Agenda packet — Laguna Beach City Council, July 7, 2026 (part 7 of 9)

@ 0' - 3" Asphalt Concrete over 3.5" Aggregate Base
R-1 2
2 4
107.3 14.9 SC @ 5' - Clayey SAND: brown, very moist, loose R-2 3
3 3
109.4 13.1 @ 7.5' - Clayey SAND: brown, very moist, loose R-3 3
6 10
112.7 16.3 CL @ 10' - Sandy CLAY: dark olive brown, moist, stiff AL CN
SPT-1 3
3 6

16.3 @ 15' - Sandy CLAY: brown, moist, stiff
R-4 19
50/5" 108.7 16.6 SM @ 20' - Silty SAND: grayish brown, very moist, very dense
SPT-2 29
50/5" 17.9 @ 25' -Silty SAND : light gray, very moist, very dense B-1 Last Edited: 6/26/2023 45 @ 0' to 7.5' - Artificial Fill by Others (afo)
@ 7.5' to 20' - Quaternary Terrace Deposits (Qt)
@ 20' to T.D. - Topanga Formation (Tt)
535
535 of 830
60 TEST TYPES: DSMD
SA
S&H

EI DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
55 50
45 40
35 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Date:

Project Name:

Project Number:

Elevation of Top of Hole:

Hole Location: See Geotechnical Map
Drilling Company:

Type of Rig:

Drop:

Drive Weight:

Hole Diameter:
30 CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS.

SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
40 35
30 25
20 Geotechnical Boring Log Borehole HS-1
6/20/2023
~74' MSL
6"
Truck Mounted Rig
30"
140 pounds
2R Drilling
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 2 of 2 ends

R-5 50/5" 104.1 13.0 ML @ 30' - Sandy SILT: gray, moist, hard SPT-3 27
50/4" 29.4 SM @ 35' - Silty SAND: gray, wet, very dense R-6 50/1" 109.3 17.6 CL @ 40' - Sandy CLAY: gray, moist, hard SPT-4 50/1" 9.9 @ 45' - Sandy CLAY: gray, moist, hard
Total Depth = 45' (Auger Refusal)
Groundwater Not Encountered
Caving: Hole Measured approximately 22' after Removal
of the Augers
Backfilled with Cuttings and Capped with AC Cold Patch
on 6/20/2023
536
536 of 830
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
70 65
60 55
50 Geotechnical Boring Log Borehole HS-2
6/20/2023
~75' MSL
6"
Truck Mounted Rig
30"
140 pounds
2R Drilling
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 1 ends

@ 0' - 1" Asphalt Concrete over 2" Aggregate Base
R-1 10
12 15
117.1 13.2 SC @ 5' - Clayey SAND: brown, moist, medium dense R-2 3
6 16
114.1 14.4 CL @ 7.5' - Sandy CLAY: olive, moist, very stiff R-3 7
14 19
114.8 15.0 @ 10' - Sandy CLAY: brown, moist, very stiff DS
R-4 12
14 18
115.3 15.2 @ 15' - Sandy CLAY: brown, moist, very stiff SPT-1 16
23 50/5"

18.9 SM @ 20' - Silty SAND: olive brown, wet, very dense R-5 50/5" 110.8 15.0 @ 25' - Silty SAND: olive gray, very moist, very dense Total Depth = 25.5'
Groundwater Not Encountered
Caving: Hole measured approximately 11' after Removal
of the Augers
Backfilled with Cuttings and Capped with AC Cold Patch
on 6/20/2023 B-1 Last Edited: 6/26/2023
@ 0' to 5' - Artificial Fill by Others (afo)
@ 5' to 20' - Quaternary Terrace Deposits (Qt)
@ 20' to T.D - Topanga Formation (Tt)
537
537 of 830
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
62 57
52 47
42 Geotechnical Boring Log Borehole HS-3
6/20/2023
67' MSL
6"
Truck Mounted Rig
30"
140 pounds
2R Drilling
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 1 ends

@ 0' - 3.5" Asphalt Concrete with no Aggregate Base -#200 MD
CR
EI
DS
R-1 3
7 17
104.4 10.1 SM @ 5' - Silty SAND: dark brown, moist, medium dense R-2 5
5 9
107.9 8.1 SM @ 7.5' - Silty SAND: yellowish brown, moist, medium dense
R-3 7
10 13
109.8 13.5 CL @ 10' - CLAY with Sand: olive, moist, very stiff AL CN
SPT-1 4
4 8

15.6 SC @ 15' - Clayey SAND: brown, moist, medium dense, after 15' water added to assist with drilling process
R-4 4
7 7
119.4 2.9 SM @ 20' - Silty SAND: yellowish brown, moist, medium dense
SPT-2 2
3 4

25.4 CL @ 25' - Sandy CLAY: brown, moist, stiff
Total Depth = 26.5'
Groundwater Not Encountered
Caving: Hole measured approximately 11.5' after Removal of the Augers
Backfilled with Cuttings and Capped with AC Cold Patch on 6/20/2023 B-1 Last Edited: 6/26/2023
@ 0' to 10' - Artificial Fill by Others (afo)
@ 10' to T.D. - Quaternary Terrace Deposits (Qt)
SC Clayey SAND: dark olive gray
538
538 of 830
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
64 59
54 49
44 Geotechnical Boring Log Borehole HS-4
6/20/2023
69' MSL
6"
Truck Mounted Rig
30"
140 pounds
2R Drilling
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 2 ends

@ 0' - 3" of AC over 3" AB
R-1 8
7 8

99.0 8.2 SC @ 5' - Clayey SAND: light brown, moist, medium dense R-2 7
10 12
112.6 10.8 SC @ 7.5' - Clayey SAND: light brown, moist, medium dense
R-3 8
9 13

99.8 16.5 CL @ 10' - Sandy CLAY: olive brown, moist, very stiff R-4 3
6 6
108.5 11.6 SM @ 15' - Silty SAND: brown, moist, loose -#200 CO
SPT-1 23
41 37

23.4 SM @ 20' - Silty SAND: gray, moist, very dense, oxidation R-5 35
50/4" 102.8 18.9 SM @ 25' - Silty SAND: olive gray, moist, very dense, signs of oxidation B-1 Last Edited: 6/26/2023
@ 0' to 15' - Artificial Fill by Others (afo)
@ 15' to 20' - Quaternary Terrace Deposits (Qt)
@ 20' to T.D. - Topanga Formation (Tt)
539
539 of 830
60 TEST TYPES: DSMD
SA
S&H

EI DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
55 50
45 40
35 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Date:

Project Name:

Project Number:

Elevation of Top of Hole:

Hole Location: See Geotechnical Map
Drilling Company:

Type of Rig:

Drop:

Drive Weight:

Hole Diameter:
30 CN CONSOLIDATION

CR CORROSION

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS.

SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
34 29
24 19
14 Geotechnical Boring Log Borehole HS-4
6/20/2023
69' MSL
6"
Truck Mounted Rig
30"
140 pounds
2R Drilling
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 2 of 2 ends

SPT-2 40
50/5"
Total Depth = 31'
Groundwater Not Encountered
Backfilled with Cuttings and Capped with AC Cold Patch
on 6/20/2023
@ 30' - Sandy SILT: light brownish gray, moist to slightly moist, hard

17.3 ML
540
540 of 830
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
82 77
72 67
62 Geotechnical Boring Log Borehole HA-1
6/21/2023
87' MSL
3"
Truck Mounted Rig
N/A"
N/A pounds
LGC Geotechnical
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 1 ends

SM @ 0' - dry vegetation
@ 1' - Silty SAND: brown, dry, some gravel DS
R-1 B-1@ 2' - Silty,Clayey SAND: brown, dry, friable, some gravel
@ 5' - Silty SAND: light brown, slightly moist, 1-2" clasts, some asphalt
Total Depth = 5'
Groundwater Not Encountered
Backfilled with Cuttings on 6/20/2023

99.5 5.5 SC-SM

4.1 SM
541
541 of 830
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
77 72
67 62
57 Geotechnical Boring Log Borehole HA-2
6/21/2023
82' MSL
3"
N/A
N/A"
N/A pounds
LGC Geotechnical
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 1 ends

10.0 SM @ 0' - Silty SAND: brown, dry, friable
GB-1 @ 1' - Silty SAND: brown, slightly moist, friable, roots GB-2
@ 3' - Clayey SAND: dark brown, moist, cohesive

13.3 CL
@ 4' - Clayey SAND: dark brown, moist, cohesive
GB-3
@ 5' - Sandy CLAY: brown, moist, pieces of roots
GB-4
@ 6' - Silty SAND: orangish brown, moist, friable GB-5

7.3 @ 7' - Silty SAND: brown, moist, friable
Total Depth = 7'
Groundwater Not Encountered
Backfilled with Cuttings on 6/21/2023 Last Edited: 6/26/2023 SM
SC
542
542 of 830
THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
79 74
69 64
59 Geotechnical Boring Log Borehole HA-3
6/21/2023
84' MSL
3"
N/A
N/A"
N/A pounds
LGC Geotechnical
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 1 ends

@ 0' - Silty SAND: brown, slightly moist, roots
@ 2' - Silty SAND: brown, thick roots, moist
@ 3' - Clayey SAND: brown, moist, roots
@ 4' - Clayey SAND: brown, very moist
@ 5' - Clayey SAND: brown, very moist
Total Depth = 5'
Groundwater Not Encountered
Backfilled with Cuttings on 6/21/2023 Last Edited: 6/26/2023 SM
SC
543
543 of 830
Appendix C
Laboratory Test Results
544
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Project No. 23106-01 C-1 December, 2025

APPENDIX C
Laboratory Test Results
The laboratory testing program was directed towards providing quantitative data relating to the relevant engineering properties of the soils. Samples considered representative of site conditions were tested in general accordance with American Society for Testing and Materials (ASTM) procedure and/or California Test Methods (CTM), where applicable. The following summary is a brief outline of the test type and a table summarizing the test results.

Moisture and Density Determination Tests: Moisture content (ASTM D2216) and dry density determinations (ASTM D2937) were performed on driven samples obtained from the test borings. The results of these tests are presented in the boring logs. Where applicable, only moisture content was determined from undisturbed or disturbed samples.

Grain Size Distribution/Fines Content: Representative samples were dried, weighed, and soaked in water until individual soil particles were separated (per ASTM D421) and then washed on a No. 200 sieve (ASTM D1140). Where applicable, the portion retained on the No. 200 sieve was dried and then sieved on a U.S. Standard brass sieve set in accordance with ASTM D6913 (sieve).

Sample Location Description % Passing #
200 Sieve
HS-3 @ 1-5 ft Clayey Sand 34
HS-4 @ 15 ft Silty Sand 45
Atterberg Limits: The liquid and plastic limits (“Atterberg Limits”) were determined per ASTM D4318 for engineering classification of fine-grained material and presented in the table below. The USCS soil classification indicated in the table below is based on the portion of sample passing the No. 40 sieve and may not necessarily be representative of the entire sample. The plots are provided in this Appendix.

Sample Location Liquid Limit
(%)
Plastic Limit
(%)
Plasticity
Index (%)
USCS
Soil
Classification
HS-1 @ 10 ft 30 14 16 CL
HS-3 @ 10 ft 36 18 18 CL
545
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APPENDIX C (Cont’d)
Laboratory Test Results
Project No. 23106-01 C-2 December, 2025
Expansion Index: The expansion potential of selected representative samples was evaluated by the Expansion Index Test per ASTM D4829. The results are presented in the table below.

Sample
Location
Expansion
Index
Expansion
Potential*
HS-3 @ 1-5 ft 4 Very Low
* Per ASTM D4829
Direct Shear: Direct shear tests were performed on selected driven and remolded (90 percent relative compaction) samples, which were soaked for a minimum of 24 hours prior to testing.

The samples were tested under various normal loads using a motor-driven, strain-controlled, direct-shear testing apparatus (ASTM D3080). The plots are provided in this Appendix.

Consolidation: Consolidation tests were performed per ASTM D2435. Samples (2.4 inches in diameter and 1 inch in height) were placed in a consolidometer and increasing loads were applied. The samples were allowed to consolidate under “double drainage” and total deformation for each loading step was recorded. The percent consolidation for each load step was recorded as the ratio of the amount of vertical compression to the original sample height.

The consolidation pressure curves are provided in this Appendix.

Collapse/Swell Potential: A collapse test was performed per ASTM D4546. Samples (2.4 inches in diameter and 1 inch in height) were placed in a consolidometer and loaded to their approximate in-situ effective stress. The curve is presented in this Appendix.

Laboratory Compaction: The maximum dry density and optimum moisture content of typical materials were determined in accordance with ASTM D1557. The results are presented in the table below.

Sample Location Sample Description
Maximum
Dry Density
(pcf)
Optimum
Moisture
Content (%)
HS-3 @ 1-5 ft Dark Olive Gray Clayey Sand 128.5 8.5
546
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APPENDIX C (Cont’d)
Laboratory Test Results
Project No. 23106-01 C-3 December, 2025
Soluble Sulfates: The soluble sulfate contents of selected samples were determined by standard geochemical methods (CTM 417). The test results are presented in the table below.

Sample Location Sulfate Content
(ppm)
Sulfate Content
( %)
HS-3 @ 1-5 ft 117 < 0.02
Chloride Content: Chloride content was tested per CTM 422. The results are presented below.

Sample Location Chloride Content
(ppm)
HS-3 @ 1-5 ft 41
Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general accordance with CTM 643 and standard geochemical methods. The results are presented in the table below.

Sample Location pH Minimum Resistivity
(ohm-cm)
HS-3 @ 1-5 ft 7.5 1,950
547
547 of 830
HS-1 R-3 10' - 30 14 16 CL
HS-3 R-3 10' - 36 18 18 CL
Laguna Beach
Project Number:

Plasticity
Index (%) PI
23106-01
Date: Jul-23
Symbol Location.: Sample No.: USCS Plastic Limit
(%) PL
Liquid Limit
(%) LL
Passing No.
200 Sieve
(%)
Depth (ft)

ATTERBERG LIMITS
(ASTM D 4318)
0 10
20 30
40 50
60 70
0 20 40 60 80 100
Plasticity Index (P.I.)
Liquid Limit (L.L.)

PLASTICITY CHART - CLASSIFICATION OF FINE-GRAINED SOILS 548
548 of 830
Project Name: Laguna Beach Tested By: G. Bathala Date: 07/06/23 Project No.: 23106-01 Checked By: J. Ward Date: 07/12/23 Boring No.: Sample Type: Ring
Sample No.: Depth (ft.): 2.0
Soil Identification:

2.415 2.415 2.415

1.000 1.000 1.000
165.83 166.47 166.44

45.58 45.53 45.18
Before Shearing
186.34 186.34 186.34
182.28 182.28 182.28

58.78 58.78 58.78

0.0000 0.2588 0.2604
-0.0546 0.3714 0.4168
After Shearing
199.35 202.23 192.86
178.71 183.87 173.85

65.21 70.32 59.15

2.70 2.70 2.70

62.43 62.43 62.43
HA-1
Olive gray silty, clayey sand (SC-SM)
Sample Diameter(in):

Weight of Wet Sample+Cont.(gm):

Vertical Rdg.(in): Final
Vertical Rdg.(in): Initial
Sample Thickness(in.):

Weight of Sample + ring(gm):

R-1

DIRECT SHEAR TEST
Consolidated Drained - ASTM D 3080
Water Density(pcf):

Specific Gravity (Assumed):

Weight of Container(gm):

Weight of Dry Sample+Cont.(gm):

Weight of Ring(gm):

Weight of Container(gm):

Weight of Dry Sample+Cont.(gm):

Weight of Wet Sample+Cont.(gm):

DS HA-1, R-1 @ 2
549
549 of 830
Normal Stress (kip/ft²)
Peak Shear Stress (kip/ft²)
Shear Stress @ End of Test (ksf)
Deformation Rate (in./min.)
Initial Sample Height (in.)
Diameter (in.)
Initial Moisture Content (%)
Dry Density (pcf)
Saturation (%)
Soil Height Before Shearing (in.)
Final Moisture Content (%)
07-23
Project No.: 23106-01
Sample Type:

Ring
Olive gray silty, clayey sand
(SC-SM) 12.0

0.9454

18.2 Laguna Beach DIRECT SHEAR TEST RESULTS
Consolidated Drained - ASTM D 3080

12.2 0.8436

16.6 1.000

0.789

0.786

0.0025

1.000

2.415

1.000

2.415

2.000

1.371

1.368

0.0025

4.000

2.738

2.732

0.0025

12.1 0.8874

16.2 Soil Identification: 3.29

97.4 3.29

96.8 97.6

1.000

2.415

3.29 Boring No.

Sample No.

Depth (ft)
HA-1
R-1
2 0.00

1.00 2.00

3.00 4.00
0 0.1 0.2 0.3
Shear Stress (ksf)
Horizontal Deformation (in.)

0.00 1.00

2.00 3.00

4.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00
Shear Stress (ksf)
Normal Stress (ksf)
DS HA-1, R-1 @ 2
550
550 of 830
Tested Sample:

HA-1 at 2 ft

33.2 Degrees 33.2 Degrees

0.11 ksf 0.10 ksf
Peak: At 0.30" Displacement:

DIRECT SHEAR PLOT
Project Number: 23106-01
Date: Jul-23
Laguna Beach
0 1
2 3
4 5
0 1 2 3 4 5
Shear Stress (ksf)
Normal Stress (ksf)
Peak At 0.30" Displacement
551
551 of 830
Project Name: Laguna Beach Tested By: G. Bathala Date: 06/29/23 Project No.: 23106-01 Checked By: J. Ward Date: 07/12/23 Boring No.: Sample Type: Ring
Sample No.: Depth (ft.): 7.5
Soil Identification:

2.415 2.415 2.415

1.000 1.000 1.000
203.33 207.42 206.36

42.48 45.69 43.05
Before Shearing
189.81 189.81 189.81
172.16 172.16 172.16

58.54 58.54 58.54

0.0000 0.2399 0.2372
-0.0118 0.2601 0.2641
After Shearing
217.59 226.54 233.00
191.97 200.85 208.69

55.47 65.21 70.32

2.70 2.70 2.70

62.43 62.43 62.43
HS-2
Olive lean clay (CL)
Sample Diameter(in):

Weight of Wet Sample+Cont.(gm):

Vertical Rdg.(in): Final
Vertical Rdg.(in): Initial
Sample Thickness(in.):

Weight of Sample + ring(gm):

R-2

DIRECT SHEAR TEST
Consolidated Drained - ASTM D 3080
Water Density(pcf):

Specific Gravity (Assumed):

Weight of Container(gm):

Weight of Dry Sample+Cont.(gm):

Weight of Ring(gm):

Weight of Container(gm):

Weight of Dry Sample+Cont.(gm):

Weight of Wet Sample+Cont.(gm):

DS HS-2, R-2 @ 7.5
552
552 of 830
Normal Stress (kip/ft²)
Peak Shear Stress (kip/ft²)
Shear Stress @ End of Test (ksf)
Deformation Rate (in./min.)
Initial Sample Height (in.)
Diameter (in.)
Initial Moisture Content (%)
Dry Density (pcf)
Saturation (%)
Soil Height Before Shearing (in.)
Final Moisture Content (%)
06-23
Project No.: 23106-01
Sample Type:

Ring
Olive lean clay (CL)

92.0 0.9882

18.8 Laguna Beach DIRECT SHEAR TEST RESULTS
Consolidated Drained - ASTM D 3080

96.7 0.9731

17.6 1.000

1.283

0.827

0.0017

1.000

2.415

1.000

2.415

2.000

1.877

1.358

0.0017

4.000

3.031

2.543

0.0017

93.6 0.9798

18.9 Soil Identification: 15.53
116.4

15.53 115.8 117.6

1.000

2.415

15.53 Boring No.

Sample No.

Depth (ft)
HS-2
R-2

7.5 0.00

1.00 2.00

3.00 4.00
0 0.1 0.2 0.3
Shear Stress (ksf)
Horizontal Deformation (in.)

0.00 1.00

2.00 3.00

4.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00
Shear Stress (ksf)
Normal Stress (ksf)
DS HS-2, R-2 @ 7.5
553
553 of 830
Tested Sample:

HS-2 at 7.5 ft

30.2 Degrees 29.9 Degrees

0.71 ksf 0.23 ksf
Peak: At 0.30" Displacement:

DIRECT SHEAR PLOT
Project Number: 23106-01
Date: Jul-23
Laguna Beach
0 1
2 3
4 5
0 1 2 3 4 5
Shear Stress (ksf)
Normal Stress (ksf)
Peak At 0.30" Displacement
554
554 of 830
Project Name: Laguna Beach Tested By: G. Bathala Date: 07/05/23 Project No.: 23106-01 Checked By: J. Ward Date: 07/12/23 Boring No.: Sample Type: 90% Remold
Sample No.: Depth (ft.): 1-5
Soil Identification:

2.415 2.415 2.415

1.000 1.000 1.000
196.73 197.27 196.36

45.38 45.57 44.61
Before Shearing
164.40 164.40 164.40
155.85 155.85 155.85

52.57 52.57 52.57

0.0000 0.2628 0.2544
-0.0097 0.2792 0.2744
After Shearing
218.00 211.89 219.61
199.85 194.63 202.84

61.83 56.84 64.65

2.70 2.70 2.70

62.43 62.43 62.43
HS-3
Dark olive gray clayey sand (SC)
Sample Diameter(in):

Weight of Wet Sample+Cont.(gm):

Vertical Rdg.(in): Final
Vertical Rdg.(in): Initial
Sample Thickness(in.):

Weight of Sample + ring(gm):

B-1

DIRECT SHEAR TEST
Consolidated Drained - ASTM D 3080
Water Density(pcf):

Specific Gravity (Assumed):

Weight of Container(gm):

Weight of Dry Sample+Cont.(gm):

Weight of Ring(gm):

Weight of Container(gm):

Weight of Dry Sample+Cont.(gm):

Weight of Wet Sample+Cont.(gm):

DS HS-3, B-1 @ 1-5
555
555 of 830
Normal Stress (kip/ft²)
Peak Shear Stress (kip/ft²)
Shear Stress @ End of Test (ksf)
Deformation Rate (in./min.)
Initial Sample Height (in.)
Diameter (in.)
Initial Moisture Content (%)
Dry Density (pcf)
Saturation (%)
Soil Height Before Shearing (in.)
Final Moisture Content (%)
07-23
Project No.: 23106-01
Sample Type:
90% Remold
Dark olive gray clayey sand
(SC) 49.7

0.9903

13.2 Laguna Beach DIRECT SHEAR TEST RESULTS
Consolidated Drained - ASTM D 3080

50.1 0.9800

12.1 1.000

0.912

0.726

0.0025

1.000

2.415

1.000

2.415

2.000

1.569

1.342

0.0025

4.000

2.842

2.713

0.0025

50.0 0.9836

12.5 Soil Identification: 8.28
116.5

8.28 116.2 116.6

1.000

2.415

8.28 Boring No.

Sample No.

Depth (ft)
HS-3
B-1
1-5

0.00 1.00

2.00 3.00

4.00 0 0.1 0.2 0.3
Shear Stress (ksf)
Horizontal Deformation (in.)

0.00 1.00

2.00 3.00

4.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00
Shear Stress (ksf)
Normal Stress (ksf)
DS HS-3, B-1 @ 1-5
556
556 of 830
Tested Sample:

HS-3 at 1-5 ft

32.7 Degrees 33.6 Degrees

0.28 ksf 0.04 ksf
Samples Remolded to 90% Relative Compaction
Peak: At 0.30" Displacement:

DIRECT SHEAR PLOT
Project Number: 23106-01
Date: Jul-23
Laguna Beach
0 1
2 3
4 5
0 1 2 3 4 5
Shear Stress (ksf)
Normal Stress (ksf)
Peak At 0.30" Displacement
557
557 of 830
Project Name: Tested By: GB/JD Date: 06/28/23
Project No.: Checked By: J. Ward Date: 07/12/23
Boring No.: Depth (ft.):

Sample No.: Sample Type:

Soil Identification:

Sample Diameter (in.): 2.415
Sample Thickness (in.): 1.000
Weight of Sample + ring (g): 209.18
Weight of Ring (g): 45.68
Height after consol. (in.): 0.9386
Before Test
Wt. of Wet Sample+Cont. (g): 191.94
Wt. of Dry Sample+Cont. (g): 174.73
Weight of Container (g): 56.13
Initial Moisture Content (%) 14.5
Initial Dry Density (pcf) 118.7
Initial Saturation (%): 87
Initial Vertical Reading (in.) 0.1105
After Test
Wt. of Wet Sample+Cont. (g): 273.18
Wt. of Dry Sample+Cont. (g): 254.24
Weight of Container (g): 65.58
Final Moisture Content (%) 13.25
Final Dry Density (pcf): 126.7
Final Saturation (%): 100
Final Vertical Reading (in.) 0.1750
Specific Gravity (assumed): 2.78
Water Density (pcf): 62.43

0.10 0.1118 0.9987 0.00 0.13 0.460 0.13

0.25 0.1221 0.9884 0.05 1.16 0.445 1.11

0.50 0.1289 0.9816 0.11 1.84 0.436 1.73

1.00 0.1380 0.9725 0.19 2.75 0.424 2.56

2.00 0.1482 0.9624 0.29 3.77 0.411 3.48

2.00 0.1483 0.9623 0.29 3.78 0.411 3.48

4.00 0.1552 0.9554 0.43 4.47 0.403 4.04

8.00 0.1701 0.9404 0.58 5.96 0.383 5.38

16.00 0.1902 0.9203 0.76 7.97 0.356 7.21

4.00 0.1859 0.9246 0.58 7.54 0.360 6.96

1.00 0.1788 0.9317 0.41 6.83 0.368 6.42

0.25 0.1750 0.9355 0.31 6.45 0.372 6.14
HS-1
R-3
Time
Corrected
Deformation (%)
PROPERTIES of SOILS
Ring
Void
Ratio
Dark olive brown sandy lean clay s(CL)
Time Readings
Elapsed
Time (min)

10.0 Pressure
(p)
(ksf) Dial Rdgs.
(in.) Date

ONE-DIMENSIONAL CONSOLIDATION
ASTM D 2435
23106-01
Laguna Beach
Deformation
% of Sample
Thickness Square
Root of
Time
Final
Reading
(in.)
Apparent
Thickness
(in.)
Load
Compliance
(%)

0.340

0.360

0.380

0.400

0.420

0.440

0.460

0.480

0.10 1.00 10.00 100.

Void Ratio
Pressure, p (ksf)
Inundate with
Tap water
Consol HS-1, R-3 @ 10
558
558 of 830
Initial Final Initial Final Initial Final Initial Final Soil Identification:

Time Readings
118.7 0.372 87 100
Degree of
Saturation (%) Dry Density (pcf)

0.462
Void Ratio
10 14.5
Dark olive brown sandy lean clay s(CL)
Project No.:

Laguna Beach
07-23
23106-01
Boring
No.

Sample
No.

Depth
(ft.)
Moisture
Content (%)

ONE-DIMENSIONAL CONSOLIDATION
PROPERTIES of SOILS
ASTM D 2435
HS-1 R-3 13.2 126.7

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

0.1 1.0
Deformation Dial Reading (in.)
Log of Time (min.)

0.00 1.00

2.00 3.00

4.00 5.00

6.00 7.00

8.00 0.10 1.00 10.00 100.00
Deformation (%)
Pressure, p (ksf)

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

0.0 10.0
Square Root of Time (min.1/2)
Inundate with
Tap water
559
559 of 830
Project Name: Tested By: GB/JD Date: 06/28/23
Project No.: Checked By: J. Ward Date: 07/12/23
Boring No.: Depth (ft.):

Sample No.: Sample Type:

Soil Identification:

Sample Diameter (in.): 2.415
Sample Thickness (in.): 1.000
Weight of Sample + ring (g): 198.67
Weight of Ring (g): 44.80
Height after consol. (in.): 0.9969
Before Test
Wt. of Wet Sample+Cont. (g): 207.01
Wt. of Dry Sample+Cont. (g): 193.18
Weight of Container (g): 56.97
Initial Moisture Content (%) 10.2
Initial Dry Density (pcf) 116.2
Initial Saturation (%): 61
Initial Vertical Reading (in.) 0.0166
After Test
Wt. of Wet Sample+Cont. (g): 264.13
Wt. of Dry Sample+Cont. (g): 241.86
Weight of Container (g): 57.93
Final Moisture Content (%) 16.01
Final Dry Density (pcf): 116.1
Final Saturation (%): 96
Final Vertical Reading (in.) 0.0225
Specific Gravity (assumed): 2.70
Water Density (pcf): 62.43

0.10 0.0170 0.9996 0.00 0.04 0.450 0.04

0.25 0.0202 0.9964 0.04 0.36 0.446 0.32

0.50 0.0223 0.9943 0.09 0.57 0.444 0.48

1.00 0.0247 0.9919 0.15 0.81 0.441 0.66

2.00 0.0275 0.9891 0.25 1.09 0.439 0.84

2.00 0.0230 0.9936 0.25 0.64 0.445 0.39

4.00 0.0273 0.9893 0.37 1.07 0.441 0.70

8.00 0.0353 0.9813 0.49 1.87 0.431 1.38

16.00 0.0470 0.9696 0.65 3.04 0.416 2.39

4.00 0.0416 0.9750 0.51 2.50 0.422 1.99

1.00 0.0295 0.9871 0.39 1.29 0.438 0.90

0.25 0.0225 0.9941 0.28 0.59 0.446 0.31
HS-3
R-3
Time
Corrected
Deformation (%)
PROPERTIES of SOILS
Ring
Void
Ratio
Olive lean clay with sand (CL)s
Time Readings
Elapsed
Time (min)

10.0 Pressure
(p)
(ksf) Dial Rdgs.
(in.) Date

ONE-DIMENSIONAL CONSOLIDATION
ASTM D 2435
23106-01
Laguna Beach
Deformation
% of Sample
Thickness Square
Root of
Time
Final
Reading
(in.)
Apparent
Thickness
(in.)
Load
Compliance
(%)

0.410

0.415

0.420

0.425

0.430

0.435

0.440

0.445

0.450

0.455

0.10 1.00 10.00 100.

Void Ratio
Pressure, p (ksf)
Inundate with
Tap water
Consol HS-3, R-3 @ 10
560
560 of 830
Initial Final Initial Final Initial Final Initial Final Soil Identification:

Time Readings
116.2 0.446 61 96
Degree of
Saturation (%) Dry Density (pcf)

0.451
Void Ratio
10 10.2
Olive lean clay with sand (CL)s
Project No.:

Laguna Beach
07-23
23106-01
Boring
No.

Sample
No.

Depth
(ft.)
Moisture
Content (%)

ONE-DIMENSIONAL CONSOLIDATION
PROPERTIES of SOILS
ASTM D 2435
HS-3 R-3 16.0 116.1

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

0.1 1.0
Deformation Dial Reading (in.)
Log of Time (min.)

0.00 0.50

1.00 1.50

2.00 2.50

3.00 0.10 1.00 10.00 100.00
Deformation (%)
Pressure, p (ksf)

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

0.0 10.0
Square Root of Time (min.1/2)
Inundate with
Tap water
561
561 of 830
Project Name: Tested By: G. Bathala Date: 07/07/23
Project No.: Checked By: J. Ward Date: 07/12/23
Boring No.: HS-4 Sample Type: Ring
Sample No.: R-4 Depth (ft.) 15.0
Sample Description: Olive gray silty clay (CL-ML)
Initial Dry Density (pcf): 110.5 Final Dry Density (pcf): 112.1 Initial Moisture (%): 11.40 Final Moisture (%) : 18.0
Initial Length (in.): 1.0000 Initial Void ratio: 0.5255 Initial Dial Reading: 0.0019 Specific Gravity(assumed): 2.70 Diameter(in): 2.415 Initial Saturation (%) 58.6

0.100 0.9999 0.00 -0.01 -0.01

2.000 0.9881 0.25 -1.19 -0.94
H2O 0.9879 0.25 -1.21 -0.96
Percent Swell (+) / Settlement (-) After Inundation = -0.02 Load
Compliance
(%)
Apparent
Thickness
(in)

ONE-DIMENSIONAL SWELL OR SETTLEMENT

POTENTIAL OF COHESIVE SOILS
ASTM D 4546
Corrected
Deformation
(%)
Laguna Beach
23106-01

0.5109

0.0020

0.0138

0.0140
Pressure (p)
(ksf)

0.5254

0.5112
Final Reading
(in) Void Ratio
Swell (+)
Settlement (-)
% of Sample
Thickness

0.5100

0.5120

0.5140

0.5160

0.5180

0.5200

0.5220

0.5240

0.5260

0.5280

0.100 1.000 10.000
Void Ratio
Log Pressure (ksf)
Void Ratio - Log Pressure Curve
Inundate with
Tap water
Swell or Settlement HS-4, R-4 @ 15
562
562 of 830
Appendix D
Infiltration Test Data
563
563 of 830
Boring Number:

Test hole dimensions (if circular)
5 8
3 Pre‐Test (Sandy Soil Criteria)*
1 8:00 8:25 25.0 1.87 1.88 0.01
2 8:25 8:50 25.0 1.88 1.89 0.01
Main Test Data
1 8:55 9:25 30.0 1.89 1.89 0.00 0.0
2 9:25 9:55 30.0 1.89 1.90 0.01 0.0
3 9:55 10:25 30.0 1.9 1.91 0.01 0.0
4 10:25 10:55 30.0 1.91 1.92 0.01 0.0
5 10:55 11:25 30.0 1.92 1.93 0.01 0.0
6 11:25 11:55 30.0 1.93 1.95 0.02 0.0
7 11:55 12:25 30.0 1.95 1.96 0.01 0.0
8 12:25 12:55 30.0 1.96 1.98 0.02 0.0
9 12:55 13:25 30.0 1.98 1.98 0.00 0.0
10 13:25 13:55 30.0 1.98 1.99 0.01 0.0
11 13:55 14:25 30.0 1.99 2.00 0.01 0.0
12 14:25 14:55 30.0 2.00 2.01 0.01 0.0
Feasibility Factor of Safety 2.0

0.0 Sketch:

Infiltration Test Data Sheet
LGC Geotechnical, Inc
131 Calle Iglesia Suite 200, San Clemente, CA 92672 tel. (949) 369‐6141 Project Name: Woodhart LLC- Laguna Beach
Project Number: 23106-01
Date: 6/22/2023
I-1
Test pit dimensions (if rectangular)
Boring Depth (feet)*: Pit Depth (feet):

Boring Diameter (inches): Pit Length (feet):

Pipe Diameter (inches): Pit Breadth (feet): *measured at time of test Trial No. Start Time
(24:HR)
Stop Time
(24:HR)
Time Interval
(min)
Initial Depth to
Water (feet)
Final Depth
to Water
(feet)
Total Change
in Water Level
(feet)
Greater Than or
Equal to

0.5 feet (yes/no)
No
No
*If two consecutive measurements show that six inches of water seeps away in less than 25 minutes, the test shall be run for an additional hour with measurements taken every 10 minutes. Otherwise, pre-soak (fill) overnight, and then obtain at least twelve measurements per hole over at least six hours (approximately 30 minute intervals) with a precision of at least 0.25 inches Trial No. Start Time
(24:HR)
Stop Time
(24:HR)
Time Interval,
Dt (min)
Initial Depth to
Water, Do (feet)
Measured Infiltration Rate (With Factor of Safety)
Based on Guidelines from: South Orange County 9/28/2017 Spreadsheet Revised on: 10/30/2019
Final Depth
to Water,
Df(feet)
Change in
Water Level,
DD (feet)
Measured
Infiltration
Rate(in/hr)
Measured Infiltration Rate (No Factor of Safety) 0.0
Notes: Standing water was observed in
infiltration boring 24 hrs after presoak
564
564 of 830
Boring Number:

Test hole dimensions (if circular)
5 8
3 Pre‐Test (Sandy Soil Criteria)*
1 8:12 8:37 25.0 3.14 3.23 0.09
2 8:38 9:03 25.0 2.97 3.07 0.10
Main Test Data
1 9:03 9:33 30.0 3.07 3.2 0.13 0.3
2 9:34 10:04 30.0 2.99 3.10 0.11 0.2
3 10:05 10:35 30.0 2.91 3.04 0.13 0.2
4 10:35 11:05 30.0 3.04 3.15 0.11 0.2
5 11:06 11:36 30.0 2.92 3.04 0.12 0.2
6 11:37 12:07 30.0 3.00 3.11 0.11 0.2
7 12:08 12:38 30.0 3.00 3.11 0.11 0.2
8 12:39 13:11 32.0 3.04 3.16 0.12 0.2
9 13:12 13:42 30.0 3.04 3.14 0.10 0.2
10 13:44 14:14 30.0 3.05 3.15 0.10 0.2
11 14:15 14:45 30.0 3.02 3.13 0.11 0.2
12 14:46 15:16 30.0 3.05 3.17 0.12 0.2
Feasibility Factor of Safety 2.0

0.1 Sketch:

Measured Infiltration Rate (With Factor of Safety)
Based on Guidelines from: South Orange County 9/28/2017 Spreadsheet Revised on: 10/30/2019
Notes: Standing water was observed in
infiltration boring 24 hrs after presoak
Final Depth
to Water,
Df(feet)
Change in
Water Level,
DD (feet)
Measured
Infiltration
Rate(in/hr)
Measured Infiltration Rate (No Factor of Safety) 0.2
Total Change
in Water Level
(feet)
Greater Than or
Equal to

0.5 feet (yes/no)
No
No
*If two consecutive measurements show that six inches of water seeps away in less than 25 minutes, the test shall be run for an additional hour with measurements taken every 10 minutes. Otherwise, pre-soak (fill) overnight, and then obtain at least twelve measurements per hole over at least six hours (approximately 30 minute intervals) with a precision of at least 0.25 inches Trial No. Start Time
(24:HR)
Stop Time
(24:HR)
Time Interval,
Dt (min)
Initial Depth to
Water, Do (feet)
Trial No. Start Time
(24:HR)
Stop Time
(24:HR)
Time Interval
(min)
Initial Depth to
Water (feet)
Final Depth
to Water
(feet)
*measured at time of test
Boring Depth (feet)*: Pit Depth (feet):

Boring Diameter (inches): Pit Length (feet):

Pipe Diameter (inches): Pit Breadth (feet):

Date: 6/22/2023
I-2
Test pit dimensions (if rectangular)
Infiltration Test Data Sheet
LGC Geotechnical, Inc
131 Calle Iglesia Suite 200, San Clemente, CA 92672 tel. (949) 369‐6141 Project Name: Woodhart LLC- Laguna Beach
Project Number: 23106-01
565
565 of 830
Appendix E
General Earthwork and Grading Specifications
566
566 of 830
General Earthwork and Grading Specifications for Rough Grading

1.0 General

1.1 Intent
These General Earthwork and Grading Specifications are for the grading and earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical report(s). These Specifications are a part of the recommendations contained in the geotechnical report(s). In case of conflict, the specific recommendations in the geotechnical report shall supersede these more general Specifications. Observations of the earthwork by the project Geotechnical Consultant during the course of grading may result in new or revised recommendations that could supersede these specifications or the recommendations in the geotechnical report(s).

1.2 The Geotechnical Consultant of Record
Prior to commencement of work, the owner shall employ a qualified Geotechnical Consultant of Record (Geotechnical Consultant). The Geotechnical Consultant shall be responsible for reviewing the approved geotechnical report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions, and recommendations prior to the commencement of the grading.

Prior to commencement of grading, the Geotechnical Consultant shall review the "work plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel to perform the appropriate level of observation, mapping, and compaction testing.

During the grading and earthwork operations, the Geotechnical Consultant shall observe, map, and document the subsurface exposures to verify the geotechnical design assumptions. If the observed conditions are found to be significantly different than the interpreted assumptions during the design phase, the Geotechnical Consultant shall inform the owner, recommend appropriate changes in design to accommodate the observed conditions, and notify the review agency where required.

The Geotechnical Consultant shall observe the moisture-conditioning and processing of the subgrade and fill materials and perform relative compaction testing of fill to confirm that the attained level of compaction is being accomplished as specified. The Geotechnical Consultant shall provide the test results to the owner and the Contractor on a routine and frequent basis.

1.3 The Earthwork Contractor
The Earthwork Contractor (Contractor) shall be qualified, experienced, and knowledgeable in earthwork logistics, preparation and processing of ground to receive fill, moistureconditioning and processing of fill, and compacting fill. The Contractor shall review and accept the plans, geotechnical report(s), and these Specifications prior to commencement of grading. The Contractor shall be solely responsible for performing the grading in accordance with the project plans and specifications. The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a work plan that indicates the sequence of earthwork grading, the number of “equipment” of work and the estimated quantities of daily earthwork General Earthwork and Grading Specifications for Rough Grading Page 1 567
567 of 830
contemplated for the site prior to commencement of grading. The Contractor shall inform the owner and the
Geotechnical Consultant of changes in work schedules and updates to the work plan at least 24 hours in advance of such changes so that appropriate personnel will be available for observation and testing. The Contractor shall not assume that the Geotechnical Consultant is aware of all grading operations.

The Contractor shall have the sole responsibility to provide adequate equipment and methods to accomplish the earthwork in accordance with the applicable grading codes and agency ordinances, these Specifications, and the recommendations in the approved geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition, inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the Geotechnical Consultant shall reject the work and may recommend to the owner that construction be stopped until the conditions are rectified. It is the contractor’s sole responsibility to provide proper fill compaction.

2.0 Preparation of Areas to be Filled

2.1 Clearing and Grubbing
Vegetation, such as brush, grass, roots, and other deleterious material shall be sufficiently removed and properly disposed of in a method acceptable to the owner, governing agencies, and the Geotechnical Consultant.

The Geotechnical Consultant shall evaluate the extent of these removals depending on specific site conditions. Earth fill material shall not contain more than 1 percent of organic materials (by volume). Nesting of the organic materials shall not be allowed.

If potentially hazardous materials are encountered, the Contractor shall stop work in the affected area, and a hazardous material specialist shall be informed immediately for proper evaluation and handling of these materials prior to continuing to work in that area.

As presently defined by the State of California, most refined petroleum products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) have chemical constituents that are considered to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment, and shall not be allowed. The contractor is responsible for all hazardous waste relating to his work. The Geotechnical Consultant does not have expertise in this area. If hazardous waste is a concern, then the Client should acquire the services of a qualified environmental assessor.

2.2 Processing
Existing ground that has been declared satisfactory for support of fill by the Geotechnical Consultant shall be scarified to a minimum depth of 6 inches. Existing ground that is not satisfactory shall be over-excavated as specified in the following section. Scarification shall continue until soils are broken down and free of oversize material and the working surface is reasonably uniform, flat, and free of uneven features that would inhibit uniform compaction.

General Earthwork and Grading Specifications for Rough Grading Page 2 568
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2.3 Over-excavation
In addition to removals and over-excavations recommended in the approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy, organic-rich, highly fractured or otherwise unsuitable ground shall be over-excavated to competent ground as evaluated by the Geotechnical Consultant during grading.

2.4 Benching
Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be stepped or benched. Please see the Standard Details for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant. Other benches shall be excavated a minimum height of 4 feet into competent material or as otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping flatter than 5:1 shall also be benched or otherwise over-excavated to provide a flat subgrade for the fill.

2.5 Evaluation/Acceptance of Fill Areas
All areas to receive fill, including removal and processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive fill. The Contractor shall obtain a written acceptance from the Geotechnical Consultant prior to fill placement. A licensed surveyor shall provide the survey control for determining elevations of processed areas, keys, and benches.

3.0 Fill Material

3.1 General
Material to be used as fill shall be essentially free of organic matter and other deleterious substances evaluated and accepted by the Geotechnical Consultant prior to placement. Soils of poor quality, such as those with unacceptable gradation, high expansion potential, or low strength shall be placed in areas acceptable to the Geotechnical Consultant or mixed with other soils to achieve satisfactory fill material.

3.2 Oversize
Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 8 inches, shall not be buried or placed in fill unless location, materials, and placement methods are specifically accepted by the Geotechnical Consultant. Placement operations shall be such that nesting of oversized material does not occur and such that oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 vertical feet of finish grade or within 2 feet of future utilities or underground construction.

General Earthwork and Grading Specifications for Rough Grading Page 3 569
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3.3 Import
If importing of fill material is required for grading, proposed import material shall meet the requirements of the geotechnical consultant. The potential import source shall be given to the Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that its suitability can be determined and appropriate tests performed.

4.0 Fill Placement and Compaction

4.1 Fill Layers
Approved fill material shall be placed in areas prepared to receive fill (per Section 3.0) in near-horizontal layers not exceeding 8 inches in loose thickness. The Geotechnical Consultant may accept thicker layers if testing indicates the grading procedures can adequately compact the thicker layers. Each layer shall be spread evenly and mixed thoroughly to attain relative uniformity of material and moisture throughout.

4.2 Fill Moisture Conditioning
Fill soils shall be watered, dried back, blended, and/or mixed, as necessary to attain a relatively uniform moisture content at or slightly over optimum. Maximum density and optimum soil moisture content tests shall be performed in accordance with the American Society of Testing and Materials (ASTM Test Method D1557).

4.3 Compaction of Fill
After each layer has been moisture-conditioned, mixed, and evenly spread, it shall be uniformly compacted to not less than 90 percent of maximum dry density (ASTM Test Method D1557). Compaction equipment shall be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified level of compaction with uniformity.

4.4 Compaction of Fill Slopes
In addition to normal compaction procedures specified above, compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation, or by other methods producing satisfactory results acceptable to the Geotechnical Consultant. Upon completion of grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of maximum density per ASTM Test Method D1557.

4.5 Compaction Testing
Field tests for moisture content and relative compaction of the fill soils shall be performed by the Geotechnical Consultant. Location and frequency of tests shall be at the Consultant's discretion based on field conditions encountered. Compaction test locations will not necessarily be selected on a random basis. Test locations shall be selected to verify adequacy of compaction levels in areas that are judged to be prone to inadequate compaction (such as close to slope faces and at the fill/bedrock benches).

General Earthwork and Grading Specifications for Rough Grading Page 4 570
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4.6 Frequency of Compaction Testing
Tests shall be taken at intervals not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils embankment. In addition, as a guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill construction is such that the testing schedule can be accomplished by the Geotechnical Consultant. The Contractor shall stop or slow down the earthwork construction if these minimum standards are not met.

4.7 Compaction Test Locations
The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of each test location. The Contractor shall coordinate with the project surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations with sufficient accuracy. At a minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than 5 feet apart from potential test locations shall be provided.

5.0 Subdrain Installation
Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for line and grade after installation and prior to burial. Sufficient time should be allowed by the Contractor for these surveys.

6.0 Excavation
Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the Geotechnical Consultant during grading. Remedial removal depths shown on geotechnical plans are estimates only.

The actual extent of removal shall be determined by the Geotechnical Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by the Geotechnical Consultant prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by the Geotechnical Consultant.

7.0 Trench Backfills

7.1 The Contractor shall follow all OHSA and Cal/OSHA requirements for safety of trench excavations.

7.2 All bedding and backfill of utility trenches shall be done in accordance with the applicable provisions of Standard Specifications of Public Works Construction. Bedding material shall have a Sand Equivalent greater than 30 (SE>30). The bedding shall be placed to 1 foot over General Earthwork and Grading Specifications for Rough Grading Page 5 571
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General Earthwork and Grading Specifications for Rough Grading Page 6 the top of the conduit and densified by jetting. Backfill shall be placed and densified to a minimum of 90 percent of maximum from 1 foot above the top of the conduit to the surface.

7.3 The jetting of the bedding around the conduits shall be observed by the Geotechnical Consultant.

7.4 The Geotechnical Consultant shall test the trench backfill for relative compaction. At least one test should be made for every 300 feet of trench and 2 feet of fill.

7.5 Lift thickness of trench backfill shall not exceed those allowed in the Standard Specifications of Public Works Construction unless the Contractor can demonstrate to the Geotechnical Consultant that the fill lift can be compacted to the minimum relative compaction by his alternative equipment and method.
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HYDROLOGY & HYDRAULICS STUDY
The Related Companies
644-034-05 & 644-034-09
TPM-2025-118

LAGUNA BEACH, CALIFORNIA
Developer:

The Related Companies
18201 Von Karman Ste 900
Irvine, CA 92619
Contact: Craig Farmer
Development Manager
(949) 660-7272
Prepared For:

The Related Companies
18201 Von Karman Ste 900
Irvine, CA 92619
Contact: Craig Farmer
Development Manager
(949) 660-7272
Prepared By:

KES
1 Venture Ste 130
Irvine, CA 92618
Contact: Daryl Kessler
(949) 339-5331
February, 2025
Attachment 12
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  Executive Summary…………………………………………………….i
Acknowledgement and Signature Page…………………………………ii
I. Introduction……………………….…………………………………...1
II. Methodology…………………………………………………………...1
III. Design Assumptions…………………………………………………...2
IV. Conclusion……………………………………………………………..3
V. References……………………………………………………………..4
 
A. Hydrology Study (100-Year Storm Event)
B. Sub-Area Runoff Summary (Existing and Proposed)
C. Area Drain Pipe Capacity Calculations
D. Overflow Calculations
List of Exhibits:

1. Proposed Q100 Hydrology Map

2. Existing Conditions Q100 Hydrology Map

3. TPM
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Hydrology Study and Hydraulic Analysis
For
TPM 2025-118

This Hydrology Study prepared by KES under the supervision of Ali Monshizadeh , P.E.
___________________________________ ____________
Ali Monshizadeh, PE 67674 Date
KES
ii
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
The purpose of this report is to provide quantitative information to verify preliminary storm drain infrastructure and hydrologic compliance of the project site. The values and statements within confirm the subject site is designed and planned in accordance to the Orange County Hydrology Manual and the City of Laguna Beach for Public and Private Drainage Facilities.  
:

The proposed project is located at the northwest corner of Saint Anns Drive and Glenneyre Street and is located in the City of Laguna Beach bordered to the west and north by single family homes and is bordered along the north east boundary by Catalina Street.

The subject project site planned to be affordable housing on the western parcel and church sanctuary use to be done by others on the easterly parcel. The proposed housing development will be a podium style development with subsurface parking and all associated uses above grade on the concrete deck.

The proposed project will also incorporate fronting landscape space and community open space on the elevated deck. The community will install community utilized parking stalls, project frontage landscape. No car washing will be allowed on the subject site.

The subject housing site is proposed to be fully demolished and nothing will be saved. The existing site basically flows to the southwest direct into the right of way. There are no water quality devices that exist on the subject site. Catalina Right of way current flows against the northerly existing wall and directed to the west, this historical flow will remain in place post development. The proposed development will surface flow and catch flows within a small area drain system around the perimeter of the podium and within the structure itself. All water quality flows will be directed into a subsurface chamber within the lower level of the podium. The volume of the chambers are controlled based on the Vbmp requirement. Once flow enters the chambers the volume gets pumped to the upper level through a MWS unit for water quality. Flows above that required volume will be allowed to flow into the right of way via under walk drain/curb cores at a location to be determined by the MEP during final engineering. Because the time of concentration for the developed condition is similar than the existing condition the 100 year flow rates are less than 1% and do not require mitigation. The proposed and existing development both have a pervious area of 13%.  / :

The proposed drainage area was analyzed by utilizing the Orange County Local Drainage Manual of Orange County. Each drainage area was divided as demonstrated on the hydrology map (Exhibit 1).

Each area was analyzed for acreage, impervious cover, and time of concentration according to the Rational Method. The flows, expressed in cubic feet per second (cfs), were totaled at connections to main storm drain lines. This information will in the future be used in conjunction with WSPG software during final engineering to validate the hydraulic grade line and other flow characteristics of each section of pipe.
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- :

1. The onsite drainage area was analyzed for a 100-year storm event using Rational Method Analysis per the County of Orange Hydrology Manual.

2. The drainage area is located in Soil Groups A according to page 4-9 of the Hydrology Manual and geotechnical soils analysis. (Map Attached).

3. The rainfall intensity for a 100-year 1-hour storm varies according to Figure D-1 (page A4-4) of the Hydrology Manual.

4. The infiltration rate for the pervious area, Fp, is 0.40 inches/hour.

5. The impervious area has been calculated to be 87% for the subject project.

6. Storm drains and catch basins onsite will be designed for a 100-year storm event, which corresponds to the design requirements for the project.

7. All flows are based on the complete future development of land and roads.

8. The Hydrology Map attached to the back of this study is made part of the study. **Note: Additional Calculation Assumptions Have Been Noted Throughout Report** 586
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:

The results from this hydrology and hydraulic analysis demonstrate the following:
• The drainage design for the “Project” has been designed to meet the County of Orange Flood Control Standards.
• The drainage system is designed to manage runoff from a 100-year storm. • Building pads will be protected and will be above the theoretical 100 year flood elevation as determined in this study
• Per FEMA the subject site is within Flood Zone X.
• The existing site conditions result in a predevelopment 100-year flow of 3.08 cfs to the right of way.
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

1. County of Orange, “Hydrology Manual” dated January 1999.

2. Water Surface and Pressure Gradient (WSPG) Hydraulic Analysis System Software, Los Angeles County Department of Public Works Program No. F0515P, April 1979.

3. Advanced Engineering Software, HELE1 Hydraulic Elements I for Street Flooding and Catch Basin Design, 1996 version.
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Hydrology Study (100-Year Storm Event)
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Sub-Area Runoff Summary
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DATE: Feb 2025
DATE:

PAGE 1 OF 1
CONC. PT. SOIL DEV. Tt Tc I Fm Q FLOW SLOPE V HYDRAULICS AND (MAP AREA) SUBAREA TOTAL TYPE (Ap) MIN. MIN. in/hr in/hr TOTAL PATH, FT FT/FT FT/SEC NOTES Proposed Area
A1 0.66 A 0.13 6.6 5.28 0.052 3.10 287 Initial Area: L=287' H=1.5'
Existing Area
X1 0.66 A 0.13 6.7 5.23 0.052 3.08 348

RATIONAL METHOD STUDY FORM
CHECKED BY:

CALCULATED BY: DK
NOTES: I(t) = at^b a=15.560, b=-0.573 ; C = 0.90 ; Q = C*(I - Fm)*A; Fm=Ap*Fp; Fp=0.40 (Soil A, OC Soils Map)

AREA (ACRES)
Orange County

HYDROLOGY MANUAL
100-YEAR STORM RATIONAL METHOD STUDY
STUDY NAME: Laguna
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Area Drain Pipe Capacities
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4in
Manning Pipe Calculator
Given Input Data:

Shape ........................... Circular
Solving for ..................... Flowrate
Diameter ........................ 4.0000 in
Depth ........................... 4.0000 in
Slope ........................... 0.0050 ft/ft
Manning's n ..................... 0.0120
Computed Results:

Flowrate ........................ 0.1458 cfs
Area ............................ 0.0873 ft2
Wetted Area ..................... 0.0873 ft2
Wetted Perimeter ................ 12.5664 in
Perimeter ....................... 12.5664 in
Velocity ........................ 1.6706 fps
Hydraulic Radius ................ 1.0000 in
Percent Full .................... 100.0000 %
Full flow Flowrate .............. 0.1458 cfs
Full flow velocity .............. 1.6706 fps
Critical Information
Critical depth .................. 3.0719 in
Critical slope .................. 0.0094 ft/ft
Critical velocity ............... 2.8101 fps
Critical area ................... 0.0734 ft2
Critical perimeter .............. 8.4269 in
Critical hydraulic radius ....... 1.2544 in
Critical top width .............. 4.0000 in
Specific energy ................. 0.4005 ft
Minimum energy .................. 0.3840 ft
Froude number ................... 0.6721
Flow condition .................. Subcritical

Page 1 ends

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6in
Manning Pipe Calculator
Given Input Data:

Shape ........................... Circular
Solving for ..................... Flowrate
Diameter ........................ 6.0000 in
Depth ........................... 6.0000 in
Slope ........................... 0.0050 ft/ft
Manning's n ..................... 0.0120
Computed Results:

Flowrate ........................ 0.4298 cfs
Area ............................ 0.1963 ft2
Wetted Area ..................... 0.1963 ft2
Wetted Perimeter ................ 18.8496 in
Perimeter ....................... 18.8496 in
Velocity ........................ 2.1891 fps
Hydraulic Radius ................ 1.5000 in
Percent Full .................... 100.0000 %
Full flow Flowrate .............. 0.4298 cfs
Full flow velocity .............. 2.1891 fps
Critical Information
Critical depth .................. 4.7575 in
Critical slope .................. 0.0084 ft/ft
Critical velocity ............... 3.5483 fps
Critical area ................... 0.1714 ft2
Critical perimeter .............. 12.9398 in
Critical hydraulic radius ....... 1.9075 in
Critical top width .............. 6.0000 in
Specific energy ................. 0.6154 ft
Minimum energy .................. 0.5947 ft
Froude number ................... 0.7191
Flow condition .................. Subcritical

Page 1 ends

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8in
Manning Pipe Calculator
Given Input Data:

Shape ........................... Circular
Solving for ..................... Flowrate
Diameter ........................ 8.0000 in
Depth ........................... 8.0000 in
Slope ........................... 0.0050 ft/ft
Manning's n ..................... 0.0120
Computed Results:

Flowrate ........................ 0.9257 cfs
Area ............................ 0.3491 ft2
Wetted Area ..................... 0.3491 ft2
Wetted Perimeter ................ 25.1327 in
Perimeter ....................... 25.1327 in
Velocity ........................ 2.6519 fps
Hydraulic Radius ................ 2.0000 in
Percent Full .................... 100.0000 %
Full flow Flowrate .............. 0.9257 cfs
Full flow velocity .............. 2.6519 fps
Critical Information
Critical depth .................. 6.4843 in
Critical slope .................. 0.0077 ft/ft
Critical velocity ............... 4.1907 fps
Critical area ................... 0.3125 ft2
Critical perimeter .............. 17.5350 in
Critical hydraulic radius ....... 2.5667 in
Critical top width .............. 8.0000 in
Specific energy ................. 0.8360 ft
Minimum energy .................. 0.8105 ft
Froude number ................... 0.7544
Flow condition .................. Subcritical

Page 1 ends

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Overflow Calculations
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598

Exhibit
Proposed Hydrology Map
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W W W W W W W W W W W W W W W W W W W W W W W W W W WWW W W W W W W W W W W W W W W W S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S 600
Exhibit
Existing Hydrology
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S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S W W W W W W W W W W W W W W W WWW W W W W W W W W W W W W W W W W W W W W W W W W W W 602
Exhibit
TPM
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’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ ’ SITE LOT 11 LOT 9 LOT 7 LOT 5 LOT 3 LOT 1 LOT 12 LOT 10 LOT 8 LOT 6 LOT 4 LOT 2 LOT 24
LOT 25
LOT 26
LOT 27
LOT 20
LOT 19
LOT 18
LOT 22
LOT 23 LOT 21 LOT 99 LOT 17 LOT 16 LOT 15 LOT 14 LOT 13 PARCEL 2
PARCEL 3 PARCEL 4
PARCEL 1 PARCEL 1 LAGUNA TERRACE MM 4/80 TENTATIVE PARCEL NO. 2025-118 FOR LAND SUBDIVISION PURPOSES CITY OF LAGUNA BEACH COUNTY OF ORANGE STATE OF CALIFORNIA EXISTING MAPPING CONDITION PROPOSED MAPPING CONDITION 604

S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S W W W W W W W W W W W W W W W WWW W W W W W W W W W W W W W W W W W W W W W W W W W W 605
W

W W W W W W W W W W W W W W W W W W W W W W W W W W W WWW W W W W W W W W W W W W W S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S 606
Sanitary Sewer Analysis
The Related Companies
644-034-05 & 644-034-09
TPM-2025-118

LAGUNA BEACH, CALIFORNIA
Developer:

The Related Companies
18201 Von Karman Ste 900
Irvine, CA 92619
Contact: Craig Farmer
Development Manager
(949) 660-7272
Prepared For:

The Related Companies
18201 Von Karman Ste 900
Irvine, CA 92619
Contact: Craig Farmer
Development Manager
(949) 660-7272
Prepared By:

KES
1 Venture Ste 130
Irvine, CA 92618
Contact: Daryl Kessler
(949) 339-5331
December, 2025
Attachment 13
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  I. Introduction……………………………………………………...1
II. Methodology……….…...………………………………………...1
III. Conclusion………………………………………………………..2
 
Exhibit (1) ..............................Site Plan
Exhibit (2) ..............................City Atlas Maps Exhibit (3) ..............................Manning’s Calculation 608
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Introduction:

No car washing will be allowed on the subject site.

The subject project site proposes to construct 29 residential units in 1,2, and 3 bedroom configurations including one (1) community space with no fixture units and a 5 unit laundry room. The proposed project will have (1) dedicated sewer lateral exciting the south side of the proposed building and flowing into the existing 8”sewer line in Glenneyre Street (ID 10001674).

Methodology/Rational:

The City of Laguna Beach has conditioned the subject site to study the amount of effluent to be discharged from the subject site. The proposed project will be supplemental flow seeing the underlying land use is parking lot.

Proposed Units:
12 – 1 bedroom units
9 – 2 bedroom units
8 – 3 bedroom units
Per OCSD assume 100 gallons per person per day with a peaking factor of 2.5 Unit Type Units per type Use per capita Peeking factor Total per day gpd 1 bedroom 12 1200 2.5 3000
2 bedroom 9 900 2.5 2250
3 bedroom 8 800 2.5 2000
Total amount of project demand is 7250 gpd – 0.008 cfs
50% flow depth in existing 8” line 1.874 cfs
Combined depth from project and maximum existing – 1.882 in crease of 0.42% Conclusions:

The results from this sewer analysis using methods provided Orange County Sanitation and mannings equation confirms the proposed development does not negatively impact the adjacent sewer system. 609
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APPENDIX
Exhibit (1) ..............................Site Plan
Exhibit (2) ..............................City Atlas Maps Exhibit (3) ..............................Manning’s Calculation 610
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18'-0"
TYP.
12'-0"
70 66.1

68.1 59'-0"
+82.5
+72.0
+80.0
+90.0
+80.0
+65

GLENNEYRE STREET

SAINT ANN'S DRIVE

CATALINA STREET
+80.5
+81
+69.5
+76.0
14'-6"
+65.0
UP TO
PODIUM

UP TO PLAZA
UP TO
GRADE

NOT A PART
TRASH

ELECTRICAL

PANEL RM
MAINT.

MAINT.
14'-0" 24'-0"
+70
+71.9
+70
+72.5
8% 5%
01 RELIGIOUS INSTITUTION - MAIN SANCTUARY
02 RELIGIOUS INSTITUTION - COURTYARD
03 RELIGIOUS INSTITUTION - ADMINISTRATION
04 COMMUNITY COURTYARD. SEE LANDSCAPE DWG.
05 LEASING
06 RESIDENTIAL AMENITY

PLAN LEGEND
07 RESIDENTIAL UNITS
08 RESIDENTIAL COURTYARD. SEE LANDSCAPE DWG.
09 TRASH STAGING AREA
10 LOADING SPACE
11 FIXED DATUM POINT/BENCHMARK
12 PROPERTY LINE
13 CENTERLINE OF RIGHT OF WAY
14 AVG. LOT DEPTH
15 AVG. LOT WIDTH
16 SITE/RETAINING WALL OR FENCE
18 TRANSFORMER
17 CORNER CUTBACK
0'

ZONING PLAN CHECK
SUBMITTAL 8' 16' 32'
17911 Von Karman Ave.

Suite 200
Irvine, CA 92614
ktgy.com
949.851.2133
Neighborhood
Congregational
Church
340 St. Ann's Drive
Laguna Beach, CA. 92651
A3.1 BUILDING PLAN - LEVEL B1
# 20240443
340 St. Ann's Drive.

Laguna Beach, CA

NCC AFFORDABLE HOUSING
December 8, 2025

RELATED
18201 Von Karman Ave
Irvine, CA 92612
611
+79.7
+76
+82.5
+72.0
+80.0
+90.0
+80.0
+65

GLENNEYRE STREET

SAINT ANN'S DRIVE

CATALINA STREET
+80.5
+82.5
+72.0
+80.0
+90.0
+80.0
+65

GLENNEYRE STREET

SAINT ANN'S DRIVE

CATALINA STREET
+79
+80.5

FIRE DEPARTMENT ACCESS
+

80.5 UNIT
3-01
UNIT
2-01
UNIT
2-01
UNIT
1-01
UNIT
3-01
150'-0"

FACE OF CURB
+/- 35'-0"
150'-0" 137'-6"
59'-1" 30'-0" 26'-0"
48'-6" 36'-0"
+81
+77.0
12'-0"
+75.0
+69.5
+76.0
10'-6"
UNIT
3-01
59'-0"
UNIT
2-01
+72.5 +72.5
+77.0 UP TO
PODIUM
DN TO

BASEMENT
DN TO

BASEMENT
+77.0
DN
TO
GRADE 12'-0"
UNIT
2-01
UNIT
0-01
UNIT
0-01
UNIT
3-01
UNIT
1-01
UNIT
0-01
UNIT
0-01

NOT A PART
DN TO
GRADE
+70
+71.9
+70
+72.5
8% 5%
01 RELIGIOUS INSTITUTION - MAIN SANCTUARY
02 RELIGIOUS INSTITUTION - COURTYARD
03 RELIGIOUS INSTITUTION - ADMINISTRATION
04 COMMUNITY COURTYARD. SEE LANDSCAPE DWG.
05 LEASING
06 RESIDENTIAL AMENITY

ZONING PLAN CHECK
SUBMITTAL 8' 16' 32'
17911 Von Karman Ave.

Suite 200
Irvine, CA 92614
ktgy.com
949.851.2133
Neighborhood
Congregational
Church
340 St. Ann's Drive
Laguna Beach, CA. 92651
A3.2 BUILDING PLAN - LEVEL 1
# 20240443
340 St. Ann's Drive.

Laguna Beach, CA

NCC AFFORDABLE HOUSING
December 8, 2025

RELATED
18201 Von Karman Ave
Irvine, CA 92612
612
ALL ROOF ELEVATIONS ARE BASED FROM LEVEL B1 GARAGE FINISH FLOOR ELEVATION 102.85

NOT A PART
2'-6"
2'-6"
2'-6"
3:12 3:12
3:12 3:12 3:12 3:12
3:12
3:12
3:12
3:12
3:12
3:12
3:12
RIDGE
RIDGE
RIDGE
RIDGE
RIDGE
RIDGE

97.26 97.26
102.46
102.46
103.97 103.97

96.51 96.51

96.51 96.51 96.13 96.13

96.99 97.26

96.51 89.02

85.00 101.48 101.47
RIDGE
0'

ZONING PLAN CHECK
SUBMITTAL 8' 16' 32'
17911 Von Karman Ave.

Suite 200
Irvine, CA 92614
ktgy.com
949.851.2133
Neighborhood
Congregational
Church
340 St. Ann's Drive
Laguna Beach, CA. 92651
A3.4 BUILDING PLANS - ROOF
# 20240443
340 St. Ann's Drive.

Laguna Beach, CA

NCC AFFORDABLE HOUSING
December 8, 2025

RELATED
18201 Von Karman Ave
Irvine, CA 92612
613
614
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Hydraflow Express - Channel Report - 12/5/25 1
Depth Q Area Veloc
(ft) (cfs) (sqft) (ft/s)

0.33 1.874 0.174 10.78
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Hydraflow Express - Channel Report - 12/5/25 2
Wp Yc TopWidth Energy
(ft) (ft) (ft) (ft)

1.05 0.62 0.67 2.14
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Water Quality
Management Plan
(WQMP)
Project Name:

NCC
TPM 2025-118
Prepared for:

The Related Companies
18201 Von Karman Ste 900
Irvine, CA 92619
Contact: Craig Farmer
Development Manager
(949) 660-7272
Prepared by:

KES Technologies
Engineer: Ali Monshizadeh
Registration No. 67674
1 Venture, Suite 130
Irvine, CA 92618
(949) 339-5331
[email protected]
Engineer’s Seal
Attachment 14
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Water Quality Management Plan (WQMP)
TPM 2025-118
TPM 2025-118 Owner’s Certification
Prepared on:

December 2025
Revised ___________
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Water Quality Management Plan (WQMP)
TPM 2025-118
TPM 2025-118 Owner’s Certification
Project Owner’s Certification
Permit/Application No. Grading Permit No.

Tract/Parcel Map No. TPM 2025-118 Building Permit No.

CUP, SUP, and/or APN (Specify Lot Numbers if Portions of Tract) 644-034-05 & 09 This Water Quality Management Plan (WQMP) has been prepared for Related Companies by KES Technologies. The WQMP is intended to comply with the requirements of the local NPDES Stormwater Program requiring the preparation of the plan.

The undersigned, while it owns the subject property, is responsible for the implementation of the provisions of this plan and will ensure that this plan is amended as appropriate to reflect up-to-date conditions on the site consistent with the current Orange County Drainage Area Management Plan (DAMP) and the intent of the non-point source NPDES Permit for Waste Discharge Requirements for the County of Orange, Orange County Flood Control District and the incorporated Cities of Orange County within the San Diego Region (South Orange County).

Once the undersigned transfers its interest in the property, its successors-in-interest shall bear the aforementioned responsibility to implement and amend the WQMP. An appropriate number of approved and signed copies of this document shall be available on the subject site in perpetuity.

Owner: The Related Companies
Title
Company The Related Companies
Address 18201 von Karman Ste 900, Irvine, CA
Email
Telephone # 949-660-7272
Signature Date
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Contents Page No.

Section 1 Discretionary Permit(s) and Water Quality Conditions...................... 3 Section 2 Project Description ........................................................................... 4

2.1 General Description ............................................................................ 4

2.2 Post Development Drainage Characteristics ................................... 6

2.3 Property Ownership/Management ....................................................7 Section 3 Site & Watershed Characterization ................................................... 8

3.1 Site Conditions .................................................................................... 8

3.1.1 Existing Site Conditions.....................................................................................8

3.1.2 Infiltration-Related Characteristics..................................................................8

3.2 Proposed Site Development Activities ............................................10

3.2.1 Overview of Site Development Activities ...................................................10

3.2.2 Project Attributes Influencing Stormwater Management ........................10

3.2.3 Effects on Infiltration and Harvest and Use Feasibility ............................ 11

3.3 Receiving Waterbodies.......................................................................11

3.4 Stormwater Pollutants or Conditions of Concern .......................... 12

3.5 Hydrologic Conditions of Concern.................................................... 12

3.6 Critical Course Sediment Yield Areas .............................................. 13 Section 4 Site Plan and Drainage Plan .............................................................14

4.1 Drainage Management Area Delineation ........................................ 14

4.2 Overall Site Design BMPs .................................................................. 14

4.3 DMA Characteristics and Site Design BMPs.................................... 15

4.3.1 DMA 1 .........................................................................................................15

4.3.X DMA Summary...........................................................................................15

4.3 Source Control BMPs ......................................................................... 16 Section 5 Low Impact Development BMPs ......................................................19

5.1 LID BMPs in DMA 1 ............................................................................ 19

5.1.1 Hydrologic Source Controls for DMA 1............................................................19

5.1.2 Structural LID BMP for DMA 1........................................................................19

5.X Summary of LID BMPs....................................................................... 19 Section 6 Hydromodification BMPs.................................................................21

6.1 Points of Compliance ......................................................................... 21

6.2 Pre-Development (Natural) Conditions .......................................... 21

6.3 Post-Development Conditions and Hydromodification BMPs ...... 21

6.4 Measures for Avoidance of Critical Coarse Sediment Yield Areas 21

6.5 Hydrologic Modeling and Hydromodification Compliance............ 21 Section 7 Educational Materials Index.............................................................22 Attachment A: Educational Materials.................................................................17 Attachment B: Technical Guidance Document: Calculation Worksheets............18 621
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Attachment C: Operations and Maintenance Plan .............................................19 Attachment D: Geotechnical Report...................................................................20 Attachment E: WQMP Exhibit............................................................................21 Attachment F: Hydromodification Map and Receiving Waters...........................22

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Section 1 Discretionary Permit(s) and Water
Quality Conditions
Project Infomation
Permit/Application No.

Site Address or
Tract/Parcel Map
No.

TPM 2025-118
Additional Information/
Comments:

One parcel for construction of Affordable housing/Church Sanctuary-housing parking structure.

Water Quality Conditions
Water Quality
Conditions from prior
approvals or applicable
watershed-based plans
WQMP required prior to building permits
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Section 2 Project Description
Guidance: Refer to Section 2.2 of the TGD for guidance.

2.1 General Description
Guidance: The table below is intended to provide a brief summary of the project. I should be complemented with additional narrative and/or tables in Section 2.2 and 3.2 to describe the project and the features that influence stormwater management.

Description of Proposed Project
Site Location
340 Saint Anns Drive
Project Area (ft2): 52,436 Number of Dwelling Units: 26 SIC Code: 6513 Narrative Project
Description:

The subject project site planned to be affordable housing and church sanctuary combined parking. The proposed development will be a podium style development with subsurface parking and all associated uses above grade on the concrete deck.

The subject site is proposed to be fully demolished and nothing will be saved. The existing site basically flows to the southwest direct into the right of way. There are no water quality devices that exist on the subject site. Catalina Right of way current flows against the northerly existing wall and directed to the west, this historical flow will remain in place post development. The proposed development will surface flow and catch flows within a small area drain system around the perimeter of the podium and within the structure itself. All water quality flows will be directed into a subsurface chamber within the lower level of the podium.

The volume of the chambers are controlled based on the Vbmp requirement. Once flow enters the chambers the volume gets pumped to the upper level through a MWS unit for water quality. Flows above that required volume will be allowed to flow into the right of way via under walk drain/curb cores or to the east storm drain at a location to be determined by the MEP during final engineering. Because the time of concentration for the developed condition is similar than the existing 624
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condition the 100 year flow rates are less than 1% and do not require mitigation.

The proposed and existing development both have a pervious area of 13%.

Project Area
Pervious Impervious
Area
(acres or sq ft) Percentage
Area
(acres or sq ft) Percentage
Pre-Project Conditions 0.08 ac. 87% 0.57 ac. 13%
Post-Project Conditions 0.08 ac. 87% 0.57 ac. 13%
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2.2 Post Development Drainage Characteristics
Water will be captured in area drains and directed to a storage area. All landscape and planter areas will have small landscape drains within the planter areas and drain via gravity to the proposed chamber system within the basement level. All slopes drain to existing or proposed retaining walls will flow into landscape drains and or wall sub drains and also drain to the proposed chamber systems. All concrete or hard surfaces will have subtle sloped cricketed surfaces that will be planned and proposed during final engineering to miss structural features and per MEP requirements. Similar to all landscape drains these also drain directly into the sub surface chamber.

All roofs will be outfitted with roof drains and drain to yet again the same chamber surface system.

The chamber system is sized to accommodate the necessary volume that is required to the manufacturers recommendations for V BMP per unit and as calculated within this report. The water will fill the chamber system during storm events. Once the chamber system is full the float control will activate solenoid valves that will direct all storm water to the positive overflow drain systems directly through curb cores via surface system. The chamber will sump pump the water in the basement to the proposed modular wetland system at an allowable flow rate per the manufacturers allow maximum treatment flow rate or lower. The MWS unit will be located within the landscape open space on top of the upper level. The pump will be sized for the Qbmp flow.

The entire system in the lower level will be pressure rated in the event of valve failures.

Water will be outlet into the curb and gutter along a combination of Glennyre Street for fronting hardscape and to the easterly storm drain upon being treated through the MWS planter via gravity pipe and curb core/under walk drain.
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2.3 Property Ownership/Management
The Related Companies will be the property owner and manager of the property. Contact information for the property owner:

The Related Companies
18201 Von Karman Ste 900
Irvine, CA 92619
Contact: Craig Farmer
Development Manager
(949) 660-7272
All BMP’s to be maintained by the owner or otherwise through a contracted company following the completion of the construction. No infrastructure will be transferred to public agencies. The property owner and the management company by the responsibility of the owner to oversee the long term maintenance required by the BMP’s and maintenance schedule per the manufacturers recommendations and the requirements in the WQMP.
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Section 3 Site & Watershed Characterization

3.1 Site Conditions
Existing site is pavement area and church use

3.1.1 Existing Site Conditions
The existing use currently does not have any water quality features in place. The site currently surface flows into the adjacent right of way.

Existing Land Uses
Land Use Description Total Area
(acres)
Impervious
Area
(acres)
Pervious Area
(acres)
Imperviousness
(%)
Developed 0.66 0.58 0.08 87%

3.1.2 Infiltration-Related Characteristics
Per Section 4.2.2.4 of the TGD and per the Geotechnical Engineer -The location is less than 50 feet away from slopes steeper than 15 percent -The depth of proposed fill is greater than 10 feet.
-Stormwater infiltration would result in significantly increased risks of geotechnical hazards on or adjacent to the project site that cannot be reasonably and technically mitigated. - There is a potential for both liquefaction and landslides on the down gradient

3.1.2.1 Hydrogeologic Conditions
Report is pending
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3.1.2.2 Soil and Geologic Infiltration Characteristics
Surface Drainage
Surface drainage shall be controlled at all times. Positive surface drainage should be provided to direct surface water away from structures and toward the street or suitable drainage facilities. Ponding of water should be avoided adjacent to the structures. Roof gutter discharge should be directed away from the building areas through solid PVC pipes to suitable discharge points. Area drains should be provided for planter areas and drainage shall be directed away from the top of slopes.

The site slopes shall be properly drained and landscaped (such as nonhomogeneous, drought-tolerant, deep-rooted plants) and maintained. All interior retaining walls shall be constructed with backdrains encased in gravel and geofabric, overlain by very low to medium expansive soils.

In general, the more the surface water can be controlled, the less surface water will infiltrate the underlying earth materials. All drainage should be controlled and diverted away from slopes and to a suitable discharge.

3.1.2.3 Geotechnical Conditions
The site is located on the coastal portion of the western border of the Peninsular Ranges Geomorphic Province of California, specifically within the San Joaquin Hills. The San Joaquin Hills are the result of a theoretical uplift along a blind thrust fault at depth below the hills. The hillsides generally consist of Tertiary bedrock formations that have been faulted and uplifted to form the hillside ascending to the northeast of the subject site. The local geology has also been influenced by changes in sea level, resulting in a series of abandoned terrace deposits on wave-cut marine platforms along the coast, generally sub-horizontal. Marine terrace deposits are typically present on the base of wave-cut platforms, and soils eroded over time (non-marine) have been deposited over the marine terrace in some locations. Localized drainages have incised into the terraces and bedrock below, throughout the region.

Our review of readily available geotechnical documents indicates that the subject site is not located within a Seismic Hazard Zone, including areas of earthquake-induced landslides and liquefaction (CDMG, 2006), or a State of California Earthquake Fault Zone (CGS, 2018). No faults were encountered during our investigation and no faults are mapped across the site on the reviewed regional geologic maps.

Per the regional geologic map of the area, the site is underlain by a veneer of Quaternary terrace deposits, over Tertiary Topanga Formation bedrock (USGS, 1957; Edgington & Tan, 1976). The materials are described below.

Older artificial fill soils are present on site that were placed during previous uses and development of the property and the adjacent property to the northwest. As encountered, older artificial fill soils were loose to medium dense, brown mottled 629
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clayey and silty sand, and sandy clay.

3.1.2.4 Summary of Infiltration Opportunities and Constraints of Existing Site Due to the development footprint, in filtration is not feasible

3.2 Proposed Site Development Activities
The project is a proposed development of a mixed use podium style structure for parking for the combination of church and residential use. The upper levels of the podium are for residential use only. A trash enclosure room will be located on the first floor within the development and covered from the second story floor. There are no loading docks, dedicated delivery areas, or outdoor storage. Routine trash collection by a maintenance individual will be conducted weekly. No activities will be associated with equipment or vehicle maintenance at the property as well.

The development is a concrete parking structure with wood framed construction above. Site area is

0.66 acres and currently is 13% pervious, however the site when completed will be 87% impervious.

3.2.1 Refer to the WQMP exhibit in Attachment E.

3.2.2 Project Attributes Influencing Stormwater Management The project is proposed as residential use which includes a Church/apartment parking on the lower level. Therefore, there will be no loading docks or hazardous materials foreseen on site. The indoor garage will drain water into the sewer system. Due to the site’s infeasibility for infiltration, all stormwater will be captured in area drains and drained through biofiltration planters to be treated prior to being outlet into downstream water bodies. There are no vehicle maintenance or cleaning areas, or fueling areas planned. The proposed slopes will be similar to the existing site condition. The project site is not in an environmentally sensitive area and drains to the Sleepy Hollow Storm Drain, and Pacific Ocean
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Proposed Land Uses
Land Use Description Total Area
(acres)
Impervious
Area
(acres)
Pervious Area
(acres)
Imperviousness
(%)
DMA 1 0.66 0.58 0.08 87

3.2.3 Effects on Infiltration and Harvest and Use Feasibility Infiltration is infeasible for this site. The project will be treating 1.5 x DSV through biofiltration planters. See attached worksheets for infeasibility justification. See Attachment E WQMP exhibit for drainage and treatment layout and details.

3.3 Receiving Waterbodies
• The project outlets water onto the right of way of Right of Way which routes water downstream into the City storm drain. The storm drain drains directly into the Pacific Ocean.
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3.4 Stormwater Pollutants or Conditions of Concern
Pollutants or Conditions of Concern
Pollutant
Expected from
Proposed Land
Uses/Activities
(Yes or No)
Receiving
Waterbody
Impaired
(Yes or No)
Priority
Pollutant
from WQIP
or other
Water
Quality
Condition?
(Yes or No)
Pollutant of
Concern
(Primary, Other,
or No)
Suspended-Solids Yes No No Other
Nutrients Yes No No Other
Heavy Metals No No No No
Bacteria/Virus/Pathogens Yes No no Other
Pesticides Yes No No Other
Oil and Grease Yes No No Other
Toxic Organic
Compounds Yes No No Other
Trash and Debris Yes No No Other
Dry Weather Runoff No No Yes Primary

3.5 Hydrologic Conditions of Concern
Does a hydrologic condition of concern exist for this project? No – An HCOC does not exist for this receiving water because (select one):

Project discharges directly to a protected conveyance (bed and bank are concrete lined the entire way from the point(s) of discharge to a receiving lake, reservoir, embayment, or the Ocean
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Project discharges directly to storm drains which discharge directly to a reservoir, lake, embayment, ocean or protected conveyance (as described above) The project discharges to an area identified in the WMAA as exempt from hydromodification concerns
Yes – An HCOC does exist for this receiving water because none of the above are applicable.

Repeat this checklist for each different receiving water to which the project would discharge.

3.6 Critical Course Sediment Yield Areas
N/A
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Section 4 Site Plan and Drainage Plan

4.1 Drainage Management Area Delineation
The project is a proposed development of a residential podium style structure for parking including residential use above grade. A trash enclosure room will be located on the first floor within the development and covered from the second story floor. There are no loading docks, dedicated delivery areas, or outdoor storage. Routine trash collection by a maintenance individual will be conducted weekly. No activities will be associated with equipment or vehicle maintenance at the property as well.

The development is a concrete parking structure with wood framed construction above. Site area is

1.20 acres and currently is 13% pervious, however the site when completed will be 87% impervious.

3.2.1 .

4.2 Overall Site Design BMPs
The proposed site plan allows for minimal pervious areas located in planters and landscaping areas, however the building footprint incorporates most of the site.

Minimize Impervious Area – DMA 1 will be 87 percent impervious (see description above) Maximize Natural Infiltration Capacity – The site is not fit for infiltration Preserve Existing Drainage Patterns and Time of Concentration – DMA 1 will maintain its natural drainage
Disconnect Impervious Areas – All impervious area on site is in one location. However, planters and landscaping are proposed to allow for impervious areas to drain onto pervious surfaces.

Protect Existing Vegetation and Sensitive Areas – The proposed site is intended to be fully developed.

Revegetate Disturbed Areas – The proposed site will be fully developed Soil Stockpiling and Site Generated Organics – N/A
Firescaping – To be determined by others.

Water Efficient Landscaping – to be installed in the above ground planter areas.

Slopes and Channel Buffers – N/A
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4.3 DMA Characteristics and Site Design BMPs

4.3.1 DMA 1
The project is a proposed development of a residential use podium style structure for parking including residential use above grade. A trash enclosure room will be located on the first floor within the development and covered from the second story floor. There are no loading docks, dedicated delivery areas, or outdoor storage. Routine trash collection by a maintenance individual will be conducted weekly. No activities will be associated with equipment or vehicle maintenance at the property as well.

The development is a concrete parking structure with wood framed construction above. Site area is

1.20 acres and currently is 13% pervious, however the site when completed will be 87% impervious.

3.2.1 4.3.X DMA Summary
Drainage Management Areas
DMA
(Number/Description)
Total
Area
(acres)
Imperviousness
(%)
Infiltration
Feasibility Category
(Full, Partial, or No
Infiltration)
Hydrologic Source
Controls Used
A 0.66 87% No Infiltration Bio Filtration
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4.4 Source Control BMPs
See Attachment C - Operations and Maintenance Plan noting the frequency and identifying the entity or party responsible for implementation of each non-structural BMP Non-Structural Source Control BMPs
Identifier Name
Check One
Reason Source Control is
Not Applicable Included Not
Applicable
N1 Education for Property Owners,
Tenants and Occupants
Property owners will be given
education materials.

N2
Activity Restrictions
Not applicable.

Commercial/Mixed Use
property
N3 Common Area Landscape
Management
All Common Area Landscape
to be maintained by subject
project
N4
BMP Maintenance
Modular Wetlands planter and
other landscaping to be
maintained
N5 Title 22 CCR Compliance (How
development will comply) Will comply with Title 22 CCR
N6
Local Industrial Permit Compliance
Not applicable.

Commercial/Mixed Use
property
N7
Spill Contingency Plan
Not applicable.

Commercial/Mixed Use
property
N8 Underground Storage Tank
Compliance
Not applicable.

Commercial/Mixed Use
property
N9 Hazardous Materials Disclosure
Compliance
Not applicable.

Commercial/Mixed Use
property
N10
Uniform Fire Code Implementation
Project will comply with Fire
Codes
N11
Common Area Litter Control
Project is a Commercial/Mixed
Use development
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N12
Employee Training
All Employees will be trained
in regards to water quality
requirements
N13
Housekeeping of Loading Docks
Not applicable.

Commercial/Mixed Use
property
N14 Common Area Catch Basin Inspection
N15 Street Sweeping Private Streets and
Parking Lots
Not applicable.

Commercial/Mixed Use
property
N16
Retail Gasoline Outlets
Not applicable.

Commercial/Mixed Use
property
Structural Source Control BMPs
Identifier Name
Check One
Reason Source Control is Not
Applicable Included Not
Applicable
S1 Provide storm drain system stenciling
and signage
S2
Design and construct outdoor material
storage areas to reduce pollution
introduction
Not applicable.

Commercial/Mixed Use property
S3
Design and construct trash and waste
storage areas to reduce pollution
introduction
Trash locations have been
designated
S4
Use efficient irrigation systems &
landscape design, water conservation,
smart controllers, and source control
Will be applied to landscaping
S5 Protect slopes and channels and
provide energy dissipation Any slope will be landscaped Incorporate requirements applicable to
individual priority project categories
(from SDRWQCB NPDES Permit)
Project will comply with Priority
Project requirements
S6 Dock areas Not applicable
S7 Maintenance bays Not applicable
S8 Vehicle wash areas Not applicable
S9 Outdoor processing areas Not applicable
S10 Equipment wash areas Not applicable
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TPM 2025-118 Section 4

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S11 Fueling areas Not applicable
S12 Hillside landscaping Not applicable
S13 Wash water control for food
preparation areas Not applicable
S14 Community car wash racks Not applicable
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Section 5 Low Impact Development BMPs

5.1 LID BMPs in DMA 1
The site has no infiltration which is why the site has been designed to contain a storage area in the basement for storm water where a sump pump will pump the water to the proposed modular wetland system located on the upper deck. Harvest and re-use will not be considered for the subject project and will not have reliable demand to use the DCV within 48 hours.

5.1.1 Hydrologic Source Controls for DMA 1
Preserve Hydrologic Drainage Pattern: DMA 1 will not be altered and will uphold its current drainage pattern. Roof downspouts, area drains, etc will be provided and installed to reduce the runoff volume.

5.1.2 Structural LID BMP for DMA 1
Water will be captured in rain gutters and through area drains and directed to a storage area. The development will sump pump the water in the basement to the proposed modular wetland system that will be located on the upper deck. The pump will be sized for the Qbmp flow. Once the tank is filled with the V/BMP required amount, solenoid valves will be activated and allow storm water flows to flow into the right of way. The entire system in the lower level will be pressure rated in the event of valve failures.

5. Summary of LID BMPs
DMA ID DMA 1
DCQ (CFS) 0.14 CFS Per Work Sheet D

1.5 X DCQ (CFS) 0.21 CFS 1.5 times for Proprietary
System non infiltration
Modular Wetlands Capacity (CFS) 0.24 CFS Per Manufactures Cut Sheet Storage Volume (CF) 1494 (1508 Proposed) CF Per Work Sheet B Pump Size (CFS) 0.24 CFS minimum per required above
Pump Size (GPM) 107 GPM Converted as required above
Rain Harvest Check (Per F.2.6) – K1 – Moderate Density
EITA= .08x1.0/(0.90X1.00) = 0.09 (Too high)
Per final engineering the proposed chamber will be fully empty and free of storm water within 6 hours and will be included in shop drawings for proposed pump cycling requirements. The project pumps will retain flowing at the design required flow rate. Proposed overflow will stack and drain 639
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in a positive nature through curb cores/adjacent storm drain. Pumps will remain to run until the storm event has passed
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Section 6 Hydromodification BMPs

6.1 Points of Compliance
The project is not subject to hydromodification

6.2 Pre-Development (Natural) Conditions
There are no critical coarse sediment yield areas. The pre-development condition is a flat vacant site with minimal slope from North to South

6.3 Post-Development Conditions and Hydromodification BMPs Post-development the site will maintain similar drainage as the pre-development condition. The site will not alter the existing drainage flows. Per proposed Hydrology the increase in Flow less than 1%.

6.4 Measures for Avoidance of Critical Coarse Sediment Yield Areas
The project does not propose any critical coarse sediment yield areas.

6.5 Hydrologic Modeling and Hydromodification Compliance N/A
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Page 22 ends

Section 7 Educational Materials Index
Educational Materials
Residential Material
(http://www.ocwatersheds.com)
Check If
Applicable
Business Material
(http://www.ocwatersheds.com)
Check If
Applicable
The Ocean Begins at Your Front Door Tips for the Automotive Industry Tips for Car Wash Fund-raisers Tips for Using Concrete and Mortar Tips for the Home Mechanic Tips for the Food Service Industry Homeowners Guide for Sustainable
Water Use
Proper Maintenance Practices for Your
Business
Household Tips Compliance BMPs for Mobile
Businesses
Proper Disposal of Household
Hazardous Waste
Other Material
Check If
Recycle at Your Local Used Oil Attached
Collection Center (North County)
Recycle at Your Local Used Oil
Collection Center (Central County)
Recycle at Your Local Used Oil
Collection Center (South County)
Tips for Maintaining a Septic Tank
System
Responsible Pest Control
Sewer Spill
Tips for the Home Improvement Projects
Tips for Horse Care
Tips for Landscaping and Gardening
Tips for Pet Care
Tips for Projects Using Paint
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Water Quality Management Plan (WQMP)
TPM 2025-118
TPM 2025-118 Appendix A
Attachment A: Educational Materials
The following educational materials are included in the Attachment A:

Ocean begins at your front door.

Tips for the Food Service Industry
Homeowners Guide for Sustainable Water Use
Household Tips
Proper Disposal of Household Hazardous Waste
Proper Maintenance Practices for Your Business
Responsible Pest Control
Sewer Spill
Tips for the Home Mechanic
Tips for Home Improvement Projects
Tips for Landscaping & Gardening
Tips for Pet Care
Tips for Residential Pool, Landscape and Hardscape Drains Tips for Projects Using Paint
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Water Quality Management Plan (WQMP)
TPM 2025-118
TPM 2025-118 Appendix B
Attachment C: Operations and Maintenance
Plan
None of the Treatment Control BMPs will be transferred to a public agency. A Property Management Company will be utilized to provide the long term maintenance and inspections required in the WQMP including funding and budgeting specific to each BMP.

Inspection and maintenance records must be kept for a minimum of five years for inspection by the regulatory agencies.

The following pages list the BMP Inspection/Maintenance requirements:
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TPM 2025-118 Appendix B
Identify the mechanism through which BMPs will be maintained. Inspection and maintenance records must be kept for a minimum of five years for inspection by the regulatory agencies. Refer to Section 7.II 4.0 in the Model WQMP.

BMP Inspection/Maintenance
BMP Reponsible
Party(s)
Inspection/
Maintenance
Activities
Required
Minimum
Frequency of
Activities
N1 Education for
Property Owner,
Tenants and
Occupants
N12 Employee
Training
Owner
Owner will ensure
that all
employees/contracto
rs/homeowners are
given a copy of the
educational materials
and activity
restrictions.

Brochures can be
downloaded from
www.ocwatersheds.c
om and are attached
as Attachment A on
the project-specific
WQMP
Educational materials
will be provided to
employees and
contractors at hire
and annually,
thereafter
N2 Activity
Restrictions Owner
The restricted
activities include, but
not limited to the
following: Cleaning
trash cans with
water, use of
chemical/additives
when washing
concrete sidewalks
Continuous
N3 Common Area
Landscape
Management
Owner
Landscape
management includes:

Mitigation of the
potential dangers of
fertilizers pesticide
Weekly
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TPM 2025-118 Appendix B
usage through the
incorporation of an
Integrated Pest
Management Plan
(IPM)
Monitor for runoff and
efficiency regularly
Implementation of a
water budget
Irrigation systems
shall be automatically
controlled and
maintained to
minimize overspray
and runoff onto
sidewalks, walls, and
fences if applicable
N11 Common Area
Litter Control Owner
Weekly sweeping
and trash pickup as
necessary within all
project areas
Daily inspection and
daily clean up and
as needed
BMP Inspection/Maintenance
BMP Reponsible
Party(s)
Inspection/
Maintenance
Activities
Required
Minimum
Frequency of
Activities
N14 Common Area
Catch Basin
Inspection
Owner
Inspect, clean and
maintain at least 80%
of drainage facilities
prior to the start of
the rainy season
Annually
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TPM 2025-118 Appendix B
N15 Street Sweeping
Private Streets and
Parking Lots
Owner Sweep driveway and
parking area monthly Monthly
S1 Provide Storm
Drain System
Stenciling and
Signage
Owner
Provide stenciling to
all catch basins and
inlets with
prohibitive language
such as “NO

DUMPING DRAINS
TO OCEAN”.

Inspect annually to
maintain legibility
Annually
S4 Efficient Irrigation
Systems &
Landscape Design,
Water Conservation,
Smart Controllers,
and Source Control
Owner
Check irrigation
heads to make sure
there are no overspray to hardscape
areas; Check
irrigation timing and
cycle lengths and
adjust as necessary;
Check water sensors
are functioning
properly
Weekly
Modular Wetland
System Owner
Check for
trash/debris/sedime
nt accumulation and
remove sediment;
inspect/replace
cartridge filer
media/trim
vegetation
Remove
trash/sediment
interval every 6 to 12
months, filter media
interval every 12 to
24 months, trim
vegetation interval
every 6 to 12 months
(see attached
Maintenance
Guidelines)
Pumps Owner
Inspect, test, and
certify annually be a
qualified inspector
Annually
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Never allow pollutants to enter the
The Ocean Begins at Your Front Door
649
Follow these simple steps to help reduce water
pollution:

Household Activities
Do not rinse spills with water. Use dry cleanup
methods such as applying cat litter or another
absorbent material, sweep and dispose of in
the trash. Take items such as used or excess
batteries, oven cleaners, automotive fluids,
painting products and cathode ray tubes, like
TVs and computer monitors, to a Household
Hazardous Waste Collection Center (HHWCC).

For a HHWCC near you call (714) 834-6752 or
visit www.oclandfills.com.

Do not hose down your driveway, sidewalk or
patio to the street, gutter or storm drain. Sweep
up debris and dispose of it in the trash.

Automotive
Take your vehicle to a commercial car
wash whenever possible. If you wash your
vehicle at home, choose soaps, cleaners, or
detergents labeled non-toxic, phosphate- free
or biodegradable. Vegetable and citrus-based
products are typically safest for the environment.

Do not allow washwater from vehicle washing
to drain into the street, gutter or storm drain.

Excess washwater should be disposed of in the
sanitary sewer (through a sink or toilet) or onto
an absorbent surface like your lawn.

Monitor your vehicles for leaks and place a pan
under leaks. Keep your vehicles well maintained
to stop and prevent leaks.

Never pour oil or antifreeze in the street, gutter
or storm drain. Recycle these substances at a
service station, a waste oil collection center or
used oil recycling center. For the nearest Used
Oil Collection Center call 1-800-CLEANUP or
visit www.1800cleanup.org.
street, gutter or storm drain!
Lawn and Garden
Pet and animal waste
Pesticides
Clippings, leaves and soil
Fertilizer
Common Pollutants
Automobile
Oil and grease
Radiator fluids and antifreeze
Cleaning chemicals
Brake pad dust
Home Maintenance
Detergents, cleaners and solvents
Oil and latex paint
Swimming pool chemicals
Outdoor trash and litter
Trash
Place trash and litter that cannot be recycled in
securely covered trash cans.

Whenever possible, buy recycled products.

Remember: Reduce, Reuse, Recycle.

Pet Care
Always pick up after your pet. Flush waste down
the toilet or dispose of it in the trash. Pet waste,
if left outdoors, can wash into the street, gutter
or storm drain.

If possible, bathe your pets indoors. If you must
bathe your pet outside, wash it on your lawn or
another absorbent/permeable surface to keep
the washwater from entering the street, gutter or
storm drain.

Follow directions for use of pet care products
and dispose of any unused products at a
HHWCC.

Pool Maintenance
Pool and spa water must be dechlorinated and free
of excess acid, alkali or color to be allowed in the
street, gutter or storm drain.

When it is not raining, drain dechlorinated pool and
spa water directly into the
sanitary sewer.

Some cities may have ordinances that do not allow
pool water to be disposed of in the storm drain.

Check with your city.

Landscape and Gardening
Do not over-water. Water your lawn and garden by
hand to control the amount of water you use or set
irrigation systems to reflect seasonal water needs.

If water flows off your yard onto your driveway or
sidewalk, your system is over-watering. Periodically
inspect and fix leaks and misdirected sprinklers.

Do not rake or blow leaves, clippings or pruning
waste into the street, gutter or storm drain. Instead,
dispose of waste by composting, hauling it to a
permitted landfill, or as green waste through your
city’s recycling program.

Follow directions on pesticides and fertilizer,
(measure, do not estimate amounts) and do not use
if rain is predicted within 48 hours.

Take unwanted pesticides to a HHWCC to be
recycled. For locations and hours of HHWCC, call
(714) 834-6752 or visit www.oclandfills.com.
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Did You Know?
Most people believe that the largest source
of water pollution in urban areas comes from
specific sources such as factories and sewage
treatment plants. In fact, the largest source
of water pollution comes from city streets,
neighborhoods, construction sites and parking
lots. This type of pollution is sometimes
called “non-point source” pollution.

There are two types of non-point source
pollution: stormwater and urban runoff
pollution.

Stormwater runoff results from rainfall.

When rainstorms cause large volumes
of water to rinse the urban landscape,
picking up pollutants along the way.

Urban runoff can happen any time of
the year when excessive water use from
irrigation, vehicle washing and other
sources carries trash, lawn clippings and
other urban pollutants into storm drains.

Where Does It Go?
Anything we use outside homes, vehicles and
businesses – like motor oil, paint, pesticides,
fertilizers and cleaners – can be blown or washed
into storm drains.

A little water from a garden hose or rain can also
send materials into storm drains.

Storm drains are separate from our sanitary
sewer systems; unlike water in sanitary sewers
(from sinks or toilets), water in storm drains is
not treated before entering our waterways.

Even if you live miles from the Pacific
Ocean, you may be unknowingly
polluting it.

Sources of Non-Point Source Pollution
Automotive leaks and spills.

Improper disposal of used oil and other engine
fluids.

Metals found in vehicle exhaust, weathered paint,
rust, metal plating and tires.

Pesticides and fertilizers from lawns, gardens and
farms.

Improper disposal of cleaners, paint and paint
removers.

Soil erosion and dust debris from landscape and
construction activities.

Litter, lawn clippings, animal waste, and other
organic matter.

Oil stains on parking lots and paved surfaces.

The Effect on the Ocean
Non-point source
pollution can have
a serious impact
on water quality
in Orange County.

Pollutants from the
storm drain system
can harm marine life
as well as coastal and wetland habitats. They can
also degrade recreation areas such as beaches,
harbors and bays.

Stormwater quality management programs have
been developed throughout Orange County to
educate and encourage the public to protect water
quality, monitor runoff in the storm drain system,
investigate illegal dumping and maintain storm
drains.

Support from Orange County residents and
businesses is needed to improve water quality
and reduce urban runoff pollution. Proper use
and disposal of materials will help stop pollution
before it reaches the storm drain and the ocean.

Dumping one quart of motor oil into a
storm drain can contaminate 250,000
gallons of water.
651
For More Information
Aliso Viejo (949) 425-2535
Anaheim Public Works Operations (714) 765-6860
Brea Engineering (714) 990-7666
Buena Park Public Works . . . . . . . . . . . . (714) 562-3655 Costa Mesa Public Services (714) 754-5323
Cypress Public Works (714) 229-6740
Dana Point Public Works (949) 248-3584
Fountain Valley Public Works . . . . . . . . . . (714) 593-4441 Fullerton Engineering Dept. (714) 738-6853
Garden Grove Public Works (714) 741-5956
Huntington Beach Public Works . . . . . . . . (714) 536-5431 Irvine Public Works (949) 724-6315
La Habra Public Services (562) 905-9792
La Palma Public Works (714) 690-3310
Laguna Beach Water Quality (949) 497-0378
Laguna Hills Public Services (949) 707-2650
Laguna Niguel Public Works . . . . . . . . . . (949) 362-4337 Laguna Woods Public Works (949) 639-0500
Lake Forest Public Works . . . . . . . . . . . . (949) 461-3480 Los Alamitos Community Dev. (562) 431-3538
Mission Viejo Public Works (949) 470-3056
Newport Beach, Code & Water
Quality Enforcement (949) 644-3215
Orange Public Works (714) 532-6480
Placentia Public Works (714) 993-8245
Rancho Santa Margarita (949) 635-1800
San Clemente Environmental Programs . . . . (949) 361-6143 San Juan Capistrano Engineering (949) 234-4413
Santa Ana Public Works . . . . . . . . . . . . . (714) 647-3380 Seal Beach Engineering . . . . . . . . . . . . . (562) 431-2527 x317 Stanton Public Works (714) 379-9222 x204
Tustin Public Works/Engineering (714) 573-3150
Villa Park Engineering (714) 998-1500
Westminster Public Works/Engineering . . . . (714) 898-3311 x446 Yorba Linda Engineering . . . . . . . . . . . . (714) 961-7138 Orange County Stormwater Program (877) 897-7455
Orange County 24-Hour
Water Pollution Problem Reporting Hotline
1-877-89-SPILL (1-877-897-7455)
On-line Water Pollution Problem Reporting Form
w w w.o c w a t e r s h e d s.c o m
The Ocean Begins
at Your Front Door
California Environmental Protection Agency
www.calepa.ca.gov
• Air Resources Board
www.arb.ca.gov
• Department of Pesticide Regulation
www.cdpr.ca.gov
• Department of Toxic Substances Control
www.dtsc.ca.gov
• Integrated Waste Management Board
www.ciwmb.ca.gov
• Office of Environmental Health Hazard
Assessment
www.oehha.ca.gov
• State Water Resources Control Board
www.waterboards.ca.gov
Earth 911 - Community-Specific Environmental
Information 1-800-cleanup or visit www.1800cleanup.
org
Health Care Agency’s Ocean and Bay Water Closure
and Posting Hotline
(714) 433-6400 or visit www.ocbeachinfo.com
Integrated Waste Management Dept. of Orange
County (714) 834-6752 or visit www.oclandfills.com for
information on household hazardous waste collection
centers, recycling centers and solid waste collection
O.C. Agriculture Commissioner
(714) 447-7100 or visit www.ocagcomm.com
Stormwater Best Management Practice Handbook
Visit www.cabmphandbooks.com
UC Master Gardener Hotline
(714) 708-1646 or visit www.uccemg.com
Printed on Recycled Paper
The Orange County Stormwater Program has created
and moderates an electronic mailing list to facilitate
communications, take questions and exchange ideas among its users about issues and topics related to stormwater and urban runoff and the implementation of program elements.

To join the list, please send an email to
[email protected]
Orange County Stormwater Program
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Ayude a prevenir
la contaminación del océano
For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
Report sewage spills and
discharges that are not
contained to your site to the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
at 1-877-89-SPILL (1-877-897-7455)
For emergencies, dial 911.

Help Prevent Ocean Pollution:

Tips for the Food
C Service Industry
lean beaches
and healthy
creeks, rivers, bays
and ocean are important to
Orange County. Fats, oils
and grease from restaurants
and food service facilities
can cause sewer line
blockages that may result
in sewage overflow into
your facility and into storm
drains. Unlike water in
sanitary sewers (from sinks
and toilets), water in storm
drains is not treated before
entering our waterways
and should never contain
washwater, trash, grease or
other materials.

You would never dump oil
and trash into the ocean, so
don’t let it enter the storm
drains. Follow these tips to
help prevent water pollution.

The Ocean Begins
at Your Front Door
Printed on Recycled Paper
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Best Kitchen Practices
Food Waste Disposal
Scrape food waste off of plates,
utensils, pots, food preparation and
cooking areas and dispose of it in the
trash.

Never put food waste down the drain.

Food scraps often contain grease,
which can clog sewer pipes and result
in sewage backups and overflows.

Grease & Oil Disposal
Never put oil or grease down the
drain. Contain grease and oil
by using covered grease storage
containers or installing a grease
interceptor.

Never overfill your grease storage
container or transport it without a
cover.

Grease control
devices must
be emptied
and cleaned
by permitted
companies.

Keep
maintenance
records on site.

For a list of oil/grease recycling
companies, contact the CIWMB at www.
ciwmb.ca.gov/foodwaste/render.htm or
contact your local sanitation district.

Minor Spill Cleanup
Always use dry cleanup methods, such
as a rag, damp mop or broom.

Never hose a spill into the street, gutter
or storm drain.

Dumpster Cleanup
Pick up all
debris around
the dumpster.

Always keep
the lid on
the dumpster
closed.

Never pour liquids into the dumpster
or hose it out.

Floor Mat Cleaning
Sweep the floor mats
regularly, discarding
the debris into the
trash.

Hose off the mats
in a mop sink, at a
floor drain, or in an
outdoor area that can
contain the water.

Never hose the mats in an area where
the wastewater can flow to the street,
gutter or storm drain.

Washwater Disposal
Dispose of washwater in a mop sink or
an area with a floor drain.

Never dispose of
washwater in the street,
gutter or storm drain.

Major Spill Cleanup
Have spill containment and cleanup kits readily available, and train all employees on how to use them.

Immediately contain and clean the spill
using dry methods.

If the spill leaves your site, call (714)
567-6363.
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Pet Waste
• Pollution: Pet waste carries bacteria through
our watersheds and eventually will be washed
out to the ocean. This can posea health risk to
swimmers and surfers.
• Solution: Pick up after your pets!
Trash and Debris
• Pollution: Trash and debris
can enter waterways by
wind, littering and careless
maintenance of trash
receptacles. Street sweeping
collects some of this trash;
however, much of what isn’t
captured ends up in our storm
drain system where it flows untreated out to the
ocean.
• Solution: Don’t litter and make sure trash
containers are properly covered. It is far more
expensive to clean up the litter and trash that ends
up in our waterways than it is to prevent it in the
first place. Come out to one of Orange County’s
many locations for Coastal and Inner-Coastal
Cleanup Day, which is held in September.

Motor Oil / Vehicle Fluids
• Pollution: Oil and petroleum products from our
vehicles are toxic to people, wildlife and plants.
• Solution: Fix any leaks
from your vehicle and
keep the maintenance
up on your car. Use
absorbent material such
as cat litter on oil spills,
then sweep it up and
dispose of it in the trash.

Recycle used motor oil
ata local Household Hazardous Waste Collection
Center
.

Low Impact Development, Water Conservation
& Pollution Prevention
The Ocean Begins atYour Front Door
DID YOU KNOW?
Homeowners Guide
for Sustainable Water Use

A TEAM EFFORT
The Orange County Stormwater Program has teamed with the Municipal Water District of Orange County (MWDOC) and the University of California Cooperative Extension Program (UCCE) to develop this pamphlet.

Low Impact Development (LID) and sustainable water use prevents water pollution and conserves water for drinking and reuse. Reducing your water use and the amount of water flowing from your home protects the environment and saves you money.

Thank you for making water protection
a priority!
For more information,
please visit
www.ocwatersheds.
com/publiced/
www.mwdoc.com
www.uccemg.com
Pesticides and Fertilizer
• Pollution: The same pesticides
that are designed to be toxic to
pests can have an equally lethal
impact on our marine life. The
same fertilizer that promotes plant
growth in lawns and gardens
can also create nuisance algae
blooms, which remove oxygen
from the water and clog waterways
when it decomposes.
• Solution: Never use pesticides or fertilizer within 48 hours of an anticipated rainstorm. Use only as much
as is directed on the label and keep it off driveways and sidewalks.

Dirt and Sediment
• Pollution: Dirt or sediment can impede the flow of the stormwater and negatively impact stream habitat as it
travels through waterways and deposits downstream.

Pollutants can attach to sediment, which can then be
transported through our waterways.
• Solution: Protect dirt stockpiles by covering them with tarps or secure plastic sheets to prevent wind or rain from allowing dirt or sediment to enter the storm drain system.

Metals
• Pollution: Metals and other toxins present in car wash water can harm important plankton, which forms the base of the aquatic food chain.
• Solution: Take your car to
a commercial car wash
where the wash water is captured and treated at
a local
wastewater treatment plant.

The Pollution Solution
Several residential activities can result in water pollution. Among these activities are car washing and hosing off driveways and sidewalks. Both activities can waste water and result in excess runoff. Water conservation methods described in this pamphlet can prevent considerable amounts of runoff and conserve water. By taking your car toa commercial car wash and by sweeping driveways and sidewalks, you can further prevent the transport of pollutants to Orange County waterways. Here are some of the common pollutants for which you can be part of the solution:

To report a spill, call the Orange County 24-Hour Water Pollution Prevention Reporting Hotline
at 1-877-89-SPILL \ (1-877-897-7455)
Special Thanks to
The City of Los Angeles Stormwater Program for the use of its artwork The Metropolitan Water District of Southern California for the use of the CaliforniaFriendly Plant and Native Habitat photos Did you know that most of the pollution found in our waterways is not from a single source, but from a “nonpoint” source meaning the accumulation of pollution from residents and businesses throughout the community
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Options for Rainwater
Harvesting and Reuse
Rainwater harvesting is a great way to save
money, prevent pollution and reduce potable
water use. To harvest your rainwater, simply
redirect the runoff from roofs and downspouts to rain barrels.

Rain gardens are another option; these reduce runoff as well as encourage infiltration.

Downspout
Disconnection/Redirection
Disconnecting downspouts
from pipes running to the gutter
prevents runoff from transporting
pollutants to the storm drain.

Once disconnected, downspouts
can be redirected to rain gardens
or other vegetated areas, or be
connected to a rain barrel.

Rain Barrels
Rain barrels capture rainwater
flow from roofs for reuse in
landscape irrigation. Capacity
of rain barrels needed for your
home will depend on the amount
of roof area and rainfall received.

When purchasing your rain barrel,
make sure it includes a screen, a
spigot to siphon water for use, an
overflow tube to allow for excess
water to run out and a connector if
you wish to connect multiple barrels to add capacity of water storage.

Mosquito growth prevention is very important when installing a rain barrel.The best way to prevent mosquito breeding is to eliminate entry points by ensuring all openings are sealed tightly. If these methods are unsuccessful, products are available to kill mosquito larvae, but that are harmless to animals and humans. Regular application of these products is essential.Please visit the Orange County Vector Control website for more information at
www.ocvcd.org/mosquitoes3.php.

Rain Gardens
Rain gardens allow runoff to be directed from your roof downspout into a landscaped area. Vegetation and rocks in the garden will slow the flow of water to allow for infiltration into the soil. Plants and soil particles will absorb pollutants from the roof runoff. By utilizing a native plant palate, rain gardens can be maintained all year with minimal additional irrigation.

These plants are adapted to the semi-arid climate of Southern California, require less water and can reduce your water bill.

Before modifying your yard to install a rain
garden, please consult your local building and/or
planning departments to ensure your garden plan
follows pertinent building codes and ordinances.

Besides codes and ordinances, some home
owner associations also have guidelines for yard
modifications. If your property is in hill areas
or includes engineered slopes, please seek
professional advice before proceeding
with changes.

R unoff , R ainwater and R euse
For information on how to disconnect a
downspout or to install and maintain a
rain barrel or rain garden at your home,
please see the Los Angeles Rainwater
Harvesting Program, A Homeowner’s
“How-To” Guide, November 2009 at
www.larainwaterharvesting.org/
Water runoff from sprinklers left
on too long will carry pollutants
into our waterways.

Permeable pavement allows water runoff to
infiltrate through the soil and prevents most
pollutants from reaching the storm drain system.

What is Low Impact Development (LID)?
Low Impact Development (LID) is a method of development that seeks to maintain the natural hydrologic character of an area. LID provides a more sustainable and pollution-preventative approach to water management.

New water quality regulations require implementation of LID in larger new developments and encourage implementation of LID and other sustainable practices in existing residential areas.

Implementing modifications to your lawn or garden can reduce pollution in our environment, conserve water and reduce your water bill.

Where Does Water Runoff Go?
Stormwater, or water from rainfall events, and runoff from outdoor water use such as sprinklers and hoses flows from homes directly into catch basins and the storm drain system. After entering the storm drain, the water flows untreated into streams, rivers, bays and ultimately the Pacific Ocean. Runoff can come from lawns, gardens, driveways, sidewalks and roofs. As it flows over hard, impervious surfaces, it picks up pollutants.

Some pollutants carried by the water runoff include trash, pet waste, pesticides, fertilizer, motor oil and more.

Water Conservation
Pollution not only impairs the water quality for habitat and recreation, it can also reduce the water available for reuse. Runoff allowed to soak into the ground is cleaned as it percolates through the soil, replenishing depleted groundwater supplies. Groundwater provides at least 50% of the total water for drinking and other indoor household activities in north and central Orange County. When land is covered with roads, parking lots, homes, etc., there is less land to take in the water and more hard surfaces over which the water can flow.

In Orange County, 60-70% of water used by residents and businesses goes to irrigation and other outdoor uses. Reusing rainwater to irrigate our lawn not only reduces the impact of water pollution from runoff, but it also is a great way to conserve our precious water resources and replenish our groundwater basin.

Permeable pavement allows water
runoff to infiltrate through the soil
and prevents most pollutants from
reaching the storm drain system.

Other Water Conservation and
Pollution Prevention Techniques
Native Vegetation and Maintenance
“California Friendly” plants or native vegetation can significantly reduce water use. These plants often require far less fertilizers and pesticides, which are two significant pollutants found in Orange County waterways. Replacing water “thirsty” plants and grass types with water efficient natives is a great way to save water and reduce the need for potentially harmful pesticides and fertilizer.

Please see the California Friendly Garden Guide produced by the Metropolitan Water District of Southern California and associated Southern California Water Agencies for a catalog of California friendly plants and other garden resources at
www.bewaterwise.com/Gardensoft.

Weed Free Yards
Weeds are water thieves.

They often reproduce quickly
and rob your yard of both
water and nutrients. Weed
your yard by hand if possible.

If you use herbicides to
control the weeds, use only
the amount recommended on
the label and never use it if
rain is forecast within the next
48 hours.

Soil Amendments
Soil amendments such as green waste (e.g. grass clippings, compost, etc.) can be a significant source of nutrients and can help keep the soil near the roots of plants moist. However, they can cause algal booms if they get into our waterways, which reduces the amount of oxygen in the water and impacts most aquatic organisms. It is important to apply soil amendments more than 48 hours prior to predicted rainfall.

IRRIGATE

EFFICIENTLY
Smart Irrigation
Controllers
Smart Irrigation Controllers have
internal clocks as well as sensors
that will turn off the sprinklers
in response to environmental
changes. If it is raining, too windy or too cold, the
smart irrigation control sprinklers will automatically shut off.

Check with your local water agency for available rebates on irrigation controllers and smart timers. • Aim your sprinklers at your lawn, not the sidewalk – By simply adjusting the direction of your sprinklers
you can save water, prevent water pollution from
runoff, keep your lawn healthy and save money.
• Set a timer for your sprinklers – lawns absorb
the water they need to stay healthy within a few
minutes of turning on the sprinklers. Time your
sprinklers; when water begins running off your
lawn, you can turn them off. Your timer can be set
to water your lawn for this duration every time.
• Water at Sunrise – Watering early in the morning
will reduce water loss due to evaporation.

Additionally, winds tend to die down in the early
morning so the water will get to the lawn as
intended.
• Water by hand – Instead of using sprinklers,
consider watering your yard by hand. Handwatering ensures that all plants get the proper amount of water and you will prevent any water
runoff, which wastes water and carries pollutants
into our waterways.
• Fix leaks - Nationwide, households waste one
trillion gallons of water a year to leaks – that is
enough water to serve the entire state of Texas for
a year. If your garden hose is leaking, replace the
nylon or rubber hose washer and ensure a tight
connection. Fix broken sprinklers immediately.
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Do your part to prevent water
pollution in our creeks, rivers, bays
and ocean.

Clean beaches and healthy creeks, rivers,
bays, and ocean are important to Orange
County. However, many common household
activities can lead to
water pollution if you’re
not careful.

Litter, oil, chemicals and
other substances that
are left on your yard or
driveway can be blown
or washed into storm
drains that flow to the
ocean. Over-watering
your lawn and washing
your car can also flush
materials into the storm
drains. Unlike water in sanitary sewers
(from sinks and toilets), water in storm
drains is not treated.

You would never pour soap, fertilizers or oil
into the ocean, so don’t let them enter
streets, gutters or storm drains. Follow the
easy tips in this brochure to help prevent
water pollution. GENUINE

RECYCLED
P APER
50% PRE-CONSUMER
AND
15% POST-CONSUMER

REMEMBER THE

WATER IN YOUR

STORM DRAIN

IS NOT TREATED
BEFORE

IT ENTERS OUR

WATERWAYS
The Ocean Begins at Your Front Door
For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
To report a spill,
call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
1-877-89-SPILL (1-877-897-7455).

For emergencies, dial 911.

The tips contained in this brochure provide useful
information to help prevent water pollution while
performing everyday household activities. If you
have other suggestions, please contact your city’s
stormwater representatives or call the Orange
County Stormwater Program.

Help Prevent Ocean Pollution:

Household Tips
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Gardening Activities
� Follow directions on pesticides and
fertilizers, (measure, do not estimate
amounts) and do not use if rain is
predicted within 48 hours.
� Water your lawn and garden by hand to
control the amount of water you use. Set
irrigation systems to reflect seasonal
water needs. If water flows off your yard
and onto your driveway or sidewalk,
your system is over-watering.
� Mulch clippings or leave them on the
lawn. If necessary, dispose in a green
waste container.
� Cultivate your garden often to control
weeds.

Washing and Maintaining Your Car
� Take your car to a commercial car wash
whenever possible.
� Choose soaps, cleaners, or detergents
labeled “non-toxic,” “phosphate free” or
“biodegradable.” Vegetable and citrusbased products are typically safest for the environment, but even these should
not be allowed into the storm drain.
� Shake floor mats into a trash can or
vacuum to clean.
� Do not use acid-based wheel cleaners and
“hose off” engine degreasers at home.

They can be used at a commercial facility,
which can properly process the washwater.
� Do not dump washwater onto your
driveway, sidewalk, street, gutter or
storm drain. Excess washwater should
be disposed of in the sanitary sewers
(through a sink, or toilet) or onto an
absorbent surface like your lawn.
� Use a nozzle to turn off water when not
actively washing down automobile.
� Monitor vehicles for leaks and place
pans under leaks. Keep your car well
maintained to stop and prevent leaks.
� Use cat litter or other absorbents and
sweep to remove any materials deposited
by vehicles. Contain sweepings and
dispose of at a HHWCC.
� Perform automobile repair and
maintenance under a covered area and
use drip pans or plastic sheeting to keep
spills and waste material from reaching
storm drains.
� Never pour oil or antifreeze in the
street, gutter or storm drains.

Recycle these substances at a service
station, HHWCC, or used oil recycling
center. For the nearest Used Oil
Collection Center call 1-800-CLEANUP
or visit www.ciwmb.ca.gov/UsedOil.

Pollution Prevention
Household Activities
� Do not rinse spills with water! Sweep
outdoor spills and dispose of in the trash.

For wet spills like oil, apply cat litter or
another absorbent material, then sweep
and bring to a household hazardous waste
collection center (HHWCC).
� Securely cover trash cans.
� Take household hazardous waste to a household hazardous waste collection center. � Store household hazardous waste in closed,
labeled containers inside or under a cover.
� Do not hose down your driveway, sidewalk or
patio. Sweep up debris and dispose of in trash.
� Always pick up after your pet. Flush waste
down the toilet or dispose of in the trash.
� Bathe pets indoors or have them
professionally groomed.

Household Hazardous Wastes include:
� Batteries
� Paint thinners, paint strippers and removers
� Adhesives
� Drain openers
� Oven cleaners
� Wood and metal cleaners and polishes
� Herbicides and pesticides
� Fungicides/wood preservatives
� Automotive fluids and products
� Grease and rust solvents
� Thermometers and other products
containing mercury
� Fluorescent lamps
� Cathode ray tubes, e.g. TVs, computer
monitors
� Pool and spa chemicals
For locations and hours of Household Hazardous Waste Collection Centers in Anaheim, Huntington Beach, Irvine and San Juan Capistrano, call (714)834-6752 or visit www.oclandfills.com. 658
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Ayude a prevenir
la contaminación del océano
Do your part to prevent
water pollution in our
creeks, rivers, bays and ocean.

Clean beaches and healthy
creeks, rivers, bays and ocean
are important to Orange County.

However, not properly disposing
of household hazardous waste can
lead to water pollution. Batteries,
electronics, paint, oil, gardening
chemicals, cleaners and other
hazardous materials cannot be
thrown in the trash. They also must
never be poured or thrown into
yards, sidewalks, driveways, gutters
or streets. Rain or other water could
wash the materials into the storm
drain and
eventually into
our waterways
and the ocean.

In addition,
hazardous
waste must not
be poured in
the sanitary
sewers (sinks
and toilets).

For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
To Report Illegal Dumping of
Household Hazardous Waste
call 1-800-69-TOXIC
To report a spill,
call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
1-877-89-SPILL (1-877-897-7455).

For emergencies, dial 911.

ORANGE COUNTY
Help Prevent Ocean Pollution:

Proper Disposal of Household
Hazardous Waste
The Ocean Begins at
Your Front Door
Printed on Recycled Paper

NEVER DISPOSE

OF HOUSEHOLD

HAZARDOUS

WASTE IN THE

TRASH, STREET,

GUTTER,

STORM DRAIN
OR SEWER.
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Pollution Prevention
Leftover household products that contain
corrosive, toxic, ignitable, or reactive
ingredients are
considered to
be “household
hazardous waste”
or “HHW.” HHW
can be found
throughout your
home, including the
bathroom, kitchen,
laundry room and
garage.

Disposal of HHW down the drain, on the
ground, into storm drains, or in the trash
is illegal and unsafe.

Proper disposal of HHW is actually easy.

Simply drop them off at a Household
Hazardous Waste Collection Center
(HHWCC) for free disposal and recycling.

Many materials including anti-freeze, latexbased paint, motor oil and batteries can be recycled. Some centers have a “Stop &
Swap” program that lets you take partially
used home, garden, and automobile
products free of charge. There are four
HHWCCs in Orange County:

Anaheim:..................1071 N. Blue Gum St
Huntington Beach:.........17121 Nichols St
Irvine:............................ 6411 Oak Canyon
San Juan Capistrano:... 32250 La Pata Ave
Centers are open Tuesday-Saturday, 9 a.m.-
3 p.m. Centers are closed on rainy days and
major holidays. For more information, call
(714) 834-6752 or visit www.oclandfills.com.

Common household hazardous
wastes
Batteries
Paint and paint products
Adhesives
Drain openers
Household cleaning products
Wood and metal cleaners and polishes
Pesticides
Fungicides/wood preservatives
Automotive products (antifreeze, motor
oil, fluids)
Grease and rust solvents
Fluorescent lamps
Mercury (thermometers & thermostats)
All forms of electronic waste including
computers and microwaves
Pool & spa chemicals
Cleaners
Medications
Propane (camping & BBQ)
Mercury-containing lamps
Television & monitors (CRTs,
flatscreens)
Tips for household hazardous
waste
Never dispose of HHW in the trash,
street, gutter, storm drain or sewer.

Keep these materials in closed, labeled
containers and store materials indoors
or under a cover.

When possible, use non-hazardous
products.

Reuse products whenever possible or
share with family and friends.

Purchase only as much of a product as
you’ll need. Empty containers may be
disposed of in the trash.

HHW can be harmful to humans,
pets and the environment. Report
emergencies to 911.

WHEN POSSIBLE,
USE

NON-HAZARDOUS
OR

LESS-HAZARDOUS
PRODUCTS.
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For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
To report a spill,
call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
at 1-877-89-SPILL (1-877-897-7455).

For emergencies, dial 911.

Proper Maintenance
Practices for
Your Business
The Ocean Begins
at Your Front Door

PROJECT

PREVENTION
Help Prevent Ocean Pollution:

Preventing water
pollution at your
commercial/industrial site
Clean beaches and healthy creeks, rivers,
bays and ocean are important to Orange
County. However, many landscape and
building maintenance activities can lead to
water pollution if you’re not careful. Paint,
chemicals, plant clippings and other materials
can be blown or washed into storm drains that
flow to the ocean. Unlike water in sanitary
sewers (from sinks and toilets), water in storm
drains is not treated before entering our
waterways.

You would never pour soap or fertilizers into
the ocean, so why would you let them enter the
storm drains? Follow these easy tips to help
prevent water pollution.

Some types of industrial facilities are required
to obtain coverage under the State General
Industrial Permit. For more information visit:
www.swrcb.ca.gov/stormwater/industrial.html
Printed on Recycled Paper
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Tips for Pool Maintenance
Call your trash hauler to replace leaking
dumpsters.

Do not dump any toxic substance or
liquid waste on the pavement, the
ground, or near a
storm drain. Even
materials that
seem harmless
such as latex paint
or biodegradable
cleaners can
damage the
environment.

Recycle paints, solvents and other
materials. For more information about
recycling and collection centers, visit
www.oclandfills.com.

Store materials indoors or under cover
and away from storm drains.

Use a construction and demolition
recycling company to recycle lumber,
paper, cardboard, metals, masonry,
carpet, plastic, pipes, drywall, rocks,
dirt, and green waste. For a listing of
construction and demolition recycling
locations in your area, visit
www.ciwmb.ca.gov/recycle.

Properly label materials. Familiarize
employees with Material
Safety Data Sheets.

Landscape Maintenance
Compost grass clippings, leaves, sticks
and other vegetation, or dispose of it at
a permitted landfill or in green waste
containers. Do not dispose of these
materials in the street, gutter or storm
drain.

Irrigate slowly and inspect the system
for leaks, overspraying and runoff.

Adjust automatic timers to avoid
overwatering.

Follow label directions for the use and
disposal of fertilizers and pesticides.

Do not apply pesticides or fertilizers if
rain is expected within 48 hours or if
wind speeds are above 5 mph.

Do not spray pesticides within 100 feet
of waterways.

Fertilizers should be worked into the
soil rather than dumped onto the
surface.

If fertilizer is spilled on the pavement
or sidewalk, sweep it up immediately
and place it back in the container.

Building Maintenance
Never allow washwater, sweepings or
sediment to enter the storm drain.

Sweep up dry spills and use cat litter,
towels or similar materials to absorb wet
spills. Dispose of it in the trash.

If you wash your building, sidewalk or
parking lot, you must contain the water.

Use a shop vac to collect the water and
contact your city or sanitation agency
for proper disposal information. Do
not let water enter the street, gutter or
storm drain.

Use drop cloths underneath outdoor
painting, scraping, and sandblasting
work, and properly dispose of materials
in the trash.

Use a ground cloth or oversized tub for
mixing paint and cleaning tools.

Use a damp mop or broom to clean
floors.

Cover dumpsters to keep insects,
animals, rainwater and sand from
entering. Keep the area around the
dumpster clear of trash and debris. Do
not overfill the dumpster.

PROJECT

PREVENTION
Proper Maintenance Practices for your Business
Never Dispose
of Anything
in the Storm
Drain.
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Clean beaches and healthy
creeks, rivers, bays and
ocean are important
to Orange County. However,
many common activities such as
pest control can lead to water
pollution if you’re not careful.

Pesticide treatments must be
planned and applied properly
to ensure that pesticides do
not enter the street, gutter or
storm drain. Unlike water in
sanitary sewers (from sinks and
toilets), water in storm drains is
not treated before entering our
waterways.

You would never dump pesticides
into the ocean, so don’t let it
enter the storm drains. Pesticides
can cause significant damage
to our environment if used
improperly. If you are thinking
of using a pesticide to control a
pest, there are some important
things to consider.

For more information,
please call
University of California Cooperative
Extension Master Gardeners at
(714) 708-1646
or visit these Web sites:
www.uccemg.org
www.ipm.ucdavis.edu
For instructions on collecting a specimen
sample visit the Orange County
Agriculture Commissioner’s website at:
http://www.ocagcomm.com/ser_lab.asp
To report a spill, call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
at 1-877-89-SPILL (1-877-897-7455).

For emergencies, dial 911.

Information From:

Cheryl Wilen, Area IPM Advisor; Darren Haver,
Watershed Management Advisor; Mary
Louise Flint, IPM Education and Publication
Director; Pamela M. Geisel, Environmental
Horticulture Advisor; Carolyn L. Unruh,
University of California Cooperative
Extension staff writer. Photos courtesy of
the UC Statewide IPM Program and
Darren Haver.

Funding for this brochure has been provided in full
or in part through an agreement with the State Water
Resources Control Board (SWRCB) pursuant to the
Costa-Machado Water Act of 2000 (Prop. 13).

Help Prevent Ocean Pollution:

The Ocean Begins
at Your Front Door
Responsible
Pest Control
Printed on Recycled Paper
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Key Steps to Follow:

Step 1: Correctly identify the pest (insect,
weed, rodent, or disease) and verify that it is
actually causing the problem.

This is important
because beneficial
insects are often
mistaken for pests
and sprayed with
pesticides needlessly.

Consult with a
Certified Nursery
Professional at a local nursery or garden center
or send a sample of the pest to the Orange
County Agricultural Commissioner’s Office.

Determine if the pest is still present – even
though you see damage, the pest may have left.

Step 2: Determine
how many pests are
present and causing
damage.

Small pest populations
may be controlled
more safely using nonpesticide techniques. These include removing food sources, washing off leaves with a strong
stream of water, blocking entry into the home
using caulking and replacing problem plants
with ones less susceptible to pests.

Step 3: If a pesticide must be used, choose
the least toxic chemical.

Obtain information on the least toxic pesticides
that are effective at controlling the target
pest from the UC Statewide Integrated Pest
Management (IPM) Program’s Web site at
www.ipm.ucdavis.edu.

Seek out the assistance of a Certified Nursery
Professional at a local nursery or garden center
when selecting a pesticide. Purchase the
smallest amount of pesticide available.

Apply the pesticide to the pest during its most
vulnerable life stage. This information can be
found on the pesticide label.

Step 4: Wear appropriate protective clothing.

Follow pesticide labels regarding specific types
of protective equipment you should wear.

Protective clothing should always be washed
separately from other clothing.

Step 5: Continuously monitor external
conditions when applying pesticides such as
weather, irrigation, and the presence of children
and animals.

Never apply pesticides when rain is predicted
within the next 48 hours. Also, do not water
after applying pesticides unless the directions say
it is necessary.

Apply pesticides when the air is still; breezy
conditions may cause the spray or dust to drift
away from your targeted area.

In case of an emergency call 911 and/or the
regional poison control number at
(714) 634-5988 or (800) 544-4404 (CA only).

For general questions you may also visit
www.calpoison.org.

Step 6: In the event of accidental spills,
sweep up or use an absorbent agent to remove
any excess pesticides. Avoid the use of water.

Be prepared. Have a broom, dust pan, or dry
absorbent material, such as cat litter, newspapers
or paper towels, ready to assist in cleaning up
spills.

Contain and clean up the spill right away. Place
contaminated materials in a doubled plastic bag.

All materials used to clean up the spill should
be properly disposed of according to your local
Household Hazardous Waste Disposal site.

Step 7: Properly store and dispose of unused
pesticides.

Purchase Ready-ToUse (RTU) products
to avoid storing
large concentrated
quantities of
pesticides.

Store unused chemicals in a locked cabinet.

Unused pesticide chemicals may be disposed
of at a Household Hazardous Waste Collection
Center.

Empty pesticide containers should be triple
rinsed prior to disposing of them in the trash.

Household Hazardous Waste
Collection Center
(714) 834-6752
www.oclandfills.com
Integrated Pest Management (IPM)
usually combines several least toxic pest
control methods for long-term prevention
and management of pest problems
without harming you, your family,
or the environment.

Three life stages of the common lady
beetle, a beneficial insect.

Tips for Pest Control
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Sewage Spill
Regulatory Requirements
This brochure was designed courtesy of the Orange County Sanitation District (OCSD).

For additional information, call (714) 962-2411, or visit their website at www.ocsd.com Your Responsibilities
as a Private Property Owner
Reference Guide
Sewage Spill
Allowing sewage to discharge to a gutter or storm
drain may subject you to penalties and/or out-ofpocket costs to reimburse cities or public agencies for clean-up efforts.

Here are the pertinent codes, fines, and agency
contact information that apply.

Orange County Stormwater Program
24 Hour Water Pollution Reporting Hotline
1-877-89-SPILL (1-877-897-7455)
! County and city water quality ordinances prohibit discharges containing pollutants.

California Health and Safety Code, Sections 5410-5416
! No person shall discharge raw or treated sewage or other waste in a manner that results in contamination, pollution or a nuisance. ! Any person who causes or permits a sewage discharge to any state waters:
• must immediately notify the local health agency of the discharge. • shall reimburse the local health agency for services that protect the public’s health and safety (water-contact receiving waters). • who fails to provide the required notice to the local health agency is guilty of a misdemeanor and shall be punished by a fine (between $500–$1,000) and/or imprisonment for less than one year. ! Requires the prevention, mitigation, response to and reporting of sewage spills.

California Water Code, Article 4, Chapter 4, Sections 13268-13271 California Code of Regulations, Title 23, Division 3, Chapter 9.2, Article 2, Sections 2250-2260
! Any person who causes or permits sewage in excess of 1,000 gallons to be discharged to state waters shall immediately notify the Office of Emergency Services.
! Any person who fails to provide the notice required by this section is guilty of a misdemeanor and shall be punished by a fine (less than $20,000) and/or imprisonment for not more than one year.

Orange County Health Care Agency
Environmental Health
(714) 433-6419
Regional Water Quality Control Board
Santa Ana Region San Diego Region
(951) 782-4130 (858) 467-2952
California Office of Emergency Services
(800) 852-7550
What is a
Sewage Spill?
You Are Responsible for a
Sewage Spill Caused by a Blockage
or Break in Your Sewer Lines!
Grease builds up inside and eventually blocks
sewer pipes. Grease gets into the sewer from food
establishments, household drains, as well as from poorly maintained commercial grease traps and interceptors.

Structure problems caused by tree roots in the lines,
broken/cracked pipes, missing or broken cleanout caps
or undersized sewers can cause blockages.

Infiltration and inflow (I/I) impacts pipe capacity and is caused when groundwater or rainwater enters the
sewer system through pipe defects and illegal
connections.

Time is of the essence in dealing with sewage spills. You are required to immediately:

Control and minimize the spill. Keep spills contained
on private property and out of gutters, storm drains and public waterways by shutting off or not using the water.

Use sandbags, dirt and/or plastic sheeting to
prevent sewage from entering the storm drain system.

Clear the sewer blockage. Always wear gloves and
wash your hands. It is recommended that a plumbing
professional be called for clearing blockages and making necessary repairs.

Always notify your city sewer/public works
department or public sewer district of sewage
spills. If the spill enters the storm drains also notify the Health Care Agency. In addition, if it exceeds 1,000
gallons notify the Office of Emergency Services. Refer to the numbers listed in this brochure.

Caution
Allowing sewage from your home, business or property
to discharge to a gutter or storm drain may subject you to penalties and/or out-of-pocket costs to reimburse cities or public agencies for clean-up and enforcement efforts.

See Regulatory Codes & Fines section for pertinent codes and fines that apply.

What to Look For
You Could Be Liable
Sewage spills can be a very noticeable gushing of water from a manhole or a slow water leak that may take time to be noticed. Don’t dismiss unaccounted-for wet areas.

Look for:
! Drain backups inside the building.
! Wet ground and water leaking around manhole lids
onto your street.
! Leaking water from cleanouts or outside drains.
! Unusual odorous wet areas: sidewalks, external
walls or ground/landscape around a building.

Rev 4/06
printed on recycled paper
Common Causes
of Sewage Spills
Overflowing
cleanout pipe
located on
private property
Keep people and pets away from the affected area.

Untreated sewage has high levels of disease-causing
viruses and bacteria. Call your local health care agency listed on the back for more information.

DTP113
Sewage spills occur when the wastewater being
transported via underground pipes overflows through
a manhole, cleanout or broken pipe. Sewage spills can
cause health hazards, damage to homes and businesses,
and threaten the environment, local waterways and
beaches.

Health Care Agency
Environmental Health
CA
IA
LIFORN

Y OF OR
TA
NN
U
G
O
E
C
If You See a Sewage Spill Occurring,
Notify Your City Sewer/Public Works
Department or Public Sewer District
IMMEDIATELY!
www.ocwatersheds.com

P R O J E C T

P R E V E N T I O N
Residences
Businesses
Homeowner/Condominium Associations
Federal and State Complexes
Military Facilities
Orange County
Sanitation District
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How a Sewer
System Works
Orange County
Agency Responsibilites
You Could Be Liable
for Not Protecting
the Environment
Local and state agencies have legal jurisdiction and enforcement authority to ensure that sewage spills are remedied.

They may respond and assist with containment, relieving pipe blockages, and/or clean-up of the sewage spill, especially if
the spill is flowing into storm drains or onto
public property.

A property owner may be charged for
costs incurred by these agencies
responding to spills from private
properties .

How You Can
Prevent Sewage Spills
A property owner's sewer pipes are called
service laterals and are connected to larger
local main and regional trunk lines. Service
laterals run from the connection at the
home to the connection with the public
sewer (including the area under the street).

These laterals are the responsibility of the
property owner and must be maintained
by the property owner. Many city agencies
have adopted ordinances requiring
maintenance of service laterals. Check with
your city sewer/local public works
department for more information.

Operation and maintenance of local and
regional sewer lines are the responsibility of the city sewer/public works departments and public sewer districts.

Preventing
Grease Blockages
The drain is not a dump! Recycle or dispose of grease
properly and never pour grease down the drain.

Homeowners should mix fats, oils and grease with absorbent waste materials such as paper, coffee grounds, or kitty litter and place it in the trash. Wipe food scraps from plates and pans and dump them in the trash.

Restaurants and commercial food service establishments
should always use “Kitchen Best Management Practices.”
These include:
! Collecting all cooking grease and liquid oil from pots, pans and fryers in covered grease containers for recycling.
! Scraping or dry-wiping excess food and grease from
dishes, pots, pans and fryers into the trash.
! Installing drain screens on all kitchen drains.
! Having spill kits readily available for cleaning up spills. ! Properly maintaining grease traps or interceptors by having them serviced regularly. Check your local city codes.
! City Sewer/Public Works Departments—
Responsible for protecting city property
and streets, the local storm drain system, sewage
collection system and other public areas.
! Pu b l i c S ew e r/ S a n i t a t i o n D i s t r i c t— Responsible for collecting, treating and disposing
of wastewater.
! County of Orange Health Care Agency—
Responsible for protecting public health by closing
ocean/bay waters and may close food-service
businesses if a spill poses a threat to public health.
! Regional Water Quality Control Boards—
Responsible for protecting State waters.
! Orange County Stormwater Program—
Responsible for preventing harmful pollutants from
being discharged or washed by stormwater runoff
into the municipal storm drain system, creeks, bays
and the ocean.
2 3
1 Never put grease down garbage
disposals, drains or toilets.

Perform per iod ic c lean ing to
eliminate grease, debris and roots in
your service laterals.

Repair any structural problems
in your sewer system and eliminate
any rainwater infiltration/inflow
leaks into your service laterals.

Sewage spills can cause
damage to the environment.

Help prevent them!
Regional
Trunk line
Sewer
Wastewater
Treatment
Plant
Cleanout
Cleanout Grease
Trap
Downspout
(rain water goes into
the storm drain system,
not the sewer)

RESIDENCE

BUSINESS
Manhole
Local Main
Sewer Line
Private
Service
Laterals
Manhole
City Sewer/Public Works Departments
Aliso Viejo . . . . . . . . . . . . . . . . . . . . . . . . . (949) 425-2500 Anaheim. . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 765-6860 Brea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 990-7691 Buena Park . . . . . . . . . . . . . . . . . . . . . . . . (714) 562-3655 Costa Mesa . . . . . . . . . . . . . . . . . . . . . . . . (949) 645-8400 Cypress . . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 229-6760 Dana Point . . . . . . . . . . . . . . . . . . . . . . . . . (949) 248-3562 Fountain Valley . . . . . . . . . . . . . . . . . . . . . (714) 593-4600 Fullerton. . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 738-6897 Garden Grove. . . . . . . . . . . . . . . . . . . . . . . (714) 741-5375 Huntington Beach . . . . . . . . . . . . . . . . . . . (714) 536-5921 Irvine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (949) 453-5300 Laguna Beach . . . . . . . . . . . . . . . . . . . . . . (949) 497-0765 Laguna Hills . . . . . . . . . . . . . . . . . . . . . . . . (949) 707-2650 Laguna Niguel . . . . . . . . . . . . . . . . . . . . . . (949) 362-4337 Laguna Woods . . . . . . . . . . . . . . . . . . . . . . (949) 639-0500 La Habra. . . . . . . . . . . . . . . . . . . . . . . . . . . (562) 905-9792 Lake Forest . . . . . . . . . . . . . . . . . . . . (949) 461-3480 La Palma . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 690-3310 Los Alamitos . . . . . . . . . . . . . . . . . . . . . . . (562) 431-3538 Mission Viejo. . . . . . . . . . . . . . . . . . . . . . . (949) 831-2500 Newport Beach . . . . . . . . . . . . . . . . . . . . . (949) 644-3011 Orange . . . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 532-6480 Orange County . . . . . . . . . . . . . . . . . . . . . . (714) 567-6363 Placentia . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 993-8245 Rancho Santa Margarita. . . . . . . . . . . . (949) 635-1800 San Clemente. . . . . . . . . . . . . . . . . . . . . . . (949) 366-1553 San Juan Capistrano . . . . . . . . . . . . . . . . (949) 443-6363 Santa Ana . . . . . . . . . . . . . . . . . . . . . . . . . (714) 647-3380 Seal Beach. . . . . . . . . . . . . . . . . . . . . . . . . (562) 431-2527 Stanton . . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 379-9222 Tustin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 962-2411 Villa Park . . . . . . . . . . . . . . . . . . . . . . . . . . (714) 998-1500 Westminster . . . . . . . . . . . . . . . . . . . . . . . (714) 893-3553 Yorba Linda . . . . . . . . . . . . . . . . . . . . . . . . (714) 961-7170 Public Sewer/Water Districts
Costa Mesa Sanitary District . . . . . . . . . . (714) 393-4433/ (949) 645-8400
El Toro Water District . . . . . . . . . . . . . . . . (949) 837-0660 Emerald Bay Service District . . . . . . . . . . (949) 494-8571 Garden Grove Sanitary District . . . . . . . . . (714) 741-5375 Irvine Ranch Water District . . . . . . . . . . . . (949) 453-5300 Los Alamitos/Rossmoor Sewer District . . . (562) 431-2223 Midway City Sanitary District (Westminster) (714) 893-3553 Moulton Niguel Water District . . . . . . . . . (949) 831-2500 Orange County Sanitation District. . . . . . . (714) 962-2411 Santa Margarita Water District . . . . . . . . (949) 459-6420 South Coast Water District . . . . . . . . . . . . (949) 499-4555 South Orange County Wastewater Authority (949) 234-5400 Sunset Beach Sanitary District . . . . . . . . . (562) 493-9932 Trabuco Canyon Sanitary District . . . . . . . (949) 858-0277 Yorba Linda Water District . . . . . . . . . . . . (714) 777-3018 Other Agencies
Orange County Health Care Agency . . . . . (714) 433-6419 Office of Emergency Services. . . . . . . . . . (800) 852-7550 Report Sewage Spills!
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Ayude a prevenir
la contaminación del océano
For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL
(1-877-897-7455)
or visit
www.ocwatersheds.com.

For information about the proper
disposal of household hazardous
waste, call the Household Waste
Hotline at 1-877-89-SPILL
(1-877-897-7455)
or visit www.oclandfills.com.

For additional information about the
nearest oil recycling center, call the
Used Oil Program at
1-800-CLEANUP
or visit www.cleanup.org.

Help Prevent Ocean Pollution:

Tips for the
Home Mechanic
The Ocean Begins at
Your Front Door
Clean beaches and healthy
creeks, rivers, bays and
ocean are important to
Orange County. However, not
properly disposing of used oil is
illegal and can lead to fines. If you
pour or drain oil onto driveways,
sidewalks or streets, it can be
washed into the storm drain.

Help prevent water pollution by
taking your used oil and oil filters
to a used oil collection center. Most
major automotive maintenance
centers will accept up to five gallons
of used motor oil at no cost. For a
list of locations, please visit
www.cleanup.org.
emc/rev9/08
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Tips for the Home Mechanic
drain to the County’s 24-Hour Water
Pollution Problem Reporting Hotline
at 1-877-89-SPILL (1-877-897-7455) or
visit www.ocwatersheds.com to fill out
an incident report.
• Report emergencies to 911.

Vehicle Fluid Management
• Vehicle fluids are hazardous waste
and must be stored and disposed of
in accordance with all local, state and
federal laws.
• Designate an area to drain vehicle
fluids away from storm drains and
sanitary drains.
• When possible, drain vehicle fluids
indoors or within covered areas, and
only over floors that are constructed
of a nonporous
material
such as
concrete.

Asphalt and
dirt floors
absorb spilled or leaked fluids, making
the cleanup extremely difficult.

Work Site
• Locate the storm drains on or near
your property. Do not allow used oil
or any materials to flow into these
drains.
• Examine your home for sources of
pollution.
• Perform automotive projects under
cover and in a controlled area to
prevent stormwater runoff.
• Sweep or vacuum your automotive
workspace regularly
• Use a
damp mop
to clean
work areas.

Never
hose down
surfaces
into the
street, gutter or storm drain.
• Pour mop water into a sink or toilet.

Never dispose of water in a parking
lot, street, gutter or storm drain.

Prevent Leaks and Spills
• Keep absorbent materials such as rags
and/or cat litter in the work area
• Empty drip pans into a labeled, seal
container before they are full
• Wipe up any spills or repair leaks as they
happen. Don’t let them sit.
• Place large pans under any wrecked cars
until all fluids are drained.
• Promptly dispose of collected fluids into a
hazardous waste drum or deliver them to
an oil recycling center. Used oil recycling
locations can be found at http://www.
ochealthinfo.com/regulatory/usedoil.htm
Cleaning Spills
• Clean up spills immediately by using
absorbent material such as rags, cat litter
or sand. If the
material spilled
is hazardous,
dispose of the
rag, litter or
sand in the
same manner
as hazardous
waste. If the material spill is nonhazardous, dispose of it in the trash. • Immediately report spills that have
entered the street, gutter or storm
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Help Prevent Ocean Pollution:

For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
To report a spill,
call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
at 1-877-89-SPILL (1-877-897-7455).

For emergencies, dial 911.

The tips contained in this brochure provide useful
information to help prevent water pollution while
performing home improvement projects. If you
have other suggestions, please contact your city’s
stormwater representatives or call the Orange
County Stormwater Program.

Clean beaches
and healthy
creeks, rivers, bays
and ocean are important to
Orange County. However, many
common activities can lead to
water pollution if you’re not
careful. Home improvement
projects and work sites must
be maintained to ensure that
building materials do not enter
the street, gutter or storm drain.

Unlike water in sanitary sewers
(from sinks and toilets), water
in storm drains is not treated
before entering our waterways.

You would never dump building
materials into the ocean, so
don’t let them enter the storm
drains. Follow these tips to help
prevent water pollution.

Printed on Recycled Paper
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Tips for Pool Maintenance
When permanently removing large quantities of
soil, a disposal location must be found prior to
excavation. Numerous businesses are available to
handle disposal needs. For disposal options, visit
www.ciwmb.ca.gov/SWIS.

Prevent erosion by planting fast-growing annual and
perennial grasses. They will shield and bind the soil.

Recycle
Use a construction and demolition recycling
company to recycle
lumber, paper,
cardboard, metals,
masonry (bricks,
concrete, etc.), carpet,
plastic, pipes (plastic,
metal and clay),
drywall, rocks, dirt and
green waste.

For a listing of construction and demolition recycling
locations in your area, visit
www.ciwmb.ca.gov/recycle.

Spills
Clean up spills immediately by using an absorbent
material such as cat litter, then sweep it up and
dispose of it in the trash.

Immediately report spills that have entered the street, gutter or storm drain to the County’s 24-Hour Water
Pollution Problem Reporting Hotline at
(714) 567-6363 or visit www.ocwatersheds.com to fill
out an incident reporting form.

Home improvement projects can cause significant
damage to the environment. Whether you hire
a contractor or work on the house yourself, it
is important to follow these simple tips while
renovating, remodeling or improving your home:

General Construction
Schedule projects for dry
weather.

Keep all construction debris
away from the street, gutter
and storm drain.

Store materials under cover
with temporary roofs or plastic
sheets to eliminate or reduce
the possibility that rainfall,
runoff or wind will carry
materials from the project site
to the street, storm drain or
adjacent properties.

Building Materials
Never hose materials into a street, gutter or storm
drain.

Exposed piles of construction material should not be
stored on the street or sidewalk.

Minimize waste by ordering only the amount of
materials needed to complete the job.

Do not mix more fresh concrete than is needed for
each project.

Wash concrete mixers and equipment in a
designated washout area where the water can flow
into a containment area or onto dirt.

Dispose of small amounts of dry excess materials in
the trash. Powdery waste, such as dry concrete, must
be properly contained within a box or bag prior to
disposal. Call your local trash hauler for weight and
size limits.

Paint
Measure the room or object to be painted, then buy
only the amount needed.

Place the lid on firmly and store the paint can upsidedown in a dry location away from the elements.

Tools such as brushes, buckets and rags should never
be washed where excess water can drain into the
street, gutter or storm drain. All tools should be
rinsed in a sink connected to the sanitary sewer.

When disposing of paint, never put wet paint in the
trash.

Dispose of water-based paint by removing the lid
and letting it dry
in the can. Large
amounts must be
taken to a Household
Hazardous Waste
Collection Center
(HHWCC).

Oil-based paint is a
household hazardous
waste. All leftover
paint should be taken
to a HHWCC.

For HHWCC locations and hours, call (714) 834-6752
or visit www.oclandfills.com.

Erosion Control
Schedule grading and excavation projects for dry
weather.

When temporarily removing soil, pile it in a
contained, covered area where it cannot spill
into the street, or obtain the required temporary
encroachment or street closure permit and follow the
conditions instructed by the permit.

Tips for Home Improvement Projects
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For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
UCCE Master Gardener Hotline:
(714) 708-1646
To report a spill,
call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
1-877-89-SPILL (1-877-897-7455)
.

For emergencies, dial 911.

The tips contained in this brochure provide useful
information to help prevent water pollution
while landscaping or gardening. If you have other
suggestions, please contact your city’s stormwater
representatives or call the Orange County
Stormwater Program.

C lean beaches
and healthy
creeks, rivers, bays
and ocean are important to
Orange County. However,
many common activities
can lead to water pollution
if you’re not careful.

Fertilizers, pesticides and
other chemicals that are left
on yards or driveways can
be blown or washed into
storm drains that flow to the
ocean. Overwatering lawns
can also send materials into
storm drains. Unlike water
in sanitary sewers (from sinks
and toilets), water in storm
drains is not treated before
entering our waterways.

You would never pour
gardening products into the
ocean, so don’t let them enter
the storm drains. Follow
these easy tips to help prevent
water pollution.

Printed on Recycled Paper
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Tips for Landscape and Gardening Tips for Landscape & Gardening Never allow gardening products or
polluted water to enter the street, gutter
or storm drain.

General Landscaping Tips
Protect stockpiles and materials from
wind and rain by storing them under
tarps or secured plastic sheeting.

Prevent erosion of slopes by planting
fast-growing, dense ground covering
plants. These will shield and bind the
soil.

Plant native vegetation
to reduce the amount
of water, fertilizers, and
pesticide applied to the
landscape.

Never apply pesticides
or fertilizers when rain is
predicted within the next 48 hours.

Garden & Lawn Maintenance
Do not overwater. Use irrigation
practices such as drip irrigation,
soaker hoses or micro spray systems.

Periodically inspect and fix leaks and
misdirected sprinklers.

Do not rake or blow
leaves, clippings or
pruning waste into
the street, gutter
or storm drain.

Instead, dispose
of green waste by
composting, hauling
it to a permitted
landfill, or recycling it through your
city’s program.

Use slow-release fertilizers to
minimize leaching, and use organic
fertilizers.

Read labels and use only as directed.

Do not over-apply pesticides or
fertilizers. Apply to spots as needed,
rather than blanketing an entire
area.

Store pesticides, fertilizers and other
chemicals in a dry covered area to
prevent exposure that may result
in the deterioration
of containers and
packaging.

Rinse empty
pesticide containers
and re-use rinse water
as you would use the
product. Do not dump rinse water
down storm drains. Dispose of empty
containers in the trash.

When available, use non-toxic
alternatives to traditional pesticides,
and use pesticides specifically
designed to control the pest you are
targeting. For more information, visit
www.ipm.ucdavis.edu.

If fertilizer is spilled, sweep up the
spill before irrigating. If the spill is
liquid, apply an absorbent material
such as cat litter, and then sweep it up
and dispose of it in the trash.

Take unwanted pesticides to a
Household Hazardous Waste
Collection Center to be recycled.

Locations are provided below.

Household Hazardous Waste
Collection Centers
Anaheim: 1071 N. Blue Gum St.

Huntington Beach: 17121 Nichols St.

Irvine: 6411 Oak Canyon
San Juan Capistrano: 32250 La Pata Ave.

For more information, call (714) 834-6752
or visit www.oclandfills.com
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C lean beaches
and healthy
creeks, rivers, bays
and ocean are important to
Orange County. However,
many common activities
can lead to water pollution
if you’re not careful. Pet
waste and pet care products
can be washed into the
storm drains that flow to
the ocean. Unlike water in
sanitary sewers (from sinks
and toilets), water in storm
drains is not treated before
entering our waterways.

You would never put pet
waste or pet care products
into the ocean, so don’t let
them enter the storm drains.

Follow these easy tips to help
prevent water pollution.

For emergencies, dial 911.

The tips contained in this brochure provide useful
information to help prevent water pollution while
caring for your pet. If you have other suggestions,
please contact your city’s stormwater representatives
or call the Orange County Stormwater Program.

Printed on Recycled Paper
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Never let any pet care products or
washwater run off your yard and into
the street, gutter or storm drain.

Washing Your Pets
Even biodegradable soaps and
shampoos can be harmful to marine
life and the environment.

If possible, bathe your pets indoors
using less-toxic shampoos or have
your pet professionally groomed.

Follow instructions on the products
and clean up spills.

If you bathe your pet outside, wash it
on your lawn or another absorbent/
permeable surface to keep the
washwater from running into the
street, gutter or storm drain.

Flea Control
Consider using oral or topical flea
control products.

If you use flea control products
such as shampoos, sprays or collars,
make sure to dispose of any unused
products at
a Household
Hazardous
Waste
Collection
Center. For
location
information,
call (714) 834-6752.

Why You Should Pick Up After
Your Pet
It’s the law!
Every city has
an ordinance
requiring you
to pick up
after your pet.

Besides being
a nuisance, pet
waste can lead to water pollution, even
if you live inland. During rainfall, pet
waste left outdoors can wash into storm
drains. This waste flows directly into our
waterways and the ocean where it can
harm human health, marine life and
the environment.

As it decomposes, pet waste demands
a high level of oxygen from water.

This decomposition can contribute to
killing marine
life by reducing
the amount of
dissolved oxygen
available to
them.

Have fun with
your pets, but
please be a
responsible pet
owner by taking
care of them and the environment.

Take a bag with you on walks to pick
up after your pet.

Dispose of the waste in the trash or in
a toilet.

Tips for Pet Care
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Help Prevent Ocean Pollution:

For emergencies, dial 911.

The tips contained in this brochure provide useful
information to help prevent water pollution. If
you have other suggestions, please contact your
city’s stormwater representatives or call the Orange
County Stormwater Program.

Printed on Recycled Paper
Tips for Residential
Pool, Landscape and
Hardscape Drains
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Pool Maintenance
All pool water discharged to the curb, gutter or
permitted pool drain from your property must meet the
following water quality criteria:

The residual chlorine does not exceed

0.1 mg/L (parts per
million).

The pH is between

6.5 and 8.5.

The water is free
of any unusual
coloration.

There is no discharge
of filter media or acid
cleaning wastes.

Some cities have ordinances that do not allow pool
water to be discharged to the storm drain. Check with
your city.

Landscape and
Hardscape Drains
The following recommendations will help reduce or
prevent pollutants from your landscape and hardscape
drains from entering the street, gutter or storm drain.

Unlike water that enters the sewer (from sinks and
toilets), water that enters a landscape or hardscape
drain is not treated before entering our creeks, rivers, bays and ocean.

Household Activities
Do not rinse spills of materials or chemicals to any
drain.

Use dry cleanup methods such as applying cat
litter or another absorbent material, then sweep it
up and dispose of it in the trash. If the material is
hazardous, dispose of it at a Household Hazardous
Waste Collection Center (HHWCC). For locations,
call (714) 834-6752 or visit www.oclandfills.com.

Do not hose down your driveways, sidewalks or
patios to your landscape or hardscape drain.

Sweep up debris and dispose of it in the trash.

Always pick up after your pet. Flush waste down
the toilet or dispose of it in the trash.

Tips for Residential Pool, Landscape and Hardscape Drains Do not store items such as cleaners, batteries,
automotive fluids, paint products, TVs, or
computer monitors uncovered outdoors. Take
them to a HHWCC for disposal.

Yard Maintenance
Do not overwater. Water by hand or set
automated irrigation systems to reflect seasonal
water needs.

Follow directions on
pesticides and fertilizers
(measure, do not estimate
amounts) and do not use
if rain is predicted within
48 hours.

Cultivate your garden
often to control weeds
and reduce the need to
use chemicals.

Vehicle Maintenance
Never pour oil or antifreeze down your
landscape or hardscape drain. Recycle these
substances at a service station, a waste collection
center or used oil recycling center. For
locations, contact the Used Oil Program at 1-800-
CLEANUP or visit www.CLEANUP.org.

Whenever possible, take your vehicle to a
commercial car wash.

If you do wash your vehicle at home, do not
allow the washwater to go down your landscape
or hardscape drain. Instead, dispose of it in
the sanitary sewer (a sink or toilet) or onto an
absorbent surface such as your lawn.

Use a spray nozzle that will shut off the water
when not in use.
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For more information,
please call the
Orange County Stormwater Program
at 1-877-89-SPILL (1-877-897-7455)
or visit
www.ocwatersheds.com
To report a spill,
call the
Orange County 24-Hour
Water Pollution Problem
Reporting Hotline
at 1-877-89-SPILL (1-877-897-7455).

For emergencies, dial 911.

The tips contained in this brochure provide useful
information to help prevent water pollution while
using, storing and disposing of paint. If you
have other suggestions, please contact your city’s
stormwater representatives or call the Orange
County Stormwater Program.

Clean beaches
and healthy
creeks, rivers, bays
and ocean are important to
Orange County. However,
many common activities
such as painting can lead
to water pollution if you’re
not careful. Paint must be
used, stored and disposed of
properly to ensure that it does
not enter the street, gutter or
storm drain. Unlike water in
sanitary sewers (from sinks
and toilets), water in storm
drains is not treated before
entering our waterways.

You would never dump paint
into the ocean, so don’t let
it enter the storm drains.

Follow these easy tips to help
prevent water pollution.

Printed on Recycled Paper
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Tips for Pool Maintenance
Paint can cause significant damage to our
environment. Whether you hire a contractor or
do it yourself, it is important to follow these simple
tips when purchasing, using, cleaning, storing and
disposing of paint.

Purchasing Paint
Measure the room or object to be painted, then buy
only the amount needed.

Whenever possible, use water-based paint since it
usually does not require hazardous solvents such as
paint thinner for cleanup.

Painting
Use only one brush or roller per color of paint to
reduce the amount of water needed for cleaning.

Place open paint containers or trays on a stable
surface and in a position that is unlikely to spill.

Always use a tarp under the area or object being
painted to collect paint drips and contain spills.

Cleaning
Never clean brushes or rinse paint containers in the
street, gutter or storm drain.

For oil-based products, use as much of the paint on
the brushes as possible. Clean brushes with thinner.

To reuse thinner, pour it through a fine filter (e.g.
nylon, metal gauze or filter paper) to remove solids
such as leftover traces of paint.

For water-based products, use as much of the paint
on the brushes as possible, then rinse in the sink.

Collect all paint chips and dust. Chips and dust
from marine paints or paints containing lead,
mercury or tributyl tin are hazardous waste. Sweep
up and dispose of at a Household Hazardous Waste
Collection Center (HHWCC).

Storing Paint
Store paint in a dry location away from the elements.

Store leftover water-based paint, oil-based paint and
solvents separately in original or clearly marked
containers.

Avoid storing paint cans directly on cement floors.

The bottom of the can will rust much faster on
cement.

Place the lid on firmly and store the paint can upsidedown to prevent air from entering. This will keep the paint usable longer. Oil-based paint is usable for up
to 15 years. Water-based paint remains usable for up
to 10 years.

Alternatives to Disposal
Use excess paint to apply another coat, for touch-ups,
or to paint a closet, garage, basement or attic.

Give extra paint to friends or family. Extra paint can
also be donated to a local theatre group, low-income
housing program or school.

Take extra paint to an exchange program such as the
“Stop & Swap” that allows you to drop off or pick up
partially used home care products free of charge.
“Stop & Swap” programs are available at most
HHWCCs.

For HHWCC locations and hours, call (714) 834-6752
or visit www.oclandfills.com.

Disposing of Paint
Never put wet paint in the trash.

For water-based paint:

If possible, brush the leftover paint on cardboard or
newspaper. Otherwise, allow the paint to dry in the
can with the lid off in a well-ventilated area protected from the elements, children and pets. Stirring the
paint every few days will speed up the drying.

Large quantities of extra paint should be taken to a
HHWCC.

Once dried, paint and painted surfaces may be
disposed of in the trash. When setting a dried paint
can out for trash collection, leave the lid off so the
collector will see that the paint has dried.

For oil-based paint:

Oil-based paint is a household hazardous waste.

All leftover paint should be taken to a HHWCC.

Aerosol paint:

Dispose of aerosol paint cans at a HHWCC.

Spills
Never hose down pavement or other impermeable
surfaces where paint has spilled.

Clean up spills immediately by using an absorbent
material such as cat litter. Cat litter used to clean
water-based paint spills can be disposed of in the
trash. When cleaning oil-based paint spills with cat
litter, it must be taken to a HHWCC.

Immediately report spills that have entered the
street, gutter or storm drain to the County’s 24-Hour
Water Pollution Problem Reporting Hotline at (714)
567-6363 or visit www.ocwatersheds.com to fill out an
incident reporting form.

Tips for Projects Using Paint
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GPM CFS
MWS-L-4-4 4.13' 6.7 3.40 22.78 23.46 0.052
MWS-L-4-6 4.13' 9.4 3.40 31.96 32.92 0.073
MWS-L-4-8 4.13' 14.8 3.40 50.32 51.83 0.115
MWS-L-4-13 4.13' 18.4 3.40 62.56 64.44 0.144
MWS-L-4-15 4.13' 22.4 3.40 76.16 78.44 0.175
MWS-L-4-17 4.13' 26.4 3.40 89.76 92.45 0.206
MWS-L-4-19 4.13' 30.4 3.40 103.36 106.46 0.237
MWS-L-4-21 4.13' 34.4 3.40 116.96 120.47 0.268
MWS-L-8-12 4.13' 44.4 3.40 150.96 155.49 0.346
MWS-L-8-16 4.13' 59.2 3.40 201.28 207.32 0.462
Shallow or Deeper Units
Available. Change in Height
Will Affect Treatment Capacity
** Not the physical height of
the unit but the max HGL in
the system at peak treatment
flow rate
Based on loading rate of
100 in/hr or 1.03 gpm/sq ft
Wetland Surface
Area (sq ft)
Treatment Capacity for Flow Based Design
**FLOW DESIGN**
Modular Wetland Systems, Inc. Copyright 2013 www.modularwetlands.com [email protected] P: 760-433-7640 2972 San Luis Rey Rd, Oceanside CA 92058 MWS Linear 2.0 Flow Based Sizing Calculations -
State of California
Model #
Physical Depth of Model
from TC, FS, TC to

INVERT OUT
Wetland Perimiter
(ft)
**Wetland Chamber Max
HGL Height (ft)
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TECHNICAL GUIDANCE DOCUMENT APPENDICES
South Orange County Version E-45 September 28, 2017
Option 1 for Supplemental Retention: Demonstrate that HSCs, upstream BMPs, and downstream BMPs collectively achieve at least 40 percent average annual runoff volume for the DMA. This can be demonstrated using the nomograph capture efficiency method in Section E.3.2, but setting the target for 40 percent rather than 80 percent.

Option 2 for Supplemental Retention: Demonstrate that the effective footprint for infiltration provided by HSCs, upstream BMPs, and downstream BMPs, as applicable, is equivalent to a conventional biofiltration BMP. The footprint to achieve partial volume reduction goals is determined via Section E.4.2. Figure E-7. Capture Efficiency Nomograph for Flow-based Biotreatment BMPs in Orange County
E.3.5.2 Guidance on Sizing Compact Biofiltration with Upstream Detention There are some design scenarios where an upstream cistern or tank could be used to detain and slow the flow entering a compact biofiltration BMP. This design approach can be used to extend the time of concentration of the catchment up to a maximum of 60 minutes. It cannot be used to 686
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Worksheets from Orange County Technical Guidance Document (5-19-2011) See TGD for instructions and/or examples related to these worksheets www.ocwatersheds.com/WQMP.aspx
Worksheet D: Capture Efficiency Method for Flow-Based BMPs Step 1: Determine the design capture storm depth used for calculating volume 1 Enter the time of concentration, Tc (min) (See Appendix IV.2) Tc= 5 2 Using Figure III.4, determine the design intensity at which the estimated time of concentration (Tc) achieves 80% capture efficiency, I1
I1= 0.27 in/hr
3 Enter the effect depth of provided HSCs upstream, dHSC (inches) (Worksheet A) dHSC= 0 inches
4 Enter capture efficiency corresponding to dHSC, Y2
(Worksheet A) Y2= 0 %
5 Using Figure III.4, determine the design intensity at which the time of concentration (Tc) achieves the upstream capture efficiency(Y2), I2
I2= 0
6 Determine the design intensity that must be provided by BMP, Idesign= I1-I2
Idesign= 0.27
Step 2: Calculate the design flowrate
1 Enter Project area tributary to BMP (s), A (acres) A= 0.66 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.87 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.80 4 Calculate design flowrate, Qdesign= (C x idesign x A) Qdesign= 0..21 cfs Supporting Calculations
Describe system:

Provide time of concentration assumptions:
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Worksheets from Orange County Technical Guidance Document (5-19-2011) See TGD for instructions and/or examples related to these worksheets www.ocwatersheds.com/WQMP.aspx
Worksheet B: Simple Design Capture Volume Sizing Method Step 1: Determine the design capture storm depth used for calculating volume 1 Enter design capture storm depth from Figure III.1, d (inches) d= 0.78 inches 2 Enter the effect of provided HSCs, dHSC (inches)
(Worksheet A) dHSC=
0 inches
3 Calculate the remainder of the design capture storm depth, dremainder (inches) (Line 1 – Line 2)
dremainder
=

0.78 inches
Step 2: Calculate the DCV
1 Enter Project area tributary to BMP (s), A (acres) A= 0.66 acres 2 Enter Project Imperviousness, imp (unitless) imp= 0.87 3 Calculate runoff coefficient, C= (0.75 x imp) + 0.15 C= 0.80 4 Calculate runoff volume, Vdesign= (C x dremainder x A x 43560 x (1/12)) Vdesign= 1494 cu-ft
Step 3: Design BMPs to ensure full retention of the DCV Step 3a: Determine design infiltration rate
1 Enter measured infiltration rate, Kmeasured (in/hr)
(Appendix VII)
Kmeasured
=
In/hr
2 Enter combined safety factor from Worksheet H, Sfinal (unitless) Sfinal=
3 Calculate design infiltration rate, Kdesign = Kmeasured / Sfinal Kdesign= In/hr
Step 3b: Determine minimum BMP footprint
4 Enter drawdown time, T (max 48 hours) T= Hours
5 Calculate max retention depth that can be drawn down within the drawdown time (feet), Dmax = Kdesign x T x (1/12) Dmax= feet 6 Calculate minimum area required for BMP (sq-ft), Amin = Vdesign/ dmax
Amin= sq-ft
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Maintenance Guidelines for
Modular Wetland System - Linear
Maintenance Summary
o Remove Trash from Screening Device – average maintenance interval is 6 to 12 months.  (5 minute average service time).
o Remove Sediment from Separation Chamber – average maintenance interval is 12 to 24 months.  (10 minute average service time).
o Replace Cartridge Filter Media – average maintenance interval 12 to 24 months.  (10-15 minute per cartridge average service time).
o Replace Drain Down Filter Media – average maintenance interval is 12 to 24 months.  (5 minute average service time).
o Trim Vegetation – average maintenance interval is 6 to 12 months.  (Service time varies).

System Diagram

Access to screening device, separation
chamber and cartridge filter
Access to drain
down filter
Pre-Treatment
Chamber
Biofiltration Chamber
Discharge
Chamber
Outflow
Pipe
Inflow Pipe
(optional)
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Maintenance Procedures
Screening Device

1. Remove grate or manhole cover to gain access to the screening device in the PreTreatment Chamber. Vault type units do not have screening device. Maintenance can be performed without entry.

2. Remove all pollutants collected by the screening device. Removal can be done manually or with the use of a vacuum truck. The hose of the vacuum truck will not damage the screening device.

3. Screening device can easily be removed from the Pre-Treatment Chamber to gain access to separation chamber and media filters below. Replace grate or manhole cover when completed.

Separation Chamber

1. Perform maintenance procedures of screening device listed above before maintaining the separation chamber.

2. With a pressure washer spray down pollutants accumulated on walls and cartridge filters.

3. Vacuum out Separation Chamber and remove all accumulated pollutants. Replace screening device, grate or manhole cover when completed.

Cartridge Filters

1. Perform maintenance procedures on screening device and separation chamber before maintaining cartridge filters.

2. Enter separation chamber.

3. Unscrew the two bolts holding the lid on each cartridge filter and remove lid.

4. Remove each of 4 to 8 media cages holding the media in place.

5. Spray down the cartridge filter to remove any accumulated pollutants.

6. Vacuum out old media and accumulated pollutants.

7. Reinstall media cages and fill with new media from manufacturer or outside supplier. Manufacturer will provide specification of media and sources to purchase.

8. Replace the lid and tighten down bolts. Replace screening device, grate or manhole cover when completed.

Drain Down Filter

1. Remove hatch or manhole cover over discharge chamber and enter chamber.

2. Unlock and lift drain down filter housing and remove old media block. Replace with new media block. Lower drain down filter housing and lock into place.

3. Exit chamber and replace hatch or manhole cover.
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Maintenance Notes

1. Following maintenance and/or inspection, it is recommended the maintenance operator prepare a maintenance/inspection record. The record should include any maintenance activities performed, amount and description of debris collected, and condition of the system and its various filter mechanisms.

2. The owner should keep maintenance/inspection record(s) for a minimum of five years from the date of maintenance. These records should be made available to the governing municipality for inspection upon request at any time.

3. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements.

4. Entry into chambers may require confined space training based on state and local regulations.

5. No fertilizer shall be used in the Biofiltration Chamber.

6. Irrigation should be provided as recommended by manufacturer and/or landscape architect. Amount of irrigation required is dependent on plant species. Some plants may require irrigation.

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Maintenance Procedure Illustration
Screening Device
The screening device is located directly
under the manhole or grate over the
Pre-Treatment Chamber. It’s mounted
directly underneath for easy access
and cleaning. Device can be cleaned by
hand or with a vacuum truck.

Separation Chamber
The separation chamber is located
directly beneath the screening device.

It can be quickly cleaned using a
vacuum truck or by hand. A pressure
washer is useful to assist in the
cleaning process.

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Cartridge Filters
The cartridge filters are located in the
Pre-Treatment chamber connected to
the wall adjacent to the biofiltration
chamber. The cartridges have
removable tops to access the
individual media filters. Once the
cartridge is open media can be
easily removed and replaced by hand
or a vacuum truck.

Drain Down Filter
The drain down filter is located in the
Discharge Chamber. The drain filter
unlocks from the wall mount and hinges
up. Remove filter block and replace with
new block.
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Trim Vegetation
Vegetation should be maintained in the
same manner as surrounding vegetation
and trimmed as needed. No fertilizer shall
be used on the plants. Irrigation
per the recommendation of the
manufacturer and or landscape
architect. Different types of vegetation
requires different amounts of
irrigation.

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Inspection Form
Modular Wetland System, Inc.

P. 760.433-7640
F. 760-433-3176
E. [email protected]
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For Office Use Only
(city) (Zip Code) (Reviewed By)
Owner / Management Company
(Date)
Contact Phone ( ) _
Inspector Name Date / / Time AM / PM
Weather Condition Additional Notes
Yes
Depth:

Yes No
Modular Wetland System Type (Curb, Grate or UG Vault): Size (22', 14' or etc.):

Other Inspection Items:

Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes Office personnel to complete section to
the left.
2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176 Inspection Report
Modular Wetlands System

Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system? Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber? Any signs of improper functioning in the discharge chamber? Note issues in comments section.

Chamber:

Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly? Structural Integrity:

Working Condition:

Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging the unit?
Is there standing water in inappropriate areas after a dry period? Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting pressure?
Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting pressure?
Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)? Project Name
Project Address
Inspection Checklist
No Comments
Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes, specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber.

Is there a septic or foul odor coming from inside the system? Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)? Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below.

Sediment / Silt / Clay
Trash / Bags / Bottles
Green Waste / Leaves / Foliage
Waste: Plant Information
No Cleaning Needed
Recommended Maintenance
Additional Notes:

Damage to Plants
Plant Replacement
Plant Trimming
Schedule Maintenance as Planned
Needs Immediate Maintenance
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Maintenance Report
Modular Wetland System, Inc.

P. 760.433-7640
F. 760-433-3176
E. [email protected]
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For Office Use Only
(city) (Zip Code) (Reviewed By)
Owner / Management Company
(Date)
Contact Phone ( ) _
Inspector Name Date / / Time AM / PM
Weather Condition Additional Notes
Site
Map #
Comments:
2972 San Luis Rey Road, Oceanside, CA 92058 P. 760.433.7640 F. 760.433.3176 Inlet and Outlet
Pipe Condition
Drain Down Pipe
Condition
Discharge Chamber
Condition
Drain Down Media
Condition
Plant Condition
Media Filter
Condition
Long:

MWS
Sedimentation
Basin
Total Debris
Accumulation
Condition of Media
25/50/75/100
(will be changed
@ 75%)
Operational Per
Manufactures'
Specifications
(If not, why?)
Lat: MWS
Catch Basins
GPS Coordinates
of Insert
Manufacturer /
Description / Sizing
Trash
Accumulation
Foliage
Accumulation
Sediment
Accumulation
Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes Office personnel to complete section to
the left.

Project Address
Project Name
Cleaning and Maintenance Report
Modular Wetlands System
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Brattle Street Ventures LLC Appendix A
Attachment D:

Geotechnical Report
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131 Calle Iglesia, Suite 200, San Clemente, CA 92672 (949) 369-6141 www.lgcgeotechnical.com December 2, 2025 Project No. 23106-01
Ms. Crystal Villalpando
Related California
18201 Von Karman Avenue, Suite 900
Irvine, CA 92612
Subject: Updated Preliminary Geotechnical Subsurface Evaluation, Proposed Multi-Family Residential Podium Development, 340 St Ann’s Drive, Laguna Beach, California In accordance with your request, LGC Geotechnical, Inc. is providing an updated preliminary geotechnical subsurface evaluation for the proposed multi-family residential podium development located at 340 St Ann’s Drive in the City of Laguna Beach, California. This report presents the results of our limited subsurface explorations and geotechnical analysis and provides a summary of our conclusions and preliminary recommendations relative to the proposed site development.

Should you have any questions regarding this report, please do not hesitate to contact our office. We appreciate this opportunity to be of service.

Respectfully,
LGC Geotechnical, Inc.

Ryan Douglas, PE, GE 3147 Katie Maes, CEG 2216
Vice President of Engineering Director of Geology

RLD/BTZ/KTM/MDP/amm
Distribution: (1) Addressee (electronic copy)
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Project No. 23106-01 Page i December 2, 2025

TABLE OF CONTENTS
Section Page

1.0 INTRODUCTION ...................................................................................................................................... 1

1.1 Purpose and Scope of Services ........................................................................................................... 1

1.2 Background ............................................................................................................................................... 1

1.3 Project Description................................................................................................................................. 1

1.4 Subsurface Exploration........................................................................................................................ 4

1.5 Laboratory Testing ................................................................................................................................. 4

2.0 GEOTECHNICAL CONDITIONS............................................................................................................. 6

2.1 Regional Geology .................................................................................................................................... 6

2.1.1 Older Artificial Fill(Map Symbol – afo)............................................................................ 6

2.1.2 Quaternary Terrace Deposits (Map Symbol - Qt)........................................................ 6

2.1.3 Tertiary Topanga Formation(Map Symbol - Tt)......................................................... 6

2.2 Generalized Subsurface Conditions................................................................................................. 7

2.3 Groundwater............................................................................................................................................. 7

2.4 Field Infiltration Testing...................................................................................................................... 7

2.5 Seismic Design Parameters................................................................................................................. 8

2.6 Faulting....................................................................................................................................................... 9

2.6.1 Liquefaction and Dynamic Settlement...........................................................................10

2.6.2 Lateral Spreading ...................................................................................................................10

2.6.3 Tsunamis and Seiches...........................................................................................................11

2.7 Oversized Material................................................................................................................................11

2.8 Expansion Potential..............................................................................................................................11

3.0 CONCLUSIONS........................................................................................................................................12

4.0 RECOMMENDATIONS..........................................................................................................................14

4.1 Site Earthwork .......................................................................................................................................14

4.1.1 Clearing and Grubbing ..........................................................................................................15

4.1.2 Removal and Recompaction Depths and Limits ..........................................................15

4.1.3 Temporary Excavations........................................................................................................16

4.1.4 Removal Bottoms and Subgrade Preparation ..............................................................17

4.1.5 Material for Fill ........................................................................................................................17

4.1.6 Placement and Compaction of Fills...................................................................................18

4.1.7 Trench and Retaining Wall Backfill and Compaction.................................................19

4.1.8 Footing Exavations .................................................................................................................20

4.2 Preliminary Foundation Design Parameters .............................................................................20

4.2.1 Building Structure..................................................................................................................20

4.2.2 Ground Improvement Alternative for Building Structure......................................21

4.2.3 Slab Underlayment Guidliens ............................................................................................21

4.3 Lateral Resistance ................................................................................................................................22

4.4 Lateral Earth Pressures for Basement/Retaining Walls .......................................................22

4.5 Temporary Shoring..............................................................................................................................25 702
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TABLE OF CONTENTS (Cont’d)
Project No. 23106-01 Page ii December 2, 2025

4.6 Soil Corrosivity ......................................................................................................................................26

4.7 Preliminary Pavement Recommendations.................................................................................26

4.8 Nonstructural Concrete Flatwork ..................................................................................................27

4.9 Control of Surface Water and Drainage Control.........................................................................28

4.10 Subsurface Water Infiltration..........................................................................................................29

4.11 Pile Shafts for Shoring.........................................................................................................................29

4.12 Pier Shafts for Temporary Shoring................................................................................................29

4.13 Geotechnical Plan Review..................................................................................................................30

4.14 Pre-Construction Monitoring...........................................................................................................30

4.15 Geotechnical Observation and Testing During Construction ................................................30

5.0 LIMITATIONS .........................................................................................................................................31

LIST OF TABLES, ILLUSTRATIONS, & APPENDICES
Tables
Table 1 – Summary of Field Infiltration Testing (Page 8) Table 2 – Seismic Design Parameters (Page 9)
Table 3 – Allowable Soil Bearing Pressures (Page 20)
Table 4A – Lateral Earth Pressures – Cut Condition (Page 23) Table 4B – Lateral Earth Pressures – Conventional Backfilled Retaining Wall (Page 24) Table 5 – Preliminary Asphalt Concrete Paving Section Options (Page 27) Table 6 – Preliminary Geotechnical Parameters for Nonstructural Concrete Flatwork Placed on Very Low to Low Expansion Potential Subgrade (Page 28)
Figures
Figure 1 – Site Location Map (Page 3)
Figure 2 – Geotechnical Map (Site Plan) (Rear of Text)
Figure 3 – Geotechnical Map (Topographic Map) (Rear of Text) Figure 4 – Multi-Period Design Response Spectrum
Figure 5 – Basement Subterranean Structure Backfill/Subdrain Detail (Rear of Text) Figure 6 – Retaining Wall Backfill Detail (Rear of Text) Appendices
Appendix A – References
Appendix B – Boring Logs
Appendix C – Laboratory Test Results
Appendix D – Infiltration Testing Results
Appendix E – General Earthwork and Grading Specifications 703
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1.0 INTRODUCTION

1.1 Purpose and Scope of Services
This updated preliminary geotechnical report is for the proposed multi-family residential podium development located at 340 St Ann’s Drive in the City of Laguna Beach, California (see Site Location Map, Figure 1). The purpose of our work was to evaluate site geotechnical conditions and to provide preliminary geotechnical recommendations with respect to the proposed development.

1.2 Background
Review of historical aerial photographs indicates the site was generally undeveloped during 1945, however Glenneyre Street and cross streets are visible (Historic Aerials, 2023). During 1952, site development occurred and some of the structures including the north half of the exiting church structure and the parsonage residence have been constructed, along with a parking lot. Based on review of background documents, an addition to the church was constructed and the parking lot was re-graded during the 1960’s (Twining Laboratories, 1962).

At that time, the existing concrete retaining walls along the northwestern boundary of the subject property were constructed, with a descending slope to the existing drainage that passes northwest of the site. Based on the referenced report (Soils International, 1978), a portion of the former church property to the northwest of the current site limits was proposed for residential construction, and residences are present there now.

1.3 Project Description
The approximately 1.2-acre site is bound to the northeast by Catalina Street, to the southeast by St Ann’s Drive, to the southwest by Glenneyre Street, and to the northwest by existing residential developments. The site is currently an existing church development with several buildings, a parking lot, and retaining walls situated throughout the site (Architectural Drawings, 2023). The main church building appears to be two levels. The parking lot is asphalt concrete. A daycare play yard and ancillary building are located on the north side of the main church building. An approximately 15-foot-tall retaining wall retains the neighboring residential property and landscape area in the eastern corner of the site adjacent to Catalina Street. An approximately 8- foot-tall retaining wall retains the church building on the southwestern property line adjacent to Glenneyre Street. The site descends to the neighboring residential neighborhood adjacent to the parking lot on the northwestern property line. A concrete retaining wall exists along a portion of the northwestern property line. Topographically the site has variable developed areas with elevations ranging from approximately 66 feet above mean sea level (msl) in the western portion of the site to approximately 84 feet above msl in the southern portion of the site and approximately 90 feet above msl in the eastern corner of the site above the existing retaining wall (T&M Surveying, 2022).

It is our understanding that the proposed development has been updated to consist of a twostory multi-family structure with a podium parking subterranean floor and other appurtenant 704
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improvements. The proposed project excludes the existing church and will remain in place. The subterranean level is anticipated to essentially encompass the entire northern and western portions of the site and consist of 42 parking stalls. The entrance driveway to the subterranean parking will be located on the western side of the site along Glenneyre Street (Related, 2025).

The proposed building footprint is depicted on Figure 2 – Geotechnical Map (Site Plan). The structure is proposed to have two levels above ground and one level below ground (subterranean). The podium structure is anticipated to be reinforced concrete. A preliminary grading plan was not available at the time of this report. Preliminary structural (dead plus live) loads have not been provided at this time. However, we have estimated maximum (dead plus live) column and wall loads of 150 kips and 5 kips/ft, respectively.

The recommendations given in this report are based upon the preliminary proposed layout and estimated structural loading information above. We understand that the project plans are currently being developed at this time; LGC Geotechnical should be provided with updated project plans and the final structural loads when they become available, in order to either confirm or modify the recommendations provided herein. 705
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Approximate
Site Location
FIGURE 1
Site Location Map
DATE December 2025
ENG. / GEOL.

PROJECT NO.

PROJECT NAME
SCALE
RLD
Not to Scale
Related - 340 St. Ann's, Laguna Beach
23106-01
706
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1.4 Subsurface Geotechnical Evaluation
A limited geotechnical field evaluation was performed by LGC Geotechnical in June of 2023. This program consisted of drilling and sampling four small-diameter exploratory hollow-stem borings (HS-1 through HS-4) and three hand-auger borings (HA-1 through HA-3) for the purpose of obtaining samples for evaluation and laboratory testing of site soils. Two of the borings (I-1 and I-2) were excavated for infiltration testing.

Four hollow-stem auger borings (HS-1 through HS-4) were drilled by 2R Drilling under subcontract to LGC Geotechnical. The depth of the borings ranged from approximately 25 to 45 feet below existing grade. Boring HS-1 was terminated at a depth of approximately 45 feet below existing grade due to auger refusal. An LGC Geotechnical representative observed the drilling operations, logged the borings, and collected soil samples for laboratory testing. The borings were performed using a truck-mounted drill rig equipped with 6-inch diameter hollow-stem augers. Driven soil samples were collected by means of the Standard Penetration Test (SPT) and Modified California Drive (MCD) sampler generally obtained at 2.5 to 5-foot vertical increments. The MCD is a split-barrel sampler with a tapered cutting tip and lined with a series of 1-inch-tall brass rings. The SPT sampler (1.4-inch ID) and MCD sampler (2.4-inch ID, 3.0-inch OD) were driven using a 140-pound automatic hammer falling 30 inches to advance the sampler a total depth of 18 inches. The raw blow counts for each 6-inch increment of penetration were recorded on the boring logs. Bulk samples of the near-surface soils were also collected and logged at select borings for laboratory testing. In select borings, after removal of the augers the depth of the boring due to caving was measured and is noted on the boring logs.

At the completion of drilling, the borings were backfilled with the native soil cuttings, tamped and the surface was replaced with asphalt cold patch, where necessary. Some settlement of the backfill soils/asphalt cold patch may occur over time.

Infiltration testing was performed within two borings, I-1 and I-2, to depths of approximately 5 feet below existing grade with an 8-inch auger. An LGC Geotechnical engineer installed standpipes, backfilled the borings with crushed rock and pre-soaked the infiltration holes prior to testing. Infiltration testing was performed per the South County of Orange testing guidelines (2017). Standpipes were removed and the locations were subsequently backfilled with native soils at the completion of testing. Some settlement of the backfill soils may occur over time.

Boring logs are presented in Appendix B and their approximate locations are depicted on Figure 3 – Geotechnical Map (Topographic Plan).

1.5 Laboratory Testing
Representative driven and bulk samples were retained for laboratory testing during our field evaluation. Laboratory testing included in-situ unit weight and moisture content, fines content, Atterberg limits, direct shear, consolidation, expansion index, and corrosion (sulfate, chloride, pH, and minimum resistivity).

The following is a summary of the laboratory test results. • Dry density of the samples collected ranged from approximately 99 pounds per cubic foot (pcf) to 119 pcf, with an average of 109 pcf. Field moisture contents ranged from 707
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approximately 3 percent to 29 percent, with an average of 14 percent. • Two fines content tests indicated a fines content (percent passing No. 200 sieve) of 34 and 45 percent. Based on the Unified Soils Classification System (USCS), the tested samples would be classified as “coarse-grained.”
• Two Atterberg Limit (liquid limit and plastic limit) tests were performed. Results indicated Plasticity Index (PI) values of 16 to 18.
• Three direct shear tests were performed. The plots are provided in Appendix C. • Two consolidation tests were performed. The stress vs. deformation plots are provided in Appendix C.
• One Expansion Index (EI) test was performed. Results were an EI of 4, corresponding to “Very Low” expansion potential.
• Corrosion testing indicated soluble sulfate content less than 0.02 percent, chloride content of 41 parts per million (ppm), pH value of 7.5, and minimum resistivity of 1,950 ohm-cm.

A summary of the laboratory test results is presented in Appendix C. 708
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2.0 GEOTECHNICAL CONDITIONS

2.1 Regional Geology
The site is located on the coastal portion of the western border of the Peninsular Ranges Geomorphic Province of California, specifically within the San Joaquin Hills. The San Joaquin Hills are the result of a theoretical uplift along a blind thrust fault at depth below the hills. The hillsides generally consist of Tertiary bedrock formations that have been faulted and uplifted to form the hillside ascending to the northeast of the subject site. The local geology has also been influenced by changes in sea level, resulting in a series of abandoned terrace deposits on wave-cut marine platforms along the coast, generally sub-horizontal. Marine terrace deposits are typically present on the base of wave-cut platforms, and soils eroded over time (non-marine) have been deposited over the marine terrace in some locations. Localized drainages have incised into the terraces and bedrock below, throughout the region.

2.1.1 Older Artificial Fill (Map Symbol - afo)
Older artificial fill soils are present on site that were placed during previous uses and development of the property and the adjacent property to the northwest. As encountered, older artificial fill soils were loose to medium dense, brown mottled clayey and silty sand, and sandy clay.

2.1.2 Quaternary Terrace Deposits (Map Symbol - Qt)
Regional geologic maps indicate Quaternary terrace deposits are present at the site; generally sandwiched between older artificial fill and the underlying bedrock unit.

Terrace deposits are typically formed by deposition of beach sand and coastal erosional deposits onto a subhorizontal, wave-cut platform of bedrock. As encountered, terrace deposits consist of olive brown to brown sandy clay, silty sand, and clayey sand.

2.1.2 Tertiary Topanga Formation (Map Symbol – Tt)
The primary bedrock formation underlying the site is the Tertiary Topanga Formation.

The material is generally described as sandstone with minor siltstone and pebble 709
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conglomerate interbeds, weakly cemented, very dense (Edgington & Tan, 1976). As encountered, the bedrock consisted of grayish brown to brown, very dense silty sandstone, and minor amounts of hard sandy claystone.

2.2 Generalized Subsurface Conditions
The field explorations (borings) generally indicate the site contains up to approximately 15 feet of previously placed undocumented artificial fill over native Terrace Deposits overlying Topanga Formation Bedrock to the maximum explored depth of approximately 45 below existing grade.

Older artificial fill soils encountered were primarily loose to medium dense clayey and silty sands and very stiff sandy clays. Native terrace deposits are primarily stiff to very stiff sandy clays and medium dense to dense silty sands and clayey sands. Bedrock consisted of primarily very dense silty sands and hard sandy clays.

It should be noted that geotechnical explorations are only representative of the location where they are performed, and varying subsurface conditions may exist outside of each location. In addition, subsurface conditions can change over time. The soil descriptions provided above should not be construed to mean that the subsurface profile is uniform, and that soil is homogeneous within the project area. For details on the stratigraphy at the exploration locations, refer to the boring logs provided in Appendix B.

2.3 Groundwater
Groundwater was not encountered in our borings to the maximum explored depth of approximately 45 feet below existing grade. Based on the Seismic Hazard Zone Report for the Laguna Beach Quadrangle (CDMG, 2006), no depth to historic high groundwater is indicated for the site. Please note, however, that a blue-line drainage is depicted as passing just west of the subject site. The nearby drainage from Bluebird Canyon that collects drainage from the ascending hillsides northeast of the subject site, has been channelized into a storm drain alignment that remains in-place northwest of the site, at a lower elevation.

It should be noted that higher localized and seasonal perched groundwater conditions may accumulate below the surface and should be expected throughout the design life of the proposed improvements. In general, groundwater conditions below any given site may vary over time depending on numerous factors including seasonal rainfall, local irrigation, and intentional infiltration of stormwater, among others.

2.4 Field Infiltration Testing
Two field percolation tests were performed in the southern and eastern portions of the site per the direction of the project civil engineer, the locations are depicted on Figure 2 – Geotechnical Map (Site Plan). Test well installation consisted of placing a 3-inch diameter perforated PVC pipe in the excavated 8-inch diameter borehole and backfilling the annulus with crushed rock including the placement of approximately 2 inches of crushed rock at the bottom of the borehole. The infiltration test wells were presoaked the day of installation and testing took 710
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place within 24 hours of presoaking. During the pre-test, the water levels in the borings were observed to drop less than 6 inches in 25 minutes for two consecutive readings. Therefore, the test procedure for fine-grained soils or “slow test” was followed. Test well installation and the estimation of infiltration rates were accomplished in general accordance with the guidelines set forth by South Orange County (2017). In general, three-dimensional flow out of the test well (percolation), as observed in the field, is mathematically reduced to one-dimensional flow out of the bottom of the test well (infiltration). Infiltration tests are performed using relatively clean water, free of particulates, silt, etc. The results of our recent field infiltration testing are presented in Appendix D and summarized in Table 1 below.

TABLE 1
Summary of Field Infiltration Testing
Infiltration Test
Identification
Approx. Depth
Below Existing
Grade (ft)
Observed
Infiltration Rate*
(in./hr.)
I-1 5 0.0
I-2 5 0.2
*Observed Infiltration Rates Do Not Include Factor of Safety.

The tested infiltration rates provided in this report are considered a general representation of the infiltration rates at the location of the proposed infiltration boring. Please note, the testing of infiltration rates is highly dependent upon the materials encountered at the point of testing (i.e., location and depth of testing). Varying subsurface conditions may exist outside of the test location which could alter the calculated infiltration rate. Please refer to Section 4.10 for subsurface water infiltration recommendations.

2.5 Seismic Design Parameters
The site seismic characteristics were evaluated per the guidelines set forth in Chapter 16, Section 1613 of the 2025 California Building Code (CBC) and applicable portions of ASCE 7-22 which has been adopted by the CBC. The code-based Multi-Period Design Response Spectrum (MPDRS) per ASCE 7-22 is provided on Figure 4. The provided MPDRS is an envelope of the applicable site class as indicated below. For each response period, T, less than 10 seconds and not equal to one of the discrete values of period (T) provided on Figure 4, the spectral response acceleration parameter (Sa) shall be determined by linear interpolation between values of Sa.

Refer to Chapter 11 of ASCE 7-22. The structural designer should contact the geotechnical consultant if structural conditions require site-specific ground motions. 711
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TABLE 2
Seismic Design Criteria
Selected Parameters from 2025 CBC,
Section 1613 - Earthquake Loads
Seismic
Design
Criteria
Notes/References
Distance to applicable faults classifies the site as a
“Near-Fault” site. Section 11.4.1 of ASCE 7
Site Latitude 33.537435 Degrees North
Site Longitude -117.777951 Degrees West
Shear Wave Determination, v̅s Estimated* Chapter 20 of ASCE 7 Applicable Site Classes CD, D Chapter 20 of ASCE 7
*Estimated v̅s requires deriving site class by vs/1.3 & 1.3vs, envelope (maximum) presented
A disaggregation of the PGA based on a 2,475-year average return period (MCE) indicates that an earthquake magnitude of 6.73 at a distance of approximately 8.84 km from the site would contribute the most to this ground motion. A disaggregation of the PGA based on a 475-year average return period (Design Earthquake) indicates that an earthquake magnitude of 6.56 at a distance of approximately 20.97 km from the site would contribute the most to this ground motion (USGS, 2018).

Section 1803.5.12 of the 2025 CBC (per Section 11.8.3 of ASCE 7) states that the maximum considered earthquake geometric mean (MCEG) Peak Ground Acceleration (PGA) should be used for liquefaction potential. The PGAM for the site is equal to 0.68g (SEAOC, 2025). The design PGA is equal to 0.45g (2/3 of PGAM).

2.6 Faulting
Prompted by damaging earthquakes in Northern and Southern California, State legislation and policies concerning the classification and land-use criteria associated with faults have been developed. Their purpose was to prevent the construction of urban developments across the trace of active faults. The result is the Alquist-Priolo Earthquake Fault Zoning Act. According to the State Geologist, an active fault is defined as one which has had surface displacement within the Holocene Epoch (roughly the last 11,000 years). A potentially active fault is defined as any fault, which has had surface displacement during Quaternary time (last 1,600,000 years), but not within the Holocene. Earthquake Fault Zones have been delineated along the traces of active faults within California. Where developments for human occupation are proposed within these zones, the state requires detailed fault evaluations be performed so that engineering geologists can mitigate the hazards associated with active faulting by identifying the location of active faults and allowing for a setback from the zone of previous ground rupture.

The subject site is not located within a State of California Earthquake Fault Zone (i.e., AlquistPriolo Earthquake Fault Act Zone) and no active faults are known to cross the site. A fault is 712
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considered “active” if evidence of surface rupture in Holocene time (the last approximately 11,000 years) is present. The possibility of damage due to ground rupture is considered low since no active faults are known to cross the site.

Secondary effects of seismic shaking resulting from large earthquakes on the major faults in the Southern California region, which may affect the site, include ground lurching, shallow ground rupture, soil liquefaction and dynamic settlement. These secondary effects of seismic shaking are a possibility throughout the Southern California region and are dependent on the distance between the site and causative fault and the onsite geology. The closest major active faults that could produce these secondary effects include the Whittier-Elsinore, San Joaquin Hills Blind Thrust, Newport Inglewood, San Andreas Fault Zones, among others. The closest major active fault to the site is the San Joaquin Hills Blind Thrust Fault located at depth below the site (no surface rupture). A discussion of these secondary effects is provided in the following sections.

2.6.1 Liquefaction and Dynamic Settlement
Liquefaction is a seismic phenomenon in which loose, saturated, granular soils behave similarly to a fluid when subject to high-intensity ground shaking. Liquefaction occurs when three general conditions coexist: 1) shallow groundwater; 2) low density noncohesive (granular) soils; and 3) high-intensity ground motion. Studies indicate that loose, saturated, near surface cohesionless soils exhibit the highest liquefaction potential, while dry, dense, cohesionless soils and cohesive soils exhibit low to negligible liquefaction potential. In general, cohesive soils are not considered susceptible to liquefaction (Bray & Sancio, 2006). Effects of liquefaction on level ground include settlement, sand boils, and bearing capacity failures below structures. Dynamic settlement of dry sands can occur as the sand particles tend to settle and densify as a result of a seismic event.

The site is not located within a State of California Seismic Hazard Zone for liquefaction potential (CDMG, 1998). Based on the lack of a shallow groundwater table at the site, relatively shallow depth to formational materials, and the generally dense nature of the material below the site, there is a very low potential for liquefaction.

2.6.2 Lateral Spreading
Lateral spreading is a type of liquefaction induced ground failure associated with the lateral displacement of surficial blocks of sediment resulting from liquefaction in a subsurface layer. Once liquefaction transforms the subsurface layer into a fluid mass, gravity plus the earthquake inertial forces may cause the mass to move downslope towards a free face (such as a river channel or an embankment). Lateral spreading may cause large horizontal displacements and such movement typically damages pipelines, utilities, bridges, and structures.

Due to the lack of groundwater in the upper 50 feet and very low potential for liquefaction, the potential for lateral spreading is considered very low. 713
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2.6.3 Tsunamis and Seiches
Based on the subject site elevation, there is a low possibility of damage to the site during a large tsunami event. The site is not located within the Tsunami Inundation Area delineated on the Tsunami Hazard Area Map for the Laguna Beach Quadrangle (CGS, 2021).

2.7 Oversized Material
Oversized material (material larger than 8 inches in maximum dimension) may be encountered during site grading. Recommendations are provided for appropriate handling of oversized materials in Appendix E. If feasible, crushing oversized materials onsite or exporting oversized materials may be considered. Incorporating oversized materials into “rock fills” (windrows, rock blankets or individual rock burial) may be feasible in some of the deeper remedial grading areas if applicable. Special handling recommendations should be provided on a case-by-case basis, if necessary.

2.8 Expansion Potential
Based on the results of our laboratory testing, site soils have a “Very Low” to “Low” expansion potential. Final expansion potential of site soils should be determined at the completion of grading. Results of expansion testing at finish grades will be utilized to confirm final foundation design.
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3.0 CONCLUSIONS
Based on the results of our subsurface evaluation and understanding of the proposed development, it is our opinion that the proposed development is feasible from a geotechnical standpoint. A summary of our conclusions are as follows:
• Based on our subsurface evaluation and review of regional geologic maps and published geotechnical literature, the site contains up to approximately 15 feet of previously placed undocumented artificial fill over native Terrace Deposits overlying Topanga Formation bedrock to the maximum explored depth of approximately 45 below existing grade. Older artificial fill soils encountered were primarily loose to medium dense clayey and silty sands and very stiff sandy clays. Native terrace deposits are primarily stiff to very stiff sandy clays and medium dense to dense silty sands and clayey sands. Bedrock consisted of primarily very dense silty sands (sandstone) and hard sandy clays.
• The previously placed artificial fill soils and near-surface soils are generally loose and are not suitable for the planned improvements in their present condition (refer to Section 4.1); removal and recompaction will be required. An alternative to performing deeper removals of existing artificial fill soils is ground improvement likely consisting of Rammed Aggregate Piers (RAP). • Groundwater was not encountered in our borings to the maximum explored depth of approximately 45 feet below existing grade. Based on the Seismic Hazard Zone Report for the Laguna Beach Quadrangle (CDMG, 2006), no depth to historic high groundwater is indicated for the site.
• The site is not located within a State of California Seismic Hazard Zone for liquefaction potential (CDMG, 1998). The potential for liquefaction is considered very low due to the lack of a groundwater table, relatively shallow formational materials, and generally dense nature of the material below the site.
• The proposed development will likely be subjected to strong seismic ground shaking during its design life. The site is not located within a State of California Earthquake Fault Zone (i.e., AlquistPriolo Earthquake Fault Act Zone) and no active faults are known to cross the site. • Due to the proximity of the proposed improvements to the property line in portions of the site, temporary shoring and/or “A-B-C” slot cuts may be required to achieve required earthwork removal and recompaction. The temporary shoring will be adjacent to an existing off-site structure in a portion of the site.
• Based on the results of preliminary laboratory testing, site soils are anticipated to have “Very Low” to “Low” expansion potential. Final design expansion potential must be determined at the completion of grading.
• Field testing resulted in infiltration rate of essentially zero and 0.2 inches per hour in Infiltration Borings I-1 and I-2, respectively. Site consists primarily of fine-grained (i.e., silts and clays) soils which have very low permeability and therefore have very low infiltration rates. • The site contains soils that are not suitable for basement/retaining wall backfill due to their fines (i.e., silt and clay) content, therefore or import of sandy soils will be required by the contractor for obtaining suitable backfill soil for planned site basement/retaining walls. 715
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• Based on the corrosion test results, soils are not considered corrosive per the Caltrans criteria (Caltrans, 2021).
• Excavations into the existing site soils should be feasible with heavy construction equipment in good working order. We anticipate that the sandy and silty earth materials generated from the excavations will be generally suitable for re-use as compacted fill, provided they are relatively free of rocks larger than 8 inches in dimension, construction debris, and significant organic material. 716
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4.0 RECOMMENDATIONS
The following recommendations are to be considered preliminary and should be confirmed upon completion of grading and earthwork operations. In addition, they should be considered minimal from a geotechnical viewpoint, as there may be more restrictive requirements from the architect, structural engineer, building codes, governing agencies, or the owner.

It should be noted that the following geotechnical recommendations are intended to provide the owner with sufficient information to develop the site in general accordance with the 2025 California Building Code (CBC) requirements. With regard to the potential occurrence of potentially catastrophic geotechnical hazards such as fault rupture, earthquake-induced landslides, liquefaction, etc. the following geotechnical recommendations should provide adequate protection for the proposed development to the extent required to reduce seismic risk to an “acceptable level.” The “acceptable level” of risk is defined by the California Code of Regulations as “that level that provides reasonable protection of the public safety, though it does not necessarily ensure continued structural integrity and functionality of the project” [Section 3721(a)]. Therefore, repair and remedial work of the proposed structures may be required after a significant seismic event. With regards to the potential for less significant geologic hazards to the proposed development, the recommendations contained herein are intended as a reasonable protection against the potential damaging effects of geotechnical phenomena such as expansive soils, soil settlement, groundwater seepage, etc. It should be understood, however, that our recommendations are intended to maintain the structural integrity of the proposed development and structures given the site geotechnical conditions but cannot preclude the potential for some cosmetic distress or nuisance issues to develop as a result of the site geotechnical conditions.

The geotechnical recommendations contained herein must be confirmed to be suitable or modified based on the actual as-graded conditions.

4.1 Site Earthwork
We anticipate that earthwork will generally consist of demolition of existing improvements and buildings, shoring installation, required removal and recompaction, subgrade preparation, precise grading and construction of the proposed new improvements including the podium structure, site buildings, site amenities, courtyards, subsurface utilities, driveways, etc.

We recommend that earthwork onsite be performed in accordance with the following recommendations, future geotechnical reports, the 2025 CBC/City of Laguna Beach requirements and the General Earthwork and Grading Specifications included in Appendix E. In case of conflict, the following recommendations shall supersede those included in Appendix E. The following recommendations should be considered preliminary and may be revised based upon future evaluation and our review of updated project plans and/or the field conditions exposed during site grading/construction.
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4.1.1 Clearing and Grubbing
Prior to earthwork of areas to receive structural fill, engineered structures or improvements, the areas should be cleared of existing vegetation, building structures, pavement, utilities, surface obstructions, existing debris and potentially compressible or otherwise unsuitable material. Vegetation and debris should be removed and properly disposed of off-site. Holes resulting from the removal of buried obstructions, which extend below proposed removal bottoms, should be replaced with properly compacted fill material. Any abandoned sewer or storm drain lines should be completely removed and replaced with properly placed compacted fill. Deeper demolition may be required in order to remove existing foundations. We recommend the trenches associated with demolition which extend below the remedial grading depth be backfilled and properly compacted prior to the demolition contractor leaving the site.

If cesspools or septic systems are encountered during earthwork, they should be removed in their entirety. The resulting excavation should be backfilled with properly compacted fill soils. As an alternative, cesspools can be backfilled with lean sand-cement slurry. At the conclusion of the clearing operations, a representative of LGC Geotechnical should observe and accept the site prior to further earthwork.

4.1.2 Removal and Recompaction Depths and Limits
In order to provide a relatively uniform bearing condition for the planned building structures and improvements we recommend the site soils be removed and recompacted. Subsurface site soils should be removed and/or over-excavated according to the criteria outlined below.

Based on the site conditions and proposed building structure, we have provided recommendations for two different earthwork/foundation design options, see below.

Option 1 – Removal of Older Artificial Fill: For Option 1, Existing artificial fill within the influence of the proposed structural improvements should be removed to suitable, competent native materials prior to placement of artificial fill to design grades. For areas with shallow competent native soils below the bottom of the proposed building, minimum overexcavation should be 4 feet below finish pad grade or 2 feet below bottom of the footings, whichever is deeper. Depth of existing fill is shown on Figure 2 & Figure 3.

Option 2 –Ground Improvement: For Option 2, the entire building structure will be supported on ground improvement such as Rammed Aggregate Piers (RAP) eliminating the requirement for deep removals. For the ground improvement option, the upper 1 foot below finish pad grade should be removed and recompacted with properly placed compacted fill.

Please refer to the encountered geologic descriptions and depths presented on the boring logs (Appendix B) and on the Geotechnical Map (Topographical Plan) (Figure 3). 718
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Where adequate space is available, the base of removal bottoms should extend laterally a minimum distance equal to the depth of removal and recompaction below finish grade. Specifically, soils located within a 1:1 (horizontal to vertical) projection of the bottom of footings must be compacted fill or competent natural ground. Building lines may be defined as the perimeter of the building proper, plus attached or adjacent foundation supported features, including canopies, elevators, or walls.

Local conditions may be encountered which could require additional removal and recompaction beyond the above-noted minimum to obtain an acceptable subgrade. The actual depths and lateral extents of removal and recompaction should be determined by the geotechnical consultant based on the subsurface conditions encountered during grading. Removal and recompaction areas and areas should be accurately staked in the field by the Project Surveyor.

4.1.3 Temporary Excavations
Temporary excavations up to approximately 10 to 20 feet are anticipated. Temporary excavations should be performed in accordance with project plans, specifications, and all Occupational Safety and Health Administration (OSHA) requirements. Excavations should be laid back or shored in accordance with OSHA requirements before personnel or equipment are allowed to enter. Based on our field investigation, the majority of site soils are anticipated to be OSHA Type “B” soils (refer to the attached boring logs). Sandy soils are present and should be considered susceptible to caving. Raveling of the sandy soils should be anticipated for temporary slopes. Flatter slope inclinations should be considered if raveling cannot be tolerated. The exposed slope surface may be kept surficially moist (but not saturated) during construction to reduce (not eliminate) potential sloughing. Soil conditions should be regularly evaluated during construction to verify conditions are as anticipated. The contractor shall be responsible for providing the “competent person” required by OSHA standards to evaluate soil conditions. Close coordination with the geotechnical consultant should be maintained to facilitate construction while providing safe excavations. Excavation safety is the sole responsibility of the contractor.

The potential for impacting the existing improvements and adjacent properties may be reduced by performing excavations using narrow “A-B-C” slot cuts. “A-B-C” slot cuts are defined as excavations perpendicular to sensitive property boundaries that are divided into multiple “slots” of equal width. If slots are labeled A, B, C, A, B, C, etc., then “A” slots should be excavated at the same time but must be backfilled before “B” slots can be excavated, etc. For preliminary planning purposes, slot cuts should be no wider than 8 feet and no deeper than 8 feet. Slot cuts are not recommended where proposed excavations are adjacent to existing building structures (and within 5 horizontal feet), Slot cuts should be backfilled immediately with properly placed compacted fill (per Section 4.1.6) to finish grade prior to excavation of adjacent slots. Due to the presence of sands at the site which are susceptible to caving, narrower slot cuts may be required.

These preliminary recommendations should be further evaluated based on the proposed grading plan. Protection of the existing improvements during grading is the responsibility of the contractor.
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Surcharge loads (vehicular traffic, soil stockpiles, construction equipment, etc.) should be set back from the perimeter of excavations a minimum distance equivalent to a 1:1 projection from the bottom of the excavation or 5 feet, whichever is greater, unless the cut is properly shored and designed for the applicable surcharge load. Once an excavation has been initiated, it should be backfilled as soon as practical. Prolonged exposure of temporary excavations may result in some localized instability. Excavations should be planned so that they are not initiated without sufficient time to shore/fill them prior to weekends, holidays, or forecasted rain.

It should be noted that any excavation that extends below a 1:1 (horizontal to vertical) projection of an existing foundation will remove existing support of the structure foundation. Temporary shoring recommendations are provided in Section 4.5.

4.1.4 Removal Bottoms and Subgrade Preparation
In general, removal bottoms and areas to receive compacted fill should be scarified to a minimum depth of 6 inches, brought to a near-optimum moisture condition (generally within optimum and 2 percent above optimum moisture content), and re-compacted per project recommendations.

Removal bottoms and areas to receive fill should be observed and accepted by the geotechnical consultant prior to subsequent fill placement. Soil subgrade for planned footings and improvements (e.g., slabs, etc.) should be firm and competent.

4.1.5 Material for Fill
From a geotechnical perspective, the onsite soils are generally suitable for use as general compacted fill, provided they are screened of oversized material (8 inches in greatest dimension), construction debris and significant organic materials.

From a geotechnical viewpoint, any required import soils for general fill (i.e., nonretaining wall backfill) should consist of soils of granular soils of “Very Low” expansion potential (expansion index 20 or less based on American Society for Testing and Materials [ASTM] D 4829), and free of organic materials, construction debris and any material greater than 3 inches in maximum dimension. Import for any required retaining wall backfill should meet the criteria outlined in the following paragraph. Source samples should be provided to the geotechnical consultant for laboratory testing a minimum of four working days prior to any planned importation.

Basement/retaining wall backfill should consist of imported or onsite clean granular (sandy) soils with a maximum of 35 percent fines (passing the No. 200 sieve) per American Society for Testing and Materials (ASTM) D1140 (or ASTM D6913/ASTM D422) and a “Very Low” expansion potential (EI of 20 or less per ASTM D4829). Soils should also be screened of organic materials, construction debris, and any material greater than 3 inches in maximum dimension. Some of the onsite soils are expansive and have high fines content and are not suitable for backfill of site retaining walls. 720
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Therefore, select grading and stockpiling of the onsite soils or import or soils meeting the criteria outlined above should be anticipated by the contractor for obtaining suitable retaining wall backfill soil. These preliminary findings should be confirmed during grading.

Aggregate base (crushed aggregate base or crushed miscellaneous base) should conform to the requirements of Section 200-2 of the Standard Specifications for Public Works Construction (“Green Book”) for untreated base materials (except processed miscellaneous base), Caltrans Class 2 aggregate base or the City of Laguna Beach requirements.

The placement of demolition materials in compacted fill is acceptable from a geotechnical viewpoint provided the demolition material is broken up into pieces not larger than typically used for aggregate base (approximately 1 to 3-inches in maximum dimension) and well blended into fill soils with essentially no resulting voids. Demolition material placed in fills must be free of construction debris (wood, brick, etc.) and reinforcing steel.

If asphalt concrete fragments will be incorporated into the demolition materials, approval from an environmental viewpoint may be required and is not the purview of the geotechnical consultant. From our previous experience, we recommend that asphalt concrete fragments be limited to fill areas within planned drive aisles and courtyards (i.e., not within building pad areas).

4.1.6 Placement and Compaction of Fills
Material to be placed as fill should be brought to near-optimum moisture content (generally within optimum and 2 percent above optimum moisture content) and recompacted to at least 90 percent relative compaction (per ASTM D1557). Moisture conditioning of site soils will be required in order to achieve adequate compaction. Drying and or mixing of very moist soils may be required prior to reusing the materials in compacted fills. In general, the site soils will require additional moisture in order to achieve the required compaction.

The optimum lift thickness to produce a uniformly compacted fill will depend on the type and size of compaction equipment used. In general, fill should be placed in uniform lifts not exceeding 8 inches in compacted thickness. Each lift should be thoroughly compacted and accepted prior to subsequent lifts. Generally, placement and compaction of fill should be performed in accordance with the local grading ordinances with observation and testing performed by the geotechnical consultant. Oversized material as previously defined should be removed from site fills.

During backfill of excavations, the fill should be properly benched into firm and competent soils of temporary backcut slopes as it is placed in lifts.

Aggregate base material should be compacted to a minimum of 95 percent relative compaction at or slightly above optimum moisture content per ASTM D1557. Subgrade below aggregate base should be compacted to a minimum of 90 percent relative compaction per ASTM D1557 at near-optimum moisture content (generally within 721
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optimum and 2 percent above optimum moisture content).

If gap-graded ¾-inch rock is used for backfill (around storm drain storage chambers, retaining wall backfill, etc.) it will require compaction. Rock shall be placed in thin lifts (typically not exceeding 6 inches) and mechanically compacted with observation by geotechnical consultant. Backfill rock shall meet the requirements of ASTM D2321. Gapgraded rock is required to be wrapped in filter fabric to prevent the migration of fines into the rock backfill.

4.1.7 Trench and Retaining Wall Backfill and Compaction Bedding material used within the pipe zone should conform to the requirements of the current Greenbook and the pipe manufacturer. Where applicable, sand having a sand equivalent (SE) of 30 or greater (per Caltrans Test Method [CTM] 217) may be used to bed and shade the pipes within the bedding zone. Sand backfill should be densified by jetting or flooding and then tamped to ensure adequate compaction. Bedding sand should be from a natural source, manufactured sand from recycled material is not suitable for jetting. The onsite soils may generally be considered suitable as trench backfill (zone defined as 12 inches above the pipe to subgrade), provided the soils are screened of rocks greater than 6 inches in maximum dimension, construction debris and organic material.

Trench backfill should be compacted in uniform lifts (as outlined in Section “Material for Fill”) by mechanical means to at least 90 percent relative compaction (per ASTM D1557).

If gap-graded rock is used for trench backfill, refer to Section 4.1.6.

Utility trenches running parallel to footings should not be excavated within a 1:1 (horizontal to vertical) downward projection from adjacent footings (“footing influence zone”) to avoid potential undermining. Depending on the utility line and structural loading of the footing, utility trenches running perpendicular to footings may require special provisions such as sand-cement slurry backfill of the utility trench in this zone or flexible sleeves through the footings. These conditions should be evaluated on a case-bycase basis.

Retaining wall backfill should consist of sandy soils as defined in the above section “Material for Fill.” For subterranean/basement walls the select sandy zone should extend a minimum of a 1:1 (horizontal to vertical) upward projection from the bottom of the basement wall subdrain, refer to Figure 3. For conventional retaining walls the limits of select sandy backfill should extend at minimum ½ the height of the retaining wall or the width of the heel (if applicable), whichever is greater, refer to Figure 4. Retaining wall backfill soils should be compacted in relatively uniform thin lifts to at least 90 percent relative compaction (per ASTM D1557). Jetting or flooding of retaining wall backfill materials should not be permitted.

In backfill areas where mechanical compaction of soil backfill is impractical due to space constraints, typically sand-cement slurry may be substituted for compacted backfill. The slurry should generally contain about one sack of cement per cubic yard. When set, such a mix typically has the consistency of compacted soil. Sand cement slurry placed near the 722
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surface within landscape areas should be evaluated for potential impacts on planned improvements.

A representative from LGC Geotechnical should observe, probe, and test backfill to verify compliance with the project recommendations.

4.1.8 Footing Excavations
Footing excavation bottoms should be firm, relatively unyielding, and free of loose material. Footing excavations should be observed and accepted by the geotechnical consultant prior to placement of steel reinforcement. Footing excavations in sandy soils left open and allowed to dry will be susceptible to caving.

4.2 Preliminary Foundation Design Parameters
Preliminary foundation recommendations are provided below. Please note that the following foundation recommendations are preliminary and must be confirmed by LGC Geotechnical at the completion of project plans (i.e., foundation, grading and site layout plans) as well as completion of earthwork. Lateral resistance is provided in Section 4.3.

4.2.1 Building Structure
Provided our earthwork removal and recompaction recommendations are implemented, and older artificial fill is removed to competent native materials, the proposed structure may be supported on a shallow foundation system. The following minimum footing widths and embedments are recommended for the corresponding allowable bearing pressures for both continuous wall and column spread footings.

TABLE 3
Allowable Soil Bearing Pressures
Allowable Static
Bearing Pressure
(psf)
Minimum Footing
Width
(feet)
Minimum Footing
Embedment*
(feet)
3,500 3 2
3,000 2 2
2,500 1.5 1.5
* Refers to minimum depth measured below lowest adjacent grade.

These net bearing pressures (exclusive of the weight of the footings) are for dead plus live loads and may be increased one-third for short-term, transient, wind and seismic 723
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loading. The maximum edge pressures induced by eccentric loading or overturning moments should not be allowed to exceed these recommended values. For any bearing pressures less than 2,500 psf, a minimum footing width of 1 feet and embedment depth of 1 feet below lowest adjacent grade should be used. These allowable bearing pressures are applicable for level (ground slope equal to or flatter than 5 horizontal feet to 1-foot vertical) conditions only.

Soil settlement is a function of footing dimensions and applied soil bearing pressure.

Based on the recommended earthwork removals and estimated structural loads, foundation settlement due to structural loads (static settlement) is anticipated to be on the order of 1-inch. Differential settlement should be anticipated between nearby columns or walls where a large differential loading condition exists. Settlement estimates should be evaluated by LGC Geotechnical when foundation plans are made available.

4.2.2 Ground Improvement Alternative for Building Structure An alternative to performing deep removals below the building structure footprint is a ground improvement technique such as Rammed Aggregate Piers (RAP). Rammed aggregate piers (RAP) consist of drilled holes filled with aggregate that is mechanically compacted as it is placed. A proprietary foundation support system such as Geopiers may be feasible for support of planned structure. Advantages of this system would significantly reduce recommended earthwork removal and recompaction depths below the structure, increase soil bearing pressure, and reduce the long-term (static) settlement. Because such systems are proprietary, the work is performed on a designbuild basis by the specialty contractor. Every aspect of the design and construction of the ground improvement system is the responsibility of the specialty contractor/designer including estimated settlements of foundations bearing on the RAPs.

It is standard of practice for the geotechnical consultant to observe the construction of the ground improvement system (e.g., RAPs, etc.) to confirm that they have been installed in accordance with the approved foundation plan. A representative of LGC Geotechnical can perform these services including confirmation of the diameter of the drilled hole, specified lift thickness and compaction effort. The locations of the RAPs should be confirmed by the project surveyor.

4.2.3 Slab Underlayment Guidelines
The following is for informational purposes only since slab underlayment (e.g., moisture retarder, sand or gravel layers for concrete curing and/or capillary break) is unrelated to the geotechnical performance of the foundation and thereby not the purview of the geotechnical consultant. Post-construction moisture migration should be expected below the foundation. The foundation engineer/architect should determine whether the use of a capillary break (sand or gravel layer), in conjunction with the vapor retarder, is necessary or required by code. Sand layer thickness and location (above and/or below 724
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vapor retarder) should also be determined by the foundation engineer/architect.

4.3 Lateral Resistance
Resistance to lateral loads can be provided by friction acting at the base of foundations and by passive earth pressure. For concrete/soil frictional resistance, an allowable coefficient of friction of 0.30 may be assumed with dead-load forces. An allowable passive lateral earth pressure of 240 pcf to a maximum of 2,400 pcf may be used for lateral resistance for properly compacted fill and suitable native soils. This allowable passive pressure may be increased to 325 pcf to a maximum of 3,250 pcf for short-duration wind or seismic loading. For isolated pole footings (e.g., sign structures, decks, etc.) generally spaced a minimum of 3 pile diameters oncenter, an allowable passive pressure of 480 pcf may be used for passive resistance. The provided passive pressure is based on an arching factor of 2 (e.g., 240 pcf x 2) and should be limited to a maximum of 10 times the value provided above (e.g., 480 pcf to a maximum of 4,800 psf). This value may be increased by one-third for short-duration wind or seismic loading. These passive pressure values are applicable for level (ground slope equal to or flatter than 5H:1V) conditions only. Frictional resistance and passive pressure may be used in combination without reduction. The provided allowable passive pressure includes a static and seismic factor of safety of 1.5 and 1.1, respectively. This increase is based on a reduced factor of safety for short duration loading.

4.4 Lateral Earth Pressures for Basement/Retaining Walls It is our understanding that basement walls up to approximately 20 feet will be required for the subterranean parking level. In addition, internal retaining walls for an access ramp may be required. Lateral earth pressures are provided as equivalent fluid unit weights, in pound per square foot (psf) per foot of depth or pcf. These values do not contain an appreciable factor of safety, so the retaining wall designer should apply the applicable factors of safety and/or load factors during design. A soil unit weight of 120 pcf may be assumed for calculating the actual weight of soil over the wall footing. At this time level backfill conditions are anticipated. If a sloping backfill condition is proposed, increased lateral earth pressures will be provided based on the planned configuration.

If the retaining wall can yield enough to mobilize the full shear strength of the soil, it can be designed for “active” pressure. If the wall cannot yield under the applied load, the earth pressure will be higher. This would include 90-degree corners of retaining walls. Such walls should be designed for “at-rest.” The equivalent fluid pressure values assume free-draining conditions and a drainage system will be installed and maintained to prevent the build-up of hydrostatic pressures. Typically, a basement wall constructed against the temporary shoring is provided with a composite drainage mat (e.g., Miradrain, etc.) placed over the lagging and collected at the wall bottom by a manifold pipe system properly outletted to a suitable discharge point. Backfilled retaining walls are backfilled with sandy soils and a subdrain pipe is wrapped in drainage aggregate and filter fabric (e.g., “burrito” subdrain) and properly outletted to a suitable discharge point (Refer to Figures 5 and 6). If a sump pump is required to outlet accumulated water behind retaining/basement walls, the owner and any subsequent owners must be made aware that it will be their responsibility to ensure the sump pump continues to perform properly for the life of 725
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the project. Basement/retaining wall structures should be provided with appropriate drainage and appropriately waterproofed. Please note that waterproofing and specification of the drainage mat and outlet system are not the purview of the geotechnical consultant. If conditions other than those assumed above are anticipated, the equivalent fluid pressure values should be provided on an individual-case basis by the geotechnical consultant.

The following lateral earth pressures are presented on Table 4A for design of site basement/retaining walls constructed against the shoring wall (i.e., cut condition not requiring select sandy backfill).

TABLE 4A
Lateral Earth Pressures – Cut Condition
Conditions
Equivalent Fluid Weight (pcf)
Level Backfill
Cut Condition w/Shoring Wall
Active 45
At Rest 70
The following lateral earth pressures are presented on Table 4B are for conventional backfilled retaining walls using approved select granular soils with a maximum of 35 percent fines (passing the No. 200 sieve per ASTM D-421/422) and a maximum Expansion Index of 20 (per ASTM D4829). Some of the onsite soils are expansive and have high fines content and are not suitable for backfill of site retaining walls. Therefore, select grading and stockpiling of the onsite soils or import or soils meeting the criteria outlined above should be anticipated by the contractor for obtaining suitable retaining wall backfill soil. The retaining wall designer should clearly indicate on the retaining wall plans the required sandy soil backfill criteria. If the limits of select sandy backfill indicated on Figures 5 and 6 cannot be extended due to property line constraints, the lateral earth pressures provided in Table 4A should be used. 726
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TABLE 4B
Lateral Earth Pressures – Conventional Backfilled
Retaining Wall
Conditions
Equivalent Fluid Weight (pcf)
Level Backfill – Sand Backfill
Approved Backfill Material
Active 35
At Rest 55
Surcharge loading effects from any adjacent structures should be evaluated by the basement/retaining wall designer. In general, structural loads within a 1:1 (horizontal to vertical) upward projection from the bottom of the proposed basement/retaining wall footing will surcharge the proposed retaining structure. In addition to the recommended earth pressure, basement/retaining walls adjacent to streets should be designed to resist vehicular traffic if applicable. Uniform surcharges may be estimated using the applicable coefficient of lateral earth pressure using a rectangular distribution. A factor of 0.33 and 0.5 may be used for the active and at-rest conditions, respectively. The vertical traffic surcharge may be determined by the structural designer. The retaining/basement wall designer should contact the geotechnical consultant for any required geotechnical input in estimating any applicable surcharge loads.

If required, the basement/retaining wall designer may use a seismic lateral earth pressure increment of 10 pcf for a level backfill. This increment should be applied in addition to the provided static lateral earth pressure using a triangular distribution with the resultant acting at H/3 in relation to the base of the retaining structure (where H is the retained height). Per Section 1803.5.12 of the 2025 CBC, the seismic lateral earth pressure is applicable to structures assigned to Seismic Design Category D through F for retaining wall structures supporting more than 6 feet of backfill height. For the restrained, at-rest condition, the seismic increment may be added to the applicable active lateral earth pressure (in lieu of the at-rest lateral earth pressure) when analyzing short duration seismic loading. It should be noted that the provided seismic lateral earth pressures are for a maximum basement/retaining wall of 20 feet in height and level backfill. While not anticipated at this time, if a basement/retaining wall greater than 20 feet in height is proposed and/or a sloping backfill condition, the retaining wall designer should contact the geotechnical consultant for specific seismic lateral earth pressure increments based on the configuration of the planned retaining wall structures. Seismic lateral earth pressures are estimated using the procedure outlined by the Structural Engineers Association of California (Lew, et al, 2010) and the Federal Highway Administration (FHWA, 2011).

Soil bearing and lateral resistance (friction coefficient and passive resistance) are provided in Sections 4.2.1 and 4.3, respectively. Earthwork considerations (temporary backcuts, backfill, compaction, etc.) for retaining walls are provided in Section 4.1 (Site Earthwork) and the subsequent earthwork related sub-sections.
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4.5 Temporary Shoring
Temporary shoring will likely be required for construction of basement walls adjacent to property lines. Due to the height of the proposed excavation, bracing will likely be required in portions of the site. If the earthwork option is chosen instead of the ground improvement option, temporary shoring must incorporate heights for required remedial grading. The earth pressures provided below are only for temporary shoring conditions, for permanent retaining structures, refer to Section 4.4.

Typical cantilever temporary shoring, where deflection of the shoring will not impact the performance of adjacent structures, with a level backfill may be designed using the active equivalent fluid pressures of 35 pounds per square foot (psf) per foot of depth (or pcf). Braced shoring may be used in areas where the shoring will be located close to existing structures in order to limit shoring defections or required due to the proposed depth of excavation. Braced shoring with a level backfill without hydrostatic pressures (above groundwater) may be designed using a uniform soil pressure of 24H in pounds per square foot (psf), where H is equal to the depth in feet of the excavation being shored. Any slopes above temporary shoring will increase the above-noted lateral earth pressures and can be provided on a case-by-case basis.

Any building, equipment or traffic loads located within a 1:1 (horizontal to vertical) projection from the base of the shoring should be added to the applicable lateral earth pressure. Refer to the surcharge loading effects discussion provided in above Section 4.4. The shoring designer should contact the geotechnical engineer for any required geotechnical input in estimating any applicable lateral surcharge loads.

Continuous lagging should be provided between the soldier piles. Lagging should be placed in a timely manner during excavation in order to minimize potential spalling and sloughing. Careful installation of the lagging will be necessary to achieve bearing against the retained earth. The backfill of the lagging should consist of sand-cement slurry. Means and methods are per the contractor in order to ultimately ensure full bearing (direct contact) of retained earth to the lagging. The soldier piles should be designed for the full anticipated lateral earth pressure; however, the pressure on the lagging will be less due to soil arching between the piles. We recommend that the lagging be designed for the recommended earth pressure but may be limited to a maximum value of 400 psf if surcharge loads are not present. Lagging placed behind the solider piles will negate the soil arching effect.

For temporary shoring piles generally spaced a minimum of 2.5 pile diameters on-center, an allowable passive pressure of 550 pcf may be used for passive resistance. The provided passive pressure is based on an arching factor of 2 (e.g., 275 pcf x 2) and should be limited to a maximum of 10 times the value provided above (e.g., 550 pcf to a maximum of 5,500 psf). The passive pressure is only applicable for level (5 horizontal feet to 1-foot vertical or flatter) soil conditions. To develop the full lateral value, provisions should be made to assure firm contact between the soldier piles and the undisturbed soils. The concrete placed in the soldier pile excavation below the excavated level should be of adequate strength to transfer the imposed loads to the surrounding soils. Structural designer should incorporate appropriate factor of safety and/or load factor in design. The provided allowable passive pressure is based on a factor of safety of 1.3.

For a deadman footing a minimum of 1-foot below lowest adjacent grade (measured from the 728
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top of the inclined footing) and a width of 4 feet inclined at 45 degrees, an allowable soil bearing of 3,000 psf may be used. To reduce the movement of the shoring, the rakers should be tightly wedged against the footings and/or shoring system.

It is difficult to accurately predict the amount of deflection of the shored mass. It should be realized, however, that some deflection will occur. The shoring should be designed to limit deflection to within tolerable limits. If greater deflection occurs during construction, additional bracing may be necessary. In areas where less deflection is desired, such as adjacent to existing settlement sensitive improvements, the shoring should be designed for higher lateral earth pressures.

The contractor should evaluate the potential drilling conditions when planning the installation methods, refer to Section 4.11.

4.6 Soil Corrosivity
Although not corrosion engineers (LGC Geotechnical is not a corrosion consultant), several governing agencies in Southern California require the geotechnical consultant to determine the corrosion potential of soils to buried concrete and metal facilities. We therefore present the results of our testing with regard to corrosion for the use of the client and other consultants, as they determine necessary.

Corrosion testing indicated soluble sulfate content less than 0.02 percent, chloride content of 41 parts per million (ppm), pH value of 7.5, and minimum resistivity of 1,950 ohm-cm. Based on Caltrans Corrosion Guidelines (2021), soils are considered corrosive if the pH is 5.5 or less, or the chloride concentration is 500 ppm or greater, or the sulfate concentration is 1,500 ppm (0.15 percent) or greater. Based on the test results, soils are not considered corrosive using Caltrans criteria.

Based on laboratory sulfate test results, the near surface soils are designated to a class “S0” per ACI 318, Table 19.3.1.1 with respect to sulfates. Concrete in direct contact with the onsite soils can be designed according to ACI 318, Table 19.3.2.1 using the “S0” sulfate classification.

Laboratory testing may need to be performed at the completion of grading by the project corrosion engineer to further evaluate the as-graded soil corrosivity characteristics.

Accordingly, revision of the corrosion potential may be needed, should future test results differ substantially from the conditions reported herein. The client and/or other members of the development team should consider this during the design and planning phase of the project and formulate an appropriate course of action.

4.7 Preliminary Pavement Recommendations
The following preliminary minimum asphalt concrete (AC) pavement sections provided in Table 5 are based on a preliminary assumed R-value of 25 for Traffic Indices of 5.0 (or less) and 6.0.

These recommendations must be confirmed with R-value testing of representative near-surface soils at the completion of earthwork and after underground utilities have been installed and 729
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backfilled. Final street sections should be confirmed by the project civil engineer based upon the final design Traffic Index. If requested, additional sections may be provided based on other provided traffic index values. Should the City of Laguna Beach have more stringent requirements, updated pavement recommendations can be provided.

TABLE 5
Preliminary Asphalt Concrete Paving Section Options
Assumed Traffic Index 5.0 (or less) 6.0
Estimated R -Value Subgrade 25 25
AC Thickness 4.0 inches 4.5 inches
Aggregate Base Thickness 5.0 inches 7.0 inches
The pavement section thicknesses provided above are considered minimum thicknesses.

Increasing the thickness of any or all of the above layers will reduce the likelihood of the pavement experiencing distress during its service life. The above recommendations are based on the assumption that proper maintenance and irrigation of the areas adjacent to the pavement will occur through the design life of the pavement. Failure to maintain a proper maintenance and/or irrigation program may jeopardize the integrity of the pavement.

Earthwork recommendations regarding aggregate base and subgrade are provided in the previous Section 4.1 “Site Earthwork” and the related sub-sections of this report.

4.8 Nonstructural Concrete Flatwork
Nonstructural concrete flatwork (such as sidewalks, patios/entryways etc.) has a potential for cracking due to changes in soil volume related to soil-moisture fluctuations. To reduce the potential for excessive cracking and lifting, concrete should be designed in accordance with the minimum guidelines outlined in Table 6 on the following page. These guidelines will reduce the potential for irregular cracking and promote cracking along construction joints but will not eliminate all cracking or lifting. Thickening the concrete and/or adding additional reinforcement will further reduce cosmetic distress.
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TABLE 6
Preliminary Geotechnical Parameters for Nonstructural Concrete Flatwork Placed on Very Low to Low Expansion Potential Subgrade
Sidewalks Patios/Courtyards City Sidewalk
Curb and Gutters
Minimum
Thickness (in.) 4 (full) 4 (full) City/Agency Standard
Presoaking Wet down prior to
placing
Wet down prior to
placing
City/Agency
Standard
Reinforcement  No. 3 at 24 inches on
centers
City/Agency
Standard
Thickened Edge
(in.)   City/Agency Standard
Crack Control
Joints
Saw cut or deep
open tool joint to a
minimum of 1/3 the
concrete thickness
Saw cut or deep
open tool joint to a
minimum of 1/3 the
concrete thickness
City/Agency
Standard
Maximum Joint
Spacing 5 feet 6 feet City/Agency Standard
Aggregate Base
Thickness (in.)   City/Agency Standard

4.9 Control of Surface Water and Drainage Control
From a geotechnical perspective, we recommend that compacted finished grade soils adjacent to proposed structures be sloped away from the proposed structure and towards an approved drainage device or unobstructed swale. Drainage swales, wherever feasible, should not be constructed within 5 feet of buildings. Where lot and building, geometry necessitates that the drainage swales be routed closer than 5 feet to structural foundations, we recommend the use of area drains together with drainage swales. Drainage swales used in conjunction with area drains should be designed by the project civil engineer so that a properly constructed and maintained system will prevent ponding within 5 feet of the foundation. Code compliance of grades is not the purview of the geotechnical consultant.

Planters with open bottoms adjacent to buildings should be avoided. Planters should not be designed adjacent to buildings unless provisions for drainage, such as catch basins, liners, and/or area drains, are made. Overwatering must be avoided.
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4.10 Subsurface Water Infiltration
Recent regulatory changes have occurred that mandate that storm water be infiltrated below grade rather than collected in a conventional storm drain system. Typically, a combination of methods are implemented to reduce surface water runoff and increase infiltration including; permeable pavements/pavers for roadways and walkways, directing surface water runoff to grass-lined swales, retention areas, and/or drywells, etc.

It should be noted that collecting and concentrating surface water for the purpose of intentionally infiltrating it below grade, conflicts with the geotechnical engineering objective of directing surface water away from slopes, structures and other improvements. The geotechnical stability and integrity of a site is reliant upon appropriately handling surface water. In general, the vast majority of geotechnical distress issues are directly related to improper drainage. In general, distress in the form of movement of improvements could occur as a result of soil saturation and loss of soil support, expansion, internal soil erosion, collapse and/or settlement.

Based on the very poor results of the infiltration testing, low permeability of the onsite soils, our knowledge of the site geologic conditions, and the relatively shallow depth of very dense formational materials, infiltration of stormwater is not feasible. Therefore, we do not recommend that surface stormwater be intentionally infiltrated into the subsurface soils at this site.

4.11 Pile Shafts for Shoring
Soldier pile boreholes for temporary and permanent shoring should be plumb and free of loose or softened material. Extreme care in drilling, placement of steel, and the pouring of concrete will be essential to avoid excessive disturbance of borehole walls. The soldier pile steel section should be installed, and the concrete pumped immediately after drilling is completed. If applicable, concrete placement by pumping or tremie tube to the bottom of drill hole excavations is recommended. No soldier pile borehole should be left open overnight. We recommend that pile borings not be drilled immediately adjacent to another pile until the concrete in the other pile has attained its initial set. A representative from LGC Geotechnical should be onsite during the drilling of soldier pile boreholes to verify the assumptions made during the design stages.

Sandy soils are present at the site and these materials are generally susceptible to caving. Some caving of drilled holes should be anticipated. The contractor should anticipate that any borehole left open for any extended period of time will likely experience additional caving and possible seepage, typically from local irrigation. Refer to the boring logs in Appendix B. If caving occurs during construction of soldier pile boreholes a temporary casing may be required.

4.12 Supplemental Geotechnical Explorations
It would be prudent to perform additional geotechnical explorations (i.e., borings) to further refine the limits and depth of previously placed artificial fill. 732
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4.13 Geotechnical Plan Review
Project plans (grading, foundation, retaining wall, temporary shoring, etc.) should be reviewed by this office prior to construction to verify that our geotechnical recommendations have been incorporated. Additional fieldwork and/or modified geotechnical recommendations may be necessary.

4.14 Pre-Construction Monitoring
Due to the proximity of the existing offsite improvements, recommended depth of remedial grading in portions of the site, and proposed retaining walls near the property lines, it is highly recommended that a program of pre-construction documentation and monitoring be devised and put into practice before the onset of any groundwork.

LGC Geotechnical can perform these services at your request. This should include, but not necessarily be limited to, detailed documentation of the existing improvements, walls, buildings, and utilities around the area of proposed excavation, with particular attention to any distress that is already present prior to the start of work. Subsequent readings should be scheduled consistent with the program of work. If shoring systems are to be constructed, routine monitoring of horizontal and vertical movement should be performed for the shoring system and adjacent improvements during construction to verify that shoring deflections are within tolerable limits.

4.15 Geotechnical Observation and Testing During Construction The recommendations provided in this report are based on limited subsurface observations and geotechnical analysis. The interpolated subsurface conditions should be checked in the field during construction by a representative of LGC Geotechnical. Geotechnical observation and testing is required per Section 1705 of the 2025 CBC.

Geotechnical observation and/or testing should be performed by LGC Geotechnical at the following stages:
• During grading (removal bottoms, fill placement, etc.); • During drilling of pier shafts for temporary shoring (if any); • During installation of ground improvements such as Geopiers (if any); • During basement/retaining wall backfill and compaction; • During utility trench backfill and compaction;
• After presoaking building pads and other concrete-flatwork subgrades, and prior to placement of aggregate base or concrete;
• After footing excavation and prior to placing concrete and/or reinforcement; • Preparation of pavement subgrade and placement of aggregate base; and • When any unusual soil conditions are encountered during any construction operation subsequent to issuance of this report.
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5.0 LIMITATIONS
Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report.

This report is based on data obtained from limited observations of the site, which have been extrapolated to characterize the site. While the scope of services performed is considered suitable to adequately characterize the site geotechnical conditions relative to the proposed development, no practical evaluation can completely eliminate uncertainty regarding the anticipated geotechnical conditions in connection with a subject site. Variations may exist and conditions not observed or described in this report may be encountered during construction.

This report is issued with the understanding that it is the responsibility of the owner, or of his/her representative, to ensure that the information and recommendations contained herein are brought to the attention of the other consultants and incorporated into the plans. The contractor should properly implement the recommendations during construction and notify the owner if they consider any of the recommendations presented herein to be unsafe, or unsuitable.

The findings of this report are valid as of the present date. However, changes in the conditions of a site can and do occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties. The findings, conclusions, and recommendations presented in this report can be relied upon only if LGC Geotechnical has the opportunity to observe the subsurface conditions during grading and construction of the project, in order to confirm that our preliminary findings are representative for the site. This report is intended exclusively for use by the client, any use of or reliance on this report by a third party shall be at such party’s sole risk.

In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and modification.
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Figure 2 - Geotechnical Map
(Site Plan) ENG.

PROJECT NO.

PROJECT NAME
SCALE
DATE
Not to Scale
December 2025
Related - 340 St. Ann's, Laguna Beach

RLD / KTM
23106-01 LGC Geotechnical, Inc.
131 Calle Iglesia, Ste. 200
San Clemente, CA 92672
TEL (949) 369-6141 FAX (949) 369-6142
735
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HS-3
HS-4
HS-2
HS-1
HA-3
HA-1
HA-2
I-2
I-1
T.D. = 26.5'
afo to 10'
Qt to T.D.

T.D. = 5'
T.D. = 5'
T.D. = 5'
T.D. = 7'
T.D. = 5'
T.D. = 31'
afo to 15'
Qt to 20'
Tt to T.D.

T.D. = 25.5'
afo to 5'
Qt to 20'
Tt to T.D.

T.D. = 45'
afo to 7.5'
Qt to 20'
Tt to T.D.
afo
afo
afo
Qt
Tt
Qt
Tt
LEGEND
Older Artificial Fill
Quaternary Terrace (Non-Marine and Marine,
Undifferentiated), Circled Where Buried
Tertiary Topanga Formation, Circled Where Buried
Approximate Location of Hollow Stem Auger Boring
by LGC Geotechnical, With Total Depth in Feet
Approximate Location of Hand Auger Boring by LGC
Geotechnical, With Total Depth in Feet
Approximate Location of Hollow Stem Auger
Infiltration Boring by LGC Geotechnical, With Total
Depth in Feet
Approximate Limits of This Report
HS-4
HA-3
I-2
afo
Qt
Tt
Figure 3 - Geotechnical Map
(Topographic Plan) ENG.

PROJECT NO.

PROJECT NAME
SCALE
DATE
1" = 40'
December 2025
Related - 340 St. Ann's, Laguna Beach

RLD / KTM
23106-01 LGC Geotechnical, Inc.
131 Calle Iglesia, Ste. 200
San Clemente, CA 92672
TEL (949) 369-6141 FAX (949) 369-6142
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Period (s) Spectral Acceleration (g)
0 0.50

0.01 0.50

0.02 0.51

0.03 0.53

0.05 0.63

0.075 0.79

0.1 0.93

0.15 1.10

0.2 1.19

0.25 1.23

0.3 1.24

0.4 1.22

0.5 1.16

0.75 0.93
1 0.77

1.5 0.54
2 0.40
3 0.25
4 0.18
5 0.13

7.5 0.078
10 0.053
Applicable Site Classes: CD D Latitude: 33.537435
Envelope Presented Longitude: -117.777951
Reference: ASCE 7-22
Project No. 23106-01 Date: December, 2025
Figure 4:

Multi-Period Design
Response Spectrum

0.0 0.2

0.4 0.6

0.8 1.0

1.2 1.4

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Spectral Acceleration (g) Period (sec.)
Envelope of Applicable Site Classes
5% Damping
737
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Minimum 4" Diameter Schedule 40
Perforated PVC Pipe to Flow to Drainage
Device or Sump Pump per Project Civil
Engineer
Proposed Building Structure by Others
Backcut/Shoring per OSHA
1:1 (H:V) or flatter slope
Earthwork Per Soils Report, Slab Underlay Per
Foundation Engineer/Architect
Compacted Native Soil Cap
Select Granular Backfill (Expansion Index £ 20, maximum 35% fines) Minimum 90% Relative Compaction (ASTM D1557)
NOTE : Granular backfill may be substituted with 3/4 inch crushed compacted rock wrapped in filter fabric.

Geotechnical drainage detail will not prevent water seepage into structure, it is only to prevent build up of water pressure against wall.

EXTENT OF SELECT BACKFILL ZONE
Minimum 1 Cubic Foot Per Linear Foot Burrito Type
Subdrain, Consisting of 3
4 Inch Crushed Rock Wrapped
in Mirafi 140N or Approved Equivalent
1 foot min.

Common Backfill
Minimum 90% Relative Compaction (ASTM D1557)
Waterproofing by Waterproofing
Engineer/Architect or Design
Engineer to be Protected During
Backfill by Contractor
(12" Minimum / 18" Maximum)
1 foot min.
1 1
FIGURE 5
Basement Subterranean
Structure Backfill/Subdrain
Detail
DATE December 2025
ENG. / GEOL.

PROJECT NO.

PROJECT NAME
SCALE

RLD / KTM
Not to Scale
Related - 340 St. Ann's, Laguna Beach
23106-01
738
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4 INCH DIAMETER, SCHEDULE 40 PERFORATED

PVC PIPE TO FLOW TO DRAINAGE DEVICE PER

PROJECT CIVIL ENGINEER

COMPACTED SAND BACKFILL
(EXPANSION INDEX £ 20,
MAXIMUM 35% FINES)

NATIVE BACKFILL COMPACTED

PER REPORT
MINIMUM 1 CUBIC FOOT PER LINEAR FOOT

BURRITO TYPE SUBDRAIN, CONSISTING OF
3/4 INCH CRUSHED ROCK WRAPPED IN
MIRAFI 140N OR APPROVED EQUIVALENT

FOOTING/WALL PER DESIGN ENGINEER

WATER PROOFING PER DESIGN ENGINEER
12" MINIMUM
18" MAXIMUM

BACKCUT PER OSHA

EXTENT OF REQUIRED IMPORTED SAND BACKFILL, MINIMUM
HEEL WIDTH OR H/2 WHICH EVER IS GREATER WALL HEIGHT, H
NOTE:

PLACEMENT OF SUBDRAIN

AT BASE OF WALL WILL NOT

PREVENT SATURATION OF SOILS

BELOW AND / OR IN FRONT OF WALL
FIGURE 6
Retaining Wall
Backfill Detail
DATE December 2025
ENG. / GEOL.

PROJECT NO.

PROJECT NAME
SCALE
RLD
Not to Scale
Related - 340 St. Ann's, Laguna Beach
23106-01
739
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Appendix A
References
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Project No. 23106-01 A-1 December 2, 2025

APPENDIX A
References
American Society of Civil Engineers (ASCE), 2022, Minimum Design Loads and Associated Criteria for Buildings and Other Structures, ASCE/SEI 7-22, 2022.

American Society for Testing and Materials (ASTM), 2025, Annual Book of ASTM Standards, Volume

04.08 Soil and Rock (I): D420 – D5876.

Architectural Drawings, 2023, Architectural Plans, Family Apartments and Spiritual Center, Laguna Beach California, dated January 24, 2023.

Bray, J.D., and Sancio, R. B., 2006, Assessment of Liquefaction Susceptibility of Fine-Grained Soils, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, pp. 1165-1177, dated September 2006.

California Building Standards Commission, 2025, California Building Code, California Code of Regulations Title 24, Volumes 1 and 2, dated July 2025.

California Department of Transportation (Caltrans), 2021, Corrosion Guidelines, Version 3.2, dated May 2021.

California Division of Mines and Geology (CDMG), 1998, Earthquake Zones of Required Investigation, Laguna Beach Quadrangle, Official Map Released April 15, 1998. ________, 2006, Seismic Hazard Zone Report for Laguna Beach 7.5 Minute Quadrangle, Orange County California, Hazard Zone Report 013, 2001, updated January 13, 2006.

California Geological Survey (CGS), 2008, Special Publication 117A: Guidelines for Evaluating and Mitigating Seismic Hazards in California.
________, 2018, Earthquake Fault Zones, Special Publication 42, Revised 2018. ________, 2021, Tsunami Hazard Area Map, Laguna Beach Quadrangle, Orange County, California, Scale 1:24,000, dated 2021.

Edginton W.J. & Tan S.S., 1976, Geology of the Laguna Beach Quadrangle, Orange County, California, Special Report 127, dated 1976
Federal Highway Administration (FHWA), 2011, LRFD Seismic Analysis and Design of Transportation Geotechnical Features and Structural Foundation, Reference Manual, Publication No. FHWA11-032, August, 2011.

Historic Aerials, 2023, Historic Aerials photographs from 1938 to 2020, from https://www/historicaerials.com, viewed July 2023,
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APPENDIX A (Cont’d)
References
Project No. 23106-01 A-2 December 2, 2025
Lew, et al, 2010, Seismic Earth Pressures on Deep Basements, Structural Engineers Association of California (SEAOC) Convention Proceedings.

Related, 2025, Zoning Plan Check Submittal, Building Plan – Podium, NCC Affordable Housing, 340 St Ann’s Drive, Laguna Beach, California, dated October 14, 2025.

Soils International Corporation, 1978, Preliminary Soils and Geologic Report, Church Property, Lot 21, Tract 870, Cleo and Catalina Streets, Project: S-0338-FG, Laguna Beach, California, dated June 9, 1978.

Structural Engineers Association of California (SEAOC), 2025, Seismic Design Maps, Retrieved November 25, 2025, from https://seismicmaps.org/
T&M Surveying, 2022, ALTA/NSPS Land Title Survey, 340 St Ann’s Drive, City of Laguna Beach, County of Orange, State of California, dated November 22, 2022.

Twining Laboratories, 1962, Congregational Church Parking Lot on Catalina between St. Anns Drive and Cleo Street, Laguna Beach, California, Project No. 340A-62-2327, dated October 29, 1962 United States Geological Survey (USGS), 1957, Geologic Map of the San Juan Hills, San Juan Capistrano Area, Orange County California Oil and Gas Investigation Map OM193, dated 1957. ________, 2004, Preliminary Digital Geologic Map of the Santa Ana 30’x60’ Quadrangle, Southern California, Version 2.0, Open File Report 99-172, Prepared in Cooperation with the California Geological Survey; Compiled by D.M. Morton.
________, 2018, Hazard Disaggregation, NSHM Conterminous U.S. 2018, Retrieved November 25, 2025, from https://earthquake.usgs.gov/hazards/interactive/
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Appendix B
Boring and CPT Logs
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THIS SUMMARY APPLIES ONLY AT THE LOCATION OF THIS BORING AND AT THE TIME OF DRILLING. SUBSURFACE CONDITIONS MAY DIFFER AT OTHER LOCATIONS AND MAY CHANGE AT THIS LOCATION WITH THE PASSAGE OF TIME. THE DATA PRESENTED IS A SIMPLIFICATION OF THE ACTUAL CONDITIONS ENCOUNTERED. THE DESCRIPTIONS

PROVIDED ARE QUALITATIVE FIELD DESCRIPTIONS

AND ARE NOT BASED ON QUANTITATIVE
ENGINEERING ANALYSIS. CN CONSOLIDATION

CR CORROSION

AL ATTERBERG LIMITS CO COLLAPSE/SWELL RV R-VALUE
-#200 % PASSING # 200 SIEVE

DIRECT SHEAR MAXIMUM DENSITY

SIEVE ANALYSIS

SIEVE AND HYDROMETER

EXPANSION INDEX
TEST TYPES: DSMD
SA
S&H
EI
SAMPLE TYPES: B BULK SAMPLE R RING SAMPLE (CA Modified Sampler) G GRAB SAMPLE

SPT STANDARD PENETRATION

TEST SAMPLE GROUNDWATER TABLE
30 25
20 15
10 5
0 Elevation (ft) Depth (ft) Graphic Log Sample Number Blow Count Dry Density (pcf) Moisture (%) USCS Symbol DESCRIPTION Type of Test Hole Diameter:

Hole Location: See Geotechnical Map
Drop:

Type of Rig:

Project Number:

Elevation of Top of Hole: Drive Weight:

Drilling Company:

Project Name:

Date:
70 65
60 55
50 Geotechnical Boring Log Borehole HS-1
6/20/2023
~74' MSL
6"
Truck Mounted Rig
30"
140 pounds
2R Drilling
Woodhart LLC- Laguna Beach
23106-01
Logged By JMN
Sampled By JMN
Checked By RLD

Page 1 of 2 ends

Laguna Beach City CouncilJuly 7, 2026

Laguna Beach City Council
July 7, 2026