction Earthmoving Activities

5.6.2. Construction Earthmoving Control Strategies

5. 7. Construction Paving

5.8. Construction Electricity Consumption and Emissions Factors

5.9. Operational Mobile Sources

5.9.1. Unmitigated

5.9.2. Mitigated

5.10. Operational Area Sources

5.10.1. Hearths

5.10.1.1. Unmitigated

5.10.1.2. Mitigated

5.10.2. Architectural Coatings

5.10.3. Landscape Equipment

5.10.4. Landscape Equipment - Mitigated
5170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

5.11. Operational Energy Consumption

5.11.1. Unmitigated

5.11.2. Mitigated

5.12. Operational Water and Wastewater Consumption

5.12.1. Unmitigated

5.12.2. Mitigated

5.13. Operational Waste Generation

5.13.1. Unmitigated

5.13.2. Mitigated

5.14. Operational Refrigeration and Air Conditioning Equipment

5.14.1. Unmitigated

5.14.2. Mitigated

5.15. Operational Off-Road Equipment

5.15.1. Unmitigated

5.15.2. Mitigated

5.16. Stationary Sources

5.16.1. Emergency Generators and Fire Pumps

5.16.2. Process Boilers
6170

5.17. User Defined

5.18. Vegetation

5.18.1. Land Use Change

5.18.1.1. Unmitigated

5.18.1.2. Mitigated

5.18.1. Biomass Cover Type

5.18.1.1. Unmitigated

5.18.1.2. Mitigated

5.18.2. Sequestration

5.18.2.1. Unmitigated

5.18.2.2. Mitigated

8. User Changes to Default Data
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 7170
1 . Basic Project Information

1.1. Basic Project Information
Data Field
Project Name
Construction Start Date
Operational Year
Lead Agency
Land Use Scale
Analysis Level for Defaults
Windspeed (m/s)
Precipitation (days)
Location
County
City
Air District
Air Basin
TAZ
EDFZ
Electric Utility
Gas Utility
App Version

1.2. Land Use Types
Land Use Subtype Size
City Park 0.86
Unit
Acre
Lot Acreage

0.86 South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Value
South San Francisco Linden and Pine Aves Project v2
3/1/2026
2027
ProjecUsite
County

4.60 37.8
616 Linden Ave, South San Francisco, CA 94080, USA
San Mateo
South San Francisco
Bay Area AQMD
San Francisco Bay Area
1212
1 Pacific Gas & Electric Company
Pacific Gas & Electric
2022.1.1.30
Building Area (sq ft) Landscape Area (sq
ft)
Special Landscape
Area (sq ft)
Population

0.00 0.40 0.00
8/70
Description
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Parking Lot 17.0 Space 0.15 0.00 0.00

1.3. User-Selected Emission Reduction Measures by Emissions Sector Sector
Construction
Construction
Construction
Construction

2. Emissions Summary
C-10-A
C-10-B
C-10-C
C-11

2.1. Construction Emissions Compared Against Thresholds Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)

0.00 Measure Title
Water Exposed Surfaces
Water Active Demolition Sites
Water Unpaved Construction Roads
Limit Vehicle Speeds on Unpaved Roads
i'M1M -alBIBl--•HIM iHIM·li4HMiiHtiiiHti·li4Uiili=M•tWHi=M•tiA •M-IBI- Daily, Summer
(Max)
Unmit. 5.92 4.59 43.4 48.0 0.09 1.69 22.7 24.4 1.56 7.62 9.18 11,708 11,708 0.80 0.58 8.15 Mit. 5.92 4.59 43.4 48.0 0.09 1.69 8.88 10.6 1.56 3.12 4.67 11 ,708 11 ,708 0.80 0.58 8.15 % 61% 57% 59% 49%
Reduced
Daily,
Winter
(Max)
Unmit. 5.91 4.59 43.7 47.8 0.09 1.69 22.7 24.4 1.56 7.62 9.18 11,672 11,672 0.80 0.60 0.21 Mit. 5.91 4.59 43.7 47.8 0.09 1.69 8.88 10.6 1.56 3.12 4.67 11 ,672 11 ,672 0.80 0.60 0.21 % 61% 57% 59% 49%
Reduced
9170
11 ,908
11 ,908
11 ,870
11 ,870
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Average
Daily
(Max)
Unmit. 1.43 1.07 9.22 11 .0 0.03 0.28 5.12 5.40 0.26 0.79 1.05 3,292 3,292 0.24 0.20 1.42 3,360 Mit. 1.43 1.07 9.22 11 .0 0.03 0.28 1.86 2.14 0.26 0.36 0.61 3,292 3,292 0.24 0.20 1.42 3,360 % 64% 60% 55% 42%
Reduced
Annual
(Max)
Unmit. 0.26 0.19 1.68 2.00 < 0.005 0.05 0.93 0.99 0.05 0.15 0.19 545 545 0.04 0.03 0.24 556 Mit. 0.26 0.19 1.68 2.00 < 0.005 0.05 0.34 0.39 0.05 0.06 0.11 545 545 0.04 0.03 0.24 556 % 64% 60% 55% 42%
Reduced

2.2. Construction Emissions by Year, Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) lllllmllmlll---•Hii·iiiHii·i·iiHIMliHti1iiHti•iiHtiiii=M•tWHi=M•titi iM-IIII- DailySummer (Max)
2026 5.92 4.59 43.4 48.0 0.09 1.69 22.7 24.4 1.56 7.62 9.18 11,708 11,708 0.80 0.58 8.15 11,908 DailyWinter
(Max)
2026 5.91 4.59 43.7 47.8 0.09 1.69 22.7 24.4 1.56 7.62 9.18 11,672 11,672 0.80 0.60 0.21 11,870 Average
Daily
2026 1.43 1.07 9.22 11 .0 0.03 0.28 5.12 5.40 0.26 0.79 1.05 3,292 3,292 0.24 0.20 1.42 3,360 Annual
2026 0.26 0.19 1.68 2.00 < 0.005 0.05 0.93 0.99 0.05 0.15 0.19 545 545 0.04 0.03 0.24 556 10 /70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

2.3. Construction Emissions by Year, Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ------•Hii·iiiHIM·ii4HMliHti1iiHti•iiHtiiii=M•t Hi=M•tiA·HM-IDII- DailySummer (Max)
2026 5.92 4.59 43.4 48.0 0.09 1.69 8.88 10.6 1.56 3.12 4.67 11,708 11,708 0.80 0.58 8.15 11 ,908 DailyWinter
(Max)
2026 5.91 4.59 43.7 47.8 0.09 1.69 8.88 10.6 1.56 3.12 4.67 11,672 11,672 0.80 0.60 0.21 11 ,870 Average
Daily
2026 1.43 1.07 9.22 11 .0 0.03 0.28 1.86 2.14 0.26 0.36 0.61 3,292 3,292 0.24 0.20 1.42 3,360 Annual
2026 0.26 0.19 1.68 2.00 < 0.005 0.05 0.34 0.39 0.05 0.06 0.11 545 545 0.04 0.03 0.24 556

2.4. Operations Emissions Compared Against Thresholds
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) i'M1MMfaralllll--•Hii·iiiHIM·liHIMli#Ui1iiHti·li#Uiili=M•t Hi=M•tii HM-IDII- Daily, Summer
(Max)
Unmit. 1.42 1.30 0.87 11 .2 0.03 0.01 3.14 3.15 0.01 0.79 0.81 0.04 3,295 3,295 0.12 0.11 8.87 3,339 Daily,
Winter
(Max)
Unmit. 1.40 1.28 1.03 11 .0 0.03 0.01 3.14 3.15 0.01 0.79 0.81 0.04 3,150 3,150 0.13 0.12 0.23 3,189 Average
Daily
(Max)
11 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Unmit. 0.60 0.55 0.41 4.56 0.01 < 0.005 1.31 1.32 0.01 0.33 0.34 0.04 1,350 1,350 0.06 0.05 1.65 1,368 Annual
(Max)
Unmit. 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 0.01 224 224 0.01 0.01 0.27 226

2.5. Operations Emissions by Sector, Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) Hhi·i+-ara11Z11--•HIMiiHH111iiHIMiiHtiiiiHti•iiHtiiii=M-t Hi=M-tiA iM_IBI_ Daily, Summer
(Max)
Mobile 1.40 1.29 0.88 11 .2 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,304 3,304 0.11 0.11 8.87 3,348 Area 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.26 3.26 < 0.005 < 0.005 3.30 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.04 0.00 0.04 < 0.005 0.00 0.14
Vegetati > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 on
Total 1.42 1.30 0.87 11 .2 0.03 0.01 3.14 3.15 0.01 0.79 0.81 0.04 3,295 3,295 0.12 0.11 8.87 3,339 Daily,
Winter
(Max)
Mobile 1.39 1.27 1.03 11 .0 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,160 3,160 0.13 0.12 0.23 3,198 Area 0.01 0.01
Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.26 3.26 < 0.005 < 0.005 3.30 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.04 0.00 0.04 < 0.005 0.00 0.14
Vegetati > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 on
Total 1.40 1.28 1.03 11 .0 0.03 0.01 3.14 3.15 0.01 0.79 0.81 0.04 3,150 3,150 0.13 0.12 0.23 3,189 12 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Average
Daily
Mobile 0.59 0.54 0.42 4.56 0.01 0.01 1.32 1.32 0.01 0.33 0.34 1,360 1,360 0.05 0.05 1.65 1,377 Area 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.26 3.26 < 0.005 < 0.005 3.30 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.04 0.00 0.04 < 0.005 0.00 0.14
Vegetati > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 on
Total 0.60 0.55 0.41 4.56 0.01 < 0.005 1.31 1.32 0.01 0.33 0.34 0.04 1,350 1,350 0.06 0.05 1.65 1,368 Annual
Mobile 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 225 225 0.01 0.01 0.27 228 Area < 0.005 < 0.005 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.54 0.54 < 0.005 < 0.005 0.55 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.01 0.00 0.01 < 0.005 0.00 0.02
Vegetati > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -2.10 -2.10 -2.10 on
Total 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 0.01 224 224 0.01 0.01 0.27 226

2.6. Operations Emissions by Sector, Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) MMl·i -a----•HIMli#MM·iiHIMli#UiiiiHti·iiHtiiii=M•t Hi=M•tii HM-IBI- Daily, Summer
(Max)
Mobile 1.40 1.29 0.88 11 .2 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,304 3,304 0.11 0.11 8.87 3,348 Area 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.26 3.26 < 0.005 < 0.005 3.30 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
13 /70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Waste 0.04 0.00 0.04 < 0.005 0.00 0.14
Vegetati > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 on
Total 1.42 1.30 0.87 11 .2 0.03 0.01 3.14 3.15 0.01 0.79 0.81 0.04 3,295 3,295 0.12 0.11 8.87 3,339 Daily,
Winter
(Max)
Mobile 1.39 1.27 1.03 11 .0 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,160 3,160 0.13 0.12 0.23 3,198 Area 0.01 0.01
Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.26 3.26 < 0.005 < 0.005 3.30 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.04 0.00 0.04 < 0.005 0.00 0.14
Vegetati > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 on
Total 1.40 1.28 1.03 11 .0 0.03 0.01 3.14 3.15 0.01 0.79 0.81 0.04 3,150 3,150 0.13 0.12 0.23 3,189 Average
Daily
Mobile 0.59 0.54 0.42 4.56 0.01 0.01 1.32 1.32 0.01 0.33 0.34 1,360 1,360 0.05 0.05 1.65 1,377 Area 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.26 3.26 < 0.005 < 0.005 3.30 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.04 0.00 0.04 < 0.005 0.00 0.14
Vegetati > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 on
Total 0.60 0.55 0.41 4.56 0.01 < 0.005 1.31 1.32 0.01 0.33 0.34 0.04 1,350 1,350 0.06 0.05 1.65 1,368 Annual
Mobile 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 225 225 0.01 0.01 0.27 228 Area < 0.005 < 0.005 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Energy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.54 0.54 < 0.005 < 0.005 0.55 Water 0.00 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005
Waste 0.01 0.00 0.01 < 0.005 0.00 0.02
14 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Vegetati > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -2.10 -2.10 -2.10 Total 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 0.01 224 224 0.01 0.01 0.27 226

3. Construction Emissions Details

3.1. Demolition (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) .;.;;;a-ara---•HIMiiHH111iiiil111 HtiiiiHti•iiHtiiii=M-t =M-tiA iM ___ Onsite Daily,
Summer
(Max)
Off-Roa 1.66 1.39 12.9 14.6 0.02 0.51 0.51 0.47 0.47 2,494 2,494 0.10 0.02 2,503 d
Equipm
ent
Demoliti 0.60 0.60 0.09 0.09
on
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 7.36 7.36 < 0.005 0.73 0.73 27.0 27.0 0.01 < 0.005 0.04 28.5 truck
Daily,
Winter
(Max)
Off-Roa 1.66 1.39 12.9 14.6 0.02 0.51 0.51 0.47 0.47 2,494 2,494 0.10 0.02 2,503 d
Equipm
ent
Demoliti 0.60 0.60 0.09 0.09
on
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 7.36 7.36 < 0.005 0.73 0.73 27.0 27.0 0.01 < 0.005 < 0.005 28.4 truck
Average
Daily
15 /70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Off-Roa 0.10 0.09 0.82 0.92 < 0.005 0.03 0.03 0.03 0.03 157 157 0.01 < 0.005 - 158 d
Demoliti 0.04 0.04 0.01 0.01
on
Onsite < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 0.42 0.42 < 0.005 0.04 0.04 1.70 1.70 < 0.005 < 0.005 < 0.005 1.79 truck
Annual
Off-Roa 0.02 0.02 0.15 0.17 < 0.005 0.01 0.01 0.01 0.01 26.0 26.0 < 0.005 < 0.005 26.1 d
Equipm
ent
Demoliti 0.01 0.01 < 0.005 < 0.005
on
Onsite < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.08 0.08 < 0.005 0.01 0.01 0.28 0.28 < 0.005 < 0.005 < 0.005 0.30 truck
Offsite
Daily,
Summer
(Max)
Worker 0.21 0.18 0.14 2.31 0.00 0.00 0.66 0.66 0.00 0.16 0.16 645 645 0.01 0.01 1.92 649 Vendor 0.02 < 0.005 0.15 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.27 118 Hauling 0.53 0.07 4.60 3.25 0.02 0.04 0.74 0.78 0.04 0.20 0.24 3,075 3,075 0.46 0.49 5.93 3,237 Daily,
Winter
(Max)
Worker 0.21 0.18 0.17 2.13 0.00 0.00 0.66 0.66 0.00 0.16 0.16 610 610 0.01 0.03 0.05 618 Vendor 0.02 < 0.005 0.16 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.01 118 Hauling 0.53 0.07 4.84 3.25 0.02 0.04 0.74 0.78 0.04 0.20 0.24 3,075 3,075 0.46 0.49 0.15 3,231 Average
Daily
Worker 0.01 0.01 0.01 0.13 0.00 0.00 0.04 0.04 0.00 0.01 0.01 38.6 38.6 < 0.005 < 0.005 0.05 39.1 Vendor < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 7.12 7.12 < 0.005 < 0.005 0.01 7.45 Hauling 0.03 < 0.005 0.30 0.20 < 0.005 < 0.005 0.05 0.05 < 0.005 0.01 0.01 194 194 0.03 0.03 0.16 204 16 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Annual
Worker < 0.005 < 0.005 < 0.005 0.02 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 6.38 6.38 < 0.005 < 0.005 0.01 6.48 Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 1.18 1.18 < 0.005 < 0.005 < 0.005 1.23 Hauling 0.01 < 0.005 0.05 0.04 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 32.1 32.1 < 0.005 0.01 0.03 33.7

3.2. Demolition (2026) - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ii·l&!M-a1B1B1--•Hl111 Hl111 •ii4HMliHtiiiHti·li4Uiili=M•tWHi=M•tiA •M-IBI- Onsite Daily,
Summer
(Max)
Off-Roa 1.66 1.39 12.9 14.6 0.02 0.51 0.51 0.47 0.47 2,494 2,494 0.10 0.02 2,503 d
Equipm
ent
Demoliti 0.39 0.39 0.06 0.06
on
Onsite 0.01 < 0.005 0.10 O.o? < 0.005 < 0.005 1.86 1.86 < 0.005 0.19 0.19 27.0 27.0 0.01 < 0.005 0.04 28.5 truck
Daily,
Winter
(Max)
Off-Roa 1.66 1.39 12.9 14.6 0.02 0.51 0.51 0.47 0.47 2,494 2,494 0.10 0.02 2,503 d
Equipm
ent
Demoliti 0.39 0.39 0.06 0.06
on
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 1.86 1.86 < 0.005 0.19 0.19 27.0 27.0 0.01 < 0.005 < 0.005 28.4 truck
Average
Daily
17 /70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Off-Roa 0.10 0.09 0.82 0.92 < 0.005 0.03 0.03 0.03 0.03 157 157 0.01 < 0.005 - 158 d
Demoliti 0.02 0.02 < 0.005 < 0.005
on
Onsite < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 0.10 0.10 < 0.005 0.01 0.01 1.70 1.70 < 0.005 < 0.005 < 0.005 1.79 truck
Annual
Off-Roa 0.02 0.02 0.15 0.17 < 0.005 0.01 0.01 0.01 0.01 26.0 26.0 < 0.005 < 0.005 26.1 d
Equipm
ent
Demoliti < 0.005 < 0.005 < 0.005 < 0.005
on
Onsite < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 < 0.005 0.28 0.28 < 0.005 < 0.005 < 0.005 0.30 truck
Offsite
Daily,
Summer
(Max)
Worker 0.21 0.18 0.14 2.31 0.00 0.00 0.66 0.66 0.00 0.16 0.16 645 645 0.01 0.01 1.92 649 Vendor 0.02 < 0.005 0.15 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.27 118 Hauling 0.53 0.07 4.60 3.25 0.02 0.04 0.74 0.78 0.04 0.20 0.24 3,075 3,075 0.46 0.49 5.93 3,237 Daily,
Winter
(Max)
Worker 0.21 0.18 0.17 2.13 0.00 0.00 0.66 0.66 0.00 0.16 0.16 610 610 0.01 0.03 0.05 618 Vendor 0.02 < 0.005 0.16 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.01 118 Hauling 0.53 0.07 4.84 3.25 0.02 0.04 0.74 0.78 0.04 0.20 0.24 3,075 3,075 0.46 0.49 0.15 3,231 Average
Daily
Worker 0.01 0.01 0.01 0.13 0.00 0.00 0.04 0.04 0.00 0.01 0.01 38.6 38.6 < 0.005 < 0.005 0.05 39.1 Vendor < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 7.12 7.12 < 0.005 < 0.005 0.01 7.45 Hauling 0.03 < 0.005 0.30 0.20 < 0.005 < 0.005 0.05 0.05 < 0.005 0.01 0.01 194 194 0.03 0.03 0.16 204 18 /70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Annual
Worker < 0.005 < 0.005 < 0.005 0.02 0.00 0.00 0.01 0.01 0.00 < 0.005 < 0.005 6.38 6.38 < 0.005 < 0.005 0.01 6.48 Vendor < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 1.18 1.18 < 0.005 < 0.005 < 0.005 1.23 Hauling 0.01 < 0.005 0.05 0.04 < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 32.1 32.1 < 0.005 0.01 0.03 33.7

3.3. Site Preparation (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ii·l&!M-a1B1B1--•Hl111 Hl111 •ii4HMliHtiiiHti·li4Uiili=M•tWHi=M•tiA •M-IBI- Onsite Daily,
Summer
(Max)
Off-Roa 1.47 1.24 11 .0 11 .7 0.02 0.51 0.51 0.47 0.47 2,065 2,065 0.08 0.02 2,072 d
Equipm
ent
Dust 6.27 6.27 3.00 3.00
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Daily,
Winter
(Max)
Off-Roa 1.47 1.24 11.0 11 .7 0.02 0.51 0.51 0.47 0.47 2,065 2,065 0.08 0.02 2,072 d
Equipm
ent
Dust 6.27 6.27 3.00 3.00
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
19 /70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Average
Daily
Off-Roa 0.01 0.01 0.06 0.06 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 11 .3 11 .3 < 0.005 < 0.005 11.4 d
Equipm
ent
Dust 0.03 0.03 0.02 0.02
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 1.87 1.87 < 0.005 < 0.005 1.88 d
Equipm
ent
Dust 0.01 0.01 < 0.005 < 0.005 - From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 20170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3.4. Site Preparation (2026) - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ii·l&! -a-lBl--•HIM iHli·i·iiHIMliHtiiiiHti•iiHtiiii=M•t Hi=M•tiA·HM-IBI- Onsite Daily,
Summer
(Max)
Off-Roa 1.47 1.24 11 .0 11 .7 0.02 0.51 0.51 0.47 0.47 2,065 2,065 0.08 0.02 2,072 d
Equipm
ent
Dust 2.44 2.44 1.17 1.17
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Daily,
Winter
(Max)
21 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Off-Roa 1.47 1.24 11 .0 11 .7 0.02 0.51 0.51 0.47 0.47 2,065 2,065 0.08 0.02 2,072 d
Equipm
Dust 2.44 2.44 1.17 1.17
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Average
Daily
Off-Roa 0.01 0.01 0.06 0.06 < 0.005 < 0.005 - < 0.005 < 0.005 - < 0.005 - 11 .3 11.3 < 0.005 < 0.005 - 11.4 d
Equipm
ent
Dust 0.01 0.01 0.01 0.01
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 1.87 1.87 < 0.005 < 0.005 1.88 d
Equipm
ent
Dust < 0.005 < 0.005 - < 0.005 < 0.005 - From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 22170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3.5. Grading (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ... ;;;a-ammm11--•HIMl Hli111iiiil111 HtiiiiHti•iiHtiiii=M-t =M-tiA·HM ___ Onsite Daily,
Summer
(Max)
Off-Roa 2.03 1.70 14.4 15.9 0.03 0.64 0.64 0.58 0.58 3,288 3,288 0.13 0.03 3,300 d
Equipm
ent
23170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Dust 7.09 7.09 3.43 3.43
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Daily,
Winter
(Max)
Off-Roa 2.03 1.70 14.4 15.9 0.03 0.64 0.64 0.58 0.58 3,288 3,288 0.13 0.03 3,300 d
Equipm
ent
Dust 7.09 7.09 3.43 3.43
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Average
Daily
Off-Roa 0.13 0.11 0.91 1.00 < 0.005 0.04 0.04 0.04 0.04 207 207 0.01 < 0.005 - 208 d
Equipm
ent
Dust 0.45 0.45 0.22 0.22
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa 0.02 0.02 0.17 0.18 < 0.005 0.01 0.01 0.01 0.01 34.3 34.3 < 0.005 < 0.005 34.4 d
Equipm
ent
24170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Dust 0.08 0.08 0.04 0.04
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3.6. Grading (2026) - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) 25170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 ii·iii& -----•Hl111 Hli+iiiH111 iiiMl-iiiHti•iiHtiiii=B-tWHi=M-tiA-t.iM_IBI_ Onsite Daily,
Summer
(Max)
Off-Roa 2.03 1.70 14.4 15.9 0.03 0.64 0.64 0.58 0.58 3,288 3,288 0.13 0.03 3,300 d
Equipm
ent
Dust 2.76 2.76 1.34 1.34
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Daily,
Winter
(Max)
Off-Roa 2.03 1.70 14.4 15.9 0.03 0.64 0.64 0.58 0.58 3,288 3,288 0.13 0.03 3,300 d
Equipm
ent
Dust 2.76 2.76 1.34 1.34
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Average
Daily
Off-Roa 0.13 0.11 0.91 1.00 < 0.005 0.04 0.04 0.04 0.04 207 207 0.01 < 0.005 - 208 d
Equipm
ent
Dust 0.17 0.17 0.08 0.08
From
Material
Movement
26170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa 0.02 0.02 0.17 0.18 < 0.005 0.01 0.01 0.01 0.01 34.3 34.3 < 0.005 < 0.005 34.4 d
Equipm
ent
Dust 0.03 0.03 0.02 0.02
From
Material
Movement
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 27170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3. 7. Building Construction (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) .;.;;;a-ara ___ iiiii·il Hli111iilil111 Htiii Hti•iiHtiil =M-t =M-tiA·HM--- Onsite Daily,
Summer
(Max)
Off-Roa 1.55 1.29 10.2 11 .8 0.03 0.35 0.35 0.32 0.32 2,634 2,634 0.11 0.02 2,643 d
Equipm
ent
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 7.36 7.36 < 0.005 0.73 0.73 27.0 27.0 0.01 < 0.005 0.04 28.5 truck
Daily,
Winter
(Max)
Off-Roa 1.55 1.29 10.2 11 .8 0.03 0.35 0.35 0.32 0.32 2,634 2,634 0.11 0.02 2,643 d
Equipm
ent
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 7.36 7.36 < 0.005 0.73 0.73 27.0 27.0 0.01 < 0.005 < 0.005 28.4 truck
Average
Daily
Off-Roa 0.83 0.69 5.46 6.34 0.01 0.19 0.19 0.17 0.17 1,415 1,415 0.06 0.01 1,419 d
Equipm
ent
Onsite 0.01 < 0.005 0.05 0.04 < 0.005 < 0.005 3.54 3.54 < 0.005 0.35 0.35 14.5 14.5 < 0.005 < 0.005 0.01 15.3 truck
Annual
28170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Off-Roa 0.15 0.13 1.00 1.16 < 0.005 0.03 0.03 0.03 0.03 234 234 0.01 < 0.005 235 Equipment
Onsite < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 0.65 0.65 < 0.005 0.06 0.06 2.40 2.40 < 0.005 < 0.005 < 0.005 2.53 truck
Offsite
Daily,
Summer
(Max)
Worker 0.21 0.18 0.14 2.31 0.00 0.00 0.66 0.66 0.00 0.16 0.16 645 645 0.01 0.01 1.92 649 Vendor 0.02 < 0.005 0.15 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.27 118 Hauling 0.27 0.04 2.30 1.63 0.01 0.02 0.37 0.39 0.02 0.10 0.12 1,537 1,537 0.23 0.24 2.96 1,619 Daily,
Winter
(Max)
Worker 0.21 0.18 0.17 2.13 0.00 0.00 0.66 0.66 0.00 0.16 0.16 610 610 0.01 0.03 0.05 618 Vendor 0.02 < 0.005 0.16 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.01 118 Hauling 0.26 0.04 2.42 1.63 0.01 0.02 0.37 0.39 0.02 0.10 0.12 1,537 1,537 0.23 0.24 0.08 1,616 Average
Daily
Worker 0.11 0.10 0.09 1.11 0.00 0.00 0.35 0.35 0.00 0.08 0.08 329 329 0.01 0.01 0.45 333 Vendor 0.01 < 0.005 0.09 0.05 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 < 0.005 60.7 60.7 0.01 0.01 0.06 63.5 Hauling 0.14 0.02 1.28 0.87 < 0.005 0.01 0.20 0.20 0.01 0.05 0.06 826 826 0.12 0.13 0.68 868 Annual
Worker 0.02 0.02 0.02 0.20 0.00 0.00 0.06 0.06 0.00 0.01 0.01 54.4 54.4 < 0.005 < 0.005 0.07 55.2 Vendor < 0.005 < 0.005 0.02 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 10.0 10.0 < 0.005 < 0.005 0.01 10.5 Hauling 0.03 < 0.005 0.23 0.16 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 137 137 0.02 0.02 0.11 144

3.8. Building Construction (2026) - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) il·i&MM-malllll---•Hii·iiiHIM·ii4H111i 1Hti1ii4Mi·iiHtiili=M•tMHi=M•titi-HM-IIIIOnsite 29170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Summer
(Max)
Off-Roa 1.55 1.29 10.2 11 .8 0.03 0.35 0.35 0.32 0.32 2,634 2,634 0.11 0.02 2,643 d
Equipm
ent
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 1.86 1.86 < 0.005 0.19 0.19 27.0 27.0 0.01 < 0.005 0.04 28.5 truck
Daily,
Winter
(Max)
Off-Roa 1.55 1.29 10.2 11 .8 0.03 0.35 0.35 0.32 0.32 2,634 2,634 0.11 0.02 2,643 d
Equipm
ent
Onsite 0.01 < 0.005 0.10 0.07 < 0.005 < 0.005 1.86 1.86 < 0.005 0.19 0.19 27.0 27.0 0.01 < 0.005 < 0.005 28.4 truck
Average
Daily
Off-Roa 0.83 0.69 5.46 6.34 0.01 0.19 0.19 0.17 0.17 1,415 1,415 0.06 0.01 1,419 d
Equipm
ent
Onsite 0.01 < 0.005 0.05 0.04 < 0.005 < 0.005 0.89 0.89 < 0.005 0.09 0.09 14.5 14.5 < 0.005 < 0.005 0.01 15.3 truck
Annual
Off-Roa 0.15 0.13 1.00 1.16 < 0.005 0.03 0.03 0.03 0.03 234 234 0.01 < 0.005 235 d
Equipm
ent
Onsite < 0.005 < 0.005 0.01 0.01 < 0.005 < 0.005 0.16 0.16 < 0.005 0.02 0.02 2.40 2.40 < 0.005 < 0.005 < 0.005 2.53 truck
Offsite
Daily,
Summer
(Max)
30170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Worker 0.21 0.18 0.14 2.31 0.00 0.00 0.66 0.66 0.00 0.16 0.16 645 645 0.01 0.01 1.92 649 Vendor 0.02 < 0.005 0.15 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.27 118 Hauling 0.27 0.04 2.30 1.63 0.01 0.02 0.37 0.39 0.02 0.10 0.12 1,537 1,537 0.23 0.24 2.96 1,619 Daily,
Winter
(Max)
Worker 0.21 0.18 0.17 2.13 0.00 0.00 0.66 0.66 0.00 0.16 0.16 610 610 0.01 0.03 0.05 618 Vendor 0.02 < 0.005 0.16 0.10 < 0.005 < 0.005 0.03 0.03 < 0.005 0.01 0.01 113 113 0.01 0.02 0.01 118 Hauling 0.26 0.04 2.42 1.63 0.01 0.02 0.37 0.39 0.02 0.10 0.12 1,537 1,537 0.23 0.24 0.08 1,616 Average
Daily
Worker 0.11 0.10 0.09 1.11 0.00 0.00 0.35 0.35 0.00 0.08 0.08 329 329 0.01 0.01 0.45 333 Vendor 0.01 < 0.005 0.09 0.05 < 0.005 < 0.005 0.02 0.02 < 0.005 < 0.005 < 0.005 60.7 60.7 0.01 0.01 0.06 63.5 Hauling 0.14 0.02 1.28 0.87 < 0.005 0.01 0.20 0.20 0.01 0.05 0.06 826 826 0.12 0.13 0.68 868 Annual
Worker 0.02 0.02 0.02 0.20 0.00 0.00 0.06 0.06 0.00 0.01 0.01 54.4 54.4 < 0.005 < 0.005 0.07 55.2 Vendor < 0.005 < 0.005 0.02 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 10.0 10.0 < 0.005 < 0.005 0.01 10.5 Hauling 0.03 < 0.005 0.23 0.16 < 0.005 < 0.005 0.04 0.04 < 0.005 0.01 0.01 137 137 0.02 0.02 0.11 144

3.9. Paving (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ii·l&!M-a1Blllll--•Hl111 HIM·liHIMiiHtiiiHti·lilUJili=M•t Hi=M•tiN iM-IBI- Onsite Daily,
Summer
(Max)
Daily,
Winter
(Max)
31 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Off-Roa 0.56 0.47 4.41 6.48 0.01 0.18 0.18 0.17 0.17 991 991 0.04 0.01 995 d
Equipm
Paving 0.04 0.04
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Average
Daily
Off-Roa 0.02 0.01 0.12 0.18 < 0.005 0.01 0.01 < 0.005 < 0.005 27.2 27.2 < 0.005 < 0.005 27.3 d
Equipm
ent
Paving < 0.005 < 0.005
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa < 0.005 < 0.005 0.02 0.03 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 4.50 4.50 < 0.005 < 0.005 4.51 d
Equipm
ent
Paving < 0.005 < 0.005
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
32170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3.10. Paving (2026) - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) .;.;;;a-mara11111--•Hii·il HIM·ii4HMliHti1ii4Mi·iiHtiiii=M•t Hi=M•tiA·HM--- Onsite Daily,
Summer
(Max)
Daily,
Winter
(Max)
Off-Roa 0.56 0.47 4.41 6.48 0.01 0.18 0.18 0.17 0.17 991 991 0.04 0.01 995 d
Equipm
ent
Paving 0.04 0.04
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Average
Daily
Off-Roa 0.02 0.01 0.12 0.18 < 0.005 0.01 0.01 < 0.005 < 0.005 27.2 27.2 < 0.005 < 0.005 27.3 d
Equipm
ent
Paving < 0.005 < 0.005 -
33 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa < 0.005 < 0.005 0.02 0.03 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 4.50 4.50 < 0.005 < 0.005 4.51 d
Equipm
ent
Paving < 0.005 < 0.005
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3.11. Architectural Coating (2026) - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) 34 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 ii·iii& -----•Hl111 Hli+iiiH111 iiiMl-iiiHti•iiHtiiii=B-tWHi=M-tiA-t.iM_IBI_ Onsite Daily,
Summer
(Max)
Daily,
Winter
(Max)
Off-Roa 0.15
d
Equipm
ent

0.12 Architect 0.71 0.71
ural
Coating
s
Onsite 0.00
truck
Average
Daily

0.00 0.86

0.00 Off-Roa < 0.005 < 0.005 0.02
d
Equipm
ent
Architect 0.02 0.02
ural
Coating
s
Onsite 0.00 0.00 0.00
truck
Annual

1.13 0.00

0.03 0.00
Off-Roa < 0.005 < 0.005 < 0.005 0.01
d
Equipm
ent
< 0.005 0.02

0.00 0.00 0.00
< 0.005 < 0.005 -

0.00 0.00 0.00
< 0.005 < 0.005

0.02 0.02 0.02 134 134 0.01 < 0.005 - 134

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
< 0.005 < 0.005 - < 0.005 - 3.66 3.66 < 0.005 < 0.005 - 3.67

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
< 0.005 < 0.005 < 0.005 0.61 0.61 < 0.005 < 0.005 0.61
35 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Architect < 0.005 < 0.005 - ural
Coating
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
Daily,
Summer
(Max)
Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3.12. Architectural Coating (2026) - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) il·i&i&-ara11Z11--•Hii·iiiHii·i·ii4H111 Hti1iiHti•iiHtiiii=M•t Hi=M•ti Onsite Daily,
---
Summer
(Max)
36 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Winter
(Max)
Off-Roa 0.15 0.12 0.86 1.13 < 0.005 0.02 0.02 0.02 0.02 134 134 0.01 < 0.005 - 134 d
Equipm
ent
Architect 0.71 0.71
ural
Coating
s
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Average
Daily
Off-Roa < 0.005 < 0.005 0.02 0.03 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 3.66 3.66 < 0.005 < 0.005 3.67 d
Equipm
ent
Architect 0.02 0.02
ural
Coating
s
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Annual
Off-Roa < 0.005 < 0.005 < 0.005 0.01 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.61 0.61 < 0.005 < 0.005 0.61 d
Equipm
ent
Architect < 0.005 < 0.005 - ural
Coating
s
Onsite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 truck
Offsite
37170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Summer
(Max)
Daily,
Winter
(Max)
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Average
Daily
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
Worker 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Vendor 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Hauling 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

4. Operations Emissions Details

4.1. Mobile Emissions by Land Use

4.1.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ••••
Summer
Daily, •••••••••••• •
(Max)
City 1.40 1.29 0.88 11 .2 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,304 3,304 0.11 0.11 8.87 3,348 Park
38170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 1.40 1.29 0.88 11 .2 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,304 3,304 0.11 0.11 8.87 3,348 Daily,
Winter
(Max)
City 1.39 1.27 1.03 11 .0 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,160 3,160 0.13 0.12 0.23 3,198 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 1.39 1.27 1.03 11 .0 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,160 3,160 0.13 0.12 0.23 3,198 Annual
City 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 225 225 0.01 0.01 0.27 228 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 225 225 0.01 0.01 0.27 228

4.1.2. Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ••••
Summer
Daily, •••••••••••• •
(Max)
City 1.40 1.29 0.88 11 .2 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,304 3,304 0.11 0.11 8.87 3,348 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 1.40 1.29 0.88 11 .2 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,304 3,304 0.11 0.11 8.87 3,348 Daily,
Winter
(Max)
39 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 City 1.39 1.27 1.03 11 .0 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,160 3,160 0.13 0.12 0.23 3,198 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 1.39 1.27 1.03 11 .0 0.03 0.02 3.14 3.16 0.02 0.80 0.81 3,160 3,160 0.13 0.12 0.23 3,198 Annual
City 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 225 225 0.01 0.01 0.27 228 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.11 0.10 0.08 0.83 < 0.005 < 0.005 0.24 0.24 < 0.005 0.06 0.06 225 225 0.01 0.01 0.27 228

4.2. Energy

4.2.1. Electricity Emissions By Land Use - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ••••
Summer
Daily, •••••••••••• •
(Max)
City 0.00 0.00 0.00 0.00 0.00
Park
Parking 3.26 3.26 < 0.005 < 0.005 3.30
Lot
Total 3.26 3.26 < 0.005 < 0.005 3.30
Daily,
Winter
(Max)
City 0.00 0.00 0.00 0.00 0.00
Park
Parking 3.26 3.26 < 0.005 < 0.005 3.30
Lot
40170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Total 3.26 3.26 < 0.005 < 0.005
Annual
City 0.00 0.00 0.00 0.00
Park
Parking 0.54 0.54 < 0.005 < 0.005
Lot
Total 0.54 0.54 < 0.005 < 0.005

4.2.2. Electricity Emissions By Land Use - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) •••••••••••••••• Daily,
Summer
(Max)
City
Park
Parking
Lot
Total
Daily,
Winter
(Max)
City
Park
Parking
Lot
Total
Annual
City
Park
Parking
Lot
41 /70

0.00 0.00 0.00 0.00

3.26 3.26 < 0.005 < 0.005

3.26 3.26 < 0.005 < 0.005

0.00 0.00 0.00 0.00

3.26 3.26 < 0.005 < 0.005

3.26 3.26 < 0.005 < 0.005

0.00 0.00 0.00 0.00

0.54 0.54 < 0.005 < 0.005

3.30 0.00

0.55 0.55
•

0.00 3.30

3.30 0.00

3.30 3.30

0.00 0.55
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Total 0.54 0.54 < 0.005 < 0.005 - 0.55

4.2.3. Natural Gas Emissions By Land Use - Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ••••
Summer
Daily, •••••••••••• •
(Max)
City 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
City 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
City 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

4.2.4. Natural Gas Emissions By Land Use - Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) 42170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 ••••
Summer
Daily, •••••••••••• •
(Max)
City 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
City 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Annual
City 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Lot
Total 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

4.3. Area Emissions by Source

4.3.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ;.;:;;;;-a----•HIM iHIM·li#HMiiHtiiiiHti·li#itiili=M•t Hi=M•tii HMalllllll- Daily, Summer
(Max)
43 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Consum 0.01 0.01
Products
Architect < 0.005 < 0.005
ural
Coating
s
Landsca 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 pe
Equipm
ent
Total 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Daily,
Winter
(Max)
Consum 0.01 0.01
er
Product
s
Architect < 0.005 < 0.005 -
ural
Coating
s
Total 0.01 0.01
Annual
Consum < 0.005 < 0.005
er
Product
s
Architect < 0.005 < 0.005 - ural
Coating
s
Landsca 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 pe
Equipm
ent
Total < 0.005 < 0.005 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 44170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

4.3.2. Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) G·Mii+.-11111---•Hii·iiiHii·i·iiWH111i 1Hti1ii4Mi·iiHtiili=M•tWHi=M•ti Daily,
Summer
(Max)
Consum 0.01 0.01
er
Product
s
Architect < 0.005 < 0.005 -
ural
Coating
s
Landsca 0.00 0.00 0.00
pe
Equipm
ent
Total 0.01 0.01 0.00
Daily,
Winter
(Max)
Consum 0.01 0.01
er
Product
s
Architect < 0.005 < 0.005 -
ural
Coating
s
Total 0.01 0.01
Annual
Consum < 0.005 < 0.005
er
Product
s

0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00
45170

0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Architect < 0.005 < 0.005
Coatings
Landsca 0.00 0.00 0.00 0.00 0.00
pe
Equipm
ent
Total < 0.005 < 0.005 0.00 0.00 0.00

4.4. Water Emissions by Land Use

4.4.1. Unmitigated

0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)

0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00
••••
Summer
Daily, ••••••••••••
(Max)
City
Park
Parking
Lot
Total
Daily,
Winter
(Max)
City
Park
Parking
Lot
Total
Annual
City
Park
46 / 70

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 0.00 0.00 0.00 0.00

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 0.00 0.00 0.00 0.00

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 0.00
•
< 0.005

0.00 < 0.005
< 0.005

0.00 < 0.005
< 0.005
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Parking
Lot
Total

4.4.2. Mitigated

0.00 0.00
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)

0.00 0.00 0.00 0.00
< 0.005 < 0.005 < 0.005 < 0.005
•••••••••••••••• Daily,
Summer
(Max)
City
Park
Parking
Lot
Total
Daily,
Winter
(Max)
City
Park
Parking
Lot
Total
Annual
City
Park
Parking
Lot
Total

4.5. Waste Emissions by Land Use
47170

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 0.00 0.00 0.00 0.00

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 0.00 0.00 0.00 0.00

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 0.00 0.00 0.00 0.00

0.00 < 0.005 < 0.005 < 0.005 < 0.005

0.00 < 0.005
•
< 0.005

0.00 < 0.005
< 0.005

0.00 < 0.005
< 0.005

0.00 < 0.005
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

4.5.1 . Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ••••
Summer
Daily, •••••••••••• •
(Max)
City 0.04 0.00 0.04 < 0.005 0.00 0.14
Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00
Lot
Total 0.04 0.00 0.04 < 0.005 0.00 0.14
Daily,
Winter
(Max)
City 0.04 0.00 0.04 < 0.005 0.00 0.14
Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00
Lot
Total 0.04 0.00 0.04 < 0.005 0.00 0.14
Annual
City 0.01 0.00 0.01 < 0.005 0.00 0.02
Park
Parking 0.00 0.00 0.00 0.00 0.00 0.00
Lot
Total 0.01 0.00 0.01 < 0.005 0.00 0.02

4.5.2. Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) •••••••••••••••• •
48170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Summer
(Max)
City
Park
Parking
Lot
Total
Daily,
Winter
(Max)
City
Park
Parking
Lot
Total
Annual
City
Park
Parking
Lot
Total

4.6. Refrigerant Emissions by Land Use

4.6.1. Unmitigated

0.04 0.00

0.04 0.04

0.00 0.04

0.01 0.00

0.01 Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual)

0.00 0.04 < 0.005 0.00

0.00 0.00 0.00 0.00

0.00 0.04 < 0.005 0.00

0.00 0.04 < 0.005 0.00

0.00 0.00 0.00 0.00

0.00 0.04 < 0.005 0.00

0.00 0.01 < 0.005 0.00

0.00 0.00 0.00 0.00

0.00 0.01 < 0.005 0.00
•••••••••••••••• Daily,
Summer
(Max)
Total
49170

0.14 0.00

0.14 0.14

0.00 0.14

0.02 0.00

0.02 •
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Winter
(Max)
Total
Annual
Total

4.6.2. Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) •••••••••••••••• Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.7. Offroad Emissions By Equipment Type

4.7.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ■ .

Daily,
Summer
(Max)
50170
•
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.7.2. Mitigated
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ■ .

Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.8. Stationary Emissions By Equipment Type

4.8.1 . Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ■ .
51 / 70
Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.8.2. Mitigated
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ■ .

Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.9. User Defined Emissions By Equipment Type

4.9.1. Unmitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) 52170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 ••••
Summer
Daily, ••••••••••••
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.9.2. Mitigated
Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ■ .

Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.10. Soil Carbon Accumulation By Vegetation Type

4.10.1. Soil Carbon Accumulation By Vegetation Type - Unmitigated 53 / 70
•
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) •••••••••••••••• Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.10.2. Above and Belowground Carbon Accumulation by Land Use Type - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) •••••••••••••••• Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.10.3. Avoided and Sequestered Emissions by Species - Unmitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) G·liiii ------•HIMiiHIM·INll111 Hti1iiHti•iiHtiiilll!!Mll!l1111!1•bll!ll 11"ii~:fll!llill!ll•b111111111!11 1111!11•b~,11-•--- 54 / 70 •
•
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Summer
(Max)
Avoided
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -4.10 -4.10 -4.10 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -4.10 -4.10 -4.10 Sequest
ered
coastal -8.60 -8.60 -8.60
live oak
Subtotal -8.60 -8.60 -8.60
Remove
d
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 Total > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 Daily,
Winter
(Max)
Avoided
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -4.10 -4.10 -4.10 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -4.10 -4.10 -4.10 Sequest
ered
coastal -8.60 -8.60 -8.60
live oak
Subtotal -8.60 -8.60 -8.60
Remove
d
55 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 Total > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 Annual
Avoided
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -0.68 -0.68 -0.68 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -0.68 -0.68 -0.68 Sequest
ered
coastal -1.42 -1.42 -1.42
live oak
Subtotal -1.42 -1.42 -1.42
Remove
d
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 Total > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -2.10 -2.10 -2.10

4.10.4. Soil Carbon Accumulation By Vegetation Type - Mitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) ••••
Summer
Daily, •••••••••••• •
(Max)
Total
56170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Daily,
Winter
(Max)
Total
Annual
Total

4.10.5. Above and Belowground Carbon Accumulation by Land Use Type - Mitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) •••••••••••••••• Daily,
Summer
(Max)
Total
Daily,
Winter
(Max)
Total
Annual
Total

4.10.6. Avoided and Sequestered Emissions by Species - Mitigated Criteria Pollutants (lb/day for daily, ton/yr for annual) and GHGs (lb/day for daily, MT/yr for annual) G·liiiii-amllllllll-lllliHIMiiHH·l·INH111 MiHti11i4Mi·liHtiili=M•t Hi=M•tiA iM-IIII- Daily.

Summer
(Max)
Avoided
coastal
live oak
Subtotal
> -0.005 > -0.005
> -0.005 > -0.005
> -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 57170
-4.10
-4.10
-4.10
-4.10
•
-4.10
-4.10
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Sequest
coastal -8.60 -8.60 -8.60
live oak
Subtotal -8.60 -8.60 -8.60
Remove
d
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 Total > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 Daily,
Winter
(Max)
Avoided
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -4.10 -4.10 -4.10 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -4.10 -4.10 -4.10 Sequest
ered
coastal -8.60 -8.60 -8.60
live oak
Subtotal -8.60 -8.60 -8.60
Remove
d
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 Total > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -0.01 > -0.005 > -0.005 > -0.005 -12.7 -12.7 -12.7 Annual
Avoided
58 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -0.68 -0.68 -0.68 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -0.68 -0.68 -0.68 Sequest
ered
coastal -1.42 -1.42 -1 .42
live oak
Subtotal -1.42 -1 .42 -1.42
Remove
d
coastal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 live oak
Subtotal > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 Total > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 > -0.005 -2.10 -2.10 -2.10

5. Activity Data

5.1. Construction Schedule
Phase Name Phase Type Start Date End Date Days Per Week Work Days per Phase Phase Description Demolition Demolition 3/1/2026 4/1/2026 5.00 23.0
Site Preparation Site Preparation 3/30/2026 4/1/2026 5.00 2.00 Grading Grading 3/1/2026 4/1/2026 5.00 23.0
Building Construction Building Construction 4/2/2026 12/31/2026 5.00 196 Paving Paving 12/4/2026 12/17/2026 5.00 10.0
Architectural Coating Architectural Coating 12/18/2026 12/31/2026 5.00 10.0

5.2. Off-Road Equipment

5.2.1. Unmitigated
59 / 70
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Phase Name Equipment Type Fuel Type Engine Tier Number per Day Hours Per Day Horsepower Load Factor Demolition Tractors/Loaders/Back Diesel Average 3.00 8.00 84.0 0.37 hoes
Demolition Rubber Tired Dozers Diesel Average 1.00 8.00 367 0.40 Demolition Concrete/Industrial Diesel Average 1.00 8.00 33.0 0.73 Saws
Site Preparation Graders Diesel Average 1.00 8.00 148 0.41 Site Preparation Rubber Tired Dozers Diesel Average 1.00 7.00 367 0.40 Site Preparation Tractors/Loaders/Back Diesel Average 1.00 8.00 84.0 0.37 hoes
Grading Graders Diesel Average 1.00 8.00 148 0.41
Grading Tractors/Loaders/Back Diesel Average 2.00 7.00 84.0 0.37 hoes
Grading Rubber Tired Dozers Diesel Average 1.00 8.00 367 0.40 Grading Off-Highway Trucks Diesel Average 1.00 5.00 376 0.38 Building Construction Cranes Diesel Average 1.00 6.00 367 0.29 Building Construction Forklifts Diesel Average 1.00 6.00 82.0 0.20 Building Construction Generator Sets Diesel Average 1.00 8.00 14.0 0.74 Building Construction Tractors/Loaders/Back Diesel Average 1.00 6.00 84.0 0.37 hoes
Building Construction Welders Diesel Average 3.00 8.00 46.0 0.45 Building Construction Off-Highway Trucks Diesel Average 1.00 5.00 376 0.38 Paving Tractors/Loaders/Back Diesel Average 1.00 8.00 84.0 0.37 hoes
Paving Pavers Diesel Average 1.00 6.00 81 .0 0.42
Paving Paving Equipment Diesel Average 1.00 8.00 89.0 0.36 Paving Rollers Diesel Average 1.00 7.00 36.0 0.38
Paving Cement and Mortar Diesel Average 1.00 6.00 10.0 0.56 Mixers
Architectural Coating Air Compressors Diesel Average 1.00 6.00 37.0 0.48 60170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

5.2.2. Mitigated
Phase Name Equipment Type Fuel Type Engine Tier Number per Day Hours Per Day Horsepower Load Factor Demolition Tractors/Loaders/Back Diesel Average 3.00 8.00 84.0 0.37 hoes
Demolition Rubber Tired Dozers Diesel Average 1.00 8.00 367 0.40 Demolition Concrete/Industrial Diesel Average 1.00 8.00 33.0 0.73 Saws
Site Preparation Graders Diesel Average 1.00 8.00 148 0.41 Site Preparation Rubber Tired Dozers Diesel Average 1.00 7.00 367 0.40 Site Preparation Tractors/Loaders/Back Diesel Average 1.00 8.00 84.0 0.37 hoes
Grading Graders Diesel Average 1.00 8.00 148 0.41
Grading Tractors/Loaders/Back Diesel Average 2.00 7.00 84.0 0.37 hoes
Grading Rubber Tired Dozers Diesel Average 1.00 8.00 367 0.40 Grading Off-Highway Trucks Diesel Average 1.00 5.00 376 0.38 Building Construction Cranes Diesel Average 1.00 6.00 367 0.29 Building Construction Forklifts Diesel Average 1.00 6.00 82.0 0.20 Building Construction Generator Sets Diesel Average 1.00 8.00 14.0 0.74 Building Construction Tractors/Loaders/Back Diesel Average 1.00 6.00 84.0 0.37 hoes
Building Construction Welders Diesel Average 3.00 8.00 46.0 0.45 Building Construction Off-Highway Trucks Diesel Average 1.00 5.00 376 0.38 Paving Tractors/Loaders/Back Diesel Average 1.00 8.00 84.0 0.37 hoes
Paving Pavers Diesel Average 1.00 6.00 81 .0 0.42
Paving Paving Equipment Diesel Average 1.00 8.00 89.0 0.36 Paving Rollers Diesel Average 1.00 7.00 36.0 0.38
Paving Cement and Mortar Diesel Average 1.00 6.00 10.0 0.56 Mixers
61 / 70
Architectural Coating Air Compressors Diesel

5.3. Construction Vehicles

5.3.1. Unmitigated
Phase Name Trip Type
Demolition
Demolition Worker
Demolition Vendor
Demolition Hauling
Demolition Onsite truck
Site Preparation
Site Preparation Worker
Site Preparation Vendor
Site Preparation Hauling
Site Preparation Onsite truck
Grading
Grading Worker
Grading Vendor
Grading Hauling
Grading Onsite truck
Building Construction
Building Construction Worker
Building Construction Vendor
Building Construction Hauling
Building Construction Onsite truck
Paving
Paving Worker
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Average 1.00 6.00 37.0 0.48
One-Way Trips per Day Miles per Trip Vehicle Mix

80.0 11 .7 LDA,LDT1 ,LDT2

4.00 8.40 HHDT,MHDT

40.0 20.0 HHDT

5.00 1.00 HHDT

0.00 11 .7 LDA,LDT1 ,LDT2

0.00 8.40 HHDT,MHDT

0.00 20.0 HHDT

0.00 0.00 HHDT

0.00 11 .7 LDA,LDT1 ,LDT2

0.00 8.40 HHDT,MHDT

0.00 20.0 HHDT

0.00 0.00 HHDT

80.0 11 .7 LDA,LDT1 ,LDT2

4.00 8.40 HHDT,MHDT

20.0 20.0 HHDT

5.00 1.00 HHDT

0.00 11 .7 LDA,LDT1 ,LDT2
62170
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Paving Vendor 0.00 8.40 HHDT,MHDT
Paving Hauling 0.00 20.0 HHDT
Paving Onsite truck 0.00 0.00 HHDT
Architectural Coating
Architectural Coating Worker 0.00 11 .7 LDA,LDT1 ,LDT2
Architectural Coating Vendor 0.00 8.40 HHDT,MHDT
Architectural Coating Hauling 0.00 20.0 HHDT
Architectural Coating Onsite truck 0.00 0.00 HHDT

5.3.2. Mitigated
Phase Name Trip Type One-Way Trips per Day Miles per Trip Vehicle Mix Demolition
Demolition Worker 80.0 11 .7 LDA,LDT1 ,LDT2
Demolition Vendor 4.00 8.40 HHDT,MHDT
Demolition Hauling 40.0 20.0 HHDT
Demolition Onsite truck 5.00 1.00 HHDT
Site Preparation
Site Preparation Worker 0.00 11 .7 LDA,LDT1 ,LDT2
Site Preparation Vendor 0.00 8.40 HHDT,MHDT
Site Preparation Hauling 0.00 20.0 HHDT
Site Preparation Onsite truck 0.00 0.00 HHDT
Grading
Grading Worker 0.00 11 .7 LDA,LDT1 ,LDT2
Grading Vendor 0.00 8.40 HHDT,MHDT
Grading Hauling 0.00 20.0 HHDT
Grading Onsite truck 0.00 0.00 HHDT
Building Construction
Building Construction Worker 80.0 11 .7 LDA,LDT1 ,LDT2
63 / 70
Building Construction Vendor
Building Construction Hauling
Building Construction Onsite truck
Paving
Paving Worker
Paving Vendor
Paving Hauling
Paving Onsite truck
Architectural Coating
Architectural Coating Worker
Architectural Coating Vendor
Architectural Coating Hauling
Architectural Coating Onsite truck

5.4. Vehicles

5.4.1. Construction Vehicle Control Strategies
Non-applicable. No control strategies activated by user.

5.5. Architectural Coatings
Phase Name
Architectural Coating

5.6. Dust Mitigation
Residential Interior Area
Coated (sq ft)

0.00 5.6.1. Construction Earthmoving Activities
Phase Name Material Imported (Cubic
Yards)
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

4.00 20.0

5.00 0.00

0.00 0.00

0.00 0.00

0.00 0.00

0.00 Residential Exterior Area
Coated (sq ft)

0.00 Material Exported (Cubic
Yards)

8.40 20.0

1.00 11 .7

8.40 20.0

0.00 11 .7

8.40 20.0

0.00 Non-Residential Interior Area
Coated (sq ft)
750
Acres Graded (acres)
64170

HHDT,MHDT
HHDT
HHDT
LDA,LDT1 ,LDT2

HHDT,MHDT
HHDT
HHDT
LDA,LDT1 ,LDT2

HHDT,MHDT
HHDT
HHDT
Non-Residential Exterior Area
Coated (sq ft)
Parking Area Coated (sq ft)
250
Material Demolished (Ton of
Debris)
400
Acres Paved (acres)
Demolition
Site Preparation
Grading
Paving

0.00 0.00

0.00 0.00

0.00 50.0
710

0.00 5.6.2. Construction Earthmoving Control Strategies Non-applicable. No control strategies activated by user.

5. 7. Construction Paving
Land Use
City Park
Parking Lot
Area Paved (acres)

0.00 0.15
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025

0.00 1.88

4.00 0.00
600

0.00 0.00

0.00 % Asphalt
0%
100%

0.15 5.8. Construction Electricity Consumption and Emissions Factors kWh per Year and Emission Factor (lb/MWh)
Year kWh per Year
2026 0.00

5.9. Operational Mobile Sources

5.9.1. Unmitigated
Land Use Type
City Park
Parking Lot

5.9.2. Mitigated
Land Use Type
City Park
Trips/Weekday
101

0.00 Trips/Weekday
101
Trips/Saturday
501

0.00 Trips/Saturday
501
204
Trips/Sunday
501

0.00 Trips/Sunday
501
Trips/Year
78,430

0.00 Trips/Year
78,430
65170

0.03 VMT/Weekday
897

0.00 VMT/Weekday
897
VMT/Saturday
4,461

0.00 VMT/Saturday
4,461
< 0.005
VMT/Sunday
4,461

0.00 VMT/Sunday
4,461
VMT/Year
699,032

0.00 VMT/Year
699,032
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Parking Lot 0.00 0.00

5.10. Operational Area Sources

5.10.1. Hearths

5.10.1.1. Unmitigated

5.10.1.2. Mitigated

5.10.2. Architectural Coatings

0.00 Residential Interior Area Coated (sq
ft)
Residential Exterior Area Coated (sq
ft)
0 0.00

5.10.3. Landscape Equipment
Season
Snow Days
Summer Days

5.10.4. Landscape Equipment - Mitigated
Season
Snow Days
Summer Days

5.11. Operational Energy Consumption

5.11.1. Unmitigated
Unit
day/yr
day/yr
Unit
day/yr
day/yr

0.00 0.00
Non-Residential Interior Area Coated
(sq ft)
750
Electricity (kWh/yr) and CO2 and CH4 and N2O and Natural Gas (kBTU/yr) 66170

0.00 Non-Residential Exterior Area
Coated (sq ft)
250
Value

0.00 180
Value

0.00 180

0.00 0.00
Parking Area Coated (sq ft)
400
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Land Use
City Park
Parking Lot

5.11.2. Mitigated
Electricity (kWh/yr)

0.00 5,838
204
204

0.0330

0.0330
Electricity (kWh/yr) and CO2 and CH4 and N2O and Natural Gas (kBTU/yr) Land Use
City Park
Parking Lot
Electricity (kWh/yr)

0.00 5,838
204
204

5.12. Operational Water and Wastewater Consumption

5.12.1. Unmitigated
Land Use
City Park
Parking Lot

5.12.2. Mitigated
Land Use
City Park
Parking Lot

5.13. Operational Waste Generation

5.13.1. Unmitigated
Land Use
City Park
Indoor Water (gal/year)

0.00 0.00
Indoor Water (gal/year)

0.00 0.00
Waste (ton/year)

0.07 0.0330

0.0330
67170

0.0040

0.0040

0.0040

0.0040
Outdoor Water (gal/year)

3.32 0.00
Outdoor Water (gal/year)

3.32 0.00
Cogeneration (kWh/year)
Natural Gas (kBTU/yr)

0.00 0.00
Natural Gas (kBTU/yr)

0.00 0.00
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Parking Lot

5.13.2. Mitigated
Land Use
City Park
Parking Lot

0.00 Waste (ton/year)

0.07 0.00

5.14. Operational Refrigeration and Air Conditioning Equipment

5.14.1. Unmitigated
Land Use Type Equipment Type Refrigerant

5.14.2. Mitigated
Land Use Type Equipment Type Refrigerant

5.15. Operational Off-Road Equipment

5.15.1. Unmitigated
Equipment Type Fuel Type Engine Tier

5.15.2. Mitigated
Equipment Type Fuel Type Engine Tier

5.16. Stationary Sources

5.16.1. Emergency Generators and Fire Pumps
Equipment Type Fuel Type Number per Day
Quantity (kg)
Quantity (kg)
Number per Day
Number per Day
Hours per Day
68 I 70
Cogeneration (kWh/year)
Operations Leak Rate Service Leak Rate Times Serviced
Operations Leak Rate Service Leak Rate Times Serviced
Hours Per Day Horsepower Load Factor
Hours Per Day Horsepower Load Factor
Hours per Year Horsepower Load Factor

5.16.2. Process Boilers
Equipment Type Fuel Type

5.17. User Defined
Equipment Type

5.18. Vegetation

5.18.1. Land Use Change

5.18.1.1. Unmitigated
Vegetation Land Use Type

5.18.1.2. Mitigated
Vegetation Land Use Type

5.18.1. Biomass Cover Type

5.18.1.1. Unmitigated
Biomass Cover Type

5.18.1.2. Mitigated
Biomass Cover Type

5.18.2. Sequestration

5.18.2.1. Unmitigated
Number
Vegetation Soil Type
Vegetation Soil Type
Initial Acres
Initial Acres
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Boiler Rating (MMBtu/hr) Daily Heat Input (MMBtu/day) Annual Heat Input (MMBtu/yr) Fuel Type
Initial Acres Final Acres
Initial Acres Final Acres
Final Acres
Final Acres
69170
Tree Type
coastal live oak
coastal live oak

5.18.2.2. Mitigated
Tree Type
coastal live oak
coastal live oak
Number

40.0 -10.0
Number

40.0 -10.0

8. User Changes to Default Data
Screen
Land Use
Construction: Construction Phases
Construction: Off-Road Equipment
Construction: Dust From Material Movement
Construction: Trips and VMT
Operations: Vehicle Data
Operations: Refrigerants
South San Francisco Linden and Pine Aves Project v2 Custom Report, 8/21/2025 Electricity Saved (kWh/year)
81,369
29,229
Electricity Saved (kWh/year)
81,369
29,229
Justification
Approx 16,200 sq feet of impervious surfaces
Natural Gas Saved (btu/year)
398
153
Natural Gas Saved (btu/year)
398
153
Project construction is expected to begin in March 2026 and occur over a period of approximately 10 months
Default equipment with the addition of the water trucks for the duration of the project 750 cubic yards of soil will need to be recycled or exported and approximately 10 cubic yards of lead-contaminated soil will also be removed.

Increased all trucks trips to ensure the model is conservative The park is expected to host approximately 100 to 250 people on a daily basis in the absence of events, most of whom would walk to the park. With events no more than 500 people. no refrigerants anticipated
70170

APPENDIX D
Geotechnical Evaluation
New Park at Linden and Pine Project
Initial Study/Mitigated Negative Declaration
Geotechnical Evaluation
Linden Avenue Park
616 Linden Avenue and
270 Pine Avenue
South San Francisco, California
City of South San Francisco 315 Maple Avenue | South San Francisco, California 94080 July 25, 2023 | Project No. 404590001
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS .
.......
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IJ an.
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Geotechnical & Environmental Sciences Consultants
NIIIHU /Vluure l(ln901cl(toore
Geoleclmlcal & Ell¥lromnentll ~ Conaullante
| www.ninyoandmoore.com
Ninon &/Vlunre
Geotechnical & Environmental Sciences Consultants YEARS Geotechnical Evaluation
Linden Avenue Park
616 Linden Avenue and 270 Pine Avenue
South San Francisco, California
Mr. Philip Vitale, Jr.

Deputy Director
Capital Projects
City of South San Francisco
33 Arroyo Drive | South San Francisco, California 94080 July 25, 2023 | Project No. 404590001
1 mask;
by Q
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no. 2461
an 06/30/24
i
Moha mad Hammoud, EIT
Senior Staff Engineer
Anthony Dover, P.E., G.E.

Principal Engineer

MXH/ARD/
Distribution: (1) Addressee (via e-mail)
2149 O'Toole Avenue, Suite 30 | San Jose, California 95131 | p. 408.435.9000 Geotechnical & Environmental Sciences Consultants
Geotechnical Evaluation
Linden Avenue Park
616 Linden Avenue and 270 Pine Avenue
South San Francisco, California
Mr. Philip Vitale, Jr.

Deputy Director
Capital Projects
City of South San Francisco
33 Arroyo Drive I South San Francisco, California 94080 July 25, 2023 I Project No. 404590001
Moha mad Hammoud, Ell
Senior taff Engineer

MXH/ARD/
Distribution: (1) Addressee (via e-mail)
Anthony Dover, P.E., G.E.

Principal Engineer
2149 O'Toole Avenue, Suite 30 I San Jose, California 95131 I p. 408.435.9000 Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 i 1 INTRODUCTION 1
2 SCOPE OF SERVICES 1
3 SITE DESCRIPTION AND BACKGROUND 1
4 PROJECT DESCRIPTION 2
5 SUBSURFACE EVALUATION AND LABORATORY TESTING 2
6 GEOLOGIC AND SUBSURFACE CONDITIONS 3

6.1 Regional Geologic Setting 3

6.2 Site Geology 3

6.3 Subsurface Conditions 3

6.3.1 Pavement Section 3

6.3.2 Alluvium 3

6.4 Groundwater 4
7 GEOLOGIC HAZARDS AND GEOTECHNICAL
CONSIDERATIONS 4

7.1 Expansive Soil 4

7.2 Seismic Hazards 4

7.2.1 Historical Seismicity 4

7.2.2 Faulting and Ground Surface Rupture 5

7.2.3 Liquefaction and Strain Softening 5

7.3 Static Settlement 6

7.4 Landsliding and Slope Stability 6

7.5 Excavation Characteristics 6

7.6 Corrosive/Deleterious Soil 7
8 CONCLUSIONS 7
9 RECOMMENDATIONS 8

9.1 Seismic Design Criteria 8

9.2 Earthwork Recommendations 8

9.2.1 Pre-Construction Conference 9

9.2.2 Site Preparation 9

9.2.3 Observation and Removals 9

CONTENTS CONTENTS
Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 ii

9.2.4 Material Recommendations 9

9.2.5 Subgrade Preparation 10

9.2.6 Fill Placement and Compaction 11

9.2.7 Temporary Excavations and Shoring 12

9.2.8 Utility Trenches 13

9.2.9 Rainy Weather Considerations 14

9.3 Structure Foundations 14

9.3.1 Shallow Foundation 14

9.3.2 Drilled Piers 16

9.4 Pavements and Flatwork 16

9.4.1 Asphalt Pavement 17

9.4.2 Concrete Pavement 18

9.4.3 Exterior Flatwork 19

9.5 Concrete 20

9.6 Surface Drainage 20

9.7 Review of Construction Plans 20

9.8 Construction Observation and Testing 21
10 LIMITATIONS 21
11 REFERENCES 23
TABLES

FIGURES
1 - California Building Code Seismic Design Criteria
2 - Recommended Material Requirements
3 - Subgrade Preparation Recommendations
4 - Fill Place Placement and Compaction Requirements
5 - OSHA Material Classifications and Allowable Slopes
6 -Asphalt Concrete Pavement Sections
8 10
11 11
12 17
1 - Site Location
2 - Exploration Locations
3 - Fault Locations and Earthquake Epicenters
4 - Regional Geology
5 - Seismic Hazard Zones
1 - California Building Code Seismic Design Criteria
2 - Recommended Material Requirements
3 - Subgrade Preparation Recommendations
4 - Fill Place Placement and Compaction Requirements
5 - OSHA Material Classifications and Allowable Slopes
6 -Asphalt Concrete Pavement Sections
1 - Site Location
2 - Exploration Locations
3 - Fault Locations and Earthquake Epicenters
4 - Regional Geology
5 - Seismic Hazard Zones
8 10
11 11
12 17
Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 iii

APPENDICES
A- Boring Log
B - Laboratory Testing
C -Corrosivity Testing
A - Boring Logs
B - Laboratory Testing
C -Corrosivity Testing
Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 1 1 INTRODUCTION
2 SCOPE OF SERVICES
3 SITE DESCRIPTION AND BACKGROUND
In accordance with your request and authorization, we have performed a geotechnical evaluation forthe Linden Avenue Park project at current addresses 270 Pine Avenue and 616 Linden Avenue in South San Francisco, California. (Figure 1). The purpose of our study was to assess geotechnical conditions and provide recommendations for the design and construction of the proposed improvements.

The services we performed included the following:
.
•
Reviewed readily available geologic and seismic literature pertinent to the project area including geologic maps and reports, regional fault maps, seismic hazard maps, and aerial photographs.

Performed site reconnaissance to observe the general site conditions and to mark the proposed locations for subsurface exploration.

Coordinated with Underground Service Alert (USA) to locate and mark underground utilities in the vicinity of the subsurface exploration locations. • Perform a private utility survey at each boring location.

Obtained a boring permit from the San Mateo County Environmental Health Services Department.
. Conducted a subsurface exploration consisting of five (4) exploratory borings advanced up to 15 feet below existing grade. A representative of Ninyo & Moore logged the subsurface conditions exposed in the borings and collected bulk and relatively undisturbed soil samples for laboratory tests. The borings were backfilled with cement grout, in compliance with the San Mateo County Environmental Health Services Department.

Performed laboratory testing of selected soil samples to evaluate the geotechnical properties of the subsurface materials including in-situ soil moisture content and density, grain size distribution, Atterberg limits, expansion index, and soil corrosivity.

Performed data compilation and engineering analysis of the information obtained from our background review, subsurface evaluation, and laboratory testing.

Prepared this geotechnical report presenting our findings and conclusions regarding the subsurface conditions encountered at the project site, and our geotechnical recommendations for the design and construction of the proposed improvements.

The project site is located at 270 Pine Avenue and 616 Linden Avenue in South San Francisco, California. (Figure 1) at about 37.6591 degrees north latitude and 122.4084 degrees west longitude. The site consists of two lots, separated by Pine Avenue in the middle and bounded to In accordance with your request and authorization, we have performed a geotechnical evaluation for the Linden Avenue Park project at current addresses 270 Pine Avenue and 616 Linden Avenue in South San Francisco, California. (Figure 1 ). The purpose of our study was to assess geotechnical conditions and provide recommendations for the design and construction of the proposed improvements.

The services we performed included the following:
• Reviewed readily available geologic and seismic literature pertinent to the project area including geologic maps and reports, regional fault maps, seismic hazard maps, and aerial photographs.
• Performed site reconnaissance to observe the general site conditions and to mark the proposed locations for subsurface exploration.
• Coordinated with Underground Service Alert (USA) to locate and mark underground utilities in the vicinity of the subsurface exploration locations. • Perform a private utility survey at each boring location. • Obtained a boring permit from the San Mateo County Environmental Health Services Department.
• Conducted a subsurface exploration consisting of five (4) exploratory borings advanced up to 15 feet below existing grade. A representative of Ninyo & Moore logged the subsurface conditions exposed in the borings and collected bulk and relatively undisturbed soil samples for laboratory tests. The borings were backfilled with cement grout, in compliance with the San Mateo County Environmental Health Services Department.
• Performed laboratory testing of selected soil samples to evaluate the geotechnical properties of the subsurface materials including in-situ soil moisture content and density, grain size distribution, Atterberg limits, expansion index, and soil corrosivity. • Performed data compilation and engineering analysis of the information obtained from our background review, subsurface evaluation, and laboratory testing. • Prepared this geotechnical report presenting our findings and conclusions regarding the subsurface conditions encountered at the project site, and our geotechnical recommendations for the design and construction of the proposed improvements.

The project site is located at 270 Pine Avenue and 616 Linden Avenue in South San Francisco, California. (Figure 1) at about 37 .6591 degrees north latitude and 122.4084 degrees west longitude. The site consists of two lots, separated by Pine Avenue in the middle and bounded to Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 2 4 PROJECT DESCRIPTION
5 SUBSURFACE EVALUATION AND LABORATORY TESTING
the west by commercial buildings, to the east by residential homes, to the north by 8th Lane, and to the south by 7th Lane. The project site is currently occupied by a landscape park area and paved parking area. The site is relatively flat with elevations ranging from approximately 51 to 55 feet above mean sea level [MSL] (Google Earth, 2023).

Based upon the information provided to us, we understand that the project will consist of site grading, demolishing existing structures, and constructing an approximately 1-acre community park at two adjacent properties on 270 Pine Avenue and 616 Linden Avenue. The project will include a sports court and a recreational space on the 616 Linden Avenue as well as a play area on 270 Pine Avenue with both having pedestrian flatwork, gathering or seating areas, overhead structures, seat walls, and landscaping areas. In addition, Pine Avenue between the two properties will include a raised road / speed table, bollards for opening and closing the street, and street parking.

Our field exploration included a site reconnaissance and subsurface exploration of the project site. The subsurface exploration was conducted on June 21, 2023, which consisted of four (4) exploratory borings. The locations of the borings are presented on Figure 2. Prior to commencing the subsurface investigation, USA was notified for field marking of existing utilities. In addition, a private utility survey was conducted to further assess and locate any utilities that might conflict with the boring locations.

The borings were advanced to depths of up to approximately 15 feet below the existing grade with a truck-mounted drill rig equipped with hollow-stem augers. A representative of Ninyo & Moore logged the subsurface conditions exposed in the borings and collected bulk and relatively undisturbed soil samples from the borings. The samples were then transported to our geotechnical laboratory for testing. The borings were backfilled with cement grout and capped off with concrete in accordance with San Mateo County Environmental Health Services Department soil boring permit. Detailed logs of the borings are presented in Appendix A.

Laboratory testing of soil samples recovered from the borings included in-place moisture content and dry density, soil gradation, Atterberg limits, expansion index, R-value, and soil corrosivity. The results of the in-place moisture content and dry density tests are shown on the boring logs in Appendix A. The results of the other laboratory tests performed are presented in Appendix B. the west by commercial buildings, to the east by residential homes, to the north by 8th Lane, and to the south by 7th Lane. The project site is currently occupied by a landscape park area and paved parking area. The site is relatively flat with elevations ranging from approximately 51 to 55 feet above mean sea level [MSL] (Google Earth, 2023).

Based upon the information provided to us, we understand that the project will consist of site grading, demolishing existing structures, and constructing an approximately 1-acre community park at two adjacent properties on 270 Pine Avenue and 616 Linden Avenue. The project will include a sports court and a recreational space on the 616 Linden Avenue as well as a play area on 270 Pine Avenue with both having pedestrian flatwork, gathering or seating areas, overhead structures, seat walls, and landscaping areas. In addition, Pine Avenue between the two properties will include a raised road / speed table, bollards for opening and closing the street, and street parking.

Our field exploration included a site reconnaissance and subsurface exploration of the project site. The subsurface exploration was conducted on June 21 , 2023, which consisted of four (4) exploratory borings. The locations of the borings are presented on Figure 2. Prior to commencing the subsurface investigation, USA was notified for field marking of existing utilities. In addition, a private utility survey was conducted to further assess and locate any utilities that might conflict with the boring locations.

The borings were advanced to depths of up to approximately 15 feet below the existing grade with a truck-mounted drill rig equipped with hollow-stem augers. A representative of Ninyo & Moore logged the subsurface conditions exposed in the borings and collected bulk and relatively undisturbed soil samples from the borings. The samples were then transported to our geotechnical laboratory for testing. The borings were backfilled with cement grout and capped off with concrete in accordance with San Mateo County Environmental Health Services Department soil boring permit. Detailed logs of the borings are presented in Appendix A Laboratory testing of soil samples recovered from the borings included in-place moisture content and dry density, soil gradation, Atterberg limits, expansion index, R-value, and soil corrosivity. The results of the in-place moisture content and dry density tests are shown on the boring logs in Appendix A The results of the other laboratory tests performed are presented in Appendix B.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 3 6 GEOLOGIC AND SUBSURFACE CONDITIONS

6.1 Regional Geologic Setting

6.2 Site Geology

6.3 Subsurface Conditions

6.3.1 6.3.2
The site is located at the northeastern end of the San Francisco Peninsula approximately 1.8 miles west of the western shore of San Francisco Bay in the Coast Ranges geomorphic province of California. The Coast Ranges are comprised of several mountain ranges and structural valleys formed by tectonic processes commonly found around the Circum-Pacific belt. Basement rocks have been sheared, faulted, metamorphosed, and uplifted, and are separated by thick blankets of Cretaceous and Cenozoic sediments that fill structural valleys and line continental margins. The San Francisco Bay Area has several ranges that trend northwest, parallel to major strike-slip faults such as the San Andreas, Hayward, and Calaveras (Figure 3). San Francisco Bay is a northwest trending structural depression that lies between the San Andreas Fault to the west and the Hayward fault to the east. Major tectonic activity associated with these and other faults within this regional tectonic framework consists primarily of right-lateral, strike-slip movement.

Published geologic maps (Bonilla, 1998) indicate that the site is underlain by Pleistocene slope debris and ravine fill. Bonilla describe this unit as stony silty to sandy clay, locally silty to clayey sand or gravel, yellowish-orange to medium gray, unstratified or poorly stratified. Where it overlies the Merced or Colma formation it is commonly a silty to clayey sand, or gravel. A map of regional geology is presented as Figure 4.

The following sections provide a generalized description of the materials encountered during our subsurface evaluation at the project site. More detailed descriptions are presented on the boring logs in Appendix A.

Pavement Section
B-3 and B-4 were drilled through asphalt concrete pavement. The pavement section encountered in the borings consisted of approximately 2 inches of asphalt concrete over 3 inches of aggregate base. Variations in the thickness of the asphalt concrete may be encountered due to past maintenance, utility work, or other factors.

Alluvium
Alluvium was encountered in all of the borings from below the pavement sections to the depths explored. The alluvium encountered in the borings generally consisted of brown, and The site is located at the northeastern end of the San Francisco Peninsula approximately 1.8 miles west of the western shore of San Francisco Bay in the Coast Ranges geomorphic province of California. The Coast Ranges are comprised of several mountain ranges and structural valleys formed by tectonic processes commonly found around the Circum-Pacific belt. Basement rocks have been sheared, faulted, metamorphosed, and uplifted, and are separated by thick blankets of Cretaceous and Cenozoic sediments that fill structural valleys and line continental margins. The San Francisco Bay Area has several ranges that trend northwest, parallel to major strike-slip faults such as the San Andreas, Hayward, and Calaveras (Figure 3). San Francisco Bay is a northwest trending structural depression that lies between the San Andreas Fault to the west and the Hayward fault to the east. Major tectonic activity associated with these and other faults within this regional tectonic framework consists primarily of right-lateral, strike-slip movement.

Published geologic maps (Bonilla, 1998) indicate that the site is underlain by Pleistocene slope debris and ravine fill. Bonilla describe this unit as stony silty to sandy clay; locally silty to clayey sand or gravel; yellowish-orange to medium gray, unstratified or poorly stratified. Where it overlies the Merced or Colma formation it is commonly a silty to clayey sand, or gravel. A map of regional geology is presented as Figure 4.

The following sections provide a generalized description of the materials encountered during our subsurface evaluation at the project site. More detailed descriptions are presented on the boring logs in Appendix A.

Pavement Section
B-3 and B-4 were drilled through asphalt concrete pavement. The pavement section encountered in the borings consisted of approximately 2 inches of asphalt concrete over 3 inches of aggregate base. Variations in the thickness of the asphalt concrete may be encountered due to past maintenance, utility work, or other factors.

Alluvium
Alluvium was encountered in all of the borings from below the pavement sections to the depths explored. The alluvium encountered in the borings generally consisted of brown, and Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 4

6.4 Groundwater
7 GEOLOGIC HAZARDS AND GEOTECHNICAL CONSIDERATIONS

7.1 Expansive Soil

7.2 Seismic Hazards

7.2.1 yellowish brown very stiff clay and sandy clay, and yellowish brown, moist, medium dense to dense silty and clayey sand.

Groundwater was not encountered during our subsurface exploration. However, groundwater may rise to a higher level due to the relatively low seepage rate in clay and the limited time for observation. Fluctuations in the groundwater level may occur due to seasonal precipitation, variations in topography or subsurface hydrogeologic conditions, or as a result of changes to nearby irrigation practices or groundwater pumping. In addition, seeps may be encountered at elevations above the historic high groundwater levels due to perched groundwater conditions, leaking pipes, preferential drainage, or other factors not evident at the time of our exploration.

This study considered a number of potential issues relevant to the proposed construction on the subject site, including expansive soils, static settlement, excavation characteristics, and soil corrosivity. These issues are discussed in the following subsections.

Some clay minerals undergo volume changes upon wetting or drying. Unsaturated soil containing those minerals will shrinklswell with the removal/addition of water. The heaving pressures associated with this expansion can damage structures and flatwork. Laboratory testing was performed on a sample of the near-surface soil to evaluate the expansion index. The tests were performed in accordance with American Society of Testing and Materials (ASTM) Standard D 4829 (Expansion Index). The results of our laboratory test indicate that the expansion index of the sample tested was 44. This result is indicative of a low expansion characteristic.

The seismic hazards considered in this study include the potential for ground rupture due to faulting, seismic ground shaking, liquefaction, and dynamic settlement. These potential hazards are discussed in the following subsections.

Historical Seismicity
The site is located in a seismically active region. Figure 3 presents the location of the site relative to the epicenters of historic earthquakes with magnitudes of 5.5 or more from 1800 to 2000. Records of historic ground effects related to seismic activity (e.g. liquefaction, sand yellowish brown very stiff clay and sandy clay, and yellowish brown, moist, medium dense to dense silty and clayey sand.

Groundwater was not encountered during our subsurface exploration. However, groundwater may rise to a higher level due to the relatively low seepage rate in clay and the limited time for observation. Fluctuations in the groundwater level may occur due to seasonal precipitation, variations in topography or subsurface hydrogeologic conditions, or as a result of changes to nearby irrigation practices or groundwater pumping. In addition, seeps may be encountered at elevations above the historic high groundwater levels due to perched groundwater conditions, leaking pipes, preferential drainage, or other factors not evident at the time of our exploration.

This study considered a number of potential issues relevant to the proposed construction on the subject site, including expansive soils, static settlement, excavation characteristics, and soil corrosivity. These issues are discussed in the following subsections.

Some clay minerals undergo volume changes upon wetting or drying. Unsaturated soil containing those minerals will shrink/swell with the removal/addition of water. The heaving pressures associated with this expansion can damage structures and flatwork. Laboratory testing was performed on a sample of the near-surface soil to evaluate the expansion index. The tests were performed in accordance with American Society of Testing and Materials (ASTM) Standard D 4829 (Expansion Index). The results of our laboratory test indicate that the expansion index of the sample tested was 44. This result is indicative of a low expansion characteristic.

The seismic hazards considered in this study include the potential for ground rupture due to faulting, seismic ground shaking, liquefaction, and dynamic settlement. These potential hazards are discussed in the following subsections.

Historical Seismicity
The site is located in a seismically active region. Figure 3 presents the location of the site relative to the epicenters of historic earthquakes with magnitudes of 5.5 or more from 1800 to 2000. Records of historic ground effects related to seismic activity (e.g. liquefaction, sand Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 5

7.2.2 7.2.3
boils, lateral spreading, and ground cracking) compiled by Knudsen et al. (2000), indicate that ground effects related to historic seismic activity have not been reported for the site, however, a point about 'A a mile west of the site along Colma Creek is recorded as having historic ground settlement, lateral spreading and miscellaneous effects.

Faulting and Ground Surface Rupture
California lies along the boundary between the North American and Pacific tectonic plates.

Movement along the plate boundary can generate earthquakes and has created zones of deformation within the Earth's crust. These zones include various types of complex geologic structures and geomorphic features such as folds, faults, sag ponds, shutter ridges, linear valleys, and scarps. During moderate to large magnitude earthquakes, the ground can rupture along well-defined zones of deformation where faults intersect the Earth's surface.

The site is not located within an Alquist-Priolo Earthquake Fault Zone established by the California State Geologist (CGS, 2018) to delineate regions of potential ground surface rupture adjacent to active faults. As defined by the California Geological Survey (CGS), active faults are faults that have caused surface displacement within Holocene time, or within approximately the last 11 ,700 years (CGS, 2007 and 2018). The closest fault rupture hazard fault zone is the San Andreas fault zone, which is located about 2 miles southwest of the site (Figure 3). The nearest mapped fault to the site is the Serra fault, which lies about 1 mile southwest of the project site. The Serra fault is not considered active and does not pose a ground rupture hazard.

Based on our review of the referenced seismic hazard and geologic maps, known active faults are not mapped on the site, and the site is not located within a fault-rupture hazard zone. Therefore, the probability of damage from surface fault rupture is considered to be low.

The site located near the San Andreas Fault has a significant potential for seismic shaking due to its close proximity to this major tectonic boundary. The accumulation of stress along the fault's locked segments results in periodic release of energy through earthquakes. As a result, the site faces an increased risk of experiencing ground shaking during seismic events.

Liquefaction and Strain Softening
The site is located within a liquefaction hazard zone established by the State Geologist (CGS, 2000a). The seismic hazard zones for the site vicinity are presented on Figure 5. Regional studies of liquefaction susceptibility (Knudsen et al., 2000) indicate that the liquefaction susceptibility at the site is high. The strong vibratory motions generated by earthquakes can boils, lateral spreading, and ground cracking) compiled by Knudsen et al. (2000), indicate that ground effects related to historic seismic activity have not been reported for the site; however, a point about ¾ a mile west of the site along Colma Creek is recorded as having historic ground settlement, lateral spreading and miscellaneous effects.

Faulting and Ground Surface Rupture
California lies along the boundary between the North American and Pacific tectonic plates.

Movement along the plate boundary can generate earthquakes and has created zones of deformation within the Earth's crust. These zones include various types of complex geologic structures and geomorphic features such as folds, faults, sag ponds, shutter ridges, linear valleys, and scarps. During moderate to large magnitude earthquakes, the ground can rupture along well-defined zones of deformation where faults intersect the Earth's surface.

The site is not located within an Alquist-Priolo Earthquake Fault Zone established by the California State Geologist (CGS, 2018) to delineate regions of potential ground surface rupture adjacent to active faults. As defined by the California Geological Survey (CGS), active faults are faults that have caused surface displacement within Holocene time, or within approximately the last 11,700 years (CGS, 2007 and 2018). The closest fault rupture hazard fault zone is the San Andreas fault zone, which is located about 2 miles southwest of the site (Figure 3). The nearest mapped fault to the site is the Serra fault, which lies about 1 mile southwest of the project site. The Serra fault is not considered active and does not pose a ground rupture hazard.

Based on our review of the referenced seismic hazard and geologic maps, known active faults are not mapped on the site, and the site is not located within a fault-rupture hazard zone. Therefore, the probability of damage from surface fault rupture is considered to be low.

The site located near the San Andreas Fault has a significant potential for seismic shaking due to its close proximity to this major tectonic boundary. The accumulation of stress along the fault's locked segments results in periodic release of energy through earthquakes. As a result, the site faces an increased risk of experiencing ground shaking during seismic events.

Liquefaction and Strain Softening
The site is located within a liquefaction hazard zone established by the State Geologist (CGS, 2000a). The seismic hazard zones for the site vicinity are presented on Figure 5. Regional studies of liquefaction susceptibility (Knudsen et al., 2000) indicate that the liquefaction susceptibility at the site is high. The strong vibratory motions generated by earthquakes can Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 6

7.3 Static Settlement

7.4 Landsliding and Slope Stability

7.5 Excavation Characteristics
trigger a rapid loss of shear strength in saturated, loose, granular soils of low plasticity (liquefaction) or in wet, sensitive, cohesive soils (strain softening). Liquefaction and strain softening can result in a loss of foundation bearing capacity or lateral spreading of sloping or unconfined ground. Liquefaction can also generate sand boils leading to subsidence at the ground surface. Liquefaction (or strain softening) is generally not a concern at depths more than 50 feet below ground surface.

Based on documents provided, we understand that the proposed improvements do not include grading that will raise grades at the site. The sustained loads for the proposed structures are expected to be relatively light. We anticipate, therefore, that the total static settlement of drilled pier foundations due to sustained loads will be less than 1/2 inch, provided the recommendations presented in this report are followed for shallow foundations.

Regional landslide mapping in the seismic hazard zone report compiled by the California Geological Survey (CGS, 2021) do not show any landslides within close proximity of the site, and the project site is relatively level. Therefore, landsliding and slope stability are not design considerations.

We anticipate that the project will involve excavations for foundations and open pits or trenches for utilities. We anticipate that conventional earthmoving equipment in good working condition should be able to make the proposed excavations. Excavations in any fill that might be present may encounter obstructions consisting of debris, rubble, abandoned structures, or over-sized materials that may require special handling or demolition equipment for removal.

Near-vertical temporary cuts in the near SLll'f3c€ deposits up to 4 eet in depth should remain stable for a limited period of time. However, sloughing of the materials exposed on the excavation sidewall may occur, particularly if the excavation extends near the groundwater level, encounters granular soil, is exposed to water, or if the sidewall is disturbed during construction operations.

Excavation subgrade may become unstable if exposed to wet conditions. The subsurface materials below the first few feet at the project site are mainly granular, and excavations for drilled piers may encounter saturated granular soils. Recommendations for excavation stabilization are provided. Excavated materials may also be wet and need to be dried out before reuse as fill. trigger a rapid loss of shear strength in saturated, loose, granular soils of low plasticity (liquefaction) or in wet, sensitive, cohesive soils (strain softening). Liquefaction and strain softening can result in a loss of foundation bearing capacity or lateral spreading of sloping or unconfined ground. Liquefaction can also generate sand boils leading to subsidence at the ground surface. Liquefaction (or strain softening) is generally not a concern at depths more than 50 feet below ground surface.

Based on documents provided, we understand that the proposed improvements do not include grading that will raise grades at the site. The sustained loads for the proposed structures are expected to be relatively light. We anticipate, therefore, that the total static settlement of drilled pier foundations due to sustained loads will be less than 1/2 inch, provided the recommendations presented in this report are followed for shallow foundations.

Regional landslide mapping in the seismic hazard zone report compiled by the California Geological Survey (CGS, 2021) do not show any landslides within close proximity of the site, and the project site is relatively level. Therefore, landsliding and slope stability are not design considerations.

We anticipate that the project will involve excavations for foundations and open pits or trenches for utilities. We anticipate that conventional earthmoving equipment in good working condition should be able to make the proposed excavations. Excavations in any fill that might be present may encounter obstructions consisting of debris, rubble, abandoned structures, or over-sized materials that may require special handling or demolition equipment for removal.

Near-vertical temporary cuts in the near surface deposits up to 4 feet in depth should remain stable for a limited period of time. However, sloughing of the materials exposed on the excavation sidewall may occur, particularly if the excavation extends near the groundwater level, encounters granular soil, is exposed to water, or if the sidewall is disturbed during construction operations.

Excavation subgrade may become unstable if exposed to wet conditions. The subsurface materials below the first few feet at the project site are mainly granular, and excavations for drilled piers may encounter saturated granular soils. Recommendations for excavation stabilization are provided. Excavated materials may also be wet and need to be dried out before reuse as fill.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 7

7.6 Corrosive/Deleterious Soil
8 CONCLUSIONS
Corrosivity analysis was performed by CERCO Analytical, Inc. of Concord, California on samples of the near-surface soil. As reported by CERCO Analytical, the samples were determined to be "moderately corrosive" based on resistivity test results. CERCOAnalytical' s report (see Appendix C) included the following recommendation: "All buried iron, steel, cast iron, ductile iron, galvanized steel and dielectric coated steel or iron should be properly protected against corrosion depending upon the critical nature of the structure. All buried metallic pressure piping such as ductile iron firewater pipelines should be protected against corrosion." The results for sulfate ion testing indicate that it is not sufficient to damage buried reinforced concrete structures or cement mortar-coated steel.

Please refer to the CERCO Analytical report included in Appendix C for more information regarding their test results and brief evaluation.

Based on our review of the referenced background data, site reconnaissance, subsurface evaluation, and laboratory testing, it is our opinion that the proposed construction is feasible from a geotechnical standpoint. Geotechnical considerations include the following:

The subsurface conditions encountered during our exploration generally consisted of moist, firm to very stiff lean clay and medium dense to dense, silty and clayey sand. . The site could experience a relatively large degree of ground shaking during a significant earthquake event on a nearby fault.
.

Groundwater was not encountered during our subsurface exploration. Variations in the groundwater level across the site and over time should be anticipated.

Static settlement should be tolerable for the proposed improvements provided that the proposed structures are supported on foundations that conform to our recommendations and fill placement to raise grades is less than 2 feet in height.

Expansion Index and Atterberg limit testing indicates that the near-surface soil on site has a low expansion characteristic.
. Laboratory corrosion testing indicates that the near-surface site soils are considered moderately corrosive. A corrosion engineer should be consulted to provide specific guidance on protective measures to mitigate corrosion.

Corrosivity analysis was performed by CERCO Analytical, Inc. of Concord, California on samples of the near-surface soil. As reported by CERCO Analytical, the samples were determined to be "moderately corrosive" based on resistivity test results. CERCO Analytical' s report ( see Appendix C) included the following recommendation: "All buried iron, steel, cast iron, ductile iron, galvanized steel and dielectric coated steel or iron should be properly protected against corrosion depending upon the critical nature of the structure. All buried metallic pressure piping such as ductile iron firewater pipelines should be protected against corrosion." The results for sulfate ion testing indicate that it is not sufficient to damage buried reinforced concrete structures or cement mortar-coated steel.

Please refer to the CERCO Analytical report included in Appendix C for more information regarding their test results and brief evaluation.

Based on our review of the referenced background data, site reconnaissance, subsurface evaluation, and laboratory testing, it is our opinion that the proposed construction is feasible from a geotechnical standpoint. Geotechnical considerations include the following:
• The subsurface conditions encountered during our exploration generally consisted of moist, firm to very stiff lean clay and medium dense to dense, silty and clayey sand. • The site could experience a relatively large degree of ground shaking during a significant earthquake event on a nearby fault.
• Groundwater was not encountered during our subsurface exploration. Variations in the groundwater level across the site and over time should be anticipated. • Static settlement should be tolerable for the proposed improvements provided that the proposed structures are supported on foundations that conform to our recommendations and fill placement to raise grades is less than 2 feet in height. • Expansion Index and Atterberg limit testing indicates that the near-surface soil on site has a low expansion characteristic.
• Laboratory corrosion testing indicates that the near-surface site soils are considered moderately corrosive. A corrosion engineer should be consulted to provide specific guidance on protective measures to mitigate corrosion.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 8 9 RECOMMENDATIONS

9.1 Seismic Design Criteria
1 California Building Code Seismic Design Criteria
Site Classification D-Stiff Soil
Site Coefficient, Fa 1.0
Site Coefficient, Fv -- Mapped Spectral Response Acceleration at 0.2-second Period, Ss 1.941g Mapped Spectral Response Acceleration at 1.0-second Period, S1 0.799g Spectral Response Acceleration at 0.2-second Period Adjusted for Site Class, SMS 1.941g Spectral Response Acceleration at 1.0-second Period Adjusted for Site Class, SM1 -- Design Spectral Response Acceleration at 0.2-second Period, SDS 1.294g Design Spectral Response Acceleration at 1.0-second Period, SD1 -- Seismic Design Category for Risk Category I, II, or III II

9.2 Earthwork Recommendations
The following guidelines should be used in the preparation of the construction plans. The project plans and specifications should be reviewed by Ninyo & Moore prior to construction bidding to check for consistency with these recommendations.

Table 1 presents the Risk-Targeted, Maximum Considered Earthquake (MCER) spectral response accelerations consistent with the 2022 California Building Code and corresponding siteadjusted and design level spectral response accelerations based on the USGS seismic design maps (SEAOC/OSHPD, 2023).

According to shear-wave velocity in upper 30 meter of surficial geology map provided by California Department of Conservation (DOC, 2020), the shear wave velocity in the upper 30 meter is about 400 m/s. According to ASCE 7-16, Table 20.3-1, the site is classified as D, defined as stiff soil.

Earthwork should be performed in accordance with the requirements of applicable governing agencies and the recommendations presented below. The geotechnical consultant should observe earthwork operations. Evaluations performed by the geotechnical consultant during the course of operations may result in new recommendations, which could supersede the recommendations in this section.

The following guidelines should be used in the preparation of the construction plans. The project plans and specifications should be reviewed by Ninyo & Moore prior to construction bidding to check for consistency with these recommendations.

Table 1 presents the Risk-Targeted, Maximum Considered Earthquake (MCER) spectral response accelerations consistent with the 2022 California Building Code and corresponding siteadjusted and design level spectral response accelerations based on the USGS seismic design maps (SEAOC/OSHPD, 2023).

According to shear-wave velocity in upper 30 meter of surficial geology map provided by California Department of Conservation (DOC, 2020), the shear wave velocity in the upper 30 meter is about 400 m/s. According to ASCE 7-16, Table 20.3-1, the site is classified as D, defined as stiff soil.

Table -
Seismic Design Parameter
Evaluated for 37.658749° North Latitude, 122.408609°West Value Earthwork should be performed in accordance with the requirements of applicable governing agencies and the recommendations presented below. The geotechnical consultant should observe earthwork operations. Evaluations performed by the geotechnical consultant during the course of operations may result in new recommendations, which could supersede the recommendations in this section.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 9

9.2.1 9.2.2

9.2.3 9.2.4
Pre-Construction Conference
We recommend that a pre-construction conference be held to discuss the grading recommendations presented in the report. Representatives of South San Francisco, the architect, the engineer, Ninyo & Moore, and the contractor should be in attendance to discuss project schedule and earthwork requirements.

Site Preparation
Site preparation should begin with the removal of vegetation, utility lines, debris and other deleterious materials from areas to be graded. Tree stumps and roots should be removed to such a depth that organic material is generally not present. Clearing and grubbing should extend to the outside of the proposed excavation and fill areas. Rubble and excavated materials that do not meet criteria for use as fill should be disposed of in an appropriate landfill. Existing utilities in the work area should be relocated away from the proposed structures. Existing utilities to be abandoned should be removed, crushed in place, or backfilled with grout.

Excavations resulting from removal of existing building foundations, buried utilities, tree stumps, or obstructions should be backfilled with compacted fill in accordance with the recommendations presented in the following sections.

Observation and Removals
Prior to placement of fill, or the placement of forms or reinforcement for foundations, the client should request an evaluation of the exposed subgrade by Ninyo & Moore. Materials that are considered unsuitable shall be excavated under the observation of Ninyo & Moore in accordance with the recommendations provided in this section or supplemental recommendations by the geotechnical engineer. Based on the materials encountered during our subsurface exploration and the type of proposed construction, we do not anticipate that unsuitable materials will be encountered.

Unsuitable materials include, but may not be limited to dry, loose, soft, wet, expansive, organic, or compressible natural soil, and undocumented or otherwise deleterious fill materials. Unsuitable materials should be removed from trench bottoms and below bearing surfaces to a depth at which suitable foundation subgrade, as evaluated in the field by Ninyo & Moore, is exposed.

Material Recommendations
Materials used during earthwork, grading, and paving operations should comply with the requirements listed in Table 2. Materials should be evaluated by the geotechnical engineer Pre-Construction Conference
We recommend that a pre-construction conference be held to discuss the grading recommendations presented in the report. Representatives of South San Francisco, the architect, the engineer, Ninyo & Moore, and the contractor should be in attendance to discuss project schedule and earthwork requirements.

Site Preparation
Site preparation should begin with the removal of vegetation, utility lines, debris and other deleterious materials from areas to be graded. Tree stumps and roots should be removed to such a depth that organic material is generally not present. Clearing and grubbing should extend to the outside of the proposed excavation and fill areas. Rubble and excavated materials that do not meet criteria for use as fill should be disposed of in an appropriate landfill. Existing utilities in the work area should be relocated away from the proposed structures. Existing utilities to be abandoned should be removed, crushed in place, or backfilled with grout.

Excavations resulting from removal of existing building foundations, buried utilities, tree stumps, or obstructions should be backfilled with compacted fill in accordance with the recommendations presented in the following sections.

Observation and Removals
Prior to placement of fill, or the placement of forms or reinforcement for foundations, the client should request an evaluation of the exposed subgrade by Ninyo & Moore. Materials that are considered unsuitable shall be excavated under the observation of Ninyo & Moore in accordance with the recommendations provided in this section or supplemental recommendations by the geotechnical engineer. Based on the materials encountered during our subsurface exploration and the type of proposed construction, we do not anticipate that unsuitable materials will be encountered.

Unsuitable materials include, but may not be limited to dry, loose, soft, wet, expansive, organic, or compressible natural soil, and undocumented or otherwise deleterious fill materials. Unsuitable materials should be removed from trench bottoms and below bearing surfaces to a depth at which suitable foundation subgrade, as evaluated in the field by Ninyo & Moore, is exposed.

Material Recommendations
Materials used during earthwork, grading, and paving operations should comply with the requirements listed in Table 2. Materials should be evaluated by the geotechnical engineer Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 10 2 Recommended Material Requirements
Controlled Low Strength
Material (CLSM) Import CSS4 Section 19-3.02F
Notes:
1 In general, fill should be free of rocks or lumps in excess of 6 inches in diameter, trash, debris, roots, vegetation or other deleterious material.
2 In general, import fill should be tested or documented to be non-corrosive3and free from hazardous materials in concentrations above levels of concern.
3 Non-corrosive as defined by the Caltrans Corrosion Guidelines (Caltrans, 2018a). 4 CSS is California Standard Specifications (Caltrans, 2018b).

9.2.5 for suitability prior to use. The contractor should notify the geotechnical consultant 72 hours prior to import of materials or use of on-site materials to permit time for sampling, testing, and evaluation of the proposed materials. On-site materials may need to be dried out before reuse as fill. The contractor should be responsible for the uniformity of import material brought to the site.

General Fill: Import
- for uses not otherwise
specified
Import
Close-graded with 35 percent or more passing No.
4 sieve and either:

Expansion Index of 50 or less,
Plasticity Index of 12 or less,
or less than 10 percent, by dry weight, passing No.
200 sieve
On-site
borrow No additional requirements*
Aggregate Subbase Import Class II, CSS4 Section 25-1 .02 Aggregate Base Import Class II, CSS4 Section 26-1 .02
Pipe/Conduit Bedding and Pipe
Zone Material
-material below pipe invert to 12
inches above pipe
Import
90 to 100 percent (by mass) should pass No. 4
sieve, and 5 percent or less should pass No. 200
sieve
Trench Backfill
- above bedding material
Import or
on-site
borrow
As per general fill and excluding rock/lumps
retained on 4-inch sieve or 2-inch sieve in top 12
inches
Subgrade Preparation
Subgrade in trenches and below flatwork or fill should be prepared as per the recommendations in Table 3. Prepared subgrade should be maintained in a moist (but not saturated) condition by the periodic sprinkling of water prior to placement of additional overlying fill. Subgrade that has been permitted to dry out and loosen or develop desiccation cracking, should be scarified, moisture-conditioned, and reconpacted as per the requirements above.
for suitability prior to use. The contractor should notify the geotechnical consultant 72 hours prior to import of materials or use of on-site materials to permit time for sampling, testing, and evaluation of the proposed materials. On-site materials may need to be dried out before reuse as fill. The contractor should be responsible for the uniformity of import material brought to the site.

Table -
Material and Use Source Requirements1•
2 General Fill: Import
- for uses not otherwise
specified
Aggregate Subbase
Aggregate Base
Pipe/Conduit Bedding and Pipe
Zone Material
-material below pipe invert to 12
inches above pipe
Trench Backfill
- above bedding material
Import
On-site
borrow
Import
Import
Import
Import or
on-site
borrow
Subgrade Preparation
Close-graded with 35 percent or more passing No.
4 sieve and either:

Expansion Index of 50 or less,
Plasticity Index of 12 or less,
or less than 10 percent, by dry weight, passing No.
200 sieve
No additional requirements1
Class II; CSS4 Section 25-1.02
Class II; CSS4 Section 26-1 .02
90 to 100 percent (by mass) should pass No. 4
sieve, and 5 percent or less should pass No. 200
sieve
As per general fill and excluding rock/lumps
retained on 4-inch sieve or 2-inch sieve in top 12
inches
Subgrade in trenches and below flatwork or fill should be prepared as per the recommendations in Table 3. Prepared subgrade should be maintained in a moist (but not saturated) condition by the periodic sprinkling of water prior to placement of additional overlying fill. Subgrade that has been permitted to dry out and loosen or develop desiccation cracking, should be scarified, moisture-conditioned, and recompacted as per the requirements above.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 11 3 Subgrade Preparation Recommendations
Below fill, slabs, and
flatwork
After clearing per Section 9.2.2, check for unsuitable materials as per Section 9.2.3.

Scarify top 8 inches then moisture-condition and compact as per Section

9.2.6. Keep in moist condition by sprinkling water.

After clearing per Section 9.2.2, check for unsuitable materials as per Section 9.2.3.

Remove or compact loose/soft material.

9.2.6 4 Fill Placement and Compaction Recommendations
Subgrade Flatwork, or fill in locations not already
specified 90 percent + 2 percent orabove
General Fill In locations not already specified 90 percent + 2 percent or above
Bedding and
Pipe Zone Fill
Material below invert to 12 inches above pipe
or conduit 90 percent Near Optimum
Trench Backfill
Top 18 inches below finish subgrade for areas
subject to vehicular loading 95 percent + 2 percent orabove In locations not already specified 90 percent + 2 percent or above
Aggregate Base 95 percent Near Optimum
Notes:
1 Expressed as percent relative compaction or ratio of field density to reference density (typically on a dry density basis for soil and aggregate). The reference density of soil and aggregate should be evaluated by ASTM D 1557. 2 Target moisture content at compaction relative to the optimum as evaluated by ASTM D 1557.

Utility Trenches
.
.
.
.
.

Fill Placement and Compaction
Fill and backfill should be compacted in horizontal lifts in conformance with the recommendations presented in Table 4. The allowable uncompacted thickness of each lift of fill depends on the type of compaction equipment utilized, but generally should not exceed 8 inches in loose thickness.
and
Below hardscape
Compacted fill should be maintained in a moist (but not saturated) condition by the periodic sprinkling of water prior to placement of additional overlying fill. Fill that has been permitted to dry out and loosen or develop desiccation cracking, should be scarified, moistureconditioned, and recompacted as per the requirements above.

Table -
Subgrade Location Source
•
•
•
•
Utility Trenches
•
Fill Placement and Compaction
Fill and backfill should be compacted in horizontal lifts in conformance with the recommendations presented in Table 4. The allowable uncompacted thickness of each lift of fill depends on the type of compaction equipment utilized, but generally should not exceed 8 inches in loose thickness.

Table -
F"II T L f Compacted Moisture
1 ype oca ,on Density1 Content2
and
Below hardscape
Compacted fill should be maintained in a moist (but not saturated) condition by the periodic sprinkling of water prior to placement of additional overlying fill. Fill that has been permitted to dry out and loosen or develop desiccation cracking, should be scarified, moistureconditioned, and recompacted as per the requirements above.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 12

9.2.7 5 OSHA Material Classifications and Allowable Slopes Type C 1½ h:1v (34°) 80×D + 72
Notes:
1 Allowable slope for excavations less than 20 feet deep. Excavation sidewalls in cohesive soil may be benched to meet the allowable slope criteria (measured from the bottom edge of the excavation). The allowable bench height is 4 feet. The bench at the bottom of the excavation may protrude above the allowable slope criteria. 2 In layered soil, layers shall not be sloped steeper than the layer below. 3 Temporary excavations less than 5 feet deep may be made with vertical side slopes and remain unshored if judged to be stable by a competent person (29 CFR, Part 1926.650).
4 soil.

Temporary Excavations and Shoring
Trench excavations shall be stabilized in accordance with the Excavation Rules and Regulations (29 Code of Federal Regulations [CFR], Part 1926) stipulated by the Occupational Safety and Health Administration (OSHA). Stabilization shall consist of shoring sidewalls or laying slopes back.

Dewatering pits or sumps should be used to depress the groundwater level (if encountered) below the bottom of the excavation. Table 5 lists the OSHA material type classifications and corresponding allowable temporary slope layback inclinations for soil deposits that may be encountered on site. Alternatively, an internally-braced shoring system or trench shield conforming to the OSHA Excavation Rules and Regulations (29 CFR, Part 1926) may be used to stabilize excavation sidewalls during construction. The lateral earth pressures listed in Table 5 may be used to design or select the internally-braced shoring system or trench shield. The recommendations listed in this table are based upon the limited subsurface data provided by our exploratory borings and reflect the influence of the environmental conditions that existed at the time of our exploration. Excavation stability, material classifications, allowable slopes, and shoring pressures should be re-evaluated and revised, as-needed, during construction. Excavations, shoring systems and the surrounding areas should be evaluated daily by a competent person for indications of possible instability or collapse.

Alluvium
(above groundwater)
'D' is depth of excavation for excavations up to 20 feet deep. Includes a surface surcharge equivalent to two feet of The shoring system should be designed or selected by a suitably qualified individual or specialty subcontractor. The shoring parameters presented in this report are preliminary design criteria, and the designer should evaluate the adequacy of these parameters and make appropriate modifications for their design. We recommend that the contractor take Temporary Excavations and Shoring
Trench excavations shall be stabilized in accordance with the Excavation Rules and Regulations (29 Code of Federal Regulations [CFR], Part 1926) stipulated by the Occupational Safety and Health Administration (OSHA). Stabilization shall consist of shoring sidewalls or laying slopes back.

Dewatering pits or sumps should be used to depress the groundwater level (if encountered) below the bottom of the excavation. Table 5 lists the OSHA material type classifications and corresponding allowable temporary slope layback inclinations for soil deposits that may be encountered on site. Alternatively, an internally-braced shoring system or trench shield conforming to the OSHA Excavation Rules and Regulations (29 CFR, Part 1926) may be used to stabilize excavation sidewalls during construction. The lateral earth pressures listed in Table 5 may be used to design or select the internally-braced shoring system or trench shield. The recommendations listed in this table are based upon the limited subsurface data provided by our exploratory borings and reflect the influence of the environmental conditions that existed at the time of our exploration. Excavation stability, material classifications, allowable slopes, and shoring pressures should be re-evaluated and revised, as-needed, during construction. Excavations, shoring systems and the surrounding areas should be evaluated daily by a competent person for indications of possible instability or collapse.

Table -
Formation
Alluvium
(above groundwater)
OSHA
Classification
Allowable
Temporary Slope1•
2•3
Lateral Earth
Pressure on
Shoring4 (psf)
'D' is depth of excavation for excavations up to 20 feet deep. Includes a surface surcharge equivalent to two feet of The shoring system should be designed or selected by a suitably qualified individual or specialty subcontractor. The shoring parameters presented in this report are preliminary design criteria, and the designer should evaluate the adequacy of these parameters and make appropriate modifications for their design. We recommend that the contractor take Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 13

9.2.8 appropriate measures to protect workers. OSHA requirements pertaining to worker safety should be obsen/ed.

Excavations made in close proximity to existing structures may undermine the foundation of those structures and/or cause soil movement related distress to the existing structures.

Stabilization techniques for excavations in close proximity to existing structures will need to account for the additional loads imposed on the shoring system and appropriate setback distances for temporary slopes. The geotechnical engineer should be consulted for additional recommendations ifthe proposed excavations cross below a plane extending down and away from the foundation bearing surfaces of the adjacent structure at an angle of 2:1 (horizontal to vertical).

The excavation bottoms may encounter wet, loose material, which may be subject to pumping under heavy equipment loads. The contractor should be prepared to stabilize the bottom of the excavations. In general, unstable bottom conditions may be mitigated by using a stabilizing geogrid, overexcavating the excavation bottom to suitable depths and replacing with compacted fill, or other suitable method. Additionally, aeration of wet soils should be anticipated.

Utility Trenches
Trenches constructed for the installation of underground utilities should be stabilized in accordance with our recommendations in Section 9.2.7. Utility trenches should be backfilled with materials that conform to our recommendations in Section 9.2.4. Trench backfill, bedding, and pipe zone fill should be compacted in accordance with Section 9.2.6 of this report. Bedding and pipe zone fill should be shoveled under pipe haunches and compacted by manual or mechanical, hand-held tampers. Trench backfill should be compacted by mechanical means. Densification of trench backfill by flooding or jetting should not be permitted.

To reduce potential for moisture intrusion into a building envelope, we recommend plugging utility trenches at locations where the trench excavations cross under a building perimeter.

The trench plug should be constructed of a compacted, fine-grained, cohesive soil that fills the cross-sectional area of the trench for a distance equivalent to the depth of the excavation.

Alternatively, the plug may be constructed of concrete or CLSM. appropriate measures to protect workers. OSHA requirements pertaining to worker safety should be observed.

Excavations made in close proximity to existing structures may undermine the foundation of those structures and/or cause soil movement related distress to the existing structures.

Stabilization techniques for excavations in close proximity to existing structures will need to account for the additional loads imposed on the shoring system and appropriate setback distances for temporary slopes. The geotechnical engineer should be consulted for additional recommendations if the proposed excavations cross below a plane extending down and away from the foundation bearing surfaces of the adjacent structure at an angle of 2: 1 (horizontal to vertical).

The excavation bottoms may encounter wet, loose material, which may be subject to pumping under heavy equipment loads. The contractor should be prepared to stabilize the bottom of the excavations. In general, unstable bottom conditions may be mitigated by using a stabilizing geogrid, overexcavating the excavation bottom to suitable depths and replacing with compacted fill, or other suitable method. Additionally, aeration of wet soils should be anticipated.

Utility Trenches
Trenches constructed for the installation of underground utilities should be stabilized in accordance with our recommendations in Section 9.2.7. Utility trenches should be backfilled with materials that conform to our recommendations in Section 9.2.4. Trench backfill, bedding, and pipe zone fill should be compacted in accordance with Section 9.2.6 of this report. Bedding and pipe zone fill should be shoveled under pipe haunches and compacted by manual or mechanical, hand-held tampers. Trench backfill should be compacted by mechanical means. Densification of trench backfill by flooding or jetting should not be permitted.

To reduce potential for moisture intrusion into a building envelope, we recommend plugging utility trenches at locations where the trench excavations cross under a building perimeter.

The trench plug should be constructed of a compacted, fine-grained, cohesive soil that fills the cross-sectional area of the trench for a distance equivalent to the depth of the excavation.

Alternatively, the plug may be constructed of concrete or CLSM.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 14

9.2.9 9.3 Structure Foundations

9.3.1 Rainy Weather Considerations
Earthwork and foundation construction should be performed during the period between approximately April 15 and October 15 to avoid the rainy season. In the event that grading is performed during the rainy season, the plans for the project should be supplemented to include a stormwater management plan prepared in accordance with the requirements of the relevant agency having jurisdiction. The plan should include details of measures to protect the subject property and adjoining off-site properties from damage by erosion, flooding or the deposition of mud, debris, or construction-related pollutants, which may originate from the site or result from the grading operation. The protective measures should be installed by the commencement of grading, or prior to the start of the rainy season. The protective measures should be maintained in good working order unless the project drainage system is installed by that date and approval has been granted by the building official to remove the temporary devices.

In addition, construction activities performed during rainy weather may impact the stability of excavation subgrade and exposed ground. Temporary swales should be constructed to divert surface runoff away from excavations and slopes. Steep temporary slopes should be covered with plastic sheeting during significant rains. The geotechnical consultant should be consulted for recommendations to stabilize the site as-needed.

Foundations should be designed in accordance with structural considerations and the following recommendations. In addition, requirements of the appropriate governing jurisdictions and applicable building codes should be considered in design of the structures.

Shallow Foundation
The proposed structures may be designed for a net allowable bearing capacity of 2,000 pounds per square foot (psf) presuming that the foundation is constructed per the recommendations in this report. This allowable bearing capacity includes a factor of safety of more than 3 and may be increased by one-third when considering wind or seismic loading combinations. Shallow foundations should have a minimum width of 24 inches and a minimum depth of the foundation base below adjacent grade of 24 inches.

The proposed structures should be designed for a total settlement of 'A-inch due to sustained loads and a differential settlement of '/-inch over a 20-foot span. The deflection of a mat foundation due to applied loads may be evaluated using a modulus of subgrade reaction equivalent to 50 pounds per cubic inch. Foundations may undergo additional settlement due Rainy Weather Considerations
Earthwork and foundation construction should be performed during the period between approximately April 15 and October 15 to avoid the rainy season. In the event that grading is performed during the rainy season, the plans for the project should be supplemented to include a stormwater management plan prepared in accordance with the requirements of the relevant agency having jurisdiction. The plan should include details of measures to protect the subject property and adjoining off-site properties from damage by erosion, flooding or the deposition of mud, debris, or construction-related pollutants, which may originate from the site or result from the grading operation. The protective measures should be installed by the commencement of grading, or prior to the start of the rainy season. The protective measures should be maintained in good working order unless the project drainage system is installed by that date and approval has been granted by the building official to remove the temporary devices.

In addition, construction activities performed during rainy weather may impact the stability of excavation subgrade and exposed ground. Temporary swales should be constructed to divert surface runoff away from excavations and slopes. Steep temporary slopes should be covered with plastic sheeting during significant rains. The geotechnical consultant should be consulted for recommendations to stabilize the site as-needed.

Foundations should be designed in accordance with structural considerations and the following recommendations. In addition, requirements of the appropriate governing jurisdictions and applicable building codes should be considered in design of the structures.

Shallow Foundation
The proposed structures may be designed for a net allowable bearing capacity of 2,000 pounds per square foot (psf) presuming that the foundation is constructed per the recommendations in this report. This allowable bearing capacity includes a factor of safety of more than 3 and may be increased by one-third when considering wind or seismic loading combinations. Shallow foundations should have a minimum width of 24 inches and a minimum depth of the foundation base below adjacent grade of 24 inches.

The proposed structures should be designed for a total settlement of ½-inch due to sustained loads and a differential settlement of ¼-inch over a 20-foot span. The deflection of a mat foundation due to applied loads may be evaluated using a modulus of subgrade reaction equivalent to 50 pounds per cubic inch. Foundations may undergo additional settlement due Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 15 to seismic shaking following a significant earthquake. To mitigate differential settlement between the structure and exterior flatwork, the exterior flatwork may be designed as a knockout slab. The geotechnical engineer should observe foundation subgrade to evaluate bearing materials and subgrade condition before the exposed subgrade is covered.

The mat slab and slab reinforcement should be designed and detailed by the structural engineer based on the anticipate loading and usage. Recommendations for concrete and concrete cover over reinforcing steel are presented in Section .5. Masonry briquettes or plastic chairs should be used to aid in the correct placement of slab reinforcement.

A moisture vapor retarding system, consisting of a Class A plastic membrane conforming to ASTM E1745 on a 6-inch thick capillary break layer of 3/-inch crushed rock, should be provided under mat slabs overlain by moisture sensitive floor coverings or underlying conditioned spaces. Where a moisture vapor retarding system is not needed, mat slabs should be constructed over 6 inches of aggregate base that conforms to the criteria for Class 2 aggregate base in Section 26-1.02 of the California Standard Specifications (Caltrans 2015) and is compacted to 95 percent of the reference density as evaluated by ASTM D1557.

A layer of coarse sand, up to 2 inches thick, may be placed over the aggregate base or moisture vapor retarder to provide a level surface for precast mat foundations.

Afriction coefficient of 0.35 and a lateral bearing pressure of 250 psf per foot of embedment depth may be used to evaluate foundation resistance to lateral loads. The lateral bearing pressure should be neglected to a depth of 12 inches where the ground adjacent to the foundation is not covered by a slab or pavement. The lateral bearing pressure may be increased by one-third when considering loads of short duration such as wind or seismic forces.

Vaults or other below grade walls should be designed to resist at-rest earth pressures. Vaults backfilled with imported fill or on-site soil meeting the criteria for general fill in Section9.2.4 should be designed to resist an at-rest lateral earth pressure equivalent to 94 psf per foot depth for undrained conditions with level backfill or 64 psf per foot depth for drained conditions with level backfill. For rising backfill conditions, the at-rest equivalent fluid earth pressure may be increased by 1 psf per foot depth per degree of inclination.

Walls retaining level ground should be designed to resist construction or live load surcharges on the backfill. The lateral earth pressure due to a backfill surcharge of 240 psf should be a uniform pressure of 120 psf for at-rest conditions. Vaults may be supported on deep mat foundations designed in conformance with the recommendations in this report. to seismic shaking following a significant earthquake. To mitigate differential settlement between the structure and exterior flatwork, the exterior flatwork may be designed as a knockout slab. The geotechnical engineer should observe foundation subgrade to evaluate bearing materials and subgrade condition before the exposed subgrade is covered.

The mat slab and slab reinforcement should be designed and detailed by the structural engineer based on the anticipate loading and usage. Recommendations for concrete and concrete cover over reinforcing steel are presented in Section 9.5. Masonry briquettes or plastic chairs should be used to aid in the correct placement of slab reinforcement.

A moisture vapor retarding system, consisting of a Class A plastic membrane conforming to ASTM E 17 45 on a 6-inch thick capillary break layer of ¾-inch crushed rock, should be provided under mat slabs overlain by moisture sensitive floor coverings or underlying conditioned spaces. Where a moisture vapor retarding system is not needed, mat slabs should be constructed over 6 inches of aggregate base that conforms to the criteria for Class 2 aggregate base in Section 26-1 .02 of the California Standard Specifications (Caltrans 2015) and is compacted to 95 percent of the reference density as evaluated by ASTM D1557.

A layer of coarse sand, up to 2 inches thick, may be placed over the aggregate base or moisture vapor retarder to provide a level surface for precast mat foundations.

A friction coefficient of 0.35 and a lateral bearing pressure of 250 psf per foot of embedment depth may be used to evaluate foundation resistance to lateral loads. The lateral bearing pressure should be neglected to a depth of 12 inches where the ground adjacent to the foundation is not covered by a slab or pavement. The lateral bearing pressure may be increased by one-third when considering loads of short duration such as wind or seismic forces.

Vaults or other below grade walls should be designed to resist at-rest earth pressures. Vaults backfilled with imported fill or on-site soil meeting the criteria for general fill in Section9.2.4 should be designed to resist an at-rest lateral earth pressure equivalent to 94 psf per foot depth for undrained conditions with level backfill or 64 psf per foot depth for drained conditions with level backfill. For rising backfill conditions, the at-rest equivalent fluid earth pressure may be increased by 1 psf per foot depth per degree of inclination.

Walls retaining level ground should be designed to resist construction or live load surcharges on the backfill. The lateral earth pressure due to a backfill surcharge of 240 psf should be a uniform pressure of 120 psf for at-rest conditions. Vaults may be supported on deep mat foundations designed in conformance with the recommendations in this report.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 16

9.3.2 9.4 Pavements and Flatwork
The foundation design parameters provided are not intended to preclude differential movement of foundations. Minor cracking may occur.

Drilled Piers
The new trellis and shade structures, art piece, and other minor pole structures may be supported on drilled pier foundations. Drilled piers embedded 5 to 15 feet deep may be designed for an allowable side friction of 200 pounds per square foot (psf) to evaluate resistance to downward axial loads and 100 psf per foot depth for upward axial loads. The allowable side friction may be increased by one-third when considering loads of short duration, such as wind or seismic loads. Soil support over the upper 1.5 feet of the pier should be assumed to be zero.

An allowable lateral bearing pressure of 250 psf per foot depth up to 2,500 psf may be used to evaluate resistance to lateral loads and overturning moments. The allowable lateral bearing pressure may be increased by a factor of two for structures that can accommodate 'A inch of lateral deflection and by 1% for wind or seismic loading conditions.

Drilled pier excavations should be cleaned of loose material prior to pouring concrete. Drilled pier excavations that encounter groundwater or cohesionless soil may be unstable, and may need to be stabilized by temporary casing or use of drilling mud. Standing water should be removed from the pier excavation, or the concrete should be delivered to the bottom of the excavation, below the water surface, by tremie pipe. Casing should be removed from the excavation as the concrete is placed. Concrete should be placed in the piers in a manner that reduces the potential for segregation of the components.

Recommendations for asphalt pavement and exterior flatwork are presented in the following sections. The design R-value used for evaluating the pavement sections was selected based on R-value testing performed on a sample collected during our subsurface exploration. The pavement subgrade should be observed by the geotechnical engineer during grading to check that the exposed materials are consistent with the findings from our subsurface exploration and the support characteristics assumed for pavement design. Additional R-value testing may be needed, based on these observations, with subsequent revision to the pavement sections.

Recommendations for preparation of subgrade are presented in Section 9.2.5.

The foundation design parameters provided are not intended to preclude differential movement of foundations. Minor cracking may occur.

Drilled Piers
The new trellis and shade structures, art piece, and other minor pole structures may be supported on drilled pier foundations. Drilled piers embedded 5 to 15 feet deep may be designed for an allowable side friction of 200 pounds per square foot (psf) to evaluate resistance to downward axial loads and 100 psf per foot depth for upward axial loads. The allowable side friction may be increased by one-third when considering loads of short duration, such as wind or seismic loads. Soil support over the upper 1.5 feet of the pier should be assumed to be zero.

An allowable lateral bearing pressure of 250 psf per foot depth up to 2,500 psf may be used to evaluate resistance to lateral loads and overturning moments. The allowable lateral bearing pressure may be increased by a factor of two for structures that can accommodate ½ inch of lateral deflection and by 1 ½ for wind or seismic loading conditions.

Drilled pier excavations should be cleaned of loose material prior to pouring concrete. Drilled pier excavations that encounter groundwater or cohesionless soil may be unstable, and may need to be stabilized by temporary casing or use of drilling mud. Standing water should be removed from the pier excavation, or the concrete should be delivered to the bottom of the excavation, below the water surface, by tremie pipe. Casing should be removed from the excavation as the concrete is placed. Concrete should be placed in the piers in a manner that reduces the potential for segregation of the components.

Recommendations for asphalt pavement and exterior flatwork are presented in the following sections. The design R-value used for evaluating the pavement sections was selected based on R-value testing performed on a sample collected during our subsurface exploration. The pavement subgrade should be observed by the geotechnical engineer during grading to check that the exposed materials are consistent with the findings from our subsurface exploration and the support characteristics assumed for pavement design. Additional R-value testing may be needed, based on these observations, with subsequent revision to the pavement sections.

Recommendations for preparation of subgrade are presented in Section 9.2.5.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 17

9.4.1 6 Asphalt Concrete Pavement Sections
Notes:

Pavement sections were evaluated for a range of traffic indexes or loading conditions. The designer may interpolate between the values provided once a traffic index or loading condition has been selected.

Asphalt Pavemen
Ninyo & Moore conducted an analysis to evaluate appropriate asphalt pavement structural sections following the methodology presented in the Highway Design Manual (Caltrans, 2020). Alternative sections were evaluated. The pavement sections were designed for a 20-year service life presuming that periodic maintenance, including crack sealing and resurfacing will be performed during the service life of the pavement. Premature deterioration may occur without periodic maintenance. Our recommendations for the pavement sections are presented in Table 6.

Paving operations and base preparation should be observed and tested by Ninyo Moore.

Subgrade enhancement geotextiles, where utilized, should be rolled out flat and tight, without folds or wrinkles, over prepared subgrade in the direction of travel. The geotextile should be pinned to the subgrade with nails and washers or u-shaped sod staples. Adjacent rolls should overlap 12 inches or more. Abutting rolls should overlap in the direction of fill placement to reduce the potential for peeling of the geotextile during fill placement. Aggregate base fill should be pushed over the geotextile into position and compacted. To reduce the potential for displacement of the geotextile or deterioration of the subgrade, construction equipment should not operate on the geotextile with 6 inches of aggregate base cover. 3 7
4 inches AC 2% inches AC
4% inches AB
6 7
10 inches AC 4 inches AC
12% inches AB
g 7
12 inches AC 5 inches AC
15 inches AB
1 AC is Type A, Dense-Graded Hot Mix Asphalt complying with Caltrans Standard Specification 39-2 (2022).

AB is Class II Aggregate Base complying with Caltrans Standard Specification 26-1 .02 (2022).

SEG is subgrade enhancement geotextile such as Mirafi 600X or equivalent.

Pavement sections were evaluated for a range of traffic indexes or loading conditions. The designer may interpolate between the values provided once a traffic index or loading condition has been selected.

Asphalt Pavement
Ninyo & Moore conducted an analysis to evaluate appropriate asphalt pavement structural sections following the methodology presented in the Highway Design Manual (Caltrans, 2020). Alternative sections were evaluated. The pavement sections were designed for a 20-year service life presuming that periodic maintenance, including crack sealing and resurfacing will be performed during the service life of the pavement. Premature deterioration may occur without periodic maintenance. Our recommendations for the pavement sections are presented in Table 6.

Paving operations and base preparation should be observed and tested by Ninyo & Moore.

Subgrade enhancement geotextiles, where utilized, should be rolled out flat and tight, without folds or wrinkles, over prepared subgrade in the direction of travel. The geotextile should be pinned to the subgrade with nails and washers or u-shaped sod staples. Adjacent rolls should overlap 12 inches or more. Abutting rolls should overlap in the direction of fill placement to reduce the potential for peeling of the geotextile during fill placement. Aggregate base fill should be pushed over the geotextile into position and compacted. To reduce the potential for displacement of the geotextile or deterioration of the subgrade, construction equipment should not operate on the geotextile with 6 inches of aggregate base cover.

Table -
Traffic Index R-value Alternative 1 Alternative 2
3 7 4 inchesAC 2½ inches AC
4½ inches AB
6 7 10 inches AC 4 inchesAC
12½ inches AB
9 7 12 inches AC 5 inchesAC
15 inches AB
1 AC is Type A, Dense-Graded Hot Mix Asphalt complying with Caltrans Standard Specification 39-2 (2022). 2 AB is Class II Aggregate Base complying with Caltrans Standard Specification 26-1 .02 (2022). 3 SEG is subgrade enhancement geotextile such as Mirafi 600X or equivalent.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 18

9.4.2 Aggregate base for pavement should be placed in lifts of no more than 8 inches in loose thickness and compacted per Section 9.2.6. Asphalt concrete should be placed and compacted per Section 9.2.6. Pavements should be sloped so that runoff is diverted to an appropriate collector (concrete gutter, swale, or area drain) to reduce the potential for ponding of water on the pavement. Concentration of runoff over asphalt pavement should be discouraged.

Concrete Pavemen
Concrete and aggregate base thickness should be 6 inches or more for flatwork subject to vehicular traffic up to periodic garbage trucks and emergency vehicles. Flatwork subject to impact from unloading of dumpsters should be 8 inches thick or more.

Appropriate jointing of concrete flatwork can encourage cracks to form at joints, reducing the potential for crack development between joints. Joints should be laid out in a square pattern at consistent intervals. Contraction and construction joints should be detailed and constructed in accordance with the guidelines OfACI Committee 302. The ratio of lateral spacing between contraction joints to the nominal thickness of the slab should not exceed 24 for jointed plain concrete. Contraction joints formed by premolded inserts, grooving plastic concrete, or sawcutting at initial hardening, should extend to a depth equivalent to 25 percent of the slab thickness and 1 inch or more for thin slabs. The joint location and layout of new or reconstructed flatwork abutting existing flatwork should be consistent with joint location/layout of the existing flatwork.

Flatwork may be reinforced with distributed steel to reduce the potential for differential slab movement where cracking occurs. The distributed reinforcing steel should be terminated about 3 inches from contraction joints and should consist of No. 3 deformed bars at 18 inches on center, both ways, or with 6x6-D4/D4 welded wire fabric supplied as sheets (not rolls).

Slabs reinforced with distributed steel should be 6 inches thick (or more) for No. 3 bar reinforcement and 5 inches thick (or more) for 6x6-D4/D4 reinforcement to provide adequate concrete cover for the steel. To reduce the potential for differential slab movement across joints, the distributed steel may be extended through the joints. This improvement will be balanced by a reduction in the functionality of the contraction joint to encourage crack formation at joints. Flatwork subject to impact from unloading of dumpsters should be reinforced with No. 4 deformed bars at 12 inches on center, both ways extending through contraction joints, if present. Masonry briquettes or plastic chairs should be used to maintain the position of the reinforcement in the upper half of the slab with 1% inches of cover over Aggregate base for pavement should be placed in lifts of no more than 8 inches in loose thickness and compacted per Section 9.2.6. Asphalt concrete should be placed and compacted per Section 9.2.6. Pavements should be sloped so that runoff is diverted to an appropriate collector (concrete gutter, swale, or area drain) to reduce the potential for ponding of water on the pavement. Concentration of runoff over asphalt pavement should be discouraged.

Concrete Pavement
Concrete and aggregate base thickness should be 6 inches or more for flatwork subject to vehicular traffic up to periodic garbage trucks and emergency vehicles. Flatwork subject to impact from unloading of dumpsters should be 8 inches thick or more.

Appropriate jointing of concrete flatwork can encourage cracks to form at joints, reducing the potential for crack development between joints. Joints should be laid out in a square pattern at consistent intervals. Contraction and construction joints should be detailed and constructed in accordance with the guidelines of ACI Committee 302. The ratio of lateral spacing between contraction joints to the nominal thickness of the slab should not exceed 24 for jointed plain concrete. Contraction joints formed by premolded inserts, grooving plastic concrete, or sawcutting at initial hardening, should extend to a depth equivalent to 25 percent of the slab thickness and 1 inch or more for thin slabs. The joint location and layout of new or reconstructed flatwork abutting existing flatwork should be consistent with joint location/layout of the existing flatwork.

Flatwork may be reinforced with distributed steel to reduce the potential for differential slab movement where cracking occurs. The distributed reinforcing steel should be terminated about 3 inches from contraction joints and should consist of No. 3 deformed bars at 18 inches on center, both ways, or with 6x6-D4/D4 welded wire fabric supplied as sheets (not rolls).

Slabs reinforced with distributed steel should be 6 inches thick ( or more) for No. 3 bar reinforcement and 5 inches thick (or more) for 6x6-D4/D4 reinforcement to provide adequate concrete cover for the steel. To reduce the potential for differential slab movement across joints, the distributed steel may be extended through the joints. This improvement will be balanced by a reduction in the functionality of the contraction joint to encourage crack formation at joints. Flatwork subject to impact from unloading of dumpsters should be reinforced with No. 4 deformed bars at 12 inches on center, both ways extending through contraction joints, if present. Masonry briquettes or plastic chairs should be used to maintain the position of the reinforcement in the upper half of the slab with 1 ½ inches of cover over Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 19

9.4.3 the steel and 3 inches of cover under the steel. Root barriers adjacent to trees may be considered to reduce the potential for pavement heave from root growth.

After demolition, clearing, and rough grading, finish subgrade for flatwork should be scarified and moisture conditioned as needed to achieve a moisture content about 2 percentage points above the optimum, before compaction, by mechanical means, to 90 percent or more of ASTM D1557 reference density on a dry density basis for flatwork that is not subject to vehicular loading and 95 percent of the reference density for flatwork that is subject to vehicular loading. Aggregate base should conform to the criteria for Class 2 aggregate base in Section 26-1.02 of the California Standard Specifications (Caltrans, 2022) and should be placed and compacted in lifts by vibrating plates, smooth drum rollers, or mechanical tampers, to 95 percent of the ASTM D1557 reference density on a dry density basis after moisture conditioning to near the optimum moisture content. The allowable lift thickness is influenced by the type of compaction equipment utilized but generally should not exceed 8 inches in loose thickness. Compacted subgrade and aggregate base should be maintained in a moist condition by sprinkling water. Compacted subgrade or aggregate base that has dried out and loosened or developed desiccation cracking should be scarified and moistureconditioned, as needed, and recompacted as per the requirements above before the material is covered with concrete or aggregate base.

Exterior Flatwor
Concrete walkways and other exterior flatwork not subject to vehicular loading should be 4 inches thick (or more) over 6 inches of aggregate base. Appropriate jointing of concrete flatwork can encourage cracks to form at joints, reducing the potential for crack development between joints. Joints should be laid out in a square pattern at consistent intervals.

Contraction and construction should be detailed and constructed in accordance with the guidelines ofACl Committee 302 (ACI, 2016). The lateral spacing between contraction joints should be 8 feet or less for a 4-inch thick slab.

Distributed reinforcing steel may be utilized to reduce the potential for differential slab movement, should cracking occur between joints. The distributed reinforcing steel should be terminated about 6 inches from contraction joints and should consist of No. 3 deformed bars at 18 inches on center, both ways. Slabs reinforced with distributed steel should be 5 inches thick (or more). To reduce the potential for differential slab movement across joints, the distributed steel may be extended through the joints. This improvement will be balanced by a reduction in the functionality of the contraction joint to encourage crack formation at joints. the steel and 3 inches of cover under the steel. Root barriers adjacent to trees may be considered to reduce the potential for pavement heave from root growth.

After demolition, clearing, and rough grading, finish subgrade for flatwork should be scarified and moisture conditioned as needed to achieve a moisture content about 2 percentage points above the optimum, before compaction, by mechanical means, to 90 percent or more of ASTM D1557 reference density on a dry density basis for flatwork that is not subject to vehicular loading and 95 percent of the reference density for flatwork that is subject to vehicular loading. Aggregate base should conform to the criteria for Class 2 aggregate base in Section 26-1.02 of the California Standard Specifications (Caltrans, 2022) and should be placed and compacted in lifts by vibrating plates, smooth drum rollers, or mechanical tampers, to 95 percent of the ASTM D1557 reference density on a dry density basis after moisture conditioning to near the optimum moisture content. The allowable lift thickness is influenced by the type of compaction equipment utilized but generally should not exceed 8 inches in loose thickness. Compacted subgrade and aggregate base should be maintained in a moist condition by sprinkling water. Compacted subgrade or aggregate base that has dried out and loosened or developed desiccation cracking should be scarified and moistureconditioned, as needed, and recompacted as per the requirements above before the material is covered with concrete or aggregate base.

Exterior Flatwork
Concrete walkways and other exterior flatwork not subject to vehicular loading should be 4 inches thick (or more) over 6 inches of aggregate base. Appropriate jointing of concrete flatwork can encourage cracks to form at joints, reducing the potential for crack development between joints. Joints should be laid out in a square pattern at consistent intervals.

Contraction and construction should be detailed and constructed in accordance with the guidelines of ACI Committee 302 (ACI, 2016). The lateral spacing between contraction joints should be 8 feet or less for a 4-inch thick slab.

Distributed reinforcing steel may be utilized to reduce the potential for differential slab movement, should cracking occur between joints. The distributed reinforcing steel should be terminated about 6 inches from contraction joints and should consist of No. 3 deformed bars at 18 inches on center, both ways. Slabs reinforced with distributed steel should be 5 inches thick (or more). To reduce the potential for differential slab movement across joints, the distributed steel may be extended through the joints. This improvement will be balanced by a reduction in the functionality of the contraction joint to encourage crack formation at joints.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 20

9.5 Concrete

9.6 Surface Drainage

9.7 Review of Construction Plans
Masonry briquettes or plastic chairs should be used to maintain the position of the reinforcement in the upper half of the slab with 1% inches of cover over the steel.

Due to the variability in the on-site soil, we recommend that Type IIN or Type V cement be used for concrete structures in contact with soil. In addition, we recommend a water-to-cement ratio of no more than 0.45. A 3-inch thick, or thicker, concrete cover should be maintained over reinforcing steel where concrete is in contact with soil in accordance with Section 20.6 of ACI Concrete Institute (ACI) Committee 318 (ACI, 2016).

To reduce the potential for shrinkage cracks in the concrete during curing, concrete for slabs and flatwork should not contain large quantities of water or accelerating admixtures containing calcium chloride. Higher compressive strengths may be achieved by using larger aggregates in lieu of increasing the cement content and corresponding water demand. Additional workability, if desired, may be obtained by including water-reducing or air-entraining admixtures. Concrete should be placed in accordance with the appropriate guidance in the ACI Manual of Concrete Practice (MCP) and project specifications. Particular attention should be given to curing techniques and curing duration. Slabs that do not receive adequate curing have a more pronounced tendency to develop random shrinkage cracks and other defects.

Positive surface drainage should be provided to divert surface water and roof runoff away from foundations. Downspouts should be connected to a closed drainage system to discharge at a suitable location 10 feet or more away from the foundations. Runoff should be diverted by the use of swales or pipes into a collective drainage system. Drainage on the site should be provided so that water is not permitted to pond. A gradient of 2 percent or steeper should be maintained and drainage patterns should be established to divert and remove water from the site to appropriate outlets. Care should be taken by the contractor during grading to preserve any berms, drainage terraces, interceptor swales or other drainage devices on or adjacent to the project site. Drainage patterns established at the time of grading should be maintained for the life of the project.

The recommendations provided in this report are based on preliminary design information for the proposed construction. We recommend that a copy of the plans be provided to Ninyo & Moore for review before bidding to check the interpretation of our recommendations and verify that the designed improvements are consistent with our assumptions. It should be noted that, upon review Masonry briquettes or plastic chairs should be used to maintain the position of the reinforcement in the upper half of the slab with 1 ½ inches of cover over the steel.

Due to the variability in the on-site soil, we recommend that Type IIN or Type V cement be used for concrete structures in contact with soil. In addition, we recommend a water-to-cement ratio of no more than 0.45. A 3-inch thick, or thicker, concrete cover should be maintained over reinforcing steel where concrete is in contact with soil in accordance with Section 20.6 of ACI Concrete Institute (ACI) Committee 318 (ACI, 2016).

To reduce the potential for shrinkage cracks in the concrete during curing, concrete for slabs and flatwork should not contain large quantities of water or accelerating admixtures containing calcium chloride. Higher compressive strengths may be achieved by using larger aggregates in lieu of increasing the cement content and corresponding water demand. Additional workability, if desired, may be obtained by including water-reducing or air-entraining admixtures. Concrete should be placed in accordance with the appropriate guidance in the ACI Manual of Concrete Practice (MCP) and project specifications. Particular attention should be given to curing techniques and curing duration. Slabs that do not receive adequate curing have a more pronounced tendency to develop random shrinkage cracks and other defects.

Positive surface drainage should be provided to divert surface water and roof runoff away from foundations. Downspouts should be connected to a closed drainage system to discharge at a suitable location 10 feet or more away from the foundations. Runoff should be diverted by the use of swales or pipes into a collective drainage system. Drainage on the site should be provided so that water is not permitted to pond. A gradient of 2 percent or steeper should be maintained and drainage patterns should be established to divert and remove water from the site to appropriate outlets. Care should be taken by the contractor during grading to preserve any berms, drainage terraces, interceptor swales or other drainage devices on or adjacent to the project site. Drainage patterns established at the time of grading should be maintained for the life of the project.

The recommendations provided in this report are based on preliminary design information for the proposed construction. We recommend that a copy of the plans be provided to Ninyo & Moore for review before bidding to check the interpretation of our recommendations and verify that the designed improvements are consistent with our assumptions. It should be noted that, upon review Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 21

9.8 Construction Observation and Testing
10 LIMITATIONS
of these documents, some recommendations presented in this report might be revised or modified to meet the project requirements.

The recommendations provided in this report are based on subsurface conditions encountered in relatively widely spaced exploratory borings. During construction, the geotechnical engineer or his representative in the field should be allowed to check the exposed subsurface conditions.

During construction, the geotechnical engineer or his representative should be allowed to:
.

Observe preparation and compaction of subgrade.

Check and test imported materials prior to use as fill. •
.

Observe placement and compaction of fill.

Perform field density tests to evaluate fill and subgrade compaction.

Observe drilling and installation of drilled piers.

The recommendations provided in this report assume that Ninyo & Moore will be retained as the geotechnical consultant during the construction phase of the project. If another geotechnical consultant is selected, we request that the selected consultant provide a letter to the architect and the owner (with a copy to Ninyo & Moore) indicating that they fully understand Ninyo & Moore's recommendations, and that they are in full agreement with the recommendations contained in this report.

The field evaluation, laboratory testing, and geotechnical analyses presented in this geotechnical report have been conducted in general accordance with current practice and the standard of care exercised by geotechnical consultants performing similar tasks in the project area. No warranty, expressed or implied, is made regarding the conclusions, recommendations, and opinions presented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist, and conditions not observed or described in this report may be encountered during construction. Uncertainties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface evaluation will be performed upon request. Please also note that our evaluation was limited to assessment of the geotechnical aspects ofthe project, and did not include evaluation of structural issues, environmental concerns, or the presence of hazardous materials.
of these documents, some recommendations presented in this report might be revised or modified to meet the project requirements.

The recommendations provided in this report are based on subsurface conditions encountered in relatively widely spaced exploratory borings. During construction, the geotechnical engineer or his representative in the field should be allowed to check the exposed subsurface conditions.

During construction, the geotechnical engineer or his representative should be allowed to:
• Observe preparation and compaction of subgrade.
• Check and test imported materials prior to use as fill. • Observe placement and compaction of fill.
• Perform field density tests to evaluate fill and subgrade compaction. • Observe drilling and installation of drilled piers.

The recommendations provided in this report assume that Ninyo & Moore will be retained as the geotechnical consultant during the construction phase of the project. If another geotechnical consultant is selected, we request that the selected consultant provide a letter to the architect and the owner (with a copy to Ninyo & Moore) indicating that they fully understand Ninyo & Moore's recommendations, and that they are in full agreement with the recommendations contained in this report.

The field evaluation, laboratory testing, and geotechnical analyses presented in this geotechnical report have been conducted in general accordance with current practice and the standard of care exercised by geotechnical consultants performing similar tasks in the project area. No warranty, expressed or implied, is made regarding the conclusions, recommendations, and opinions presented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist, and conditions not observed or described in this report may be encountered during construction. Uncertainties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface evaluation will be performed upon request. Please also note that our evaluation was limited to assessment of the geotechnical aspects of the project, and did not include evaluation of structural issues, environmental concerns, or the presence of hazardous materials.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 22 This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document.

This report is intended for design purposes only. It does not provide sufficient data to prepare an accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant perform an independent evaluation of the subsurface conditions in the project areas. The independent evaluations may include, but not be limited to, review of other geotechnical reports prepared for the adjacent areas, site reconnaissance, and additional exploration and laboratory testing.

Our conclusions, recommendations, and opinions are based on an analysis of the observed site conditions. If geotechnical conditions different from those described in this report are encountered, our office should be notified and additional recommendations, if warranted, will be provided upon request. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur because of government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties' sole risk.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document.

This report is intended for design purposes only. It does not provide sufficient data to prepare an accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant perform an independent evaluation of the subsurface conditions in the project areas. The independent evaluations may include, but not be limited to, review of other geotechnical reports prepared for the adjacent areas, site reconnaissance, and additional exploration and laboratory testing.

Our conclusions, recommendations, and opinions are based on an analysis of the observed site conditions. If geotechnical conditions different from those described in this report are encountered, our office should be notified and additional recommendations, if warranted, will be provided upon request. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur because of government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties' sole risk.

Ninyo & Moore | 616 Linden Avenue and 270 Pine Avenue, South San Francisco, California | 404590001 | July 25, 2023 23 11 REFERENCES
American Concrete Institute, 2016, Building Code Requirements for Structural Concrete (ACI 318- 14) - Commentary on Building Code Requirements for Structural Concrete (ACI 318R-14).

American Concrete Institute, 2017, ACI Manual of Concrete Practice.

American Society for Testing and Materials (ASTM), 2019, Annual Book of ASTM Standards, West Conshohocken, Pennswvanb.

American Society of Civil Engineer (ASCE), 2010, Minimum Design Loads for Buildings and Other Structures, Standard 7-10.

Bonilla, M.G, Geologic Map of the San Francisco South, California: U.S. Geological Survey OpenFile Report 98-137.

California Building Standards Commission (CBSC), 2016, California Building Code (CBC), Title 24, Part 2, Volumes 1 and 2, based upon the 2015 International Building Code (IBC).

California Department of Transportation (Caltrans), 2018a, Corrosion Guidelines, Version 3.0, Division of Engineerin Services, Materials Engineering and Testing Services, Corrosion Branch: dated March.

California Department of Transportation (Caltrans), 2018b, Standard Specifications.

California Geological Survey (CGS), 1982, State of California Special Studies Zones, Newark 7.5 Minute Quadrangle, Alameda County, California, Scale: 1:24,000, dated January 1.

California Geological Survey (CGS), 2003a, Seismic Hazard Report 090 for the Newark 7.5 Minute Quadrangle, Alameda County, California.

California Geological Survey (CGS), 2003b, Seismic Hazard Zone Map for the Newark 7.5 Minute Quadrangle, Alameda County, California, Scale: 1:24,000, dated July 2.

California Department of Transportation (Caltrans), 2020, Highway Design Manual, https://dot.ca.gov/programs/design/manual-highway-design-manual-hdm, dated July 1.

California Department of Transportation (Caltrans), 2021, Corrosion Guidelines, Version 3.2, Division of Engineering Services, Materials Engineering and Testing Services, Corrosion Branch: dated May.

California Department of Transportation (Caltrans), 2022, Standard Specifications.

Google Earth, 2023, Google Earth 7.3.2.5776, http://earth.google.com/.

Occupational Safety and Health Administration (OSHA), 1989, Occupational Safety and Health Standards - Excavations, Department of Labor, Title 29 Code of Federal Regulations (CFR) part 1926, dated October 31.

California Department of Conservation (DOC) 2020, Shear Wave Velocity map in Upper 30m of Surficial Geology (Vs30).

American Concrete Institute, 2016, Building Code Requirements for Structural Concrete (ACI 318- 14) - Commentary on Building Code Requirements for Structural Concrete (ACI 318R-14 ).

American Concrete Institute, 2017, ACI Manual of Concrete Practice.

American Society for Testing and Materials (ASTM), 2019, Annual Book of ASTM Standards, West Conshohocken, Pennsylvania.

American Society of Civil Engineer (ASCE), 2010, Minimum Design Loads for Buildings and Other Structures, Standard 7-10.

Bonilla, M.G, Geologic Map of the San Francisco South, California: U.S. Geological Survey OpenFile Report 98-137.

California Building Standards Commission (CBSC), 2016, California Building Code (CBC), Title 24, Part 2, Volumes 1 and 2, based upon the 2015 International Building Code (IBC).

California Department of Transportation (Caltrans), 2018a, Corrosion Guidelines, Version 3.0, Division of Engineering Services, Materials Engineering and Testing Services, Corrosion Branch: dated March.

California Department of Transportation (Caltrans), 2018b, Standard Specifications.

California Geological Survey (CGS), 1982, State of California Special Studies Zones, Newark 7.5 Minute Quadrangle, Alameda County, California, Scale: 1 :24,000, dated January 1.

California Geological Survey (CGS), 2003a, Seismic Hazard Report 090 for the Newark 7.5 Minute Quadrangle, Alameda County, California.

California Geological Survey (CGS), 2003b, Seismic Hazard Zone Map for the Newark 7.5 Minute Quadrangle, Alameda County, California, Scale: 1 :24,000, dated July 2.

California Department of Transportation (Caltrans), 2020, Highway Design Manual, https://dot.ca.gov/programs/design/manual-highway-design-manual-hdm, dated July 1.

California Department of Transportation (Caltrans), 2021, Corrosion Guidelines, Version 3.2, Division of Engineering Services, Materials Engineering and Testing Services, Corrosion Branch: dated May.

California Department of Transportation (Caltrans), 2022, Standard Specifications.

Google Earth, 2023, Google Earth 7.3.2.5776, http://earth.google.com/.

Occupational Safety and Health Administration (OSHA), 1989, Occupational Safety and Health Standards - Excavations, Department of Labor, Title 29 Code of Federal Regulations (CFR) part 1926, dated October 31.

California Department of Conservation (DOC) 2020, Shear Wave Velocity map in Upper 30m of Surficial Geology (Vs30).

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