Agenda packet — La Mesa City Council, March 28, 2023 (part 2 of 4)

20203667.001A/LH20R110080 Page 25 of 29 May 8, 2020
Copyright 2020 Kleinfelder
6 ADDITIONAL SERVICES

6.1 PLANS AND SPECIFICATIONS REVIEW
We recommend that Kleinfelder perform a general review of the project plans and specifications before they are finalized to verify that our geotechnical recommendations have been properly interpreted and implemented during design. If we are not accorded the privilege of performing this review, we can assume no responsibility for misinterpretation of our recommendations.

6.2 CONSTRUCTION OBSERVATION AND TESTING
The construction process is an integral design component with respect to the geotechnical aspects of a project. Because geotechnical engineering is an inexact science due to the variability of natural processes, and because we sample only a limited portion of the soils affecting the performance of the proposed structure, unanticipated or changed conditions can be encountered during grading. Proper geotechnical observation and testing during construction are imperative to allow the geotechnical engineer the opportunity to verify assumptions made during the design process. Therefore, we recommend that Kleinfelder be retained during the construction of the proposed improvements to observe compliance with the design concepts and geotechnical recommendations, and to allow design changes in the event that subsurface conditions or methods of construction differ from those assumed while completing this study.

Our services are typically needed at the following stages of grading. • After demolition;
• During grading;
• After the overexcavation, but prior to scarification; • During utility trench backfill;
• During base placement and site paving; and
• After excavation for foundations.

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20203667.001A/LH20R110080 Page 26 of 29 May 8, 2020
Copyright 2020 Kleinfelder
7 LIMITATIONS
This geotechnical study has been prepared for the exclusive use of Costco Wholesale and their agents for specific application to the proposed building addition at Costco Wholesale Warehouse No. 469 located at 8125 Fletcher Parkway in La Mesa, California. The findings, conclusions and recommendations presented in this report were prepared in accordance with generally accepted geotechnical engineering practice. No other warranty, express or implied, is made.

The scope of services was limited to a background data review and the field exploration described in Section 1.2. It should be recognized that definition and evaluation of subsurface conditions are difficult. Judgments leading to conclusions and recommendations are generally made with incomplete knowledge of the subsurface conditions present due to the limitations of data from field studies. The conclusions of this assessment are based on our field exploration and laboratory testing programs, and engineering analyses.

Kleinfelder offers various levels of investigative and engineering services to suit the varying needs of different clients. Although risk can never be eliminated, more detailed and extensive studies yield more information, which may help understand and manage the level of risk. Since detailed study and analysis involves greater expense, our clients participate in determining levels of service, which provide information for their purposes at acceptable levels of risk. The client and key members of the design team should discuss the issues covered in this report with Kleinfelder, so that the issues are understood and applied in a manner consistent with the owner’s budget, tolerance of risk and expectations for future performance and maintenance.

Recommendations contained in this report are based on our field observations and subsurface explorations, limited laboratory tests, and our present knowledge of the proposed construction. It is possible that soil or groundwater conditions could vary between or beyond the points explored. If soil or groundwater conditions are encountered during construction that differ from those described herein, the client is responsible for ensuring that Kleinfelder is notified immediately so that we may reevaluate the recommendations of this report. If the scope of the proposed construction, including the estimated Traffic Index or locations of the improvements, changes from that described in this report, the conclusions and recommendations contained in this report are not considered valid until the changes are reviewed, and the conclusions of this report are modified or approved in writing, by Kleinfelder.

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20203667.001A/LH20R110080 Page 27 of 29 May 8, 2020
Copyright 2020 Kleinfelder
The scope of services for this subsurface exploration and geotechnical report did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site.

Kleinfelder cannot be responsible for interpretation by others of this report or the conditions encountered in the field. Kleinfelder must be retained so that all geotechnical aspects of construction will be monitored on a full-time basis by a representative from Kleinfelder, including site preparation, preparation of foundations, and placement of structural fill and trench backfill. These services provide Kleinfelder the opportunity to observe the actual soil and groundwater conditions encountered during construction and to evaluate the applicability of the recommendations presented in this report to the site conditions. If Kleinfelder is not retained to provide these services, we will cease to be the engineer of record for this project and will assume no responsibility for any potential claim during or after construction on this project. If changed site conditions affect the recommendations presented herein, Kleinfelder must also be retained to perform a supplemental evaluation and to issue a revision to our original report.

This report, and any future addenda or reports regarding this site, may be made available to bidders to supply them with only the data contained in the report regarding subsurface conditions and laboratory test results at the point and time noted. Bidders may not rely on interpretations, opinion, recommendations, or conclusions contained in the report. Because of the limited nature of any subsurface study, the contractor may encounter conditions during construction which differ from those presented in this report. In such event, the contractor should promptly notify the owner so that Kleinfelder’s geotechnical engineer can be contacted to confirm those conditions. We recommend the contractor describe the nature and extent of the differing conditions in writing and that the construction contract include provisions for dealing with differing conditions. Contingency funds should be reserved for potential problems during earthwork and foundation construction.

This report may be used only by the client and only for the purposes stated, within a reasonable time from its issuance, but in no event later than one year from the date of the report. Land use, site conditions (both on site and off site) or other factors may change over time, and additional work may be required with the passage of time. Any party, other than the client who wishes to use this report shall notify Kleinfelder of such intended use. Based on the intended use of this report and the nature of the new project, Kleinfelder may require that additional work be performed and that an updated report be issued. Non-compliance with any of these requirements by the client or anyone else will release Kleinfelder from any liability resulting from the use of this report by any unauthorized party and the client agrees to defend, indemnify, and hold harmless Kleinfelder from any claims or liability associated with such unauthorized use or non-compliance.

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20203667.001A/LH20R110080 Page 28 of 29 May 8, 2020
Copyright 2020 Kleinfelder
8 REFERENCES
American Concrete Institute (ACI), 2014, Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14).

American Society of Civil Engineers (ASCE), 2016, Minimum Design Load for Buildings and Other Structures (ASCE/SEI 7-16).

California Geologic Survey (CGS), 2002, Note 36, California Geomorphic Provinces.

California Geologic Survey (CGS), 2003, The Revised 2002 California Probabilistic Seismic Hazard Maps, released June 2003.

California Geological Survey (CGS), 2018, Earthquake Fault Zones - A Guide for Government Agencies, Property Owners/Developers, and Geoscience Practitioners for Assessing Fault Rupture Hazards in California: California Geological Survey Special Publication 42, 83p.

City of La Mesa, 2016, BMP Design Manual, dated February 2016.

Costco Wholesale, 2018, Costco Wholesale Development Requirements, Version 2018, dated October 26, 2018.

FEMA, Map Service Center, 2012, Flood Insurance Rate Maps (FIRM), Flood Zone Panel 06073C1366G, FEMA Map Service Center, https://msc.fema.gov/portal Geotechnics Incorporated, 1994, “Report of Geotechnical Investigation, Price Costco, La Mesa Gateway Center, La Mesa, California,” pages 10-12, dated November 22, 1994.

Geotechnics Incorporated, 1997a, “Interim Compaction Report, Price Costco Building Pad and Driveway/Parking Areas, and Geogrid Retaining Wall, La Mesa Gateway Project, La Mesa, California,” dated January 7, 1997.

Geotechnics Incorporated, 1997b, “Report of Compaction Test Results, Keystone Retaining Wall, Costco Building Site, La Mesa Gateway Redevelopment, La Mesa, California”, dated January 27, 1997.

H.P. Ritzema, 1994, "Drainage Principles and Applications", International Institute for Land Reclamation and Improvement, Publication 16, 2nd revised edition, Wageningen, The Netherlands.

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20203667.001A/LH20R110080 Page 29 of 29 May 8, 2020
Copyright 2020 Kleinfelder
International Code Council, Inc., 2019 California Building Code.

Jennings, C.W. and Bryant, W.A., 2010, Fault Activity Map of California, California Geological Survey, Scale 1:750,000.

Kleinfelder, 2018, Geotechnical Study, Proposed Fuel Facility, Costco Wholesale Warehouse No. 469, 8125 Fletcher Parkway, La Mesa, California, CW#17-0814, dated May 18, 2018.

MG2, 2020, Concept Site Plan, Costco Wholesale, Location #469, 6125 Fletcher Parkway, La Mesa, CA 91942, Sheet DD11-14, dated January 31, 2020.

National Association of Corrosion Engineers (NACE), 2006, “Corrosion Basics, An Introduction, 2nd Edition” National Association of Corrosion Engineers.

Norris, R.M. and Webb, R.W., 1990, Geology of California, John Wiley and Sons, Second Edition.

OSHPD, 2018, Seismic Design Maps website https://seismicmaps.org/

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20203667.001A/LH20R110080 May 8, 2020
Copyright 2020 Kleinfelder

FIGURES

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Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), (c) OpenStreetMap contributors, and the GIS User Community

COSTCO LA MESA

SAN DIEGO, CALIFORNIA

SITE VICINITY MAP
FIGURE
1 20203667
-
7/15/2019
B.CRYSTAL
T.CISNEY
£
PROJECT NO.

DRAWN BY:

CHECKED BY:

DATE:

REVISED:

GIS FILE: C:\Users\tcisney\OneDrive - Kleinfelder\Desktop\Costco\La Mesa\Figure 1 Site Map.mxd PLOTTED: 3/10/2020 9:22:05 A M BY: TCisney
)
SITE
1 " = 1 miles
0 5300 10000
Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942 Page 208 of 585

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A@ A@
A@
B-2 B-1
B-3
Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942

BORING LOCATION PLAN
FIGURE
2 20203667
-
04/01/2020
B.CRYSTAL
R.ALVAREZ
£
PROJECT NO.

DRAWN BY:

CHECKED BY:

DATE:

REVISED:

The information included on this graphic representation has been compiled from a variety of sources and is subject to change without notice. Kleinfelder makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. This document is not intended for use as a land survey product nor is it designed or intended as a construction design document. The use or misuse of the information contained on this graphic representation is at the sole risk of the party using or misusing the information. 1 " = 100 feet Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community
0 50 100
Feet
LEGEND
A@ B-3 Approximate
Boring Location
GIS FILE: C:\Workspace\GIS_Projects\Costco\LaMesa\FIGURE 2 LA MESA UPDATE.mxd PLOTTED: 4/1/2020 3:03:39 PM BY: RAlvarez

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N
OTE:

KENNEDY,M.P.ANDOTHERS,1975,GEOLOGY

OFTHELAMESAQUADRANGLESANDIEGO

COUNTYCALIFORNIA,SANDIEGOMETROPOLITAN
AREABULLETIN200,PLATE3B.

COSTCOLAMESA

SANDIEGO,CALIFORNIA

REGIONALGEOLOGICMAP
FIGURE
3 20203667-
5/30/2019
B.CRYSTAL
T.CISNEY
£
1"=1500SCALEINFEET
0 15003000
PROJECTNO.

DRAWNBY:

CHECKEDBY:

DATE:

REVISED:

GIS FILE: C:\Users\tcisney\OneDrive - Kleinfelder\Desktop\Costco\La Mesa\FIGURE 3 LA MESA.mxd PLOTTED: 3/15/2020 8:44:43 PM BY: TCisney LEGEND
)
SITE
Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942

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Faulting Legend
Historic displacement (< 200 years)
Mapped Fault Location
Dashed were Approximated
! ! ! ! ! Concealed
Holocene displacement (< 11,000 years)
Mapped Fault Location
Dashed were Approximated
! ! ! ! ! Concealed
Late Quaternary displacement (< 750,000 years)
Mapped Fault Location
Dashed were Approximated
! ! ! ! ! Concealed
Quaternary displacement (< 1,600,000 years)
Mapped Fault Location
Dashed were Approximated
! ! ! ! ! Concealed
Pre-Quaternary Geologic Structures (CGS, 2000)
fault, approx. located
@ fault, approx. located, queried
fault, certain
fault, concealed
@ fault, concealed, queried
@ fault, inferred, queried
ANSS Earthquakes
Magnitude

4.0 - 4.9

5.0 - 5.9

6.0 - 6.9

7.0 - 7.9

8.0 - 8.9
SITE
1 0
0 K i l o m e t e r
R
a d i
u s
Los Angeles
Riverside
Santa Ana
El Centro
Los Angeles
Metro Area
Mexico
115°30'0"W
117°0'0"W
117°0'0"W
33°0'0"N
33°0'0"N
35 17.5 0 35
Kilometers
PROJECT NO.

DRAWN:

DRAWN BY:

CHECKED BY:

FILE NAME: www.kleinfelder.com
FIGURE
The information included on this graphic representation has been compiled from a variety of sources and is subject to change without notice. Kleinfelder makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. This document is not intended for use as a land survey product nor is it designed or intended as a construction design document. The use or misuse of the information contained on this graphic representation is at the sole risk of the party using or misusing the information.

Quaternary Faults (Bryant, 2005; USGS, 2009)
£
3/10/2020
T.CISNEY
LA MESA FIGURE 4.MXD C:\Users\TCisney\Desktop\LA
MESA FIGURE 4.mxd

REGIONAL FAULT MAP

AND EARTHQUAKE EPICENTERS
(1800 - JULY 2019)
4 20203667
B.CRYSTAL

COSTCO LA MESA

SAN DIEGO, CALIFORNIA
)
Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942

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20203667.001A/LH20R110080 May 8, 2020
Copyright 2020 Kleinfelder

APPENDIX A

FIELD EXPLORATIONS

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20203667.001A/LH20R110080 May 8, 2020
Copyright 2020 Kleinfelder

APPENDIX A

FIELD EXPLORATION

GENERAL
Our recent field exploration program consisted of three soil borings. The borings were drilled on March 5, 2020. Prior to commencement of the fieldwork, various geophysical techniques were used at the boring locations to identify potential conflicts with subsurface structures. Exploration locations were also cleared for buried utilities through Underground Service Alert (USA).

Subsurface conditions were explored by drilling three borings in the area of the proposed building addition to depths of approximately 20 feet below ground surface (bgs). The borings were drilled by Cascade Drilling of San Diego, California with a (CME-95) truck-mounted, hollow stem auger (HSA) drill rig. The approximate locations of the explorations are presented on Figure 2, Boring Location Plan.

The logs for the borings are presented in Appendix A. The boring logs describes the earth materials encountered, samples obtained and show field and laboratory tests performed. The log also shows the location, boring number, drilling date, and the name of the drilling subcontractor.

The borings were logged by a Kleinfelder engineer using the Unified Soil Classification System.

The boundaries between soil types shown on the log are approximate because the transition between different soil layers may be gradual. Bulk and drive samples of selected earth materials were obtained from the borings.

Bulk and drive samples of selected earth materials were obtained from the borings. A Standard Penetration (SPT) sampler were used to obtain drive samples of the soils encountered. The SPT sampler consists of a 2-inch O.D., 1.5-inch I.D. split-barrel shaft. The SPT sampler was driven a total of 18 inches into the soil at the bottom of the boring. The soil was retained in tubes and ziplocked bags for laboratory testing. An additional 2 inches of soil from each drive remained in the cutting shoe and was usually discarded after visually classifying the soil per ASTM D2488. The sampler was driven using a 140-pound hammer falling 30 inches. The total number of blows required to drive the sampler the final 12 inches is termed blow count and is recorded on the boring logs except where refusal was encountered.

Bulk and grab samples of the near-surface soils were directly retrieved from the auger cuttings from the borings.

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A-1

FIGURE GRAPHICS KEY
Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942
The report and graphics key are an integral part of these logs. All data and interpretations in this log are subject to the explanations and limitations stated in the report.

Lines separating strata on the logs represent approximate boundaries only. Actual transitions may be gradual or differ from those shown.

No warranty is provided as to the continuity of soil or rock conditions between individual sample locations.

Logs represent general soil or rock conditions observed at the point of exploration on the date indicated.

In general, Unified Soil Classification System designations presented on the logs were based on visual classification in the field and were modified where appropriate based on gradation and index property testing.

Fine grained soils that plot within the hatched area on the Plasticity Chart, and coarse grained soils with between 5% and 12% passing the No. 200 sieve require dual USCS symbols, ie., GW-GM, GP-GM, GW-GC, GP-GC, GC-GM, SW-SM, SP-SM, SW-SC, SP-SC, SC-SM.

If sampler is not able to be driven at least 6 inches then 50/X indicates number of blows required to drive the identified sampler X inches with a 140 pound hammer falling 30 inches.

ABBREVIATIONS
WOH - Weight of Hammer
WOR - Weight of Rod

WELL-GRADED GRAVELS,

GRAVEL-SAND MIXTURES WITH

LITTLE FINES

WELL-GRADED GRAVELS,

GRAVEL-SAND MIXTURES WITH

LITTLE CLAY FINES

POORLY GRADED GRAVELS,

GRAVEL-SAND MIXTURES WITH

LITTLE FINES

POORLY GRADED GRAVELS,

GRAVEL-SAND MIXTURES WITH

LITTLE CLAY FINES

SILTY GRAVELS, GRAVEL-SILT-SAND

MIXTURES

CLAYEY GRAVELS,

GRAVEL-SAND-CLAY-SILT MIXTURES

WELL-GRADED SANDS,

SAND-GRAVEL MIXTURES WITH

LITTLE CLAY FINES

POORLY GRADED SANDS,

SAND-GRAVEL MIXTURES WITH

LITTLE CLAY FINES
SW
SW-SC

POORLY GRADED SANDS,

SAND-GRAVEL MIXTURES WITH

LITTLE FINES
Cu 4 and/
or 1 Cc 3 >
>

INORGANIC SILTS AND VERY FINE SANDS, SILTY OR

CLAYEY FINE SANDS, SILTS WITH SLIGHT PLASTICITY

ORGANIC CLAYS & ORGANIC SILTS OF

MEDIUM-TO-HIGH PLASTICITY

INORGANIC CLAYS OF HIGH PLASTICITY, FAT
CLAYS

INORGANIC SILTS, MICACEOUS OR

DIATOMACEOUS FINE SAND OR SILT

INORGANIC CLAYS-SILTS OF LOW PLASTICITY, GRAVELLY

CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS
_

SILTY SANDS, SAND-GRAVEL-SILT

MIXTURES

CLAYEY SANDS,

SAND-GRAVEL-CLAY MIXTURES
SW-SM

CLAYEY SANDS, SAND-SILT-CLAY

MIXTURES
CL
CL-ML
>
<
<
SANDS
WITH
5% TO
12%
FINES
SANDS
WITH >
12%
FINES

WELL-GRADED SANDS,

SAND-GRAVEL MIXTURES WITH

LITTLE FINES
Cu 4 and/
or 1 Cc 3>
CLEAN
GRAVEL
WITH
<5%
FINES

GRAVELS
WITH
5% TO
12%
FINES
OL
CH

CLAYEY GRAVELS,

GRAVEL-SAND-CLAY MIXTURES

FINE GRAINED SOILS
(Half or more of material is
smaller than
the #200 sieve)

GRAVELS
WITH >
12%
FINES
>
Cu 4 and
1 Cc 3
>_
_ BAG SAMPLE

BULK SAMPLE

STANDARD PENETRATION SPLIT SPOON SAMPLER
(2 in. (50.8 mm.) outer diameter and 1-3/8 in. (34.9 mm.) inner diameter)
_
GM
GC
GW
GP
GW-GM
GW-GC
_ _
_

INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY

CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS
<

SAMPLE/SAMPLER TYPE GRAPHICS
>
<
<
>
CLEAN
SANDS
WITH
<5%
FINES
GRAVELS (More than half of coarse fraction is larger than the #4 sieve) Cu 6 and/
or 1 Cc 3
Cu 6 and/
or 1 Cc 3
>
Cu 6 and
1 Cc 3
SC-SM
Cu 4 and
1 Cc 3
< _

ORGANIC SILTS & ORGANIC SILTY CLAYS OF

LOW PLASTICITY

SILTS AND CLAYS
(Liquid Limit
less than 50)

WELL-GRADED SANDS,

SAND-GRAVEL MIXTURES WITH

LITTLE OR NO FINES

POORLY GRADED SANDS,

SAND-GRAVEL MIXTURES WITH

LITTLE OR NO FINES
MH
OH
ML
GC-GM
COARSE GRAINED SOILS (More than half of material is larger than the #200 sieve) UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D 2487)
<
Cu 6 and
1 Cc 3
GP-GM
GP-GC
_
_ _<
>
<
<
>
SP
SP-SM
SP-SC
SM
SC
< _<
>

WELL-GRADED GRAVELS,

GRAVEL-SAND MIXTURES WITH

LITTLE OR NO FINES

POORLY GRADED GRAVELS,

GRAVEL-SAND MIXTURES WITH

LITTLE OR NO FINES

SILTS AND CLAYS
(Liquid Limit
50 or greater)
SANDS (Half or more of coarse fraction is smaller than the #4 sieve)

GROUND WATER GRAPHICS

OBSERVED SEEPAGE
WATER LEVEL (level after exploration completion)
WATER LEVEL (level where first observed)
WATER LEVEL (additional levels after exploration)
NOTES
gINT FILE: Klf_gint_master_2020 PROJECT NUMBER: 20203667.001A OFFICE FILTER: LAGUNA HILLSgINT TEMPLATE: E:KLF_STANDARD_GINT_LIBRARY_2020.GLB [__KLF_GEO-LEG1 (GRAPHICS KEY) WITH USCS] PLOTTED: 03/25/2020 09:26 AM BY: HMarquez DATE:

CHECKED BY:

DRAWN BY:
20203667.001A
PROJECT NO.:
3/9/2020
BC
TC

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CALIFORNIA

SAMPLER
(# blows/ft)

MODIFIED CA

SAMPLER
(# blows/ft)
SPT-N60
(# blows/ft)
FIGURE
A-2

SOIL DESCRIPTION KEY
Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942
> 50
Medium (M)
High (H)

RELATIVE

DENSITY
(%)

APPARENT

DENSITY
30 - 50
10 - 30
4 - 10
<4
>60
35 - 60
12 - 35
5 - 12
<4
>70
40 - 70
15 - 40
5 - 15

CONSISTENCY
<2
Moist
The thread is easy to roll and not much time is required to reach the plastic limit. The thread cannot be rerolled after reaching the plastic limit. The lump or thread crumbles when drier than the plastic limit.

It takes considerable time rolling and kneading to reach the plastic limit. The thread can be rerolled several times after reaching the plastic limit. The lump or thread can be formed without crumbling when drier than the plastic limit.
30 - 50

DESCRIPTION
Strongly

FIELD TEST
Alternating layers of varying material or color with the layer less than 1/4-in. thick, note thickness.

FIELD TEST
Absence of
moisture, dusty,
dry to the touch
Moderately
Will not crumble or
break with finger
pressure
Pocket Pen
(tsf)
Term
of
Use
<5%
With
Modifier
5 to <15%
15%
Trace <15%
15 to <30%
30%
AMOUNT
>30
Very Soft

DESCRIPTION
Damp but no
visible water
Boulders
Cobbles
coarse
fine
Gravel
Sand
Fines

GRAIN SIZE
>12 in. (304.8 mm.)
3 - 12 in. (76.2 - 304.8 mm.) Fist-sized to basketball-sized 3/4 -3 in. (19 - 76.2 mm.) Thumb-sized to fist-sized

0.19 - 0.75 in. (4.8 - 19 mm.) Pea-sized to thumb-sized #10 - #4 0.079 - 0.19 in. (2 - 4.9 mm.)

0.017 - 0.079 in. (0.43 - 2 mm.)
#200 - #40
coarse
fine
medium

SIEVE SIZE APPROXIMATE SIZE
>12 in. (304.8 mm.) Larger than basketball-sized
3 - 12 in. (76.2 - 304.8 mm.)
3/4 -3 in. (19 - 76.2 mm.)
#4 - 3/4 in. (#4 - 19 mm.)
Rock salt-sized to pea-sized
#40 - #10 Sugar-sized to rock salt-sized

0.0029 - 0.017 in. (0.07 - 0.43 mm.) Flour-sized to sugar-sized Passing #200 <0.0029 in. (<0.07 mm.) Flour-sized and smaller

DESCRIPTION
Secondary
Constituent is
Fine Grained
Secondary
Constituent is
Coarse Grained
SPT - N60
(# blows / ft)
Soft
Stiff
Very Stiff
Hard
2 - 4
4 - 8
8 - 15
15 - 30
Weakly
Crumbles or breaks
with handling or slight
finger pressure
Crumbles or breaks
with considerable finger
pressure

UNCONFINED

COMPRESSIVE
STRENGTH (Qu)(psf)

VISUAL / MANUAL CRITERIA
<500

0.5 PP <1
1 PP <2
2 PP <4
4 PP >8000
4000 - 8000
500 - 1000
1000 - 2000
2000 - 4000
Rounded
Subrounded
Dry
Wet
Visible free water,
usually soil is below
water table
Thumb will penetrate more than 1 inch (25 mm). Extrudes between fingers when squeezed.

Thumb will penetrate soil about 1 inch (25 mm).

Remolded by light finger pressure.

Thumb will penetrate soil about 1/4 inch (6 mm).

Remolded by strong finger pressure.

Can be imprinted with considerable pressure from thumb.

Thumb will not indent soil but readily indented with
thumbnail.

Thumbnail will not indent soil.

Particles have nearly plane sides but have well-rounded corners and edges.

Angular Particles have sharp edges and relatively plane sides with unpolished surfaces.

DESCRIPTION
Fissured
Slickensided
Blocky
Lensed

CRITERIA
Stratified
Laminated
Fracture planes appear polished or glossy, sometimes striated.

Alternating layers of varying material or color with layers at least 1/4-in. thick, note thickness.

Breaks along definite planes of fracture with
little resistance to fracturing.

Cohesive soil that can be broken down into small angular lumps which resist further breakdown.

Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay; note thickness.

Subangular
Particles have smoothly curved sides and no edges.

Particles are similar to angular description but have rounded edges.

None
Weak
Strong
No visible reaction

DESCRIPTION CRITERIA
A 1/8-in. (3 mm.) thread cannot be rolled at any water
content. NPNon-plastic
The thread can barely be rolled and the lump or thread
cannot be formed when drier than the plastic limit. < 30Low (L) 85 - 100
65 - 85
35 - 65
15 - 35
<5 0 - 15
Very Dense
Dense
Medium Dense
>50
Loose
Very Loose
FROM TERZAGHI AND PECK, 1948

LLDESCRIPTION FIELD TEST
Some reaction,
with bubbles
forming slowly
Violent reaction,
with bubbles
forming
immediately

DESCRIPTION FIELD TEST
PP < 0.25
Medium Stiff

0.25 PP <0.5

APPARENT / RELATIVE DENSITY - COARSE-GRAINED SOIL PLASTICITY

SECONDARY CONSTITUENT MOISTURE CONTENT CEMENTATION

CONSISTENCY - FINE-GRAINED SOIL
FROM TERZAGHI AND PECK, 1948; LAMBE AND WHITMAN, 1969; FHWA, 2002; AND ASTM D2488

REACTION WITH

HYDROCHLORIC ACID

STRUCTURE ANGULARITY

GRAIN SIZE
gINT FILE: Klf_gint_master_2020 PROJECT NUMBER: 20203667.001A OFFICE FILTER: LAGUNA HILLSgINT TEMPLATE: E:KLF_STANDARD_GINT_LIBRARY_2020.GLB [_KLF_GEO-LEG 2 (SOIL DESC KEY)] PLOTTED: 03/25/2020 09:26 AM BY: HMarquez DATE:

CHECKED BY:

DRAWN BY:
20203667.001A
PROJECT NO.:
3/9/2020
BC
TC

Page 219 of 585 ends

76 66
23 18
ASPHALT: approx. 4 inches, aggregate base
thickness not apparent due to similarity with
underlying material
Artificial Fill (af)
Clayey SAND with Gravel (SC): fine to
coarse-grained sand, low plasticity, light olive brown
(2.5YR 5/4), moist, medium dense, fine angular
gravel
Silty SAND with Gravel (SM): fine to coarse-grained
sand, olive gray (5Y 4/2), moist, medium dense,
gravel up to 1.5"
Clayey SAND with Gravel (SC): fine to
coarse-grained, low plasticity, black (10YR 2/1),
moist, dense, gravel is angular and mechincally
broken
becomes mottled yellowish brown (10YR 5/8) and
loose
red brick fragments in culttings
Stadium Conglomerate (Tst)
Clayey SAND with Gravel (SC): fine to
coarse-grained sand, black (10YR 2/1) mottled
yellowish brown (10YR 5/6), wet, very dense,
oxidized, gravel is rounded
The boring was terminated at approximately 20 ft.
below ground surface. The boring was backfilled
with grout and patched at surface on March 05, 2020.
8"
6"
2"
8"
NR"
10"
SC 10.2

10.4 7.7
BC=6
12 12
BC=7
13 10
BC=16
20 14
BC=3
5 4
BC=20
9 23
BC=6
14 27
37 hand auger approx. 2 feet
heavy grinding
19 Groundwater was observed at approximately 18 ft. below ground surface during drilling.

GENERAL NOTES:

GROUNDWATER LEVEL INFORMATION:
1 of 1

FIELD EXPLORATION
FIGURE
A-3

LABORATORY RESULTS
Lithologic Description
BORING LOG B-1
PAGE:

BORING LOG B-1
Dry Unit Wt. (pcf)Passing #4 (%)Passing #200 (%)
Latitude: 32.77419°
Longitude: -117.02496°
Surface Condition: Asphalt
Not Available
Drilling Company: Casacade
Drilling Method:

Drilling Equipment:

Sunny Exploration Diameter:

Hammer Type - Drop: 140 lb. Auto - 30 in.

Logged By:

Date Begin - End:

Hor.-Vert. Datum:

Weather:

Drill Crew:

CME-95
8 in. O.D.

T.Cisney
Plunge: -90 degrees Hollow Stem Auger
Javier and Jose
3/05/2020
Depth (feet)
5 10
15 20
25 30
Graphical LogBlow Counts(BC)= Uncorr. Blows/6 in.Recovery(NR=No Recovery)USCSSymbolWaterContent (%)Liquid LimitPlasticity Index(NP=NonPlastic)Additional Tests/Remarks Costco Wholesale Warehouse No. 469
8125 Fletcher Parkway
La Mesa, California 91942
PLOTTED: 03/26/2020 09:10 AM BY: HMarquez
gINT FILE: Klf_gint_master_2020 PROJECT NUMBER: 20203667.001A OFFICE FILTER: LAGUNA HILLSgINT TEMPLATE: E:KLF_STANDARD_GINT_LIBRARY_2020.GLB [__KLF_BORING/TEST PIT SOIL LOG] DATE: 3/9/2020
CHECKED BY: BC
DRAWN BY: TC
PROJECT NO.:
20203667.001ASample Type

Page 220 of 585 ends

73 22
ASPHALT: approx. 4 inches, aggregate base
thickness not apparent due to similarity with
underlying material
Artificial Fill (af)
Clayey SAND with Gravel (SC): fine to
coarse-grained sand, medium plasticity, dark
yellowish brown (10YR 4/4), moist, medium dense,
fine grained, angular gravel
micaeous and oxidation present
becomes dark brown (10YR 3/3)
becomes brown (10YR 4/3)
Stadium Conglomerate (Tst)
Well-Graded SAND with Gravel (SW): fine to
coarse-grained, yellowish brown (10YR 5/4), moist,
very dense
becomes wet and dark yellowish brown (10YR 4/4)
with some silt
The boring was terminated at approximately 20 ft.
below ground surface. The boring was backfilled
with grout and patched at surface on March 05, 2020.
2"
10"
18"
10"
6"
2"
SC 9.9

8.4 6.6
BC=8
13 12
BC=10
11 18
BC=19
7 9
BC=7
6 8
BC=18
20 50/6"
BC=23
22 36
34 hand auger approx. 2 feet
R-Value Test
Corrosion Testing
rig grinding
heavy grinding
gravel stuck in shoe of sampler
15 Groundwater was observed at approximately 18 ft. below ground surface during drilling.

GENERAL NOTES:

GROUNDWATER LEVEL INFORMATION:
1 of 1

FIELD EXPLORATION
FIGURE
A-4

LABORATORY RESULTS
Lithologic Description
BORING LOG B-2
PAGE:

BORING LOG B-2
Dry Unit Wt. (pcf)Passing #4 (%)Passing #200 (%)
Latitude: 32.77395°
Longitude: -117.02570°
Surface Condition: Asphalt
Not Available
Drilling Company: Casacade
Drilling Method:

Drilling Equipment:

Sunny Exploration Diameter:

Hammer Type - Drop: 140 lb. Auto - 30 in.

Logged By:

Date Begin - End:

Hor.-Vert. Datum:

Weather:

Drill Crew:

CME-95
8 in. O.D.

Page 221 of 585 ends

100 21
ASPHALT: approx. 3 inches, aggregate base
thickness not apparent due to similarity with
underlying material
Artificial Fill (af)
Clayey SAND (SC): fine to coarse-grained sand,
medium plasticity, brown (7.5YR 4/4) mottled red
(2.5YR 5/6), moist, medium dense, gravel is very
angular
becomes very dark brown (2.5Y 3/2)
becomes gray (2.5Y 5/1) and dense
becomes very dark grayish brown (10YR 4/2) and
medium dense with carbonate throughout
subrounded gravel and cobbles in cuttings
becomes black (5Y 2.5/1) and medium dense
Stadium Conglomerate (Tst)
Poorly Graded SAND with Gravel (SP): fine to
coarse-grained, brown (10YR 4/3) mottled strong
brown (7.5YR 5/8), wet, very dense, oxidized, with
minor silt and clay
The boring was terminated at approximately 20 ft.
below ground surface. The boring was backfilled
with grout and patched at surface on March 05, 2020.
12"
10"
3"
14"
4"
14"
SC 11.0

11.3 11.6
BC=5
13 11
BC=11
13 8
BC=28
23 22
BC=3
4 16
BC=8
6 7
BC=40
50/5"
34 hand suger upper approx. 2 feet,
drilled slow to 5'
rig grinding
no grinding, smooth drilling
rig grinding
16 Groundwater was observed at approximately 18 ft. below ground surface during drilling.

GENERAL NOTES:

GROUNDWATER LEVEL INFORMATION:
1 of 1

FIELD EXPLORATION
FIGURE
A-5

LABORATORY RESULTS
Lithologic Description
BORING LOG B-3
PAGE:

BORING LOG B-3
Dry Unit Wt. (pcf)Passing #4 (%)Passing #200 (%)
Latitude: 32.77362°
Longitude: -117.02557°
Surface Condition: Asphalt
Not Available
Drilling Company: Casacade
Drilling Method:

Drilling Equipment:

Sunny Exploration Diameter:

Hammer Type - Drop: 140 lb. Auto - 30 in.

Logged By:

Date Begin - End:

Hor.-Vert. Datum:

Weather:

Drill Crew:

CME-95
8 in. O.D.

Page 222 of 585 ends

20203667.001A/LH20R110080 May 8, 2020
Copyright 2020 Kleinfelder

APPENDIX B
Laboratory Testing

Page 223 of 585 ends

20203667.001A/LH20R110080 B-1 May 8, 2020
Copyright 2020 Kleinfelder

APPENDIX B

LABORATORY TESTING

GENERAL
Laboratory tests were performed on selected samples as an aid in classifying the soils and to evaluate physical properties of the soils that may affect foundation design and construction procedures. The tests were performed in general conformance with the current ASTM standards by Kleinfelder’s San Diego, California laboratory, unless noted otherwise. A description of the laboratory-testing program is presented below.

MOISTURE AND UNIT WEIGHT
Moisture content and dry unit weight testing was performed on a selected sample recovered from our borings. Moisture contents were determined in general accordance with ASTM Test Method D2216; dry unit weight was calculated using the entire weight of the samples collected in general accordance with ASTM Test Method D7263. Results of the testing are presented on the boring logs in Appendix A.

SIEVE ANALYSIS
Sieve analysis of selected samples was performed to evaluate the grain size distribution of the onsite soils and to aid in classification of the soils. Sieve analysis was performed in accordance with ASTM Standard Test Method D6913. The results of the tests are presented on the boring logs in Appendix A and as an attachment in this appendix.

PLASTICITY TESTING
Plasticity testing was performed on samples to evaluate the plasticity of the onsite soils and to aid in classification of the soils. Plasticity testing (Atterberg limits) was performed in accordance with ASTM Standard Test Method D4318. The results of the tests are presented on the boring logs in Appendix A and as an attachment in this appendix.

R-VALUE TESTS
One resistance value (R-value) test was performed on a bulk soil sample obtained within the proposed fuel facility area to evaluate pavement support characteristics of the near-surface onsite soils. R-value tests were performed in accordance with ASTM Standard Test Method D2844.

Results of the testing are attached to this appendix.

Page 224 of 585 ends

20203667.001A/LH20R110080 B-2 May 8, 2020
Copyright 2020 Kleinfelder

SOIL CORROSIVITY
A series of chemical tests were performed on selected samples of the near-surface soils to estimate pH, resistivity and sulfate and chloride contents. The samples were tested for pH and minimum resistivity, soluble chlorides, and soluble sulfates, respectively. Corrosivity testing was performed by Clarkson Laboratory and Supply, Inc. of Chula Vista, California. Test results may be used by a qualified corrosion engineer to evaluate the general corrosion potential with respect to construction materials. The results of the tests are presented in the text of the report and attached to this appendix.

Page 225 of 585 ends

Coarse Fine Coarse Fine Silt Clay
3" 1-1/2" 1" 3/4" 1/2" 3/8" 4 10 20 40 60 100 200
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
Sieve
Analysis
No 100 0.15 mm 28
No 200 .075 mm 22.6
No. 40 0.425 mm 48
No. 60 0.25 mm 36
No. 10 2.0 mm 68
No. 20 0.85 mm 61
3/8" 9.5 mm 87
No. 4 4.75 mm 76
3/4" 19 mm 100
1/2" 12.5 mm 92

1.5" 37.5 mm 100
1" 25 mm 100
3" 75 mm 100
2" 50 mm 100
Date Tested: 3/16/2020

GRAVEL SAND FINES
Medium
Boring No. Sample No. Depth (ft) Passing 200 (%)
Clayey sand with gravel
USCS Classification
B-1 Bulk 1
Costco La Mesa, CA Bldg Add GEO B-1
Tech: T.C.

GRADATION TEST RESULTS FIGURE

22.6 SC
Project No. 20203667.001A Date: 25-Mar-20
Sample Description Light Brown
Checked by:

Sieve Size % Passing
0 10
20 30
40 50
60 70
80 90
100
100 10 1 0.1 0.01 0.001 0.0001

PERCENT FINER BY WEIGHT

GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS

HYDROMETER
USCS

Page 226 of 585 ends

Coarse Fine Coarse Fine Silt Clay
3" 1-1/2" 1" 3/4" 1/2" 3/8" 4 10 20 40 60 100 200
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
Sieve
Analysis
No 100 0.15 mm 23
No 200 .075 mm 18.2
No. 40 0.425 mm 39
No. 60 0.25 mm 30
No. 10 2.0 mm 58
No. 20 0.85 mm 50
3/8" 9.5 mm 100
No. 4 4.75 mm 66
3/4" 19 mm 100
1/2" 12.5 mm 100

1.5" 37.5 mm 100
1" 25 mm 100
3" 75 mm 100
2" 50 mm 100
Date Tested: 3/17/2020

GRAVEL SAND FINES
Medium
Boring No. Sample No. Depth (ft) Passing 200 (%)
Clayey sand with gravel
USCS Classification
B-1 S-4 10
Costco La Mesa, CA Bldg Add GEO B-2
Tech: T.C.

GRADATION TEST RESULTS FIGURE

18.2 SC
Project No. 20203667.001A Date: 25-Mar-20
Sample Description Brown
Checked by:

Sieve Size % Passing
0 10
20 30
40 50
60 70
80 90
100
100 10 1 0.1 0.01 0.001 0.0001

PERCENT FINER BY WEIGHT

GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS

HYDROMETER
USCS

Page 227 of 585 ends

Coarse Fine Coarse Fine Silt Clay
3" 1-1/2" 1" 3/4" 1/2" 3/8" 4 10 20 40 60 100 200
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
Project No. 20203667.001A Date: 25-Mar-20
Sample Description Brown
Checked by:

Sieve Size % Passing
Costco La Mesa, CA Bldg Add GEO B-3
Tech: T.C.

GRADATION TEST RESULTS FIGURE

22.2 SC
Boring No. Sample No. Depth (ft) Passing 200 (%)
Clayey sand with gravel
USCS Classification
B-2 Bulk 1
Date Tested: 3/17/2020

GRAVEL SAND FINES
Medium
3" 75 mm 100
2" 50 mm 100

1.5" 37.5 mm 100
1" 25 mm 100
3/4" 19 mm 100
1/2" 12.5 mm 100
3/8" 9.5 mm 100
No. 4 4.75 mm 73
43 No. 60 0.25 mm 34
No. 10 2.0 mm 61
No. 20 0.85 mm 52
Sieve
Analysis
No 100 0.15 mm 28
No 200 .075 mm 22.2
No. 40 0.425 mm
0 10
20 30
40 50
60 70
80 90
100
100 10 1 0.1 0.01 0.001 0.0001

PERCENT FINER BY WEIGHT

GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS

HYDROMETER
USCS

Page 228 of 585 ends

Sieve Size % Passing
Costco La Mesa, CA Bldg Add GEO B-4
Tech: T.C.

GRADATION TEST RESULTS FIGURE

20.5 SC
Boring No. Sample No. Depth (ft) Passing 200 (%)
Clayey sand
USCS Classification
B-3 Bulk 1
Date Tested: 3/16/2020

GRAVEL SAND FINES
Medium
3" 75 mm 100
2" 50 mm 100

1.5" 37.5 mm 100
1" 25 mm 100
3/4" 19 mm 100
1/2" 12.5 mm 100
3/8" 9.5 mm 100
No. 4 4.75 mm 100
43 No. 60 0.25 mm 34
No. 10 2.0 mm 63
No. 20 0.85 mm 54
Sieve
Analysis
No 100 0.15 mm 26
No 200 .075 mm 20.5
No. 40 0.425 mm
0 10
20 30
40 50
60 70
80 90
100
100 10 1 0.1 0.01 0.001 0.0001

PERCENT FINER BY WEIGHT

GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS

HYDROMETER
USCS

Page 229 of 585 ends

to
USCS

CLASSIFICATION USCS
(Entire Sample)
+
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
CL

LL PL PI
37 18
SC
19 Checked by TECH Uly P.
16 B-2 Bulk

SYMBOL SAMPLE NAME DEPTH
(ft)
B-5

FIGURE ATTERBERG LIMITS TEST

RESULTS
Costco La Mesa, CA Bldg
Add GEO
19 15
B-1 Bulk
25-Mar-20
Limitations: Pursuant to applicable codes, the results presented in this report are for the exclusive use of the client and the registered design professional in responsible charge. The results apply only to the samples tested. If changes to the specification were made and not communicated to Kleinfelder, Kleinfelder assumes no responsibility for pass/fail statements (meets/did not meet), if provided. This report may not be reproduced, except in full, without written approval of Kleinfelder.

B-3 Bulk SC
1 1
1 34 18
34 PROJECT NO: 20203667.001A
(Minus No. 40
Sieve Fraction)
CL
Date Tested : 3/16/2020 3/19/2020
CL SC
CH
CL

MH & OH

ML&OL CL - ML
0 10
20 30
40 50
60 70
0 10 20 30 40 50 60 70 80 90 100

PLASTICITY INDEX (PI)

LIQUID LIMIT (LL)
Atterberg Limits Page 230 of 585
Boring No. Sample No. Depth
3 4 4
350 160 110

9.5 9.5 9.5
1200 1200 1200
1096.3 1096.3 1096.3
10 30 45

10.4 12.2 13.6

2.5 2.5 2.51
3240.1 3240.7 3242.3
2105.3 2112.5 2113.1
1134.8 1128.2 1129.2
124.7 122.0 120.2
18 43 60
45 114 138

3.01 3.2 3.22
5750 3516 1672
457.8 279.9 133.1
68 24 11
CORRECTED R-VALUE 68 24 11

0.0275 0.0270 0.0254

0.0297 0.0309 0.0278
-0.0022 -0.0039 -0.0024

0.0 0.0 0.0
703.5
642.7

9.5 R-VALUE:

Location:

FIGURE
Checked By: TECH: Uly P.

Job Number: 20203667.001A DATE: 25-Mar-20
1 ft
Date Tested
3/20/2020
Description
Brown clayey sand
B-6
R-Value (ASTM D2844)
Costco La Mesa CA Bldg Add
GEO

INITIAL MOISTURE
28 WEIGHT OF WATER

WEIGHT OF SAMPLE
MOISTURE CONTENT %
Limitations: Pursuant to applicable codes, the results presented in this report are for the exclusive use of the client and the registered design professional in responsible charge. The results apply only to the samples tested. If changes to the specification were made and not communicated to Kleinfelder, Kleinfelder assumes no responsibility for pass/fail statements (meets/did not meet), if provided. This report may not be reproduced, except in full, without written approval of Kleinfelder.

WET WEIGHT, g
DRY WEIGHT, g

DIAL READING, END

DIAL READING, START

DIFFERENCE

EXPANSION PRESSURE, PSF
STABILOMETER, 1000 lbs
2000lbs
DISPLACEMENT, in
EXUDATION LOAD, lbs
EXUDATION PRESSURE, psi

R-VALUE

TEST SPECIMEN
MOLD NO.

FOOT PRESSURE, psi
B-2 Bulk
DRY DENSITY, pcf
INITIAL MOISTURE, %
"AS-IS" WEIGHT, g
DRY WEIGHT, g
WATER ADDED, ml
COMPACTION MOISTURE, %
HEIGHT OF BRIQUETTE, in.

WEIGHT BRIQUETTE/MOLD, g
WEIGHT OF MOLD, g
WEIGHT OF BRIQUETTE, g
0 10
20 30
40 50
60 70
80 90
100
800 700 600 500 400 300 200 100 0

R-VALUE

EXUDATION PRESSURE

Page 231 of 585 ends

20203667.001A/LH20R110080 May 8, 2020
Copyright 2020 Kleinfelder

APPENDIX C
Infiltration BMP Work Sheets

Page 232 of 585 ends

Appendix I: Forms and Checklists
I-10 February 2016
Categorization of Infiltration Feasibility Condition Form I-8 Part 1 - Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
1 Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D.

Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.
2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2.

Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.

Our review of Natural Resources Conservation Service (NRCS) Soil Survey Maps (a.k.a. USDA Soil Maps) indicate the near-surface soils at the percolation test locations are of the Riverwash unit. This material is designated as being of the Hydrologic Soils Group "D" when throughly wet. Additionally, our geotechnical study performed at the site included percolation testing. Percolation tests B-1, B-2, and B-3 indicated unfactored infiltration rates of 0.03, 0.01, and 0.16 inches/hr resulting in an average unfactored infiltration rate of 0.07 inches per hour. The average factored infiltration rate is 0.035 inches per hour using a Safety Factor of 2 from the Storm Water Standards. Therefore, the infiltration rate is not greater than 0.5 inches per hour.

X
X
As discussed in Criteria 1 above, site-specific test results for the percolation test locations indicate an average unfactored infiltration rate of 0.07 inches per hour; therefore, an infiltration rate greater than 0.5 inches per hour is not feasible. Perched groundwater was encountered above the Stadium Conglomerate at a depth of approximately 18 feet below ground surface. Therefore, there is a possibility of groundwater mounding on the relatively impervious Stadium Conglomerate. Additionally, groundwater was encountered at a former Texaco fuel station just north of Fletcher Parkway at depths of 2 to 8 feet below ground surface in 2008.

Page 233 of 585 ends

Appendix I: Forms and Checklists
I-11 February 2016
Form I-8 Page 2 of 4
Criteria Screening Question Yes No
3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3.

Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.
4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3.

Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.

Part 1
Result
*
If all answers to rows 1 - 4 are “Yes” a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration
If any answer from row 1-4 is “No”, infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a “full infiltration” design.

Proceed to Part 2
*To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings

X
Perched groundwater was encountered at a depth of approximately 18 feet below ground surface. Additionally, based on a previous geotechnical report from the current site development, perched water was encountered at the site during grading and groundwater was encountered at 2 to 8 feet below ground surface at a former Texaco fuel facility in 2008.

Additionally, the previous geotechnical report indicates that the Alvarado Stream Channel in the site vicinity was captured in a continuous box culvert. In this respect, the potential for contamination of the local groundwater is considered low.

However, perched groundwater may be present at the site and infiltrating groundwater may result in groundwater mounding as discussed in Criteria 2.

As discussed in Criteria 1 above, site-specific test results for the percolation test locations indicate an average unfactored infiltration rate of 0.07 inches per hour; therefore, an infiltration rate greater than 0.5 inches per hour is not feasible. However, since the nearby Alvarado stream channel is captured in an enclosed box culvert, it may be assumed that there is a low probability of causing a potential water balance issue that would change seasonally ephemeral streams or increased discharged of contaminated groundwater to surface waters. X
NO,
Proceed
to Part 2

Page 234 of 585 ends

Appendix I: Forms and Checklists
I-12 February 2016
Form I-8 Page 3 of 4
Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
5 Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D.

Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2.

Provide basis:

The site conditions at the percolation test locations have been characterized as noted in Criteria 1 to have an average unfactored infiltration rate of 0.07 inches per hour and a factored rate of 0.035 inches per hour using a Factor of 2 from the Storm Water Standards. However, two of our percolation tests (B-1 and B-2) indicated a percolation rate of less than 0.03 inches per hour. Additionally, laboratory testing on the percolation test that indicated a faster percolation rate (B-3) indicates that the soil is similar to the soil encountered in percolation tests B-1 and B-2. Therefore, it is our opinion that the geologic conditions (soil types and depth to bedrock) do not allow for infiltration in an appreciable rate.

X
X
As discussed in Criteria 1 above, it is our opinion that infiltration in any appreciable quantity is not feasble.

Additionally, bedrock (Stadium Conglomerate) was encountered in our borings was and perched groundwater was encountered at approximately 18 feet bgs. Therefore, there is a possibility of groundwater mounding on the relatively impervious Stadium Conglomerate. Additionally, groundwater was encountered at a former Texaco fuel station just north of Fletcher Parkway at depths of 2 to 8 feet below ground surface in 2008. Page 235 of 585 Appendix I: Forms and Checklists
I-13 February 2016
Form I-8 Page 4 of 4
Criteria Screening Question Yes No
7 Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3.

Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3.

Provide basis:

Part 2
Result*
If all answers from row 5-8 are yes then partial infiltration design is potentially feasible.

The feasibility screening category is Partial Infiltration.

If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. *To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings X
X
It may be assumed that there is a low probability of violating downstream water right as the nearby Alvarado stream channel is enclosed in a box culvert.

No
Infiltration
Perched groundwater was encountered at a depth of approximately 18 feet below ground surface. Additionally, based on a previous geotechnical report from the current site development, perched water was encountered at the site during grading and groundwater was encountered at 2 to 8 feet below ground surface at a former Texaco fuel facility in 2008.

However, perched groundwater may be present at the site and infiltrating groundwater may result in groundwater mounding as discussed in Criteria 2.

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Appendix I: Forms and Checklists
I-14 February 2016
Factor of Safety and Design Infiltration Rate
Worksheet Form I-9
Factor Category Factor Description Assigned
Weight (w)
Factor
Value (v)
Product (p)
p = w x v
A Suitability
Assessment
Soil assessment methods 0.25
Predominant soil texture 0.25
Site soil variability 0.25
Depth to groundwater / impervious
layer 0.25
Suitability Assessment Safety Factor, SA = p
B Design
Level of pretreatment/ expected
sediment loads 0.5
Redundancy/resiliency 0.25
Compaction during construction 0.25
Design Safety Factor, SB = p
Combined Safety Factor, Stotal= SA x SB
Observed Infiltration Rate, inch/hr, Kobserved
(corrected for test-specific bias)
Design Infiltration Rate, in/hr, Kdesign = Kobserved / Stotal Supporting Data
Briefly describe infiltration test and provide reference to test forms:

0.03 (B1); 0.01
(B2); 0.16 (B3) 2 0.5 2
1 1

0.25 0.5 0.25 1.5 2
2 2

1.00.5 0.5 2.0 3.0
Not applicable,
No Infiltration
The percolation tests were performed with the existing parking lot at the site. The tests resulted in infiltration rates of 0.03, 0.01, and 0.16 inches per hour at boring locations B-1, B-2, and B-3, respectively. Laboratory testing indicated that the soils associated with the faster percolation rate in B-3 were similar to the soils in the slower percolation tests in B-1 and B-2. Therefore, it is our opinion that the lower infiltration rates (less than 0.03 inches per hour) are representative of the site conditions. Additionally, bedrock (Stadium Conglomerate) underlies the clayey fill soils and perched groundwater was encountered on top of the Stadium Conglomerate during site grading, indicating the bedrock's low capacity to infiltrate water. For these reasons (as discussed on the above Form I-8 worksheets), it is our opinion that the site should be considered "no infiltration."

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United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
San Diego County
Area, California Natural
Resources
Conservation
Service

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Preface
Soil surveys contain information that affects land use planning in survey areas.

They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers.

Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment.

Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions.

The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations.

Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951).

Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations.

The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey.

Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2

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alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.
3

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Contents
Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map.................................................................................................................. 8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................ 11 Map Unit Descriptions.........................................................................................11 San Diego County Area, California.................................................................13 RhC—Redding-Urban land complex, 2 to 9 percent slopes........................13 RhE—Redding-Urban land complex, 9 to 30 percent slopes......................14 Rm—Riverwash.......................................................................................... 15 References............................................................................................................17 4

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How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity.

Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA.

The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape.

Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries.

Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units).

Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5

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scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research.

The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas.

Soil scientists make many field observations in the process of producing a soil map.

The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded.

These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape.

Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties.

While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management.

Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil.

Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date.

After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report
6

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identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately.

Custom Soil Resource Report
7

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Soil Map
The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8

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9 Custom Soil Resource Report
Soil Map
3626180 3626240 3626300 3626360 3626420 3626480 3626540 3626180 3626240 3626300 3626360 3626420 3626480 3626540 497590 497650 497710 497770 497830 497890 497950 498010 498070 498130 498190 498250 498310 497590 497650 497710 497770 497830 497890 497950 498010 498070 498130 498190 498250 498310 32° 46' 37'' N
117° 1' 33'' W
32° 46' 37'' N
117° 1' 4'' W
32° 46' 23'' N
117° 1' 33'' W
32° 46' 23'' N N 117° 1' 4'' W
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 50 100 200 300
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,040 if printed on B landscape (17" x 11") sheet.

Soil Map may not be valid at this scale.

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MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map
measurements.

Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 12, Sep 13, 2017
Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 7, 2014—Jan 4, 2015
The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Custom Soil Resource Report
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Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI RhC Redding-Urban land complex, 2
to 9 percent slopes

6.0 16.7%
RhE Redding-Urban land complex, 9
to 30 percent slopes

12.3 34.2%
Rm Riverwash 17.7 49.2%
Totals for Area of Interest 36.0 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit.

A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class.

Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils.

Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape.

The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The Custom Soil Resource Report
11 Page 249 of 585
delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas.

An identifying symbol precedes the map unit name in the map unit descriptions.

Each description includes general facts about the unit and gives important soil properties and qualities.

Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement.

Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.

Some map units are made up of two or more major soils or miscellaneous areas.

These map units are complexes, associations, or undifferentiated groups.

A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps.

The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.

An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.

An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.

Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example.

Custom Soil Resource Report
12 Page 250 of 585
San Diego County Area, California
RhC—Redding-Urban land complex, 2 to 9 percent slopes
Map Unit Setting
National map unit symbol: hbg1
Elevation: 100 to 1,500 feet
Mean annual precipitation: 14 to 25 inches
Mean annual air temperature: 61 to 63 degrees F
Frost-free period: 230 to 320 days
Farmland classification: Not prime farmland
Map Unit Composition
Redding and similar soils: 50 percent
Urban land: 30 percent
Minor components: 5 percent
Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Redding
Setting
Landform: Marine terraces
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Alluvium derived from mixed sources
Typical profile
H1 - 0 to 15 inches: gravelly loam
H2 - 15 to 30 inches: gravelly clay loam, gravelly clay H2 - 15 to 30 inches: indurated
H3 - 30 to 45 inches:

Properties and qualities
Slope: 2 to 9 percent
Depth to restrictive feature: About 15 inches to abrupt textural change; 20 to 45 inches to duripan
Natural drainage class: Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Very low (about 1.8 inches) Interpretive groups
Land capability classification (irrigated): 6e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: D
Hydric soil rating: No
Description of Urban Land
Typical profile
H1 - 0 to 6 inches: variable
Custom Soil Resource Report
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Interpretive groups
Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8
Hydric soil rating: No
Minor Components
Oliventain
Percent of map unit: 5 percent
Hydric soil rating: No
RhE—Redding-Urban land complex, 9 to 30 percent slopes
Map Unit Setting
National map unit symbol: hbg2
Elevation: 100 to 1,500 feet
Mean annual precipitation: 14 to 25 inches
Mean annual air temperature: 61 to 63 degrees F
Frost-free period: 230 to 320 days
Farmland classification: Not prime farmland
Map Unit Composition
Redding and similar soils: 50 percent
Urban land: 30 percent
Minor components: 5 percent
Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Redding
Setting
Landform: Marine terraces
Down-slope shape: Concave
Across-slope shape: Linear
Parent material: Alluvium derived from mixed sources
Typical profile
H1 - 0 to 15 inches: gravelly loam
H2 - 15 to 30 inches: gravelly clay loam, gravelly clay H2 - 15 to 30 inches: indurated
H3 - 30 to 45 inches:

Properties and qualities
Slope: 9 to 30 percent
Depth to restrictive feature: About 15 inches to abrupt textural change; 20 to 40 inches to duripan
Natural drainage class: Well drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr)
Custom Soil Resource Report
14 Page 252 of 585
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Very low (about 1.8 inches) Interpretive groups
Land capability classification (irrigated): 6e
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: D
Hydric soil rating: No
Description of Urban Land
Typical profile
H1 - 0 to 6 inches: variable
Interpretive groups
Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8
Hydric soil rating: No
Minor Components
Oliventain
Percent of map unit: 5 percent
Hydric soil rating: No
Rm—Riverwash
Map Unit Setting
National map unit symbol: hbg6
Elevation: 700 to 2,900 feet
Mean annual precipitation: 8 to 15 inches
Mean annual air temperature: 46 to 52 degrees F
Frost-free period: 110 to 180 days
Farmland classification: Not prime farmland
Map Unit Composition
Riverwash: 100 percent
Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Riverwash
Setting
Landform: Drainageways
Parent material: Sandy, gravelly, or cobbly alluvium derived from mixed sources Typical profile
H1 - 0 to 6 inches: gravelly coarse sand
H2 - 6 to 60 inches: stratified extremely gravelly coarse sand to gravelly sand Custom Soil Resource Report
15 Page 253 of 585
Properties and qualities
Slope: 0 to 4 percent
Natural drainage class: Excessively drained
Runoff class: Negligible
Capacity of the most limiting layer to transmit water (Ksat): High to very high (5.95 to 19.98 in/hr)
Depth to water table: About 60 to 72 inches
Frequency of flooding: Occasional
Available water storage in profile: Very low (about 1.9 inches) Interpretive groups
Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8
Hydrologic Soil Group: D
Hydric soil rating: Yes
Custom Soil Resource Report
16 Page 254 of 585
References
American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition.

American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00.

Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31.

Federal Register. July 13, 1994. Changes in hydric soils of the United States.

Federal Register. September 18, 2002. Hydric soils of the United States.

Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States.

National Research Council. 1995. Wetlands: Characteristics and boundaries.

Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.

U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section.

United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1.

United States Department of Agriculture, Natural Resources Conservation Service.

National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.

National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 17 Page 255 of 585
United States Department of Agriculture, Natural Resources Conservation Service.

National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report
18 Page 256 of 585

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Attachment C
Storm Water Quality Management Plan

Page 258 of 585 ends

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STORM WATER QUALITY MANAGEMENT PLAN

PREPARED FOR

COSTCO LA MESA
8125 FLETCHER PARKWAY
LA MESA, CA 91942
FUSCOE ENGINEERING, INC.
6390 GREENWICH DR. STE: 170
SAN DIEGO, CA 92122
BRYAN D. SMITH P.E.

PROJECT MANAGER

DATE PREPARED: JUNE 2021
REVISED: OCTOBER 2022
JOB#: 756-061 Page 260 of 585
County of San Diego
Stormwater Quality Management Plan (SWQMP)
For Priority Development Projects (PDPs)
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Approval Date

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COSTCO LA MESA - BUILDING ADDITION 8125 FLETCHER PARKWAY, LA MESA, CA 91942 464-600-15 & 464-600-26 X BRYAN D. SMITH – FUSCOE ENGINEERING, INC. 6390 GREENWICH DRIVE, STE 170, SAN DIEGO 92122 858.554.1500 [email protected] BRYAN D. SMITH BRYAN D. SMITH – FUSCOE ENGINEERING, INC. 6390 GREENWICH DRIVE, STE 170, SAN DIEGO 92122 858.554.1500 [email protected] RCE 75822 09/30/2021 10/04/2022

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(1) Elements addressed in current submittal (streets, common areas, first project phase, etc.):

(2) Elements to be addressed in future submittal(s) (individual lots, future project phases, etc.)

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3 Initial Submittal
Initial Submittal
Final Design
Plan Changes
X
06/23/2021 09/30/2021 09/30/2021 12/07/2021
Project has been revised for a phased project, and this SWQMP Covers Phase 1 (Phase 2 will require future amendment) 8/4/2022
This SWQMP was approved for Phase 1 Building Permit under Permit No B22-051. This revised SWQMP presents minor modifications to the Phase 2 design to incorporate minor site modifications for refrigeration equipment 10/4/2022 This SWQMP was approved for Phase 1 Building Permit under Permit No B22-051. This revised SWQMP presents minor modifications to the Phase 2 design to incorporate minor site modifications for refrigeration equipment

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Template Date: September 15, 2020
PDP SWQMP Page | i
General Directions
Note: These directions may be omitted from the print version of the SWQMP submittal. c Scope of SWQMP Submittal and Submittal Record (inside front cover) Use the Submittal Scope table to document the scope of activities covered under this SWQMP Form. Select one of the three options presented.
x SWQMP addresses the entire project. If this SWQMP form addresses the entire project from start to finish, additional documentation of the project scope is not required. x SWQMP implements requirements of an earlier master SWQMP submittal. If this SWQMP Form implements requirements identified in an earlier master SWQMP Form, documentation of those earlier requirements must be provided. Include a copy of the previous submittal as Attachment 4.
x First of multiple SWQMP submittals. If this is the first of multiple SWQMP submittals, use the spaces provided under Part c to identify and briefly describe which project elements are addressed in this submittal and which ones will be addressed in future submittals. For example, this PDP addresses only streets and roads, but individual lots will be documented in future submittals.

Use the Submittal Record table to list the dates of any updates to the SWQMP or construction plans.

Briefly describe key changes from previous versions. If responding to plan check comments, note this in the entry and attach the responses as applicable.
d PDP SWQMP Submittal Checklist
The checklist on Page 1 summarizes the tables and attachments to be included with this PDP SWQMP submittal. It should be filled out after completing the remainder of the form. Tables and attachments with boxes already checked (_) are required for all projects. All tables are required. The applicability of attachments not already checked will be identified during the completion of this form. e Attachment 1: Stormwater Intake Form
Submit a copy of your completed Storm Water Intake Form as Attachment 1. f Tables 1, 2, and 3: Baseline Site Design and Source Control BMPs Table 1 Completion: Complete Table 1 to document existing and proposed site features and the BMPs to be implemented for them. All BMPs must be implemented where applicable and feasible. Applicability is generally assumed if a feature exists or is proposed.

Table 2 Completion: Table 2 is not required for Small Residential Projects. Applicants should check the box at the top of the table to confirm it does not apply.

Small Residential Projects are those requiring either: a Building Permit, Minor Residential Grading Permit, or Site Plan Permit for a single family home; or a Tentative Parcel Map Permit for up to 4 single family homes and a remainder parcel.

All other projects must complete Table 2 to identify applicable requirements for documenting pollutantgenerating sources/ features and source control BMPs.

BMPs must be implemented for Table 1 and 2 features where feasible. Leaving the box for a BMP unchecked means it will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided in Table 3. Tables 1 and 2 both provide specific instructions on when explanations are required.

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PDP SWQMP Page | ii
g Attachment 5: Existing Site and Drainage Description
Complete Attachment 5 to provide a description of (1) the existing pre-development condition of the site, and (2) existing and proposed drainage conditions for the site. If required, include a copy of the site Drainage Study with Attachment 5.
h Structural Performance Standards
Determine which Structural Performance Standards apply to the PDP, where they apply, and which compliance strategies you will use to satisfy them. Record your selections in Table 4 as follows.

Table 4, Part A.1, Selection of Standards: First select the standards that apply to the project. x Pollutant control plus
hydromodification Select if the PDP is not exempt from hydromodification management requirements. It must satisfy both the Pollutant Control Performance Standard (BMPDM Section 2.2) and the Hydromodification Management Performance Standard (BMPDM Section 2.3).
x Pollutant control only Select if the PDP is exempt from hydromodification management requirements per BMPDM Section 6.1. Document the exemption in Attachment 9.

Table 4, Part A.2, Application of Standards: Next indicate where on the site the standards apply. x If this is a New Development Project, the standards apply to all impervious surfaces on the site. x If this is a Redevelopment Project, their applicability will depend on the ratio of created or replaced impervious areas to existing impervious areas (see BMPDM Section 1.7). Complete the calculations in the table to determine your obligation. The percent (%) impervious created or replaced (c) is determined by dividing the impervious area created or replaced (b) by the existing impervious area (a) and multiplying the result by 100.
o If c is 50% or more: The standards apply to all impervious surfaces on the site (a + b). o If c is less than 50%: The standards apply only to created or replaced impervious surfaces (b only).

Table 4, Part B.1: Summary of Required Attachments (1 through 5) Use this part of the table to summarize which of Attachments 1 through 5 will be included with the SWQMP submittal. If you are completing an electronic version of this form, your selections will be automatically recorded based on your previous input. If you are completing a hard copy of this form, you must manually select Attachments 3 and 4 as applicable (see pages 4 and 6). Note that Attachments 1,2, and 5 are required for all projects.

Table 4, Part B.2: Selection of Compliance Strategies
Complete Part B.2 to document which compliance options will be used to satisfy the applicable standards for the site. Before doing so, you must determine which option will be used for each DMA. The following four potential design options are presented in detail in BMPDM Chapters 5 and 6.

1. Self-mitigating DMAs (BMPDM Section 5.2.1)

2. De Minimis DMAs (BMPDM Section 5.2.2)

3. Self-retaining DMAs (BMPDM Section 5.2.3)

4. Structural BMPs
o Pollutant Control BMPs (BMPDM Sections 5.4)
o Hydromodification BMPs (BMPDM Chapter 6)
o Alternative Compliance Project (BMPDM Section 1.8)
Only one compliance option may be used per individual DMA. Regardless of which option is selected for any DMA, it must fully satisfy the applicable standard(s) determined in Part A.1.

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Template Date: September 15, 2020
PDP SWQMP Page | iii
On the left side of Part B, check the applicable boxes for each compliance option to be used. i Summary of Additional Required Attachments (6 through 12) You must complete and submit each attachment identified for the compliance options selected. Applicable attachments are listed to the right of each compliance option. If you are completing an electronic version of this form, the required attachments for each design option will automatically be selected when you choose the compliance option. As noted above, these selections will also be recorded on the PDP SWQMP Submittal Checklist (Page 1). If you are completing a hard copy of this form, you will need to manually check the boxes for each applicable attachment on both pages.

Note that Attachment 9 (Critical Coarse Sediment Yield Areas) is required for all PDPs. If the PDP is exempt from hydromodification requirements, the exemption must be documented in Attachment 9. j Table 5: Critical Coarse Sediment Yield Area Requirements Complete Table 5 to select a compliance pathway for addressing Critical Coarse Sediment Yield Area (CCSYA) requirements for the PDP. See BMPDM Appendix H for additional description of requirements and options. Document Table 5 selections, including hydromodification management exemptions, in Attachment 9.
k Tables 6 and 7: Temporary Construction Phase BMPs
Complete Table 6 to document the minimum construction BMPs to be implemented for the project. Each BMP must be implemented where applicable and feasible. At least one BMP must be selected for each construction activity listed in the table (except Erosion Control for Disturbed Slopes, which requires one BMP per season).

If applicable, use Table 7 to describe why BMPs not selected in Table 6 are either infeasible or are only partially feasible. Justifications must be provided for all construction activity types for which NO BMPs were selected. If requested by County staff, also justify why specific individual BMPs were not selected. l Attachment 2: DMA Exhibits and Construction Plans
Exhibits and construction plan sets incorporating all applicable site features, activities, and BMPs identified in Tables 1, 2, and 6 must be submitted as Attachment 2 (DMA Exhibits and Construction Plan Sheets). See the Attachment 2 cover sheet for additional instructions.

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feature on the site.

2. Select the BMPs to be implemented for each identified feature.

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2. Select the BMPs to be implemented for each proposed feature. If neither BMP SD-B nor SD-I is selected for a feature, explain why both BMPs are infeasible in Table 3.

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*The Phase 1 (Building Permit) condition of the project only includes repaving/ grind & overlay of parking stalls for ADA compliance, reconstruction of concrete apron, and other minor site improvements under the Building Permit.

See Attachment 2 Exhibit for clarification of scope.

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Template Date: September 15, 2020 Preparation Date:

PDP SWQMP Page | 3
Table 2 – Baseline BMPs for Pollutant-generating Sources ☐ If this is a Small Residential Project, check this box and skip the rest of this table.

A. Management of Stormwater Discharges

1. Identify all proposed outdoor
work areas below

2. Which BMPs will be used to prevent
materials from contacting rainfall or runoff?
(See Fact Sheet BL-5)

3. Where will runoff from the work area be routed?
(See Fact Sheet BL-6)
(☐ Check here if none are proposed) (Select all feasible BMPs for each work area2) (Select one or more option for each work area) Overhead
covering (rooftops, etc.)
(SC-A)
Separation of flows from
adjacent areas (berms, etc.)
(SC-B)
Wind
protection (screens, etc.)
(SC-C)
Sanitary
sewer3
(SC-D)
Containment
system
(SC-E)
Stormwater
S-BMP or SSDBMP4 Other5
☐ Trash & Refuse Storage ☐ ☐ ☐ ☐ ☐ ☐ ☐☐ Materials & Equipment Storage ☐ ☐ ☐ ☐ ☐ ☐ ☐☐ Loading & Unloading ☐ ☐ --- ☐ ☐ ☐ ☐☐ Fueling ☐ ☐ --- ☐ ☐ ☐ ☐☐ Maintenance & Repair ☐ ☐ --- ☐ ☐ ☐ ☐☐ Vehicle & Equipment Cleaning ☐ ☐ --- ☐ ☐ ☐ ☐☐ Other: ☐ ☐ --- ☐ ☐ ☐ ☐ B. Prevention of Non-stormwater Discharges (See Fact Sheet BL-7)Select one option for each feature below:
• Storm drain inlets and catch basins … ☐ are not proposed ☐ will be labeled with stenciling or signage to discourage dumping (SC-F)• Educational BMP Signage … ☐ are not proposed ☐ will be labeled with educational signage for BMP (SC-G)• Interior work surfaces, floor drains, & sumps … ☐ are not proposed ☐ will not discharge directly or indirectly to the MS4 or receiving waters• Drain lines (e.g., air conditioning, boiler, etc.) … ☐ are not proposed ☐ will not discharge directly or indirectly to the MS4 or receiving waters• Fire sprinkler test water … ☐ are not proposed ☐ will not discharge directly or indirectly to the MS4 or receiving waters Note: All outdoor features and BMPs in this table must be shown on applicable construction plans. See applicable Fact Sheets in Appendix C of the BMP Design Manual for additional information. Note: Use Table 3 to explain BMP infeasibility or inapplicability, or to describe features or BMPs not listed in this table. Additional explanation may be required by the County. 2 Each BMP is required where feasible. If none are selected for any feature, explain why they are infeasible in Table 3.3 Separate wastewater agency approvals may be required.4 Structural Treatment Control BMPs (S-BMPs) and Significant Site Design BMPs (SSD-BMPs) may not receive discharges from work areas that concentrate pollutants in a manner that will impair their functioning. Discharges from the proposed work area must also be included in DCV calculations for the applicable BMP.
5 Describe other proposed options for managing stormwater discharges in Table 3.

X X XXXX 09/30/2021

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Not feasible due to existing site conditions. An area swap of existing impervious will be treated for the equivalent area not being treated.

Sidewalks and
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Not feasible due to existing site conditions. An area swap of existing impervious will be treated for the equivalent area not being treated. 09/30/2021

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Template Date: September 15, 2020 Preparation Date:

PDP SWQMP Page | 5
Table 4: DMA Structural Compliance Strategies and DocumentationPart A – Selection and Application Structural Performance Standards1. Selection of Standards (select one; see BMPDM Section 6.1)☐ a. Pollutant control + hydromodification ☐ b. Pollutant control only (project is exempt from hydromodification requirements)2. Application of Structural Performance Standards (select one; see BMPDM Section 1.7)☐ New Development Projects: Standards apply to all impervious surfaces.☐ Redevelopment Projects: Complete the calculations below. Select the applicable scenario based on the results. a. Existing impervious area (ft2) b. Impervious area created / replaced (ft2) c. % Impervious created / replaced [(b/a)*100] ☐ Scenario 1: c is 50% or more: Performance standards apply to all impervious surfaces (a + b). ☐ Scenario 2: c is less than 50%: Performance standards apply only to created or replaced impervious surfaces (b only).

Part B – Compliance Strategies and Required Attachments1.Complete and submit each of the applicable attachments on the right.

Att. 1 Att. 2 Att. 3 Att. 4 Att. 5
Storm Water Intake
Form
DMA Exhibits and
Construction Plan
Sheets
N/A
Previous SWQMP
Submittals
(see inside cover)
Existing Site and
Drainage Description
  ☐ ☐ 

2. Indicate each compliance strategy below that will be used for one or more DMAs on the site.

Att. 6 Att. 7 Att. 8 Att. 9 Att. 10 Att. 11 Att. 12
DMAs
without
Structural
BMPs
DMAs w/
Structural
Pollutant
Control
BMPs
DMAs w/
Structural
Hydromod.

BMPs
Critical
Coarse
Sediment
Yield
Areas
BMP
Installation
Verification
Form
Maintenance Agreements/
Plans
Alternative
Compliance
Projects
Self-mitigating DMAs (BMPDM Section 5.2.1) De Minimis DMAs (BMPDM Section 5.2.2) Self-retaining DMAs (BMPDM Section 5.2.3) Structural BMPs (select all that apply)
Pollutant Control BMPs (BMPDM Section 5.4)
Hydromodification Control BMPs (BMPDM Chapter 6)Alternative Compliance Project (BMPDM Section 1.8) • Attachments 1, 2, and 5 are required for all projects.

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Rev 06/2016
“APPENDIX A” STORM WATER APPLICABILITY CHECKLIST

PUBLIC WORKS DEPARTMENT / ENGINEERING DIVISION
8130 Allison Avenue, La Mesa, CA 91942
Phone: 619.667.1166 • Fax: 619.667.1380
PROJECT DATA:

Owner’s Name & Phone No: .

Address: Permit No: .

Project: Date Applied: ___ .

PROJECT SITE DATA:

1. Area of the lot/parcel = sf

2. Existing impervious area = sf

3. Impervious area after development = sf

4. Total area to be disturbed = sf
a. Total disturbed area includes impervious area, construction material storage, staging area, graded slopes, new slopes and landscape areas.

Notes:
 The applicant may be required to submit WQTR or Standard LID Plan depending on the “Priority” as stated below.
 A Hydrology report may be required.

STORM WATER REQUIREMENTS APPLICABILITY CHECKLIST
Complete the checklist to determine which permanent best management practices (BMPs) and which construction BMPs are required for your project for storm water. This form must be completed and submitted with your permit application.

PROJECT DETERMINATION CHECKLIST
Yes No

1. Is the project a new development that creates 10,000 square feet or more of impervious surface (collectively over the entire project site).

2. Is the project a redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site which has 10,000 square feet or more impervious surface).

Diana Salazar, Costco Wholesale (714) 978-5026
8125 FLETCHER PKWY
16,371 SF addition to the northwest corner of the warehouse

14.26 acres
X
X

12.01 acres *0.86 acres *11.96 acres
*Signifies the Ultimate Condition of the Project, which includes both Phases 1 & 2, see Attachment 2 Exhibits for clarification of scope. **12.01 acres
*0.34 ac Phase 1 + 0.52ac Phase 2 17,749sf of total building addition

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Rev 06/2016

3. New and redevelopment projects that creates and/or replaces 5,000 square feet or more of impervious surface (collectively over the entire project site), and supports one or more of the following uses.
 Restaurants, including lunch counters, food stands, and SIC Code 5812.  Hillside Development Projects. This includes development on any natural slope 25% or greater.
 Parking lots
 Streets, roads, highways, freeways, and driveways.

4. New or redevelopment projects that create or replace 2,500 square feet or more of impervious surface (collectively over the entire project site), and discharging directly to an Environmentally Sensitive Area (ESA). “Discharging directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands.) Note: ESAs are all 303(d) water bodies, ASBS, water bodies designated with the RARE beneficial use, and any other designated by the Copermitees.

5. New development projects or redevelopment projects that create and or replace 500 square feet or more of impervious surface, that support one or more of the following uses:
 Automotive Repair Shops. SIC codes 5013, 5014, 5541, 7532‐7534, 7536‐ 7539.
 Retail gasoline outlets 5,000 square feet or more, or a projected Average Daily Traffic of 100 or more vehicles per day.

6. New or redevelopment projects that result in the disturbance or one or more acres of land and are expected to generate pollutants post construction.  If any of the boxes above are checked “yes”, a WQTR must be prepared.  If all of the boxes above are checked “no” and the project includes any outdoor work and exposure to rainfall, a Standard LID Plan Sheet must be completed.

CONSTRUCTION STORM WATER BMP REQUIREMENTS:

WOULD THE PROJECT MEET ANY OF THESE CRITERIA DURING CONSTRUCTION? Yes No

1. Does the project proposed grading or soil disturbance over one acre?

2. Does the project propose any grading or soil disturbance?

3. Would storm water or urban runoff have the potential to contact any portion of the construction area, including washing and staging areas?

4. Would the project use any construction materials that could negatively affect water quality if discharged from the site (such as paints, solvents, concrete and stucco)? If the answer to question 1 is answered “Yes,” your project is subject to California’s statewide General NPDES Permit for Storm Water Discharges Associated with Construction Activities and the City’s Construction Storm Water BMP Performance Standards. A Storm Water Pollution Prevention Plan (SWPPP) and Notice of Intent to enroll in the General Construction Permit must be prepared. Parts D and E of this form must also be completed.

If the answer to question 1 is “No,” but the answer to any of the remaining questions is “Yes,” your project is subject to Construction Storm Water BMP Performance Standards and a Construction Storm Water Management Plan (CSWMP) must be prepared and Part E of this form must be completed.

X
X
X
X
X
X
X
X

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Rev 06/2016
If every question is answered “No,” you do not need to completed the rest of this form and neither a SWPPP nor a CSWMP is required.

DETERMINE ADVANCE TREATMENT SUBJECTIVITY
WOULD THE PROJECT MEET ANY OF THESE CRITERIA DURING CONSTRUCTION? Yes No

1. Is the project located within, adjacent to, or a portion of the site within 200 feet of waters listed on the CWA Section 303(d) list of Water Quality Limited Segments as impaired for sedimentation or turbidity?

2. Will the project disturb more than five acres, including all phases of the development?
If the answers to 1 and 2 are both “yes”, please answer questions 3 and 4 below.

3. Will the project disturbed slopes steeper than 4:1 (horizontal: vertical) and higher than 10 feet that drain toward the 303(d) listed receiving water?

4. Does the project contain a predominance of soils with USDA‐NRCS Erosion factors kf greater than or equal to 0.4?
If all answers are “yes”, the project is subject to the City’s advanced treatment requirements for construction. Note that even if the above criteria do not apply, advanced treatment may be required at the discretion of the City Engineer based.

Required submittals, Section 2: □SWPPP, NOI □CSWMP □Advanced Treatment

DETERMINE CONSTRUCTION SITE PRIORITY
In accordance with the Municipal Permit, each construction site with construction storm water BMP requirements must be designated with a priority: high, medium or low. This prioritization must be completed with this form, noted on the plans and included in the SWPPP or CSWMP. See the attached flow chart for guidance on determining the construction prioritization. The City Engineer may adjust the priority of the projects both before and during construction.

X
X
X

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Rev 06/2016
According to the attached flow chart this project has the following threat to water quality priority:

A) High Priority B) Medium Priority C) Low Priority [Note: The construction priority DOES NOT change construction BMP requirements that apply to projects; all construction BMP requirements must be identified on a case‐by‐case basis. The construction priority DOES affect the frequency of inspections that will be conducted by the City.] Completed By:

Name, Address & Phone Number
X
Fuscoe Engineering
6390 Greenwich Drive, San Diego, 92122
8585541500

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County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 2: DMA Exhibits and Construction Plans
County of San Diego SWQMP Attachment 2 Page 2.0-1
Template Date: January 16, 2019 Preparation Date: 6/23/2021

2.0 General Requirements
• Attachment 2 consolidates exhibits and plans required for the entire project. • Complete the table below to indicate which sub-attachments are included with the submittal.

Sub-attachments that are not applicable can be excluded from the submittal. • Unless otherwise stated, features and BMPs identified and described in each corresponding Attachment (6 through 9) must be shown on applicable DMA Exhibits and construction plans submitted for the project.

Sub-attachments Requirement
☒ 2.1: DMA Exhibits All PDPs
☐ 2.2: Individual Structural BMP DMA Mapbook PDPs with structural BMPs ☒ 2.3: Construction Plan Sets All projects
09/30/2021

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County of San Diego SWQMP Sub-attachment 2.1 (DMA Exhibits) Page 2.1-2 Template Date: January 16, 2019 Preparation Date: 6/23/2021

2.1 DMA Exhibits
• DMA Exhibits must show all DMAs on the project site. Exhibits must include all applicable features identified in applicable SWQMP attachments.
• Exhibits may be prepared individually for the BMPs associated with each applicable SWQMP Attachment (6, 7, 8, and/or 9) or combined into one or more consolidated exhibits. • Use this checklist to ensure required information is included on each exhibit (copy as needed).

DMA Exhibit ID #: Attachment 2 – DMA Exhibit and DMA Details A. Features required for all exhibits

1. Existing Site Features
☒ Underlying hydrologic soil group (A, B, C, D)
☒ Approximate depth to groundwater
☒ Natural hydrologic features
☒ Topography and impervious areas
☒ Existing drainage network, directions,
and offsite connections

2. Drainage Management Area (DMA) Information
☐ Proposed drainage network, directions, and
offsite connections
☒ DMA boundaries, ID numbers, areas,
and type (structural BMP, de minimis,
etc.)

3. Proposed Site Changes, Features, and BMPs
☐ Proposed demolition and grading
☐ Group 1, 2, and 3 Features1
☐ Group 4 Features
☐ Construction BMPs2
☐ Baseline source control BMPs
☐ Baseline source control BMPs
B. Proposed Features and BMPs Specific to Individual SWQMP Attachments3 ☐ Attachment 6 ☐ SSD-BMP impervious dispersion areas
☐ SSD-BMP tree wells
☒ Attachment 7 ☒ Structural pollutant control BMPs
☒ Attachment 8 ☒ Structural hydromodification management BMPs ☒ Point(s) of Compliance (POC) for hydromodification management ☒ Proposed drainage boundary and drainage area to each POC ☒ Attachment 9 ☐ Onsite CCSYAs ☐ Bypass of onsite CCSYAs ☐ Bypass of upstream offsite CCSYAs
1 Group 1-4 features and baseline BMPs from PDP SWQMP Tables 2 and 3. 2 Minimum Construction Stormwater BMPs from PDP SWQMP Table 7. 3 Identify the location, ID numbers, type, and size/detail of BMPs. 09/30/2021

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VAN VAN VAN VAN DMA 3B DMA 4 FLETCHER PARKWAY DMA 3C DMA 3A BMP 2 MWS L-4-4-V CONTROL STRUCTURE ORIFICE: 0.50" HMP 2 STORMTECH SC-310 3 ROWS REFER TO SITE CONSTRAINTS EXHIBIT ON SHEET 3 DMA 3D COSTCO LA MESA BUILDING ADDITION ATTACHMENT 2: PHASE 1 - DMA EXHIBIT (APPROVED PER BUILDING PERMIT NUMBER B22-051) JOB NO. E N G I N E E R I N G 6390 Greenwich Dr., Suite 170 San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com DRAWN BY: SHEET 1 of 4 LEGEND DMA 1 POC #1 DMA SUMMARY TABLE HMP SUMMARY TABLE PERMANENT STORM WATER BMP NOTES PROJECT SITE INFO SOURCE CONTROL BMPs MWS 4-6.5 BMP SUMMARY TABLE Page 280 of 585

Page 281 of 585 ends

VAN VAN VAN VAN DMA 3B DMA 4 FLETCHER PARKWAY DMA 1 DMA 3C DMA 3A POC 1 BMP 1 CONTROL STRUCTURE ORIFICE: 0.625" BMP 1 BMP 2 MWS L-4-4-V CONTROL STRUCTURE ORIFICE: 0.50" HMP 2 STORMTECH SC-310 3 ROWS POC 1 REFER TO SITE CONSTRAINTS EXHIBIT ON SHEET 3 DMA 3D DMA 2 DMA 5 PHASE 1 PER PERMIT #B22-051 PHASE 2 PHASE 2 NOTE: THE CONCRETE PROPOSED IN THIS AREA IS OVER EXISTING AC PAVEMENT TO REMAIN AND IS NOT INCLUDED IN THE DISTURBED AREA. COSTCO LA MESA BUILDING ADDITION ATTACHMENT 2: ULTIMATE CONDITION DMA EXHIBIT JOB NO. E N G I N E E R I N G 6390 Greenwich Dr., Suite 170 San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com DRAWN BY: SHEET2 of 4 LEGEND BMP 1 DMA 1 POC #1 DMA SUMMARY TABLE HMP SUMMARY TABLE PERMANENT STORM WATER BMP NOTES PROJECT SITE INFO SOURCE CONTROL BMPs MWS 4-6.5 BMP SUMMARY TABLE Page 282 of 585

Page 283 of 585 ends

COSTCO LA MESA BUILDING ADDITION ATTACHMENT 2: DMA EXHIBIT DETAILSJOB NO. E N G I N E E R I N G 6390 Greenwich Dr., Suite 170 San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com DRAWN BY: SHEET3 of 4 BMP 1 - BIO)ILTRATION PLANTER BMP 2 - MODULAR WETLAND SYSTEM HMP 2 - UNDERGROUND DETENTION SYSTEM DETAIL - BMP 1 BIORETENTION )LOW CONTROL STRUCTURE PHASE 2 (PHASE 1 PER PERMIT #B22-051) (PHASE 1 PER PERMIT #B22-051) COSTCO Page 284 of 585

Page 285 of 585 ends

VAN VAN VAN VAN DMA 3B DMA 4 FLETCHER PARKWAY DMA 1 DMA 3C DMA 3A POC 1 BMP 1 CONTROL STRUCTURE ORIFICE: 0.625" BMP 1 BMP 2 MWS L-4-4-V CONTROL STRUCTURE ORIFICE: 0.50" HMP 2 STORMTECH SC-310 3 ROWS POC 1 REFER TO SITE CONSTRAINTS EXHIBIT ON SHEET 3 DMA 3D DMA 2 DMA 5 PHASE 1 PER PERMIT #B22-051 PHASE 2 PHASE 2 NOTE: THE CONCRETE PROPOSED IN THIS AREA IS OVER EXISTING AC PAVEMENT TO REMAIN AND IS NOT INCLUDED IN THE DISTURBED AREA. COSTCO LA MESA BUILDING ADDITION ATTACHMENT 2: EXISTING SITE CONSTRAINTS JOB NO. E N G I N E E R I N G 6390 Greenwich Dr., Suite 170 San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com DRAWN BY: SHEET4 of 4 LEGEND Page 286 of 585

Page 287 of 585 ends

County of San Diego SWQMP Sub-attachment 2.2 (DMA Mapbook) Page 2.2-1 Template Date: January 16, 2019 Preparation Date: 6/23/2021

2.2 Individual Structural BMP DMA Mapbook
• Use this page as a cover sheet for the Structural DMA Mapbook. • An individual Structural DMA Mapbook must be submitted for any project site with one or more structural BMPs. One Mapbook is required for each unique subsequent owner with responsibility for maintenance of a Structural BMP. Mapbook exhibits will be incorporated as exhibits in Stormwater Maintenance Agreements (SWMAs) and Maintenance Notifications (MNs). See Attachment 11 for additional information on maintenance agreements. If the Mapbook has been provided for each subsequent owner in Attachment 11, they are not required here. • Place each map on 8.5”x11” paper.
• Show at a minimum the DMA, Structural BMP, Assessor’s parcel boundaries with parcel numbers, and any existing hydrologic features within the DMA.
☐ All Mapbooks are attached
☒ All Mapbooks are in Attachment 11
09/30/2021

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County of San Diego SWQMP Sub-attachment 2.3 (Construction Plans) Page 2.3-1 Template Date: January 16, 2019 Preparation Date: 6/23/2021

2.3 Construction Plan Sets
• DMAs, features, and BMPs identified and described in this attachment must also be shown on all applicable construction and landscape plans.
• As applicable, plan sheets must identify:
o All features and BMPs identified in Sub-attachment 2.1 (DMA Exhibits). o The additional information listed below.
• Use this checklist to ensure required information is included on each plan (copy as needed).

Plan Type Conceptual Grading Plan Set
Required Information4
☒ Structural BMP(s) and Significant Site Design BMPs (if applicable) with ID numbers. ☒ The grading and drainage design shown on the plans must be consistent with the delineation of DMAs shown on the DMA exhibit.
☒ Details and specifications for construction of Structural BMP(s) and Significant Site Design BMPs (if applicable).
☒ Signage indicating the location and boundary of structural BMP(s) as required by County staff. ☒ How to access the structural BMP(s) to inspect and perform maintenance. ☒ Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds).
☒ Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP).
☒ Recommended equipment to perform maintenance.
☒ When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management. ☒ Include landscaping plan sheets (if available) showing vegetation requirements for vegetated structural BMP(s).
☒ All BMPs must be fully dimensioned on the plans.
☒ When proprietary BMPs are used, site-specific cross-section with outflow, inflow, and manufacturer model number must be provided. Photocopies of general brochures are not acceptable.
☒ Include all source control and site design measures described in the SWQMP. ☒ Include all construction BMPs described in the SWQMP. 4 For Building Permit Applications, refer to Form PDS 272, https://www.sandiegocounty.gov/content/dam/sdc/pds/docs/pds272.pdf 09/30/2021 Final Grading Plan Set

Page 289 of 585 ends

County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 5: Site and Drainage Description
County of San Diego SWQMP Attachment 5.0 (Cover Sheet) Page 5.0-1 Template Date: December 28, 2018 Preparation Date: 6/22/2021

5.0 General Requirements
• Each Priority Development Project (PDP) must provide a description of existing site conditions and proposed changes to them, including changes to topography and drainage. • Has a Drainage Report has been prepared for the PDP?
☐ Yes
o Review of the Drainage Report must be concurrent with the PDP SWQMP. o Include the summary page of the Drainage Report with this cover page, and provide the following information:

Title: Click here to enter text.

Prepared By: Click here to enter text.

Date: Click here to enter text.
o Do not complete the rest of this attachment (also exclude these additional pages from your submittal). Additional documentation of site and drainage conditions is not required unless requested by County staff.
☒ No -- Complete and submit the remainder of this attachment below. 09/30/2021

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County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 5: Site and Drainage Description
County of San Diego SWQMP Attachment 5.1 (Existing Site Condition) Page 5.1-1 Template Date: December 28, 2018 Preparation Date: 6/22/2021

5.1 Description of Existing Site Condition
Provide the requested information below for the project site in its existing condition. a. Current Site Status
Select all that apply to any portion of the site.
☒ Existing development
☐ Previously graded but not built out
☐ Agricultural or other non-impervious use
☐ Vacant, undeveloped/natural
☐ Demolition completed without new construction
b. Existing Land Cover
Provide the area (in acres or square feet) within all applicable categories of land cover below. The total area should equal that of the entire project site.

Area (acres or ft2)
☐ Vegetative Cover Click here to enter text.
☐ Non-Vegetated Pervious Areas Click here to enter text. ☒ Impervious Areas 12.01 AC
c. Underlying Soil
Select all soil groups that are present on the site.

NRCS Hydrologic Soil Group(s)
Type A Type B Type C Type D
☐ ☐ ☐ ☒
09/30/2021

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County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 5: Site and Drainage Description
County of San Diego SWQMP Attachment 5.2 (Existing Site Drainage) Page 5.2-1 Template Date: December 28, 2018 Preparation Date: 6/22/2021

5.2 Description of Existing Site Drainage
Describe how storm water runoff is conveyed from the site. At a minimum, address the following:
• Is the existing drainage conveyance ☐ natural or ☒ urban? • Is runoff from offsite conveyed through the site? ☐ Yes ☒ No If yes, quantify all offsite drainage areas, design flows, and locations where offsite flows enter the project site, and summarize how such flows are conveyed through the site. • Describe the existing project site drainage conveyance network (including any existing storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels).
• Identify all discharge locations from the existing project site along with a summary of conveyance system size and capacity for each of the discharge locations. Summarize the preproject drainage areas and design flows to each of the existing runoff discharge locations. • Provide additional information as necessary or requested to describe the site drainage.

Description (add pages as necessary to provide all requested information).

The site is an existing developed commercial site consisting of one-story commercial building, existing parking lot and pedestrian hardscape. The paved parking lot includes landscape planter islands. Stormwater runoff generated from the existing site discharges via sheet flow, curb inlets and storm drain conveyance system. Runoff ultimately discharges to the Alverado Channel Box Culvert in Fletcher Parkway.

According to the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map locates the site in Flood Zone X, which is defined as an area of minial flood hazard. 09/30/2021

Page 292 of 585 ends

County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 5: Site and Drainage Description
County of San Diego SWQMP Attachment 5.3 (Proposed Site Development) Page 5.3-1 Template Date: December 28, 2018 Preparation Date: 6/22/2021

5.3 Description of Proposed Site Development
Provide a general description of the proposed site development, including at a minimum the information requested below. Add pages as necessary.
a. Project description/ Proposed land use and/or activities (project location, development type, size, numbers of units, etc.)
The project proposes to expand the current square footage of the existing one-story commercial building. There will be hardscape and parking lot modifications, addition of a diary cooler and modification to driveway entrance from Fletcher Parkway. b. List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features).

Proposed impervious features include new diary cooler, expansion of the building footprint, hardscape and paved parking lot modifications, and modification of the driveway. c. List/describe proposed pervious features of the project (e.g., landscape areas):

Minor modifications to existing planter islands.
d. Does the project include grading and changes to site topography? ☒ Yes ☐ No If yes, describe below.

The project will include minor grading to accomade the proposed diary cooler and the modifications to the hardscape and paved parking lot.
09/30/2021
The Phase 1 (Building Permit B22-051) condition of the project only includes repaving/ grind & overlay of parking stalls for ADA compliance, reconstruction of concrete apron, and other minor site improvements under the Building Permit. See Attachment 2 Exhibit for clarification of scope.

Phase 2 of the project is proposed under a separate permit and is included in this report for reference only. The Phase 2 project scope includes expanding the current square footage of the existing one-story commercial building, a dairy cooler addition, refrigeration equipment and modifications to the driveway entrance from Fletcher Parkway.

Proposed impervious features of the Phase 1 (Building Permit B22-051) condition of the project only include repaving/ grind & overlay of parking stalls for ADA compliance, reconstruction of concrete apron, and other minor site improvements under the Building Permit. See Attachment 2 Exhibit for clarification of scope. The Phase 2 impervious areas include a new dairy cooler, refrigeration equipment, expansion of the building footprint, hardscape, and modification of the driveway.

Minor modifications to existing planter islands and regrading of existing slope in DMA 5.

Phase 1 of the project will include minor grading for hardscape and landscape modifications.

Phase 2 of this project will include minor grading to accommodate the proposed dairy cooler and parking lot modifications. See Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. Page 293 of 585 County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 5: Site and Drainage Description
County of San Diego SWQMP Attachment 5.4 (Proposed Site Drainage) Page 5.4-1 Template Date: December 28, 2018 Preparation Date: 6/22/2021

5.4 Description of Proposed Site Drainage
A. Changes to Site Drainage -- Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? ☒ Yes ☐ No
If yes:
• Describe (1) the proposed project site drainage conveyance network (including storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels), and (2) the method for conveying offsite flows through or around the proposed project site.
• Identify all discharge locations from the proposed project site along with a summary of the conveyance system size and capacity for each of the discharge locations. • Provide a summary of pre- and post-project drainage areas and design flows to each of the runoff discharge locations.

Description (add pages as necessary to provide all requested information).

The proposed project includes a diary cooler, expansion of the existing building footprint and hardscape and parking lot modifications. The proposed drainage pattern will mimic the existing drainage pattern to the maximum extent practical. The imperviousness of the proposed hardscape and parking lot modifications will remain similar to the existing conditions.

Due to existing utility site constraints, the proposed hardscape and parking lot modifications are infeasible to be treated for pollutant and hydromodification control prior to discharging to the existing storm drain system. An equivalent existing impervious runoff area will be treated along with the roof runoff from the proposed diary cooler. Runoff will sheet flow into an existing catch basin that will discharge into a underground detention storage styem and proprietary biofiltration system before discharging into the existing storm drain system. The existing storm drain system ultimately discharges into the existing Alverado Channel Box Culvert in Fletcher Parkway. 09/30/2021
*The installation of the biofiltration planter BMP will occur under the Phase 2 (Grading Permit) portion of the project, see Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. **
*
**The installation of this proprietary biofiltration planter unit and underground detention system will occur under the Phase 1 (Building Permit B22-051) portion of the project, but will be sized to treat the areas delineated in the Ultimate Condition of the project (Phases 1 & 2). See Attachment 2: DMA Exhibit - Phase 1 and Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. Alvarado Phase 1 of the proposed project includes mainly hardscape and parking lot modifications as shown on Attachment 2: Phase 1 - DMA Exhibit. The proposed drainage pattern will mimic the existing drainage pattern to the maximum extent practical. The imperviousness of the proposed hardscape and parking lot modifications will remain similar to the existing conditions.

Phase 2 of the project includes a dairy cooler and an expansion of the existing building footprint.

Runoff from the building expansion will discharge into a proposed biofiltration planter for pollutant and hydromodification control before discharing into the existing storm drain system. The existing storm drain system ultimately discharges into the existing Alverado Channel Box Culvert in Fletcher Parkway. Page 294 of 585
County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 7: Documentation of DMAs with Structural Pollutant Control BMPs County of San Diego SWQMP Attachment 7.0 (Cover Sheet) Page 7.0-1 Template Date: January 3, 2019 Preparation Date: 6/23/2021

7.0 General Requirements
• Submit this cover page and all required Sub-attachments for all structural BMPs proposed for the project.
• See the BMPDM sections and appendices listed under “BMPDM Design Resources” in the table below for additional explanation of design requirements. Constructed features must fully satisfy the requirements described in these resources, and any other guidance identified by the County. • PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management. Completion of SWQMP Attachment 8 is also required for these BMPs.
• DMA Exhibits and Construction Plans: DMAs, features, and BMPs identified and described in this attachment must be shown on DMA Exhibits and all applicable construction plans submitted for the project. See Attachment 2 for additional instruction on exhibits and plans. • Structural BMP Certification. All structural BMPs documented this attachment and in Attachment 8 must be certified by a registered engineer in Sub-attachment 7.1. • Structural BMP Verification. Structural BMP installation must be verified by the County at the completion of construction. Applicants must complete an Installation Verification Form (Attachment 10).

Sub-attachments
(check all that are completed)
Requirement BMPDM Design Resources
☒ 7.1: Preparer’s Certification Required • N/A
☒ 7.2: Structural BMP Strategy Required • BMPDM Sections 5.1., 5.3,

5.4, and Chapter 6
• BMPDM Appendix E
(pages E-78 through E-
☒ 7.3: Structural BMP Checklist(s) Required 210)
☒ 7.4: Stormwater Pollutant Control
Worksheet Calculations
Required • BMPDM Appendix B
☐ 7.5: Identification and Narrative
of Receiving Water and Pollutants of
Concern
Required if flow-thru
BMPs are proposed
• N/A
09/30/2021

Page 295 of 585 ends

County of San Diego SWQMP Sub-attachment 7.1 (Engineer Certification) Page 7.1-1 Template Date: January 3, 2019 Preparation Date: 6/23/2021

7.1 Engineer of Work Certification for Structural BMPs
Project Name Costco La Mesa – Building Expansion
Permit Application Number

CERTIFICATION
I hereby declare that I am the Engineer in Responsible Charge of design of structural storm water best management practices (BMPs) for this project, and that I have exercised responsible charge over the design of the BMPs as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the PDP requirements of the County of San Diego BMP Design Manual, which is a design manual for compliance with local County of San Diego Watershed Protection Ordinance (Sections 67.801 et seq.) and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2013-0001 as amended by R9-2015-0001 and R9-2015-0100) requirements for storm water management. I have read and understand that the County of San Diego has adopted minimum requirements for managing urban runoff, including storm water, from land development activities, as described in the BMP Design Manual.

I certify that this PDP SWQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this PDP SWQMP by County staff is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of structural storm water BMPs for this project, of my responsibilities for their design.
☒ In addition to the structural pollutant control BMPs described in this attachment, this certification applies to the Structural Hydromodification Management BMPs described in Attachment 8 (check if applicable).

Engineer of Work's Signature, PE Number & Expiration Date Bryan D. Smith
Print Name
Fuscoe Engineering Inc.

Company
06/22/2021 Engineer's Seal:

Date
RCE 75822 EXP. 06-30-24 09/30/2021 10/04/2022

Page 296 of 585 ends

County of San Diego SWQMP Sub-attachment 7.2 (Structural BMP Strategy) Page 7.2-1 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.2 Structural BMP Strategy

7.2.1 Narrative Strategy (Continue description on subsequent pages as necessary) Describe the general strategy for structural BMP implementation at the project site. For pollutant control BMPs, your description must address the key points outlined in Section 5.1 of the BMP Design Manual, and the type of BMPs selected. For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated or separate.

The project falls into the priority development project category, therefore both pollutant control and hydromodification requirements apply.

BMP 1 was designed to satisfy the minimum three percent of the weighted area required to meet the effective area required for evapotranspiration. BMP 1 is designed to integrate pollutant control and hydromodification management. DMA 1 is designed to discharge into the raised biofiltration planter.

Since the project proposes modifications to the existing commercial building and parking lot, harvest and reuse was deemed infeasible. Based on the geotechnical report, the project is classified as a no infiltration condition. Therefore, the other effective BMP that is feasible to implement is a priority biofiltration unit. The BMP implemented for this project is a Modular Wetland System (MWS). BMP 2 (MWS) is designed for pollutant control only. A separate underground detention system (Stormtech Chambers) will be implemented for hydromodification management (HMP 2).

Per Section F.1.2.2 in Appendix F of the County of San Diego BMP Design Manual, BMP 2 is sized for as flow based. The minimum flow-rate calculation for water quality treatment was determined using Worksheet J.5-1 included in this Section 7.4 of this report. The calculated treatment flow-rate was then used to select the appropriately sized model unit. The selected biofiltration unit has a small footprint and meets the requirements per Section J.5.3 in Appendix J. The MWS will be maintained in accordance with manufacturer guidelines and conditions.

Due to existing utility site constraints per Existing Site Constraints Exhibit in Attachment 2.1 Sheet 3, DMAs 3A-3D are infeasible to provide pollutant control and hydromodification management prior to discharging to the existing storm drain system. An equivalent weighted area of existing impervious area will be treated for pollutant control and hydromodification management within DMA4 as shown in DMA Summary Table on DMA Exhibit in Attachment 2.1. DMA 4 encompasses the runoff from the proposed dairy cooler and the existing equivalent weighted area that will be swapped for DMAs 3A-3D. DMA 4 will discharge into HMP 2 and BMP 2 for hydromodification management and pollutant control before ultimately discharging into the storm drain system.

09/30/2021
*The installation of the biofiltration planter BMP will occur under the Phase 2 (Grading Permit) portion of the project, see Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. *
**
**The installation of this proprietary biofiltration planter unit and underground detention system will occur under the Phase 1 (Building Permit B22-051) portion of the project, but will be sized to treat the areas delineated in the Ultimate Condition of the project (Phases 1 & 2). See Attachment 2: DMA Exhibit - Phase 1 and Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification.

The project falls into the priority development project category, therefore both pollutant control and hydromodification requirements apply.

Harvest and reuse was deemed infeasible due to the retrofit nature of the project, and lack of demand for storm water reuse. Based on the geotechnical report, the project is classified as a no infiltration condition. The BMP implemented in Phase 1 of this project is a Modular Wetland System** (MWS Proprietary Biofiltration). BMP 2 (MWS) is designed for pollutant control only. A separate underground detention system (Stormtech Chambers) will be implemented for hydromodification management (HMP 2).

Per Section F.1.2.2 in Appendix F of the County of San Diego BMP Design Manual, BMP 2 is sized as volume based. The minimum volume calculation for water quality treatment was determined using Worksheet J.5-1 included in this Section 7.4 of this report. The calculated treatment Design Capture Volume (DCV) was then used to select the appropriately sized model unit. The selected biofiltration unit has a small footprint and meets the requirements per Section J.5.3 in Appendix J. The MWS will be maintained in accordance with manufacturer guidelines and conditions. The hydromod control weir and orifice are in the MWS unit downstream of the Stormtech Chambers. *BMP 1 will be installed with the 2nd Phase of this project. BMP 1 was designed to satisfy the minimum three percent of the weighted area required to meet the effective area required for evapotranspiration. BMP 1 is designed to integrate pollutant control and hydromodification management. DMA 1 is designed to discharge into the raised biofiltration planter.

Due to existing utility site constraints per Existing Site Constraints Exhibit in Attachment 2.1 Sheet 3, DMAs 3A-3D and DMA 5 are infeasible to provide pollutant control and hydromodification management prior to discharging to the existing storm drain system due to site constraints as depicted on Attachment 2, Sheet 4. An equivalent weighted area of existing impervious area will be treated for pollutant control and hydromodification management within DMA4 as shown in DMA Summary Table on DMA Exhibit in Attachment 2.1. DMA 4 encompasses the runoff from the proposed dairy cooler and the existing equivalent weighted area that will be swapped for DMAs 3A-3D and DMA 5. DMA 4 will discharge into HMP 2 and BMP 2 for hydromodification management and pollutant control before ultimately discharging into the storm drain system. Page 297 of 585 County of San Diego SWQMP Sub-attachment 7.2 (Structural BMP Strategy) Page 7.2-2 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.2.2 Structural BMP Summary Table (Complete for all proposed structural BMPs) • List and provide the information requested below for all pollutant control and hydromodification management BMPs proposed for the project.
• For each BMP listed, complete the Structural BMP Checklist on the next page. Copy the Checklist as many times as needed.

Structural BMP Type
BMP
ID #
DMA
#
DMA
Area
(ft2)
Harvest and Use Infiltration Unlined BiofiltrationLined Biofiltration Flow-thru treatmentHydromodification Management 1 Other Permit # and Sheet #
BMP1 DMA1 16,525 ☐ ☐ ☐ ☒ ☐ ☒ ☐
BMP2 DMA4 9,968 ☐ ☐ ☐ ☒ ☐ ☐ ☐
HMP2 DMA4 9,968 ☐ ☐ ☐ ☐ ☐ ☒ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
☐ ☐ ☐ ☐ ☐ ☐ ☐
Copy and Paste table here for additional BMPs
1 Hydromodification Management BMPs must be accompanied by BMPs that provide pollutant control. 09/30/2021 *
**
**
*The installation of the biofiltration planter BMP will occur under the Phase 2 (Grading Permit) portion of the project, see Attachment 2:

DMA Exhibit - Ultimate Condition for scope clarification. **The installation of this proprietary biofiltration planter unit and underground detention system will occur under the Phase 1 (Building Permit) portion of the project, but will be sized to treat the areas delineated in the Ultimate Condition of the project.

See Attachment 2: DMA Exhibit - Phase 1 and Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. 16,032

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_________________________
2 Indicate which onsite retention or biofiltration BMP the pre-treatment/forebay serves. 3 Hydromodification Management BMPs must be accompanied by BMPs that provide pollutant control.

County of San Diego SWQMP Sub-attachment 7.3 (Structural BMP Checklist) Page 7.3-1 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.3 Structural BMP Checklist (Complete once for each proposed structural BMP) Structural BMP ID # BMP 1 Permit # and Sheet #
BMP Type
Infiltration
☐ Infiltration basin (INF-1)
☐ Bioretention (INF-2)
☐ Permeable pavement (INF-3)
Unlined Biofiltration
☐ Biofiltration with partial retention (PR-1)
Lined Biofiltration
☒ Biofiltration (BF-1)
☐ Nutrient Sensitive Media Design (BF-2)
☐ Proprietary Biofiltration (BF-3)
Harvest and Use
☐ Cistern (HU-1)
Flow-thru Treatment (describe below)
☐ With prior lawful approval to meet earlier PDP
requirements
☐ Pre-treatment/forebay for an onsite retention
or biofiltration BMP2
☐ With alternative compliance
Hydromodification Management3
☐ Detention pond or vault
☐ Other (describe below)
BMP Purpose
☐ Pollutant control only
☐ Hydromodification control only
☒ Combined pollutant control and
hydromodification
☐ Pre-treatment/forebay for another BMP
☐ Other (describe below)
BMP Verification (See BMPDM Section 8.3)
Provide name and contact information
for the party responsible to sign BMP
verification forms
Bryan D. Smith, Fuscoe Engineering Inc.
6390 Greenwich Drive, Suite 170
San Diego, CA 92117
BMP Ownership and Maintenance (See BMPDM Section 7.3 and Attachment 11) BMP Maintenance Category Cat. 1 Cat. 2 Cat. 3 Cat. 4
☐ ☒ ☐ ☐
Final owner of BMP ☐ HOA ☒ Property Owner ☐ County
☐ Other (describe):

Maintenance of BMP into perpetuity ☐ HOA ☒ Property Owner ☐ County ☐ Other (describe):

Discussion (As needed; Continue on subsequent pages as necessary) 09/30/2021
*The installation of the biofiltration planter BMP will occur under the Phase 2 (Grading Permit) portion of the project, see Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. *

Page 299 of 585 ends

County of San Diego SWQMP Sub-attachment 7.3 (Structural BMP Checklist) Page 7.3-2 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.3 Structural BMP Checklist (Complete once for each proposed structural BMP) Structural BMP ID # BMP 2 Permit # and Sheet #
BMP Type
Infiltration
☐ Infiltration basin (INF-1)
☐ Bioretention (INF-2)
☐ Permeable pavement (INF-3)
Unlined Biofiltration
☐ Biofiltration with partial retention (PR-1)
Lined Biofiltration
☐ Biofiltration (BF-1)
☐ Nutrient Sensitive Media Design (BF-2)
☒ Proprietary Biofiltration (BF-3)
Harvest and Use
☐ Cistern (HU-1)
Flow-thru Treatment (describe below)
☐ With prior lawful approval to meet earlier PDP
requirements
☐ Pre-treatment/forebay for an onsite retention
or biofiltration BMP2
☐ With alternative compliance
Hydromodification Management3
☐ Detention pond or vault
☐ Other (describe below)
BMP Purpose
☒ Pollutant control only
☐ Hydromodification control only
☐ Combined pollutant control and
hydromodification
☐ Pre-treatment/forebay for another BMP
☐ Other (describe below)
BMP Verification (See BMPDM Section 8.3)
Provide name and contact information
for the party responsible to sign BMP
verification forms
Bryan D. Smith, Fuscoe Engineering Inc.
6390 Greenwich Drive, Suite 170
San Diego, CA 92117
BMP Ownership and Maintenance (See BMPDM Section 7.3 and Attachment 11) BMP Maintenance Category Cat. 1 Cat. 2 Cat. 3 Cat. 4
☐ ☒ ☐ ☐
Final owner of BMP ☐ HOA ☒ Property Owner ☐ County
☐ Other (describe):

Maintenance of BMP into perpetuity ☐ HOA ☒ Property Owner ☐ County ☐ Other (describe):

Discussion (As needed; Continue on subsequent pages as necessary) 09/30/2021
**The installation of this proprietary biofiltration planter unit and underground detention system will occur under the Phase 1 (Building Permit) portion of the project, but will be sized to treat the areas delineated in the Ultimate Condition of the project. See Attachment 2: DMA Exhibit - Phase 1 and Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. **

Page 300 of 585 ends

County of San Diego SWQMP Sub-attachment 7.3 (Structural BMP Checklist) Page 7.3-3 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.3 Structural BMP Checklist (Complete once for each proposed structural BMP) Structural BMP ID # HMP 2 Permit # and Sheet #
BMP Type
Infiltration
☐ Infiltration basin (INF-1)
☐ Bioretention (INF-2)
☐ Permeable pavement (INF-3)
Unlined Biofiltration
☐ Biofiltration with partial retention (PR-1)
Lined Biofiltration
☐ Biofiltration (BF-1)
☐ Nutrient Sensitive Media Design (BF-2)
☐ Proprietary Biofiltration (BF-3)
Harvest and Use
☐ Cistern (HU-1)
Flow-thru Treatment (describe below)
☐ With prior lawful approval to meet earlier PDP
requirements
☐ Pre-treatment/forebay for an onsite retention
or biofiltration BMP2
☐ With alternative compliance
Hydromodification Management3
☒ Detention pond or vault
☐ Other (describe below)
BMP Purpose
☐ Pollutant control only
☒ Hydromodification control only
☐ Combined pollutant control and
hydromodification
☐ Pre-treatment/forebay for another BMP
☐ Other (describe below)
BMP Verification (See BMPDM Section 8.3)
Provide name and contact information
for the party responsible to sign BMP
verification forms
Bryan D. Smith, Fuscoe Engineering Inc.
6390 Greenwich Drive, Suite 170
San Diego, CA 92117
BMP Ownership and Maintenance (See BMPDM Section 7.3 and Attachment 11) BMP Maintenance Category Cat. 1 Cat. 2 Cat. 3 Cat. 4
☐ ☒ ☐ ☐
Final owner of BMP ☐ HOA ☒ Property Owner ☐ County
☐ Other (describe):

Maintenance of BMP into perpetuity ☐ HOA ☒ Property Owner ☐ County ☐ Other (describe):

Discussion (As needed; Continue on subsequent pages as necessary) 09/30/2021 **
**The installation of this proprietary biofiltration planter unit and underground detention system will occur under the Phase 1 (Building Permit) portion of the project, but will be sized to treat the areas delineated in the Ultimate Condition of the project. See Attachment 2: DMA Exhibit - Phase 1 and Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification.

Page 301 of 585 ends

County of San Diego SWQMP Sub-attachment 7.4 (Pollutant Control Worksheet) Page 7.4-1 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.4 Storm Water Pollutant Control Worksheet Calculations • Use this page as a cover sheet for the submittal of any required worksheets below. • Complete the checklist to identify which BMPDM Appendix B (Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods) worksheets are included with this attachment. • See BMPDM Appendix B for an explanation of the applicability of individual worksheets and detailed guidance on their completion.

Worksheet Requirement
☒ Worksheet B.1 Calculation of Design Capture Volume (DCV) Required ☒ Worksheet B.2 Retention Requirements Required
☒ Worksheet B.3 BMP Performance Required
☐ Worksheet B.4 Major Maintenance Intervals for Reduced-sized BMPs If applicable ☒ Other worksheets As required
09/30/2021

Page 302 of 585 ends

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Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name BMP 1 BMP 2 unitless2 85th Percentile 24-hr Storm Depth 0.54 0.54 inches3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 16,032 9,968 sq-ft 4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30) sq-ft5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10) sq-ft6 Natural Type A Soil Not Serving as Dispersion Area (C=0.10) sq-ft7 Natural Type B Soil Not Serving as Dispersion Area (C=0.14) sq-ft8 Natural Type C Soil Not Serving as Dispersion Area (C=0.23) sq-ft9 Natural Type D Soil Not Serving as Dispersion Area (C=0.30) sq-ft 10 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels? No No No No No No No No No No yes/no11 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft12 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30) sq-ft13 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10) sq-ft14 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10) sq-ft15 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14) sq-ft16 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23) sq-ft17 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30) sq-ft18 Number of Tree Wells Proposed per SD-A #19 Average Mature Tree Canopy Diameter ft20 Number of Rain Barrels Proposed per SD-E # 21 Average Rain Barrel Size gal
22 Total Tributary Area 16,032 9,968 0 0 0 0 0 0 0 0 sq-ft23 Initial Runoff Factor for Standard Drainage Areas 0.90 0.90 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless25 Initial Weighted Runoff Factor 0.90 0.90 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless26 Initial Design Capture Volume 649 404 0 0 0 0 0 0 0 0 cubic-feet27 Total Impervious Area Dispersed to Pervious Surface 0 0 0 0 0 0 0 0 0 0 sq-ft28 Total Pervious Dispersion Area 0 0 0 0 0 0 0 0 0 0 sq-ft29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a ratio30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ratio31 Runoff Factor After Dispersion Techniques 0.90 0.90 n/a n/a n/a n/a n/a n/a n/a n/a unitless32 Design Capture Volume After Dispersion Techniques 649 404 0 0 0 0 0 0 0 0 cubic-feet33 Total Tree Well Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet34 Total Rain Barrel Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet35 Final Adjusted Runoff Factor 0.90 0.90 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless36 Final Effective Tributary Area 14,429 8,971 0 0 0 0 0 0 0 0 sq-ft37 Initial Design Capture Volume Retained by Site Design Elements 0 0 0 0 0 0 0 0 0 0 cubic-feet38 Final Design Capture Volume Tributary to BMP 649 404 0 0 0 0 0 0 0 0 cubic-feet FalseFalse
Automated Worksheet B.1: Calculation of Design Capture Volume (V2.0) Dispersion
Area, Tree Well
& Rain Barrel
Inputs
(Optional)
Standard
Drainage Basin
Inputs
Results
Tree & Barrel
Adjustments
Initial Runoff
Factor
Calculation
Dispersion
Area
Adjustments
No Warning Messages

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Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name BMP 1 BMP 2 - - - - - - - - unitless2 85th Percentile Rainfall Depth 0.54 0.54 - - - - - - - - inches3 Predominant NRCS Soil Type Within BMP Location D D unitless4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Restricted Restricted unitless5 Nature of Restriction Structures Structures unitless6 Do Minimum Retention Requirements Apply to this Project? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes yes/no7 Are Habitable Structures Greater than 9 Stories Proposed? No No yes/no8 Has Geotechnical Engineer Performed an Infiltration Analysis? Yes Yes yes/no9 Design Infiltration Rate Recommended by Geotechnical Engineer 0.000 0.000 in/hr 10 Design Infiltration Rate Used To Determine Retention Requirements 0.000 0.000 - - - - - - - - in/hr11 Percent of Average Annual Runoff that Must be Retained within DMA 4.5% 4.5% - - - - - - - - percentage12 Fraction of DCV Requiring Retention 0.02 0.02 - - - - - - - - ratio13 Required Retention Volume 13 8 - - - - - - - - cubic-feet FalseFalse
Automated Worksheet B.2: Retention Requirements (V2.0)
Advanced
Analysis
Basic Analysis
Result
No Warning Messages

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Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name BMP 1 BMP 2 - - - - - - - - sq-ft2 Design Infiltration Rate Recommended 0.000 0.000 - - - - - - - - in/hr3 Design Capture Volume Tributary to BMP 649 404 - - - - - - - - cubic-feet4 Is BMP Vegetated or Unvegetated? Vegetated Unvegetated unitless 5 Is BMP Impermeably Lined or Unlined? Lined Lined unitless 6 Does BMP Have an Underdrain? Underdrain Underdrain unitless7 Does BMP Utilize Standard or Specialized Media? Standard Standard unitless8 Provided Surface Area 1,220 26 sq-ft 9 Provided Surface Ponding Depth 12 inches
10 Provided Soil Media Thickness 18 inches11 Provided Gravel Thickness (Total Thickness) 18 inches12 Underdrain Offset 3 inches13 Diameter of Underdrain or Hydromod Orifice (Select Smallest) 0.63 inches14 Specialized Soil Media Filtration Rate in/hr 15 Specialized Soil Media Pore Space for Retention unitless16 Specialized Soil Media Pore Space for Biofiltration unitless17 Specialized Gravel Media Pore Space unitless 18 Volume Infiltrated Over 6 Hour Storm 0 0 0 0 0 0 0 0 0 0 cubic-feet19 Ponding Pore Space Available for Retention 0.00 0.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 unitless 20 Soil Media Pore Space Available for Retention 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 unitless21 Gravel Pore Space Available for Retention (Above Underdrain) 0.00 0.00 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless22 Gravel Pore Space Available for Retention (Below Underdrain) 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless23 Effective Retention Depth 2.10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches24 Fraction of DCV Retained (Independent of Drawdown Time) 0.33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio25 Calculated Retention Storage Drawdown Time 120 0 0 0 0 0 0 0 0 0 hours26 Efficacy of Retention Processes 0.33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio27 Volume Retained by BMP (Considering Drawdown Time) 216 0 0 0 0 0 0 0 0 0 cubic-feet28 Design Capture Volume Remaining for Biofiltration 433 404 0 0 0 0 0 0 0 0 cubic-feet29 Max Hydromod Flow Rate through Underdrain 0.0198 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 cfs30 Max Soil Filtration Rate Allowed by Underdrain Orifice 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 in/hr31 Soil Media Filtration Rate per Specifications 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 in/hr32 Soil Media Filtration Rate to be used for Sizing 0.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 in/hr33 Depth Biofiltered Over 6 Hour Storm 4.21 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches34 Ponding Pore Space Available for Biofiltration 1.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless35 Soil Media Pore Space Available for Biofiltration 0.20 0.35 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 unitless36 Gravel Pore Space Available for Biofiltration (Above Underdrain) 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless37 Effective Depth of Biofiltration Storage 21.60 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches38 Drawdown Time for Surface Ponding 17 >120 0 0 0 0 0 0 0 0 hours 39 Drawdown Time for Effective Biofiltration Depth 31 #DIV/0! 0 0 0 0 0 0 0 0 hours40 Total Depth Biofiltered 25.81 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches41 Option 1 - Biofilter 1.50 DCV: Target Volume 650 606 0 0 0 0 0 0 0 0 cubic-feet42 Option 1 - Provided Biofiltration Volume 650 0 0 0 0 0 0 0 0 0 cubic-feet43 Option 2 - Store 0.75 DCV: Target Volume 325 303 0 0 0 0 0 0 0 0 cubic-feet 44 Option 2 - Provided Storage Volume 325 0 0 0 0 0 0 0 0 0 cubic-feet45 Portion of Biofiltration Performance Standard Satisfied 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements? Yes No - - - - - - - - yes/no 47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor) 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio48 Deficit of Effectively Treated Stormwater 0 -404 n/a n/a n/a n/a n/a n/a n/a n/a cubic-feet Retention
Calculations
Automated Worksheet B.3: BMP Performance (V2.0)
FalseFalse
BMP Inputs
Biofiltration
Calculations
-This BMP does not fully satisfy the performance standards for pollutant control for the drainage area.- BMPs sized at <3% of the effective tributary areas must be accompanied by Reduced Size BMP Maintenance calculations (see last tab).-Vegetated BMPs with surface ponding drawdown times over 24 hours must be certified by a landscape architect or agronomist. All BMPs must have a surface ponding drawdown time of 96 hours or less.False Result
-Minimum annual retention criteria are not satisfied for each individual drainage area. Implement additional site design elements, increase structural BMP retention capacity, or demonstrate that such requirements are satisfied at the project-level.FalseAttention! See Worksheet J.5-1 forflow rate sizing of BMP 2

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Appendix J: Offsite Alternative Compliance Requirements and Guidance www.sandiegocounty.gov/stormwater J-15 Effective September 15, 2020 Worksheet J.5-1: Flow-Thru Design Flows
BMP 2 9,968 0.90 404
0 4041

0.041 YES
* The draindown time for this system (11.9 hrs) is within the required 36 hours. See BMP 2 - Modular Wetland System Detail on Attachment 2: DMA Exhibit Details Sheet and BioClean Modular Wetland Volume Based Sizing Table on next sheet.

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BioClean Modular Wetland Volume Based Sizing Table - 36 Hour Drain Down Time Requirement

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County of San Diego SWQMP Sub-attachment 7.5 (Pollutants of Concern) Page 7.5-1 Template Date: January 03, 2019 Preparation Date: 6/23/2021

7.5 Identification and Narrative of Receiving Water and Pollutants of Concern • Complete this sub-attachment only if flow-thru treatment BMPs are implemented onsite in lieu of retention or biofiltration BMPs. Unless excepted because of a Prior Lawful Approval4, PDPs must also participate in an alternative compliance program5.

A. General Description
Describe flow path of storm water from the project site discharge location(s), through urban storm conveyance systems as applicable, to receiving creeks, rivers, and lagoons as applicable, and ultimate discharge to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable).

B. Water Body Impairments and Priorities
List any 303(d) impaired water bodies6 within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs and/or Highest Priority Pollutants from the WQIP for the impaired water bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s)
TMDLs / WQIP
Highest Priority Pollutant

C. Identification of Project Site Pollutants
Identify pollutants expected from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix J.5)
Pollutant
Not Applicable to
the Project Site
Anticipated from
the Project Site
Also a Receiving Water
Pollutant of Concern
Sediment ☐ ☐ ☐
Nutrients ☐ ☐ ☐
Heavy Metals ☐ ☐ ☐
Organic Compounds ☐ ☐ ☐
Trash & Debris ☐ ☐ ☐
Oxygen Demanding Substances ☐ ☐ ☐
Oil & Grease ☐ ☐ ☐
Bacteria & Viruses ☐ ☐ ☐
Pesticides ☐ ☐ ☐
4 See BMPDM Appendix L: Prior Lawful Approval Requirements and Guidance. 5 See SWQMP Attachment 12 (Alternative Compliance Projects) and BMPDM Appendix J (Offsite Alternative Compliance Requirements and Guidance).
6 The current list of Section 303(d) impaired water bodies can be found at:
https://www.waterboards.ca.gov/water_issues/programs/tmdl/integrated2014_2016.shtml 09/30/2021

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County of San Diego Stormwater Quality Management Plan (SWQMP) Attachment 8: Documentation of DMAs with Structural Hydromodification BMPs County of San Diego SWQMP Attachment 8.0 (General Requirements) Page 8.0-1 Template Date: January 8, 2019 Preparation Date: 6/23/2021

8.0 General Requirements
• Completion of this attachment is required for all PDPs subject to hydromodification management requirements (see PDP SWQMP Form Table 5). Do not submit this attachment if exempt from Hydromodification Management requirements. Document the PDP exemption in Attachment 9. • Submit this cover page and all required Sub-attachments for all structural hydromodification management BMPs proposed for the project.
• Constructed features must fully satisfy the requirements described in applicable BMPDM sections and appendices, and any other guidance identified by the County. • DMA Exhibits and Construction Plans: DMAs, features, and BMPs identified and described in this attachment must be shown on DMA Exhibits and all applicable construction plans submitted for the project. See Attachment 2 for additional instruction on exhibits and plans. • Structural BMP Certification. All structural hydromodification management BMPs documented this attachment must be certified by a registered engineer in Attachment 7, Sub-attachment 7.1. • Structural BMP Verification. BMP installation must be verified by the County at the completion of construction. Applicants must complete an Installation Verification Form (Attachment 10).

Sub-attachments (check all that are completed)
☒ 8.1: Flow Control Facility Design (required)1
Submit using ☒ the Sub-attachment 8.1 cover sheet provided, or ☐ as a separate stand-alone document labeled Sub-attachment 8.1.
☒ 8.2: Hydromodification Management Points of Compliance (required) Complete the table provided in Sub-attachment 8.2.

8.3: Geomorphic Assessment of Receiving Channels

1. Has a geomorphic assessment been performed for the receiving channel(s)? ☒ No, the low flow threshold is 0.1Q2 (default low flow threshold) ☐ Yes (provide the information below):

Low flow threshold: ☐ 0.1Q2 ☐ 0.3Q2 ☐ 0.5Q2
Title:

Date: Preparer:

Submit using ☐ the Sub-attachment 8.3 cover sheet provided, or ☐ as a separate stand-alone document labeled Sub-attachment 8.3.

8.4: Vector Control Plan (required if BMPs will not drain in less than 96 hours) ☐ Included with this attachment ☒ Not required
1 Including Structural BMP Drawdown Calculations and Overflow Design Summary. See BMPDM Chapter 6 and Appendix G for additional design guidance.
09/30/2021

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County of San Diego SWQMP Sub-attachment 8.1 (Flow Control Facility Design) Page 8.1-1 Template Date: January 8, 2019 Preparation Date: 6/23/2021

8.1 Flow Control Facility Design
Insert Flow Control Facility Design behind this cover page or submit as a separate stand-alone document labeled Sub-attachment 8.1.
09/30/2021

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Project Name: Costco La Mesa
Project Applicant:

Jurisdiction: City of La Mesa
Parcel (APN): 464-600-26-00
Hydrologic Unit: La Mesa
Rain Gauge: Oceanside
Total Project Area (sf):

Channel Susceptibility: HIGH
BMP Sizing Spreadsheet V3.0

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Project Name: Hydrologic Unit:

Project Applicant: Rain Gauge:Jurisdiction: Total Project Area:Parcel (APN): Low Flow Threshold:BMP Name: BMP Type:BMP Native Soil Type: BMP Infiltration Rate (in/hr):

HMP Sizing Factors Minimum BMP Size
DMA
Name Area (sf)
Pre Project Soil
Type Pre-Project Slope
Post Project
Surface Type
Area Weighted Runoff
Factor
(Table G.2-1)1
Surface Area Surface Area (SF)
DMA 1 16,032 D Flat Roofs 1.0 0.07 1122
refrigeration 890 D Flat Concrete 1.0 0.07 62
0 00 00 00 00 00 00 00 00 00 00 00 00 0
BMP Tributary Area 16,922 Minimum BMP Size 1185
Proposed BMP Size* 1220 * Assumes standard configuration

12.00 in18.00 in

6.00 in
12 in

3.5 in3.5
Notes:1. Runoff factors which are used for hydromodification management flow control (Table G.2-1) are different from the runoff factors used for pollutant control BMP sizing (Table B.1-1). Table references are taken from the San Diego Region Model BMP Design Manual, April 2018.Describe the BMP's in sufficient detail in your PDP SWQMP to demonstrate the area, volume, and other criteria can be met within the constraints of the site.BMP's must be adapted and applied to the conditions specific to the development project such as unstable slopes or the lack of available head. Designated Staff have final review and approval authority over the project design.This BMP Sizing Spreadsheet has been updated in conformance with the San Diego Region Model BMP Design Manual, April 2018. For questions or concerns please contact the jurisdiction in which your project is located.

Underdrain Offset
464-600-26-00 0.1Q2
BMP1 Biofiltration
D 0.025
Areas Draining to BMP
Surface Ponding Depth
Bioretention Soil Media Depth
Filter Coarse
Gravel Storage Layer Depth
City of La Mesa 0
BMP Sizing Spreadsheet V3.0
Costco La Mesa La Mesa
0 Oceanside

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Project Name: Hydrologic Unit:

Project Applicant: Rain Gauge:Jurisdiction: Total Project Area:Parcel (APN): Low Flow Threshold:BMP Name BMP Type:

Rain Gauge Unit Runoff Ratio DMA Area (ac) Orifice Flow - %Q2 Orifice Area Soil Type Slope (cfs/ac) (cfs) (in2)
DMA 1 Oceanside D Flat 0.571 0.368 0.021 0.30
refrigeration Oceanside D Flat 0.571 0.020 0.001 0.02

3.71 0.022 0.32 0.64
Max Orifice Head
Max Tot. Allowable
Orifice Flow
Max Tot. Allowable
Orifice Area
Max Orifice
Diameter
(feet) (cfs) (in2) (in)

0.020 0.021 0.31 0.625
Average outflow during
surface drawdown Max Orifice Outflow Actual Orifice Area Selected Orifice Diameter (cfs) (cfs) (in2) (in)
Drawdown (Hrs) 17.0
No Orifice Required for
Infiltration Facilities
Drawdown time exceeds 96 Hrs. Project must implement a vector control program. 464-600-26-00 0.1Q2
BMP1 Biofiltration
DMA
Name
Pre-developed Condition
City of La Mesa 0
BMP Sizing Spreadsheet V3.0
Costco La Mesa La Mesa
0 Oceanside

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Project Name: Hydrologic Unit:

Project Applicant: Rain Gauge:Jurisdiction: Total Project Area:Parcel (APN): Low Flow Threshold:BMP Name: BMP Type:BMP Native Soil Type: BMP Infiltration Rate (in/hr):

HMP Sizing Factors Minimum BMP Size
DMA
Name Area (sf)
Pre Project Soil
Type Pre-Project Slope
Post Project
Surface Type
Area Weighted Runoff
Factor
(Table G.2-1)1
Volume Volume (CF)
DMA 4 9,968 D Flat Concrete 1.0 0.12 1196
0 00 00 00 00 00 00 00 00 00 00 00 00 00 0
BMP Tributary Area 9,968 Minimum BMP Size 1196
Proposed BMP Size* 1205 * Assumes standard configuration

3.5 ft3.5 ft
342 CF
Notes:1. Runoff factors which are used for hydromodification management flow control (Table G.2-1) are different from the runoff factors used for pollutant control BMP sizing (Table B.1-1). Table references are taken from the San Diego Region Model BMP Design Manual, April 2018.

Provided Cistern Depth (Overflow Elevation)
Minimum Required Cistern Footprint)
Describe the BMP's in sufficient detail in your PDP SWQMP to demonstrate the area, volume, and other criteria can be met within the constraints of the site.

BMP's must be adapted and applied to the conditions specific to the development project such as unstable slopes or the lack of available head. Designated Staff have final review and approval authority over the project design.This BMP Sizing Spreadsheet has been updated in conformance with the San Diego Region Model BMP Design Manual, April 2018. For questions or concerns please contact the jurisdiction in which your project is located.

Standard Cistern Depth (Overflow Elevation)
464-600-26-00 0.1Q2
HMP 2 Cistern
D NA
Areas Draining to BMP
City of La Mesa 0
BMP Sizing Spreadsheet V3.0
Costco La Mesa La Mesa
0 Oceanside

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Project Name: Hydrologic Unit:

Project Applicant: Rain Gauge:Jurisdiction: Total Project Area:Parcel (APN): Low Flow Threshold:BMP Name BMP Type:

Rain Gauge Unit Runoff Ratio DMA Area (ac) Orifice Flow - %Q2 Orifice Area Soil Type Slope (cfs/ac) (cfs) (in2)
DMA 4 Oceanside D Flat 0.571 0.229 0.013 0.19

3.50 0.013 0.19 0.50
Max Orifice Head Max Tot. Allowable Orifice Flow Max Tot. Allowable Orifice Area Max Orifice Diameter (feet) (cfs) (in2) (in)
Provide Hand Calc. 0.013 0.20 0.500
Average outflow during
surface drawdown Max Orifice Outflow Actual Orifice Area Selected Orifice Diameter (cfs) (cfs) (in2) (in)
Drawdown (Hrs) Provide Hand Calculation
No Orifice Required for
Infiltration Facilities
Drawdown time exceeds 96 Hrs. Project must implement a vector control program. 464-600-26-00 0.1Q2
HMP 2 Cistern
DMA
Name
Pre-developed Condition
City of La Mesa 0
BMP Sizing Spreadsheet V3.0
Costco La Mesa La Mesa
0 Oceanside

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Lower Flow Threshold Soil Group Slope Rain Gauge A

0.1Q2 A Flat Lindbergh 0.0550.1Q2 A Moderate Lindbergh 0.0550.1Q2 A Steep Lindbergh 0.0550.1Q2 B Flat Lindbergh 0.0450.1Q2 B Moderate Lindbergh 0.0450.1Q2 B Steep Lindbergh 0.0450.1Q2 C Flat Lindbergh 0.0350.1Q2 C Moderate Lindbergh 0.0350.1Q2 C Steep Lindbergh 0.0350.1Q2 D Flat Lindbergh 0.030.1Q2 D Moderate Lindbergh 0.030.1Q2 D Steep Lindbergh 0.030.1Q2 A Flat Oceanside 0.060.1Q2 A Moderate Oceanside 0.060.1Q2 A Steep Oceanside 0.060.1Q2 B Flat Oceanside 0.050.1Q2 B Moderate Oceanside 0.050.1Q2 B Steep Oceanside 0.050.1Q2 C Flat Oceanside 0.050.1Q2 C Moderate Oceanside 0.050.1Q2 C Steep Oceanside 0.0450.1Q2 D Flat Oceanside 0.0350.1Q2 D Moderate Oceanside 0.0350.1Q2 D Steep Oceanside 0.0350.1Q2 A Flat Lake Wohlford 0.0850.1Q2 A Moderate Lake Wohlford 0.0850.1Q2 A Steep Lake Wohlford 0.0850.1Q2 B Flat Lake Wohlford 0.07 Table G.2-3: Sizing Factors for Hydromodification Flow Control Infiltration BMPs Designed Using Sizing Factor Method

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0.1Q2 B Moderate Lake Wohlford 0.07

0.1Q2 B Steep Lake Wohlford 0.070.1Q2 C Flat Lake Wohlford 0.0550.1Q2 C Moderate Lake Wohlford 0.0550.1Q2 C Steep Lake Wohlford 0.0550.1Q2 D Flat Lake Wohlford 0.040.1Q2 D Moderate Lake Wohlford 0.040.1Q2 D Steep Lake Wohlford 0.04 Lower Flow Threshold Soil Group Slope Aggregate below low orifice invert (inches) Rain Gauge A

0.1Q2 A Flat 18 Lindbergh 0.080.1Q2 A Moderate 18 Lindbergh 0.080.1Q2 A Steep 18 Lindbergh 0.080.1Q2 B Flat 18 Lindbergh 0.0650.1Q2 B Moderate 18 Lindbergh 0.0650.1Q2 B Steep 18 Lindbergh 0.060.1Q2 C Flat 6 Lindbergh 0.05

0.1Q2 C Moderate 6 Lindbergh 0.05

0.1Q2 C Steep 6 Lindbergh 0.05

0.1Q2 D Flat 3 Lindbergh 0.050.1Q2 D Moderate 3 Lindbergh 0.050.1Q2 D Steep 3 Lindbergh 0.050.1Q2 A Flat 18 Oceanside 0.080.1Q2 A Moderate 18 Oceanside 0.0750.1Q2 A Steep 18 Oceanside 0.0750.1Q2 B Flat 18 Oceanside 0.070.1Q2 B Moderate 18 Oceanside 0.070.1Q2 B Steep 18 Oceanside 0.070.1Q2 C Flat 6 Oceanside 0.07

0.1Q2 C Moderate 6 Oceanside 0.07
Table G.2-4: Sizing Factors for Hydromodification Flow Control Biofiltration with Partial Retention Designed Using Sizing Factor Method

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0.1Q2 C Steep 6 Oceanside 0.07

0.1Q2 D Flat 3 Oceanside 0.070.1Q2 D Moderate 3 Oceanside 0.070.1Q2 D Steep 3 Oceanside 0.070.1Q2 A Flat 18 Lake Wohlford 0.110.1Q2 A Moderate 18 Lake Wohlford 0.110.1Q2 A Steep 18 Lake Wohlford 0.1050.1Q2 B Flat 18 Lake Wohlford 0.090.1Q2 B Moderate 18 Lake Wohlford 0.0850.1Q2 B Steep 18 Lake Wohlford 0.0850.1Q2 C Flat 6 Lake Wohlford 0.065

0.1Q2 C Moderate 6 Lake Wohlford 0.065

0.1Q2 C Steep 6 Lake Wohlford 0.065

0.1Q2 D Flat 3 Lake Wohlford 0.060.1Q2 D Moderate 3 Lake Wohlford 0.060.1Q2 D Steep 3 Lake Wohlford 0.06 Lower Flow Threshold Soil Group Slope Rain Gauge A

0.1Q2 A Flat Lindbergh 0.320.1Q2 A Moderate Lindbergh 0.30.1Q2 A Steep Lindbergh 0.2850.1Q2 B Flat Lindbergh 0.1050.1Q2 B Moderate Lindbergh 0.10.1Q2 B Steep Lindbergh 0.0950.1Q2 C Flat Lindbergh 0.0550.1Q2 C Moderate Lindbergh 0.050.1Q2 C Steep Lindbergh 0.050.1Q2 D Flat Lindbergh 0.050.1Q2 D Moderate Lindbergh 0.050.1Q2 D Steep Lindbergh 0.050.1Q2 A Flat Oceanside 0.150.1Q2 A Moderate Oceanside 0.140.1Q2 A Steep Oceanside 0.135 Table G.2-5: Sizing Factors for Hydromodification Flow Control Biofiltration BMPs Designed Using Sizing Factor Method

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0.1Q2 B Flat Oceanside 0.085

0.1Q2 B Moderate Oceanside 0.0850.1Q2 B Steep Oceanside 0.0850.1Q2 C Flat Oceanside 0.0750.1Q2 C Moderate Oceanside 0.0750.1Q2 C Steep Oceanside 0.0750.1Q2 D Flat Oceanside 0.070.1Q2 D Moderate Oceanside 0.070.1Q2 D Steep Oceanside 0.070.1Q2 A Flat Lake Wohlford 0.2850.1Q2 A Moderate Lake Wohlford 0.2750.1Q2 A Steep Lake Wohlford 0.270.1Q2 B Flat Lake Wohlford 0.150.1Q2 B Moderate Lake Wohlford 0.1450.1Q2 B Steep Lake Wohlford 0.1450.1Q2 C Flat Lake Wohlford 0.070.1Q2 C Moderate Lake Wohlford 0.070.1Q2 C Steep Lake Wohlford 0.070.1Q2 D Flat Lake Wohlford 0.060.1Q2 D Moderate Lake Wohlford 0.060.1Q2 D Steep Lake Wohlford 0.06 Lower Flow Threshold Soil Group Slope Rain Gauge V

0.1Q2 A Flat Lindbergh 0.540.1Q2 A Moderate Lindbergh 0.510.1Q2 A Steep Lindbergh 0.490.1Q2 B Flat Lindbergh 0.190.1Q2 B Moderate Lindbergh 0.180.1Q2 B Steep Lindbergh 0.180.1Q2 C Flat Lindbergh 0.110.1Q2 C Moderate Lindbergh 0.110.1Q2 C Steep Lindbergh 0.110.1Q2 D Flat Lindbergh 0.09 Table G.2-6: Sizing Factors for Hydromodification Flow Control Cistern Facilities Designed Using Sizing Factor Method

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0.1Q2 D Moderate Lindbergh 0.09

0.1Q2 D Steep Lindbergh 0.090.1Q2 A Flat Oceanside 0.260.1Q2 A Moderate Oceanside 0.250.1Q2 A Steep Oceanside 0.250.1Q2 B Flat Oceanside 0.160.1Q2 B Moderate Oceanside 0.160.1Q2 B Steep Oceanside 0.160.1Q2 C Flat Oceanside 0.140.1Q2 C Moderate Oceanside 0.140.1Q2 C Steep Oceanside 0.140.1Q2 D Flat Oceanside 0.120.1Q2 D Moderate Oceanside 0.120.1Q2 D Steep Oceanside 0.120.1Q2 A Flat Lake Wohlford 0.530.1Q2 A Moderate Lake Wohlford 0.490.1Q2 A Steep Lake Wohlford 0.490.1Q2 B Flat Lake Wohlford 0.280.1Q2 B Moderate Lake Wohlford 0.280.1Q2 B Steep Lake Wohlford 0.280.1Q2 C Flat Lake Wohlford 0.140.1Q2 C Moderate Lake Wohlford 0.140.1Q2 C Steep Lake Wohlford 0.140.1Q2 D Flat Lake Wohlford 0.120.1Q2 D Moderate Lake Wohlford 0.120.1Q2 D Steep Lake Wohlford 0.12

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County of San Diego SWQMP Sub-attachment 8.2 (Points of Compliance) Page 8.2-1 Template Date: January 8, 2019 Preparation Date: 6/23/2021

8.2 Hydromodification Management Points of Compliance
• List and describe all points of compliance (POCs) for flow control for hydromodification management.
• For each POC, provide a POC identification name or number, and a receiving channel identification name or number correlating to the project's HMP Exhibit (see Attachment 2).

POC name or # Channel name or # POC Description
POC 1 Alverado Channel Box Culvert

09/30/2021

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County of San Diego SWQMP Sub-attachment 8.3 (Geomorphic Assessment) Page 8.3-1 Template Date: January 8, 2019 Preparation Date: 6/23/2021

8.3 Geomorphic Assessment of Receiving Water Channels
Insert Geomorphic Assessment behind this cover page or submit as a separate stand-alone document labeled Sub-attachment 8.3.

09/30/2021

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County of San Diego SWQMP Sub-attachment 8.4 (Vector Control Plan) Page 8.4-1 Template Date: January 8, 2019 Preparation Date: 6/23/2021

8.4 Vector Control Plan
Insert Vector Control Plan behind this cover page or submit as a separate stand-alone document labeled Sub-attachment 8.4.

09/30/2021

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County of San Diego Stormwater Quality Management Plan (SWQMP) Attachment 9: Management of Critical Coarse Sediment Yield Areas County of San Diego SWQMP Attachment 9.0 (General Requirements) Page 9.0-1 Template Date: January 11, 2019 Preparation Date: 6/22/2021

9.0 General Requirements
• Complete the table below to indicate which compliance pathway was selected in PDP SWQMP Table 6. Include the corresponding sub-attachment with your SWQMP submittal. Other subattachments do not need to be included. • See the BMPDM sections and appendices listed under “BMPDM Design Resources” for additional explanation of design requirements. Constructed features must fully satisfy the requirements described in these resources, and any other guidance identified by the County. • DMA Exhibits and Construction Plans: CCSYAs and applicable BMPs identified and described in this attachment must be shown on DMA Exhibits and all applicable construction plans submitted for the project. See Attachment 2 for additional instruction on exhibits and plans.

Sub-attachments BMPDM Design
Resources
☐ 9.1: Documentation of Hydromodification Management Exemption1 Section 1.6 ☒ 9.2: Watershed Management Area Analysis (WMAA) Mapping1 Appendix H.1.1.2 ☐ 9.3: Resource Protection Ordinance (RPO) Methods Appendix H.1.1.1 ☐ 9.4: No Net Impact Analysis Appendix H.4
1 The San Diego County Regional comprehensive WMAA mapping data can be found on the Project Clean Water website here: http://www.projectcleanwater.org/download/wmaa_attc_data/ 09/30/2021

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County of San Diego SWQMP Sub-attachment 9.1 (Hydromodification Exemption) Page 9.1-1 Template Date: January 11, 2019 Preparation Date: 6/22/2021

9.1 Documentation of Hydromodification Management Exemption (BMPDM Section 1.6) • If the PDP is exempt from hydromodification management requirements (see Table 4 Part A.1 of the PDP SWQMP), use this Sub-attachment to document the exemption. • Select the type of exemption below that applies and provide an explanation of the selection, including maps or other applicable documentation. Additional documentation may be requested by County staff.

Exemption Type per BMPDM Figure 1-2 (select one)
☐ a. The proposed project will discharge runoff directly to existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
☐ b. The proposed project will discharge runoff directly to conveyance channels whose bed and bank are concrete lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
☐ c. The proposed project will discharge runoff directly to an area identified by the County as appropriate for an exemption by the WMAA for the watershed in which the project resides2.

Explanation (add or attach pages as necessary)
2 This option must include an analysis of the project using the methodology presented in Attachment E of the Regional Watershed Management Area Analysis.
09/30/2021

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County of San Diego SWQMP Sub-attachment 9.2 (Mapping Results) Page 9.2-1 Template Date: January 11, 2019 Preparation Date: 6/22/2021

9.2 Watershed Management Area Analysis (WMAA) Mapping (BMPDM Appendix H.1.1.2) Watershed Management Area Analysis (WMAA) mapping is a simple way to screen projects to determine the presence of onsite or offsite upstream Potential Critical Coarse Sediment Yield Areas (PCCSYAs). The San Diego County Regional WMAA mapping data can be found on the Project Clean Water website here: http://www.projectcleanwater.org/download/wmaa_attc_data/ . 3 • Based on the WMAA map and the proposed project design, demonstrate below that both of the following conditions apply to the PDP:
(a) Less than 5% of PCCSYAs will be impacted (built on or obstructed) by the PDP, and (b) All upstream offsite PCCYSAs will be bypassed (see BMPDM Appendix H.3).

A. Mapping Results -- At a minimum, show: (1) the project footprint, (2) areas of proposed development, (3) impacted onsite PCCSYAs, (4) offsite tributary areas4, and (5) bypass of upstream offsite PCCSYAs.

3 Applicants may refine initial mapping results using options identified in BMPDM Appendix H.1.2. 4 Tributary areas must be shown to demonstrate that upstream offsite PCCSYAs do not exist. If bypassing these areas, only the bypass should be shown.

See next page for exhibit 09/30/2021

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COSTCO WHOLE SALE

FLETCHER PARKWAY

LA MESA, CA
CCSYA
(1.5 MILES AWAY) CCSYA
(1.5 MILES AWAY)

PROJECT

LOCATION

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County of San Diego SWQMP Sub-attachment 9.2 (Mapping Results) Page 9.2-1 Template Date: January 11, 2019 Preparation Date: 6/22/2021 B. Explanation -- Provide documentation as needed to demonstrate that (1) impacts to PCCSYAs are below 5%, and (2) upstream offsite PCCYSAs are effectively bypassed. Add pages as necessary.

There are no PCCSYAs within the project parcel or draining through the project parcel 09/30/2021

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County of San Diego SWQMP Sub-attachment 9.3 (Compliance Documentation) Page 9.3-1 Template Date: January 11, 2019 Preparation Date: 6/22/2021

9.3 Resource Protection Ordinance (RPO) Methods (BMPDM Appendix H.1.1.1) • Either of two Resource Protection Ordinance (RPO) methods may also be used to demonstrate compliance with CCSYA requirements. Select either option and document the selection below:
☐ RPO Scenario 1: PDP is subject to and in compliance with RPO requirements5 o Select if the project requires one or more discretionary permits; o Demonstrate that onsite AND upstream offsite CCSYAs will be avoided and/or bypassed. ☐ RPO Scenario 2: PDP is entirely exempt/not subject to RPO requirements6 o Select if the project does not require discretionary permits; o Demonstrate that all upstream offsite CCSYAs will be bypassed7.

A. Mapping Results -- At a minimum, show as applicable: (1) the project footprint, (2) areas of proposed development, (3) locations of onsite and upstream offsite CCSYAs, and (4) bypass of all identified CCSYAs.
5 RPO applicability is normally confirmed during discretionary review. Check with your project manager if you’re not sure of your status.
6 Does not include PDPs utilizing exemption(s) via RPO Section 86.604(e)(2)(cc) or 86.604(e)(3). 7 This scenario does not impose requirements for onsite CCSYAs. 09/30/2021

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County of San Diego SWQMP Sub-attachment 9.3 (Compliance Documentation) Page 9.3-2 Template Date: January 11, 2019 Preparation Date: 6/22/2021 B. Explanation -- Provide documentation as needed to demonstrate that (1) onsite CCSYAs are avoided and bypassed [if applicable], and (2) upstream offsite CCYSAs are effectively bypassed.

Add pages as necessary.
09/30/2021

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County of San Diego SWQMP Sub-attachment 9.4 (No Net Impact Analysis) Page 9.4-1 Template Date: January 11, 2019 Preparation Date: 6/22/2021

9.4 No Net Impact Analysis (BMPDM Appendix H.4)
• When impacts to CCSYAs cannot be avoided or effectively bypassed, applicants must demonstrate that their project generates no net impact to the receiving water per the performance metrics identified in BMPDM Appendix H.4.
• Use the space below to document that the PDP will generate no net impact to any receiving water.

No Net Impact Analysis (add or attach pages as necessary) 09/30/2021

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County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 10: BMP Installation Verification for Priority Development Projects County of San Diego SWQMP Attachment 10
Template Date: September 15, 2020

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Preparation Date: 6/23/2021
This form must be accepted by the County prior to the release of construction permits or granting of occupancy for applicable portions of a Priority Development Project (PDP). Its purpose is to provide documentation of the final installation of permanent Best Management Practices (BMPs) used to satisfy Structural Performance Standards for the development project. Compliance with these standards reduces the discharge of pollutants and flows from the completed project site.

Applicable standards may be satisfied using Structural BMPs (S-BMPs), Significant Site Design BMPs (SSD-BMPs), or both. Applicants are responsible for providing all requested information.

PART 1 PROJECT INFORMATION
A. Project Summary Information
Project Name Costco La Mesa – Building Expansion
Record ID
(e.g. grading/improvement plan
number, building permit)
Project Address 8125 Fletcher Parkway, La Mesa, CA 91942 Assessor's Parcel Number(s) APN(s) 464-600-15 & 464-600-26 Project Watershed
(Hydrologic Unit, Area, and Subarea
Name with Numeric Identifier)
San Diego Hydrologic Unit, Lower San Diego Hydraulic
Area, Mission San Diego Sub-Area (907.11)

B. Owner Information
Name Costco Wholesale
Address 9 Corporate Park, Suite 230, Irvine, CA 92606
Email Address
Phone Number 714-978-5026
COUNTY – OFFICIAL USE ONLY
INTAKE ID#
ACCEPTANCE ID#

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09/30/2021
County of San Diego
Stormwater Quality Management Plan (SWQMP)
Attachment 10: BMP Installation Verification for Priority Development Projects County of San Diego SWQMP Attachment 10
Template Date: September 15, 2020

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Preparation Date: 6/23/2021
**THIS PAGE IS FOR PARTIAL VERIFICATIONS ONLY **
If final grade release or granting of occupancy is being requested for only a portion of the Priority Development Project (PDP) please fill out the table below. Include ALL of the Structural BMPs and/or Significant Site Design BMPs for the entire project in the table. Include a mark-up of the DMA map from the approved SWQMP with this Verification package that clearly shows which DMAs you are submitting for approval and which DMAs have already been accepted (if any).

DMA # APN or Lot # BMP ID #
WPP
Acceptance
Date
(If applicable)
WPP
Acceptance ID#
(If applicable,
e.g. 20/21-001)

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Preparation Date: 6/23/2021
PART 2 BMP INVENTORY INFORMATIONUse this table to document Structural BMPs (S-BMPs) and Significant Site Design BMPs (SSD-BMPs) for the PDP. All DMAs that are not self-mitigating or de minimis must have at least one Structural BMP or Significant Site Design BMP. • In Part A list all Structural BMPs (including both Pollutant Control and/or Hydromodification as applicable) by DMA. • Complete Part B for all DMAs that contain only Significant Site Design BMPs. SSD-BMPs are Site Design BMPs (SD-BMPs) that are sized and constructed to satisfy Structural Performance Standards for a DMA. • The information provided for each BMP in the table must match that provided in the Stormwater Quality Management Plan (SWQMP), construction plans, maintenance agreements, and other relevant project documentation.

DMA # BMP Information Maintenance
Category
Maintenance
Agreement
Recorded Doc #
Construction
Plan Sheet #
Landscape
Plan Sheet #

FOR DPW-WPP

USE ONLY
Quantity Description/Type of Structural BMP BMP ID #
A. Structural BMPs (S-BMPs)
DMA1 1 Biofiltration Planter BMP1 Cat 2
DMA4 1 Proprietary BMP BMP2 Cat 2 DMA4 1 Underground Detention HMP 2 Cat 2 Add rows as needed. Click into the last column in the row below this, then press TAB to add a new row.B. Significant Site Design BMPs (SSD-BMPs) Choose an item. --- --- Choose an item. --- --- Choose an item. --- --- Choose an item. --- --- Choose an item. --- --- Choose an item. --- --- Add rows as needed. Click into the last column in the row below this, then press TAB to add a new row. --- ---
09/30/2021 ** **The installation of this proprietary biofiltration planter unit and underground detention system will occur under the Phase 1 (Building Permit) portion of the project, but will be sized to treat the areasdelineated in the Ultimate Condition of the project. See Attachment 2: DMA Exhibit - Phase 1 and Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. ** *The installation of the biofiltration planter BMP will occur under the Phase 2 (Grading Permit) portion of the project, see Attachment 2: DMA Exhibit - Ultimate Condition for scope clarification. *

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Preparation Date: 6/23/2021
PART 3 REQUIRED ATTACHMENTS
For the permanent BMPs listed in Part 2, submit the following to the County inspector along with this Verification form as a package (check all that are attached):
☐ PHOTOGRAPHS: Final construction photos of every permanent BMP listed in Part 2 are required. Final photos must be recent and be labeled with the date and a BMP Identifier.

Additional photographs illustrating proper construction of the BMPs are recommended to be included and may be requested by WPP prior to acceptance of this Verification (e.g. excavation depths, liners, hydromodification orifices, Biofiltration Soil Media (BSM), vegetation, mulch).
☐ MAINTENANCE AGREEMENTS: Copies of approved and recorded Storm Water Maintenance Agreements (SWMA), Category 1 Maintenance Notification Agreements (MN), or Encroachment Maintenance and Removal Agreements (EMRA) for all S-BMPs.

Note: Significant Site Design (SSD) BMPs and most Category 4 BMPs do not require recorded maintenance agreements.
☐ CONSTRUCTION PLANS: Submit electronic and/or 11” X 17” hard copies of the current approved Construction Plan sheets for the Record ID(s) listed on Page 1:
☐ Grading Plans
☐ Improvement Plans
☐ Precise Grading Plan
☐ Building Plan (Applicable BMP Sheets only)
☐ Other (Please specify)
For each Construction Plan, the sheets submitted must incorporate all of the following:
• A BMP Table on Sheet 1, AND
• A plan detail cross-section of each verified as-built BMP, AND • The location of each verified as-built BMP
☐ LANDSCAPE PLANS: If the PDP includes vegetated BMPs and has a Landscape Plan, submit the following:
☐ Final Landscape Plans
☐ Water Use Authorization from PDS Landscape Architect

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Preparation Date: 6/23/2021
PART 4 PREPARER’S CERTIFICATION
By signing below, I certify that the BMP(s) listed in Part 2 of this Verification Form have been constructed and are in substantial conformance with the approved plans and applicable regulations. I understand the County reserves the right to inspect the above BMPs to verify compliance with the approved plans and Watershed Protection Ordinance (WPO). Should it be determined that the BMPs were not constructed to plan or code, corrective actions may be necessary before permits can be closed.

Note: Structural BMPs must be certified by a licensed professional engineer.

Please sign and, if applicable, provide your seal below.

Preparer’s Name:

Email Address:

Phone Number:

Preparer’s Signature:

Date:
[SEAL]

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Preparation Date: 6/23/2021

COUNTY - OFFICIAL USE ONLY
County Inspector Approval:
*NOTE: The County approved SWQMP document and any Addendums or Revisions must be included with this BMP Installation Verification submittal package. □ DPW Private Development Construction Inspection (PDCI) □ PDS Building (Inspector Supervisor signature required) □ DGS
□ DPR
By signing below, the County Inspector concurs that every BMP listed in Part 2 of this BMP Installation Verification form has been installed per plan.

Inspector Name: _______________________________________________ Inspector’s Signature: ___________________________ Date: ________________ DPW Watershed Protection Program (WPP) Acceptance:

Date Received: _________________________________________ WPP Reviewer: __________________________________________ WPP Reviewer concurs that the BMPs accepted in Part 2 above may be entered into County inventory.

WPP Reviewer’s Signature: ___________________________ Date: _______ Enter Acceptance ID# on page 1.

NOTES:

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09/30/2021
PHASE 1 STORMWATER

MAINTENANCE AGREEMENT
PER BUILDING PERMIT B22-051
NOTE: PHASE 2 STORMWATER

AGREEMENT TO BE PROVIDED AT

TIME OF FINAL ENGINEERING

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County of San Diego Stormwater Quality Management Plan (SWQMP) Attachment 11: BMP Maintenance Plans and Agreements
County of San Diego SWQMP Attachment 11 Page 11.0-1
Template Date: December 28, 2018 Preparation Date: 6/22/2021

11.0 Cover Sheet and General Requirements
• All Structural BMPs must have a plan and mechanism to ensure on-going maintenance. Use the table below to document the types of agreements to be submitted for the PDP and submit them under cover of this sheet.
• See BMPDM Section 7.3 for a description of maintenance categories and responsibilities. Note that since Category 3 and 4 BMPs are County-maintained, they do not require maintenance agreements.
a. Applicability of Maintenance Agreements
Check the boxes below to indicate which types of agreements are included with this attachment. ☐ Maintenance Notification (Category 1 BMPs)
• Exhibit A: Project Site Vicinity; Project Site Map; and a map for each BMP and its Drainage Management Area
• Exhibit B: BMP Maintenance Plan (see below)
☒ Stormwater Maintenance Agreement (Category 2 BMPs)
• Exhibit A: Legal Description of Property
• Exhibit B: BMP Maintenance Plan (see below)
• Exhibit C: Project Site Vicinity Map
Maintenance agreement templates and instructions are provided on the County’s website:
www.sandiegocounty.gov/stormwater under the Development Resources tab.

PDP applicants contact County staff to ensure they have the most current forms. b. Maintenance Plan Requirements
Use this checklist to confirm that each maintenance plan includes the following that as applicable. ☐ Specific maintenance indicators and actions for proposed structural BMP(s). These must be based on based on maintenance indicators presented in BMP Design Fact Sheets in Appendix E and enhanced to reflect actual proposed components of the structural BMP(s). ☒ Access to inspect and perform maintenance on the structural BMP(s). ☒ Features to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds).
☒ Manufacturer and part number for proprietary parts of structural BMP(s) when applicable. ☒ Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP).
☒ Recommended equipment to perform maintenance.
☒ When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management. 09/30/2021

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EXHIBIT "A" SHEET 1

LEGAL DESCRIPTION
LOT 2 LA MESA TRACT 96-01 FILED AS MAP NO. 13346 IN THE OFFICE OF THE COUNTY RECORDER OF SAN DIEGO, STATE OF CALIFORNIA, ON AUGUST 7, 1996 AS FILE NO. 96-399715 OF OFFICIAL RECORDS.

VICINITY MAP

E N G I N E E R I N G
6390 Greenwich Dr., Suite 170, San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com

PROJECT SITE

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EXHIBIT "B" SHEET 2

KEY MAP

E N G I N E E R I N G
6390 Greenwich Dr., Suite 170, San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com

FLETCHER PARKWAY

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EXHIBIT "B" SHEET 3 EXHIBIT "B" SHEET 3

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EXHIBIT "C"

E N G I N E E R I N G
6390 Greenwich Dr., Suite 170, San Diego, California 92122 tel 858.554.1500 fax 858.597.0335 www.fuscoe.com
SHEET 5

OPERATION & MAINTENANCE PROCEDURE DETAILS

BMP DESCRIPTION

POST-CONSTRUCTION PERMANENT BMP

TREATMENT CONTROL

HYDROMODIFICATION CONTROL

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ATTACHMENT 3A – BMP MAINTENANCE PLAN - BIOFILTRATION BASIN

STORM WATER QUALITY MANAGEMENT PLAN COSTCO LA MESA
Operation & Maintenance Manual – BIOFILTRATION BMP

1. PURPOSE OF THE BIOFILTRATION BMP MAINTENANCE MANUAL
The purpose of this manual is to provide maintenance instructions for the Biofiltration BMPs located within Costco La Mesa Building Expansion The Biofiltration basin is a pollution control device designed to treat urban runoff before it enters in to the storm drain systems located on the project site. Regular maintenance will help to ensure that the biofiltration functions as it has been designed.

This manual will serve as a reference guide and filed manual to assist the property owner with:
• An overview of the Biofiltration BMP and how it functions • A description of the location of the Biofiltration BMP • An understanding of the procedures required to effectively maintain the Biofiltration BMP on a regular basis
• Reproducible copies of the forms, logs and guidance sheets necessary for recording maintenance activities associated with the Biofiltration BMP.

2. GENERAL DESCRIPTION AND FUNCTION OF THE BIOFILTRATION BMP The Biofiltration BMP is a structure filled with gravel soil and vegetation that drain to an underdrain which connects to the storm drain system. These systems also have an overflow structure to prevent high flows from leaving the planter area. From the top of the curb or concrete step-off to the bottom, the porous materials consist of BMP 1:
• 3” of well-aged shredded mulch
• 18” of Biofiltration Soil Media (BSM)
• 6" Washed Pea Gravel Filter Course Layer
• 12” Open Graded Sub-Base Course rounded #57 Stone, 40% Voids A 6" diameter perforated pvc underdrain will be installed 3” from the bottom of the open graded sub-base. This pipe connects to the storm drain.

Pollution is mitigated through infiltration of runoff into the porous materials within the planter and ultimately through infiltration through the biofiltration soil media and stone layers.

3. MAINTENANCE RESPONSIBILITY
Costco will be responsible for Site Design, Source Control and Treatment Control BMPs and is ultimately responsible for maintaining the Biofiltration BMP. The goal in maintaining the planter is to ensure that Infiltration is occurring. Regular inspection and replacement of materials within the planter once it becomes ineffective in performing as designed are the major components in the maintenance program. In order to achieve this, the following general procedures shall be followed:
• Qualified maintenance personnel should periodically inspect the planter at least twice a year. The first inspection should happen prior to August 1 and the subsequent inspection should happen during the period between February l and March 31. • If a problem is identified, it should be rectified as soon as possible to ensure that the trench functions as designed,

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ATTACHMENT 3A – BMP MAINTENANCE PLAN - BIOFILTRATION BASIN

STORM WATER QUALITY MANAGEMENT PLAN COSTCO LA MESA
• Regular removal of trash and debris should occur as needed. Trash and debris, visible along the surface of the trench shall be promptly removed.

Detailed maintenance procedures are outlined 5.

4. MAINTENANCE INDICATORS AND ACTIVITIES
Functional Maintenance:

Regular functional maintenance is required to ensure that the Biofiltration BMP performs in an effective manner. Functional maintenance consists of both preventative and corrective activities.

Logs and guidance sheets are contained herein to use in recording vital information while performing operation Inspection and other infiltration trench maintenance activities.

Maintenance records shall be maintained by the property owner for a minimum of five years.

The proper use and subsequent storage of these records will assure the City of La Mesa that the Biofiltration BMP is functioning as designed.

Preventative Maintenance:

Preventative maintenance shall be performed on a regular basis. Checklists are included herein to track and record preventative maintenance activities. These activities include trash and debris removal and sediment management,
Trash and debris removal shall be performed to ensure that runoff has adequate surface area to infiltrate through the various layers that comprise the cross section of the trench.

Sediment management will occur when testing Indicates that the Infiltration rate has diminished below the stated acceptable rate.

Corrective Maintenance:

Corrective maintenance will be required on an emergency or non-routine basis to correct problems and restore the intended operation and safe function of the Biofiltration BMP.

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ATTACHMENT 3A – BMP MAINTENANCE PLAN - BIOFILTRATION BASIN

STORM WATER QUALITY MANAGEMENT PLAN COSTCO LA MESA
Biofiltration BMP Maintenance
• Inspect a minimum of once per year, before the rainy season, and after large storm events or more frequently as needed.
• Clean the planter when the loss of infiltrative capacity is observed. When the standing water is present for a period of time in excess of 72 hours, removal of sediment may be necessary.
• Control mosquitoes as necessary.
• Remove litter and debris from surface as required.

Maintenance Indicators:

Maintenance Indicators are signs or triggers that indicate that maintenance personnel need to check the Biofiltration BMP for maintenance needs. The most common triggers include warnings or accounts of standing water and sediment accumulation. Inspection and Maintenance Checklist in Section 5 below shows conditions and criteria that trigger the need for some specific routine infiltration trench maintenance activities. Emergencies may occasionally arise that would require a more urgent, critical response.

Sediment Management:

The types of storm water pollutants that accumulate in sediment varies, but may include contaminants such as heavy metals, petroleum hydrocarbons, and other organic compounds such as pesticides or solvents. When the sediment has clogged the Biofiltration BMP, remove and properly dispose of Sediment. Regrade if necessary.

Sediment Disposal:

Several methods for disposal are available depending on the concentration of toxins in the waste. Methods can range from recycling the material, to depositing the sediment into appropriate landfills.

At the time of disposal, if the wastes are deemed to be unfit for disposal in a municipal landfill, a full and comprehensive testing program should be run by a qualified person to test for all the constituents outlined under California code of Regulations (CCR) Title 22. Title 22 list concentrations of certain chemicals and their soluble threshold limit concentrations (STLC's) and their total threshold limit concentrations (TTLC's). Chemicals that exceed the allowable concentrations are considered hazardous wastes and must be removed from the sediment.

5. INSPECTION AND MAINTENANCE CHECKLIST
See following page.

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ATTACHMENT 3A – BMP MAINTENANCE PLAN - BIOFILTRATION BASIN

STORM WATER QUALITY MANAGEMENT PLAN COSTCO LA MESA
Biofiltration BMP Inspection and Maintenance Checklist Date of Inspection: ____________________ BMP Name/Location:_____________________________ Inspected by:_____________________________ Type of Inspection: ☐ Monthly ☐ Pre-Wet Season ☐ After Heavy Runoff (1” or greater) ☒ Annual Prior to Start of Wet Season ☐ Other _________________________________
__
Defect Conditions When Maintenance is Required Field Measurement Measurement Frequency Maintenance Activity Maintenance Needed (yes/no) Comments (Describe maintenance completed and if needed maintenance was not conducted, note when it will be done) Vegetation Management for Aesthetics (optional)
Visual observation and random measurements throughout the side slope area Visual observation and random measurements throughout the side slope area Annually, prior to start of wet season
Cut vegetation to an average height of 6-inches and remove trimmings. Remove any trees, or woody vegetation.

Standing Water Visual observation Visual observation
Annually, 96 hours after a target storm (0.60 in) event Drain facility. Corrective action prior to wet season. Consult engineers if immediate solution is not evident.

Trash and Debris Visual observation Visual observation
Annually, prior to start of wet season
Remove and dispose of trash and debris
Sediment Management
Measure depth at apparent maximum and minimum accumulation of sediment. Calculate average depth Measure depth at apparent maximum and minimum accumulation of sediment. Calculate average depth Annually, prior to start of wet season
Remove and properly dispose of sediment. Regrade if necessary. (expected every 2 years) Underdrains Visual Observation Visual Observation
Annually, prior to start of wet season
Corrective action prior to wet season. Consult engineers if immediate solution is not evident.

General Maintenance Inspection
Visual observation Visual observation
Annually, prior to start of wet season
Corrective action prior to wet season. Consult engineers if immediate solution is not evident.

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ATTACHMENT 3A – BMP MAINTENANCE PLAN - BIOFILTRATION BASIN

STORM WATER QUALITY MANAGEMENT PLAN COSTCO LA MESA
Erosion Visual observation Visual observation
Annually, prior to start of wet season
Corrective action prior to wet season. Consult engineers if immediate solution is not evident.

Poor Vegetation Establishment
Visual observation Visual observation
Annually, prior to start of wet season
Corrective action prior to wet season. Consult engineers if immediate solution is not evident.

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Inspection Guidelines for
Modular Wetland System - Linear
Inspection Summary
o Inspect Pre-Treatment, Biofiltration and Discharge Chambers – average inspection interval is 6 to 12 months.
 (15 minute average inspection time).
o NOTE: Pollutant loading varies greatly from site to site and no two sites are the same. Therefore, the first year requires inspection monthly during the wet season and every other month during the dry season in order to observe and record the amount of pollutant loading the system is receiving.

System Diagram

Access to separation chamber and pre-filter cartridges
1 Pre-treatment Chamber
2 Biofiltration Chamber
3 Discharge Chamber
Access to discharge chamber and orifice control

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Inspection Overview
As with all stormwater BMPs inspection and maintenance on the MWS Linear is necessary.

Stormwater regulations require that all BMPs be inspected and maintained to ensure they are operating as designed to allow for effective pollutant removal and provide protection to receiving water bodies. It is recommended that inspections be performed multiple times during the first year to assess the site specific loading conditions. This is recommended because pollutant loading and pollutant characteristics can vary greatly from site to site. Variables such as nearby soil erosion or construction sites, winter sanding on roads, amount of daily traffic and land use can increase pollutant loading on the system. The first year of inspections can be used to set inspection and maintenance intervals for subsequent years to ensure appropriate maintenance is provided. Without appropriate maintenance a BMP will exceed its storage capacity which can negatively affect its continued performance in removing and retaining captured pollutants.

Inspection Equipment
Following is a list of equipment to allow for simple and effective inspection of the MWS Linear:
 Modular Wetland Inspection Form
 Flashlight
 Manhole hook or appropriate tools to remove access hatches and covers  Appropriate traffic control signage and procedures
 Measuring pole and/or tape measure.
 Protective clothing and eye protection.
 7/16” open or closed ended wrench.
 Large permanent black marker (initial inspections only – first year)  Note: entering a confined space requires appropriate safety and certification. It is generally not required for routine inspections of the system.

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Inspection Steps
The core to any successful stormwater BMP maintenance program is routine inspections. The inspection steps required on the MWS Linear are quick and easy. As mentioned above the first year should be seen as the maintenance interval establishment phase. During the first year more frequent inspections should occur in order to gather loading data and maintenance requirements for that specific site. This information can be used to establish a base for long term inspection and maintenance interval requirements.

The MWS Linear can be inspected though visual observation without entry into the system. All necessary pre-inspection steps must be carried out before inspection occurs, especially traffic control and other safety measures to protect the inspector and near-by pedestrians from any dangers associated with an open access hatch or manhole. Once these access covers have been safely opened the inspection process can proceed:
 Prepare the inspection form by writing in the necessary information including project name, location, date & time, unit number and other info (see inspection form).  Observe the inside of the system through the access hatches. If minimal light is available and vision into the unit is impaired utilize a flashlight to see inside the system and all of its chambers.
 Look for any out of the ordinary obstructions in the inflow pipe, pre-treatment chamber, biofiltration chamber, discharge chamber or outflow pipe. Write down any observations on the inspection form.
 Through observation and/or digital photographs estimate the amount of trash, debris and sediment accumulated in the pre-treatment chamber. Utilizing a tape measure or measuring stick estimate the amount of trash, debris and sediment in this chamber. Record this depth on the inspection form.

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 Through visual observation inspect the condition of the pre-filter cartridges. Look for excessive build-up of sediments on the cartridges, any build-up on the top of the cartridges, or clogging of the holes. Record this information on the inspection form. The pre-filter cartridges can further be inspected by removing the cartridge tops and assessing the color of the BioMediaGREEN filter cubes (requires entry into pre-treatment chamber – see notes above regarding confined space entry). Record the color of the material. New material is a light green in color. As the media becomes clogged it will turn darker in color, eventually becoming dark brown or black. Using the below color indicator record the percentage of media exhausted.  The biofiltration chamber is generally maintenance free due to the system’s advanced pretreatment chamber. For units which have open planters with vegetation it is recommended that the vegetation be inspected. Look for any plants that are dead or showing signs of disease or other negative stressors. Record the general health of the plants on the inspection and indicate through visual observation or digital photographs if trimming of the vegetation is needed.
 The discharge chamber houses the orifice control structure and is connected to the outflow pipe. It is important to check to ensure the orifice is in proper operating conditions and free of any obstructions. Generally, the discharge chamber will be clean and free of debris. Inspect the water marks on the side walls. If possible, inspect the discharge chamber during a rain event to assess the amount of flow leaving the system while it is at 100% capacity (pretreatment chamber water level at peak HGL). The water level of the flowing water should be compared to the watermark level on the side walls which is an indicator of the highest discharge rate the system achieved when initially installed. Record on the form is there is any difference in level from watermark in inches.
0% -- Percent Clogged -- 100%
New
BioMediaGREEN
Exhausted
BioMediaGREEN
85%

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 NOTE: During the first few storms the water level in the outflow chamber should be observed and a 6” long horizontal watermark line drawn (using a large permanent marker) at the water level in the discharge chamber while the system is operating at 100% capacity. The diagram below illustrates where a line should be drawn. This line is a reference point for future inspections of the system:
 Water level in the discharge chamber is a function of flow rate and pipe size. Observation of water level during the first few months of operation can be used as a benchmark level for future inspections. The initial mark and all future observations shall be made when system is at 100% capacity (water level at maximum level in pre-treatment chamber). If future water levels are below this mark when system is at 100% capacity this is an indicator that maintenance to the pre-filter cartridges may be needed.  Finalize inspection report for analysis by the maintenance manager to determine if maintenance is required.

Water Level
Mark
Water Level
Marks
Using a permanent marker draw a 6 inch long horizontal line, as shown, at the higher water level in the MWS Linear discharge chamber.

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Maintenance Indicators

Based upon observations made during inspection, maintenance of the system may be required based on the following indicators:
 Missing or damaged internal components or cartridges.  Obstructions in the system or its inlet or outlet.
 Excessive accumulation of floatables in the pre-treatment chamber in which the length and width of the chamber is fully impacted more than 18”.
 Excessive accumulation of sediment in the pre-treatment chamber of more than 6” in depth.

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 Excessive accumulation of sediment on the BioMediaGREEN media housed within the prefilter cartridges. The following chart shows photos of the condition of the BioMediaGREEN contained within the pre-filter cartridges. When media is more than 85% clogged replacement is required.
 Overgrown vegetation.
 Water level in discharge chamber during 100% operating capacity (pre-treatment chamber water level at max height) is lower than the watermark by 20%. 0% -- Percent Clogged -- 100%
New
BioMediaGREEN
Exhausted
BioMediaGREEN
85%

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Inspection 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 not require irrigation after initial establishment.

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Maintenance Guidelines for
Modular Wetland System - Linear
Maintenance Summary
o Remove Sediment from Pre-Treatment Chamber – average maintenance interval is 12 to 24 months.
 (10 minute average service time).
o Replace Pre-Filter Cartridge Media – average maintenance interval 12 to 24 months.  (10-15 minute per cartridge average service time).
o Trim Vegetation – average maintenance interval is 6 to 12 months.  (Service time varies).

System Diagram

Access to separation chamber and pre-filter cartridge
1 Pre-treatment Chamber
2 Biofiltration Chamber
3 Discharge Chamber

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Maintenance Overview
The time has come to maintain your Modular Wetland System Linear (MWS Linear). To ensure successful and efficient maintenance on the system we recommend the following. The MWS Linear can be maintained by removing the access hatches over the systems various chambers. All necessary pre-maintenance steps must be carried out before maintenance occurs, especially traffic control and other safety measures to protect the inspector and near-by pedestrians from any dangers associated with an open access hatch or manhole. Once traffic control has been set up per local and state regulations and access covers have been safely opened the maintenance process can begin. It should be noted that some maintenance activities require confined space entry. All confined space requirements must be strictly followed before entry into the system. In addition the following is recommended:
 Prepare the maintenance form by writing in the necessary information including project name, location, date & time, unit number and other info (see maintenance form).  Set up all appropriate safety and cleaning equipment.  Ensure traffic control is set up and properly positioned.  Prepare a pre-checks (OSHA, safety, confined space entry) are performed.

Maintenance Equipment
Following is a list of equipment required for maintenance of the MWS Linear:
 Modular Wetland Maintenance Form
 Manhole hook or appropriate tools to access hatches and covers  Protective clothing, flashlight and eye protection.
 7/16” open or closed ended wrench.
 Vacuum assisted truck with pressure washer.
 Replacement BioMediaGREEN for Pre-Filter Cartridges if required (order from manufacturer).

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Maintenance Steps

1. Pre-treatment Chamber (bottom of chamber)
A. Remove access hatch or manhole cover over pre-treatment chamber and position vacuum truck accordingly.

B. With a pressure washer spray down pollutants accumulated on walls and pre-filter cartridges.

C. Vacuum out Pre-Treatment Chamber and remove all accumulated pollutants including trash, debris and sediments. Be sure to vacuum the floor until pervious pavers are visible and clean.

D. If Pre-Filter Cartridges require media replacement move onto step 2. If not, replace access hatch or manhole cover.

Removal of access hatch to gain access below. Insertion of vacuum hose into separation chamber.

Removal of trash, sediment and debris. Fully cleaned separation chamber.

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2. Pre-Filter Cartridges (attached to wall of pre-treatment chamber) A. After finishing step 1 enter pre-treatment chamber.

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

C. Place the vacuum hose over each individual media filter to suck out filter media.

D. Once filter media has been sucked use a pressure washer to spray down inside of the cartridge and it’s containing media cages. Remove cleaned media cages and place to the side. Once removed the vacuum hose can be inserted into the cartridge to vacuum out any remaining material near the bottom of the cartridge.

Pre-filter cartridges with tops on.

Inside cartridges showing media filters ready for
replacement.

Vacuuming out of media filters.

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E. Reinstall media cages and fill with new media from manufacturer or outside supplier.

Manufacturer will provide specification of media and sources to purchase. Utilize the manufacture provided refilling trey and place on top of cartridge. Fill trey with new bulk media and shake down into place. Using your hands slightly compact media into each filter cage. Once cages are full removed refilling trey and replace cartridge top ensuring bolts are properly tightened.

F. Exit pre-treatment chamber. Replace access hatch or manhole cover.

3. Biofiltration Chamber (middle vegetated chamber)
A. In general, the biofiltration chamber is maintenance free with the exception of maintaining the vegetation. Using standard gardening tools properly trim back the vegetation to healthy levels. The MWS Linear utilizes vegetation similar to surrounding landscape areas therefore trim vegetation to match surrounding vegetation. If any plants have died replace plants with new ones:

Refilling trey for media replacement. Refilling trey on cartridge with bulk media.

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Inspection Notes

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.

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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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Project Address
Project Name
Cleaning and Maintenance Report
Modular Wetlands System

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Attachment D
Warehouse Expansion Traffic Assessment Letter

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FILENAME: H:\22\22492 - LA MESA COSTCO\REPORT\FINAL\LA MESA COSTCO - WAREHOUSE EXPANSION TRIP GENERATION MEMORANDUM UPDATE.DOCX

MEMORANDUM
Date: October 27, 2022 Project #: 22492
To: Diana Salazar-Chu, Costco Wholesale
From: Sonia Daleiden, PTOE & Kristine Connolly
Project: La Mesa Costco Expansion
Subject: Warehouse Expansion Traffic Assessment Letter
Kittelson & Associates, Inc. (Kittelson) has prepared a trip generation estimate for proposed warehouse building expansion to the existing Costco Wholesale development located along Fletcher Parkway in La Mesa, California.

There is an existing Costco warehouse and Costco Gasoline fuel station on the site today. The proposed Project will expand the Costco warehouse building from 133,472 square-foot to approximately 152,805 square-feet (a 19,333 sq-ft expansion). The expansion of the existing Costco Warehouse will provide additional space for dairy refrigeration, food preparation, and an employee locker room.

Approximately 11,347 sq-ft of the expansion will provide additional retail floor space. The proposed expansion site plan as well as the floor plans indicating the dairy refrigeration and food preparation expansion locations are provided as an attachment to this memorandum.

COSTCO TRIP GENERATION DATABASE
For the past 20 years, Kittelson has maintained a database of traffic data and travel characteristics for Costco Wholesale. The database contains transportation information such as trip rates, trip type percentages, and parking demand for Costco locations in the United States, as well as Canada and Mexico. The database is updated and refined each time new Costco traffic counts or information become available to Kittelson. To best evaluate the anticipated transportation characteristics of the proposed changes to the existing La Mesa Costco, the Costco database was used to develop the trip generation estimate since it provides use-specific data that most accurately represents the anticipated traffic characteristics of the unique development type. Costco has invested significant time and effort into developing this use-specific trip generation database for both its warehouses and its fuel stations.

The unique nature of Costco operations and its membership requirements result in different trip characteristics than those observed at typical discount club retailers summarized in the standard

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La Mesa Costco Expansion Project #: 22492
October 27, 2022 Page 2
Kittelson & Associates, Inc. Portland, Oregon
reference manuals such as the SANDAG (Not So) Brief Guide to Traffic Generation Rates for the San Diego Region or Institute of Transportation Engineers (ITE) Trip Generation Handbook, 11th Edition.

Trip data has been collected at Costco Warehouses across the United States and documented that they typically generate higher traffic volumes than other commercial land uses with similar building sizes. In addition to the number of trips, the Costco trip generation database also documents trip type based on member survey information that provides the percentage of pass-by, diverted, and primary trips, as further described below.
 Pass-by Trips (existing trips that are on roadways adjacent to the site that allow the motorist to turn into the Costco development, and then continue to their ultimate destination when their shopping is concluded),
 Diverted Trips (existing trips on nearby roadways in which the motorist decidesto drive outof-direction for a distance to stop at Costco, and when their shopping is concluded, continue on their trip to the ultimate destination), and  Primary Trips (an entirely new trip on the roadway system for the express purpose of driving to and from Costco, after deducting pass-by and diverted trips).

COSTCO WAREHOUSE EXPANSION TRIP GENERATION ESTIMATE
Since the La Mesa Costco currently exists, and the market area of the La Mesa Costco is already defined through existing membership and operations, trip generation to the warehouse is not expected to increase directly in proportion to the increased building size. In addition, other Costco warehouse facilities are located within 10 miles to the north, west and south of the site and therefore the region is sufficiently served by multiple warehouses. The proposed Project warehouse addition also does not solely consist of floor space addition and includes additions to the receiving and food service areas, which will likely not affect member trips to the site.

In recognition of this fact, available before and after data from other Costco expansion sites was reviewed to determine a more representative relationship between new trip generation and additional building size. Table 1 shows the sizes of the sites where warehouse expansion data was available. To work with a representative sample size, Costco provided door counts collected daily for a month-long period before and after the expansion of each of these warehouses. Assuming average vehicle occupancy does not vary significantly over time, door count data can be used as an indicator for changes in trip generation to and from the site. Only data that was collected during similar months of the year, prior to and after the expansion has been included in this summary (i.e., door counts for the month of March before the expansion were compared to door counts for the month of March after the expansion).

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La Mesa Costco Expansion Project #: 22492
October 27, 2022 Page 3
Kittelson & Associates, Inc. Portland, Oregon
Table 1. Costco Warehouse Expansion Sites Before & After Size Comparison Location Previous Size (SF) Expansion (SF) Current Size (SF) % Difference Santa Cruz, CA 133,973 12,775 146,748 9.5%
Westminster, CO 136,628 12,000 148,628 8.8%
Sterling, VA 127,484 21,925 149,409 17.2%
Brick, NJ 115,328 22,522 137,850 19.5%
Clifton, NJ 114,537 23,520 138,057 20.5%
Milford, CT 123,210 6,660 129,870 5.4%
Westbury, NY 147,611 7,962 155,573 5.4%
Hazlet, NJ 115,254 18,250 133,504 15.8%
Average 126,753 15,702 142,455 12.8%
La Mesa Site Proposed Expansion
La Mesa, CA 133,472 19,333 152,805 14.5%
Table 2 summarizes the results of the before and after activity comparison for all eight sites reviewed.

Table 2: Costco Warehouse Expansion Before & After Door Count Comparison Location Before Expansion After Expansion % Difference
Santa Cruz, CA 3,041 3,239 6.5%
Westminster, CO 2,554 2,570 0.6%
Sterling, VA 3,826 4,004 4.7%
Brick, NJ 2,473 2,430 -1.7%
Clifton, NJ 2,674 2,747 2.7%
Milford, CT 2,214 2,315 4.6%
Westbury, NY 4,750 4,689 -1.3%
Hazlet, NJ 2,407 2,369 -1.6%
Average 2,992 3,045 1.8%
As shown in Table 2, on average there was a slight increase in activity at the warehouses after expansion, however, the increase was significantly less than what would be calculated from a direct linear relationship to expansion size. Door counts at the warehouses only increased by an average of

1.8% with an average building expansion of 12.8%. Assuming average vehicle occupancy to and from the site does not change after the expansion, it can be correlated that trip generation to and from the La Mesa warehouse will follow the same trend pattern of an approximate 2% (rounded up for conservative analysis) increase after the expansion.

The existing La Mesa Costco Warehouse is located within a shopping center with multiple shared access points. As such, it is difficult to determine the number of trips in and out of the existing driveways that are dedicated to the Costco warehouse. As such, the Costco Warehouse trip database was used to estimate trips for the existing warehouse. Table 3 shows the trip generation estimate for the existing Costco warehouse. Based on the database, approximately 956 total trips would be on-site during the Weekday PM peak hour and 1,306 during the Weekend Midday peak hour. The new trips expected with the Costco warehouse expansion are outlined in Table 3.

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La Mesa Costco Expansion Project #: 22492
October 27, 2022 Page 4
Kittelson & Associates, Inc. Portland, Oregon
Table 3. Warehouse Expansion Trip Generation Estimate
Trip Type
Weekday PM Peak Hour
Trip Ends
Weekend Midday Peak Hour
Trip Ends
Existing Total Trip Ends 956 1,306
Expected Increase with Expansion
Additional Total Trip Ends (2% increase) 19 26
Total Trip Ends with Expansion 975 1,332
As shown in the table, the Costco warehouse expansion component of the project is expected to generate 19 additional weekday p.m. peak hour trip ends and 26 additional weekend midday peak hour trip ends. For conservative analysis, no reductions for pass-by or diverted trips have been applied to the additional Costco warehouse trips.

The estimated trip generation increase due to the expansion outlined above is a conservative estimate when compared to that projected using the SANDAG trip generation rates for “Discount Club.” The SANDAG values would estimate a trip generation as summarized in Table 4.

Table 4. SANDAG Trip Generation Estimate
Size
SANDAG Daily Trip Rate
(trips/sq-ft)
Weekday Daily
Trip Ends
Peak Hour
Factor
Weekday PM Peak Hour
Trip Ends
Existing: 133,472 60/1,000 8,008 9% 721
Expansion: 19,333 60/1,000 1,160 9% 104
Total Trip Ends 825
As can be seen from Table 4, calculating the trip generation for the Costco development using the standard reference SANDAG information results in a lower trip generation rate than using the conservative Costco-specific data.

We trust this memorandum provides you the required trip generation related information associated with the La Mesa Costco project. Please contact us at 503.535.7448 or [email protected] if you have any questions or require additional information.

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16'-0" 25'-0" 19'-0" 19'-0" 63'-0" 63'-0" 63'-0" EXISTING TRANSFORMER 14'-0" SAN DIEGO TROLLEY 12'-0" EXISTING RECEIVINGEXISTING COMPACTOR EXISTING DOCK LOADING 25'-0" FLETCHER PARKWAY EXISTING UTILITY EASEMENT LA MESA, CA #469 ACCESSIBILITY ENTRANCE SIGN, TYP OF 3 BUILDING ADDITION 19,146 SF 15 15 13 40 6 9 34 6 5 34 C B A 12 D FEV FEV FEV FEV FEV FEV CLEAN AIR / VANPOOL VAN VAN DAIRY COOLER ADDITION 1,645 SF 2628 16 15 12 8 CLEAN AIR / VANPOOL ADA 2 ADA 1 ADA 2 ADA 1 6 FEV 2 9 26 1 31 9 11 46 40 4835 2 16 4 4 4 2 4 9 EXISTING ELECT. EXISTING ELECT. PANELS 10 40 VAN ADA 1 NO PARKING ADA 1 34 NO PARKING ADA 4 18 NO PARKING VAN VAN 5 ADA 2 6 ADA 2 ADA 9 NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING GAS VAN SERVICE 16' 24' 6'
17' 24' 5' 23' 3' 15'-5 5/8" 29'-7 1/2" 17' 17'-8"
4' 12' THIS AREA IS UNDER SEPARATE ADA UPGRADE PERMIT #B22-051 NEW REFRIGERATION EQUIPMENT NEW 8'-0" H. CHAIN LINK FENCE NEW PAIR OF 3'-0" W. CHAIN LINK GATES WITH KNOX LOCK FOR FIRE ACCESS NEW UNDERGROUND BIOFILTRATION SYTEM FLETCHER PARKWAY PROJECT DATA VICINITY MAP EXISTING TOTAL BUILDING EXISTING SITE AREA: EXISTING FOOD SERVICE EXISTING TIRE CENTER EXISTING BUILDING AREA EXISTING BUILDING DATA: PROJECT ADDRESS: CLIENT: 133,472 SF JACKSON DRIVE 126,477 SF 4,893 SF 1,056 SF LA MESA, CA 91942 ISSAQUAH, WA 98027 999 LAKE DRIVE COSTCO WHOLESALE 8125 FLETCHER PKWY EL CAJON BLVDLA MESA COSTCOEAST 8 8 BALTIMORE DRIVE0 30' 60' 120' 1" = 60'-0" ZONING: CM-F-D 14.26 ACRES (621,080 SF) PROPOSED BUILDING DATA: NEW BUILDING ADDITION 16,032 SF EXISTING BUILDING AREA 133,472 SF NEW TOTAL BUILDING AREA 152,805 SF # HC ACCESSIBLE STALLS (2% REQ.) TOTAL PARKING 10' WIDE STALLS 9' WIDE STALLS EXISTING PARKING: ## 20 STALLS 57 STALLS 666 STALLS 764 STALLS NOTES: EXISTING CONDITIONS TO BE FIELD VERIFIED. NO. OF STALLS PER 1000 S.F. OF BUILDING AREA: 5.46 STALLS REQUIRED PARKING SPACES 1 PER EACH 250 SF GLA 133,472 SF / 250 SF: 534 STALLS # HC ACCESSIBLE STALLS 5 STALLS (1 IN 6 VAN) ## 6 STALLS 1 STALLS FUTURE ELECTRICAL CAR CHARGING STATIONS (6% REQ'D) ACCESSIBLE FUTURE ELECTRICAL CAR CHARGING STATIONS # LOW EMISSION/VAN POOL ELECTRIC VEHICLE PARKING (8%REQ'D) 9 STALLS NEW DAIRY COOLER ADDITION 1,717 SF SCALE: SITE PLAN 1" = 60'-0" # HC ACCESSIBLE STALLS (2% REQ.) TOTAL PARKING 10' WIDE STALLS 9' WIDE STALLS ## 20 STALLS 49 STALLS 613 STALLS 703 STALLS NOTES: EXISTING CONDITIONS TO BE FIELD VERIFIED. NO. OF STALLS PER 1000 S.F. OF BUILDING AREA: 4.65 STALLS REQUIRED PARKING SPACES 1 PER EACH 250 SF GLA 152,805 SF / 250 SF: 612 STALLS # HC ACCESSIBLE STALLS 5 STALLS (1 IN 6 VAN) ## 6 STALLS 1 STALLS FUTURE ELECTRICAL CAR CHARGING STATIONS (6% REQ'D) ACCESSIBLE FUTURE ELECTRICAL CAR CHARGING STATIONS # LOW EMISSION/VAN POOL ELECTRIC VEHICLE PARKING (8%REQ'D) 9 STALLS PROPOSED PARKING PROVIDED WITH ADDITION: © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE CONCEPT SITE PLAN L A M E S A, C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PKWY. LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 CONCEPT SITE PLAN DD11-19 LA MESA, CA #469 EXISTING LOCKER RM. MEZZ. 1,046 SF NEW LOCKER RM. MEZZ. ADDITION 1,584 SF Page 378 of 585

Page 379 of 585 ends

16'-0" 25'-0" 19'-0" 19'-0" 63'-0" 63'-0" 63'-0" EXISTING TRANSFORMER 14'-0" SAN DIEGO TROLLEY 12'-0" EXISTING RECEIVINGEXISTING COMPACTOR EXISTING DOCK LOADING 25'-0" FLETCHER PARKWAY EXISTING UTILITY EASEMENT LA MESA, CA #469 24 30 12 37 15 13 17 40 6 9 6 4 5 34 C B A 12 D FEV FEV FEV FEV FEV FEV CLEAN AIR / VANPOOL VAN VAN EXISTING ELECT. EXISTING ELECT. PANELS 10 40 NO VAN PARKING NO PARKING 18 NO PARKING VAN VAN 5 NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING VAN THIS AREA IS UNDER SEPARATE ADA UPGRADE PERMIT #B22-051 FLETCHER PARKWAY VICINITY MAP JACKSON DRIVE EL CAJON BLVDLA MESA COSTCOEAST 8 BALTIMORE DRIVE 8 0 30' 60' 120' 1" = 60'-0" LA MESA, CA #469 © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE DEMOLITION SITE PLAN L A M E S A, C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PKWY. LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 DEMOLITION SITE PLAN DD12-19 Page 380 of 585

Page 381 of 585 ends

DO NOT MIRROR DO NOT MIRROR DO NOT MIRROR DO NOT MIRROR DO NOT MIRROR 12 10 8 7 6 5 4 2 1 12 11 9 7 6 5 4 3 1.1 1 9.9 GFEDCBA 10.6 11 10.2 9.3 8.8 7.9 7.4 6.7 5.9 5.5 5.1 4.6 4.2 3.2 8.1 7.1 6.3 5.4 4.8 4.3 AA.1 AA AA.9 A.5 B.5 C.5 D.5 DD.9 2.9 TALL PRODUCE COOLER 107 TALL DAIRY COOLER 105 TALL DELI / MEAT COOLER 116 DELI / DISH PREP 110 ROTISSERIE 111 ROTISSERIE PREP 112 MEAT PREP 115 TALL BAKERY FREEZER 119 BAKERY 117 BAKERY COOLER 118 RTV 106 DEMO ROOM 159 ANTE ROOM 150 VAULT 148 MPU 154 OFFICE 151 MANAGER 152 EXIST. EDP EXIST. JANITOR MIMO RECEPTION ROOM 173 OPTICAL SALES 172 MEMBERSHIP COUNTER 109 RETURNS COUNTER 108 EXIST. QUIET EXIST. EMPLOYEE LOCKER ROOM WOMEN RR MEN RR EXIST. TIRE INSTALLATION EXIST. TIRE SALES EXIST. FOOD SERVICE EXIST. PHARMACY SCRUBBER PIT 123 UNISEX RESTROOM 124 POS FREEZER 103 POS SUB-ZERO FREEZER 104 CONVERT POS COOLER CONVERT AND EXPAND 16'-0" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 36'-3" 3'-0" 9'-9" 26'-6" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 36'-3" 3'-0" 3'-0" 16'-0" 3'-0" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 15'-0" 4'-0" 16'-0" 3'-0" 16'-0" 3'-0" 64'-0" 26'-10" 10'-8" 72'-0" EXIST. HEARING CENTER EXIST. ELECT. 1'-8" 3'-4"
1'-0" 3'-0"
1'-8" 1'-8" 2'-0" 2'-0" 1'-8"
26' D-2 CASE (SIO) 8' HED 12' D-2 8' D-2
8' CAKE DISPLAY
(SIO) 22' M-1 CASE (SIO) 56' M-1 CASE (SIO)
28' D-5 CASE (SIO) 56' D-5 CASE (SIO) 56' D-5 CASE (SIO) 56' M-1 CASE (SIO) 56' D-5 CASE (SIO) MOVABLE BAKERY RACKS (NIC) 34' M-1 CASE (SIO) DT 8' D-5 CASE
(SIO) 57'-4" 36'-0" 36'-0" 54'-0" 54'-0" 350'-0" 1'-8" 3'-0" 53'-4" 91'-6" 8'-8" 67'-2" 8'-8" 37'-4" COMPACTOR UP 15' STEEL
15' STEEL
15' STEEL TRANSFORMER 95'-3" 5'-1" 6'-7" 10'-9"
3'-8" 3'-10" 9'-8" 6'-0" 1'-5" 20'-1" 20'-1" 15'-6" 27'-9" 11'-8" 8' D-2 OFFICE 153 6'-2 1/2" 23'-10 1/2" EXISTING PLANTER EXISTING CONCRETE
23'-0"
166'-6" GREASE INTERCEPTOR CONFERENCE ROOM MEZZANINE LOCKER ROOMELECTRICAL ROOM DN PROPOSED RACK COUNT: GROCERY RACKS (15 ft) CENTER SECTION HARDLINE RACKS (15 ft) 212 19,150 SF44 PROPOSED BUILDING DATA EXISTING BUILDING DATA TOTAL BUILDING EXISTING RACK COUNT: GROCERY RACKS (15 ft) CENTER SECTION HARDLINE RACKS (15 ft) EXIST. FOOD SERVICE EXIST. TIRE CENTER 4,893 SF 1,056 SF 133,472 SF 224 16,497 SF 140 NOTES: EXISTING CONDITIONS TO BE FIELD VERIFIED. EXIST. BUILDING AREA 126,477 SF GROCERY PALLETS HARDLINE PALLETS 4020 HARDLINE PALLETS 127 GROCERY PALLETS 60 MASTER BUILDING DATA BUILDING DATA: 5,318 SF 154,431 SF BUILDING AREA 149,113 SF TIRE CENTER TOTAL BUILDING RACK COUNT: GROCERY RACKS (15 ft) CENTER SECTION HARDLINE RACKS (15 ft) 276 19,808 SF HARDLINE PALLETS 36 170 GROCERY PALLETS 134 NEW BUILDING ADDITION 16,032 SF EXISTING BUILDING AREA 133,472 SF NEW TOTAL BUILDING AREA 152,805 SF NEW DAIRY COOLER ADDITION 1,717 SF NET AREA BREAKDOWN 133,472 SF MAIN SALES 102,370 SF TOTAL BUILDING MASTER PROPOSED EXISTING 114,008 SF RETURN COUNTER 176 SF MEMBERSHIP 228 SF TIRE SALES 2,603 SF FS SEATING 492 SF TIRE INSTALL 2,715 SF FOOD SERVICE 1,437 SF JANITOR 101 SF MPU 318 SF FAMILY RESTROOM 118 SF ELECT. ROOM 296 SF RESTROOM 847 SF ANTE ROOM 35 SF OFFICE 1,295 SF QUIET ROOM 114 SF LOCKER ROOM 1,451 SF OPTICAL 1,654 SF HEARING CENTER 514 SF PHARMACY 1,290 SF POS FREEZER (1) 1,425 SF POS FREEZER (2) 1,425 SF POS COOLER (1) 1,425 SF MECHANICAL ROOM 1,918 SF FIRE DEPT ROOM 511 SF DAIRY COOLER 1,129 SF RECEIVING ELECT RM 580 SF DEMO ROOM 327 SF RETURN TO VENDER 197 SF RECEIVING 6,674 SF BAKERY 3,648 SF PRODUCE COOLER 1,676 SF MEAT PREP 1,226 SF DELI / MEAT COOLER 1,040 SF ROTISSERIE PREP 214 SF ROTISSERIE 500 SF DELI / DISH PREP 824 SF 154,431 SF 112,000 SF 176 SF 228 SF 2,109 SF 772 SF 2,324 SF 1,425 SF 1,425 SF 1,056 SF 33 SF 210 SF 99 SF 0,000 SF 791 SF 43 SF 1,185 SF 0,000 SF 370 SF 1,495 SF 413 SF 1,283 SF 1,425 SF 0,000 SF 0,000 SF 1,717 SF 339 SF 389 SF 209 SF 7,075 SF 1,867 SF 4,048 SF 1,258 SF 1,040 SF 195 SF 633 SF 959 SF 115 SF 220 SF 2,569 SF 2,324 SF 1,056 SF 88 SF 177 SF 99 SF 0,000 SF 1,045 SF 0,000 SF 1,001 SF 0,000 SF 370 SF 554 SF 413 SF 1,283 SF 1,397SF 0,000 SF 0,000 SF 1,000 SF 339 SF 0,000 SF 286 SF 4,637 SF 1,486 SF 2,799 SF 1,270 SF 1,096SF 105 SF 341 SF 563 SF 1,226 SF 772 SF 152,805 SF LOCKER ROOM MEZZ 2,630 SF 1,046 SF POS COOLER (2) 0,000 SF 1,425 SF 0,000 SF 0,000 SF EXIST. LOCKER RM. MEZZ. 1,046 SF LOCKER RM. MEZZ. ADDITION 1,584 SF LEGEND EXISTING NEW SCALE: EQUIPMENT PLATFORM 1/16" = 1'-0" © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE CONCEPT FLOOR PLAN L A M E S A , C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PARKWAY LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 CONCEPT FLOOR PLAN DD21-19 LA MESA, CA #469 SCALE: CONCEPT MEZZANINE LOCKER ROOM 1/16" = 1'-0" 0 4' 8' 16' 1/8" = 1'-0" NET AREA BREAKDOWN 1,046 SF MEZZ. LOCKER ROOM 895 SF TOTAL MEZZANINE MASTER PROPOSED EXISTING - CONFERENCE ROOM -- 2,055 SF 408 SF - SF 2,630 SF ELECTRICAL ROOM - 167 SF 151 SF Page 382 of 585

Page 383 of 585 ends

12 10 8 7 6 5 4 2 1 12 11 9 7 6 5 4 3 1.1 1 9.9 GFEDCBA 56' D-5 ISLAND ENTRANCE EXIT MEMBERSHIP COUNTER 335 SF BATTERY CHARGERS COMPACTOR STORAGE 94 SF JANITOR 55 SF R.R. DRESSING R.R. R.T.V. CAGE 286 SF PRODUCE COOLER 1,486 SF MEAT COOLER 1,096 SF MEAT PREP. 1,254 SF FREEZER 360 SF COOLER 197 SF BAKERY 2256 SF OPTICAL KIOSK 554 SF FOOD SERVICE 1,056 SF RECEPT 161 SF EXAM 136 SF TIRE SALES 2,569 SF JAN. 33 SF R.R. 99 SF TIRE INSTALLATION 2,324 SF 40' D-5 CASES 16' D-5 CASES CAKE
90'-0" 12'-3" 5'-2" 10'-10" 10'-11" 10'-0" 10'-0" 12'-10" 10'-0" 12'-9" 68'-0" 72'-0" 36'-0" 36'-0" 54'-0" 54'-0" 54'-0" 60'-0" 434'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 37'-0" 217'-0"
37'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 31'-0" 320'-0" 57'-6" 47'-0" 36'-0" 54'-0" 54'-0" 45'-0" 21'-0" 48'-0" 434'-0" EYEWASH 8' HED GREASE INTERCEPTOR ROTISSERIE PREP 105 SF UP 56' D-5 ISLAND P.O.S. DAIRY 21'-6" HT. 8' D-5 CASE
8' M-1 CASE 60' M-1 CASE 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 15' STEEL
15' STEEL
15' STEEL
15' STEEL BALER COMPACTOR TRANSFORMER EYEWASH GREASE INTERCEPTOR 56' D-5 ISLAND 56' M-1 ISLAND 48' M-1 ISLAND WOMEN

RESTROOM
395 SF MEN

Page 385 of 585 ends

Attachment E
Required Fire Flow

Page 386 of 585 ends

Page 387 of 585 ends

This letter is in response to the City of La Mesa plan review comment to confirm the existing underground fire line meets the required fire flow.

The Costco Warehouse is adding approximately 18,237 square feet to the building. The total square footage of the building after the building addition will be 151,658 square feet and is classified as a Type V, non-rated construction. The building is constructed of non-combustible materials. The building will be provided with an automatic sprinkler system.

The existing Costco was built in 1996. It is assumed the building code of record is the Uniform Building Code (UBC) and the Uniform Fire Code (UFC), 1994 Edition. The current code of record is the California Codes, 2019 Edition as amended by the La Mesa Municipal Code.

In accordance with the Uniform Fire Code, Appendix III-A, “Fire Flow Requirements for Buildings”, Section

5.2 Exception allows a reduction in required fire flow of up to 75 percent, as approved by the chief, when the building is provided with an approved automatic sprinkler system. The minimum flow cannot be less than 1,500 gallons per minute. In accordance with Table A-III-A-1, the required fire flow with the reduction of 75 percent for a fully sprinklered building is 2,000 gallons per minute for a duration of 2 hours.

In accordance with the California Fire Code, Appendix B “Fire Flow Requirements for Buildings”, Section B105.2 allows the use of 25 percent of the value in Table B105.1(2) resulting in a required fire flow for a fully sprinklered building of 2,000 gallons per minute for a duration of 2 hours.

Based on the water supply model provided by Helix Water District dated June 1, 2021 (Appendix A), the most remote (demanding) hydrant on the Costco site is capable of supplying the following:

Page 388 of 585 ends

Mr. Shaun Richardson
Heartland Fire & Rescue
June 8, 2021

Page 2 ends

Table 1 - Water Pressure
Static Pressure
(psi)
Residual Pressure
(psi)
Flow at Residual Pressure
(gpm)
77 68 1,062
The measured flow and pressure can be used to calculate the available fire flow at 20 pounds per square inch (psi)
=
−

−

.
Using the aforementioned data, the calculated available fire flow at 20 psi is 2,877 gpm.

Therefore, the required fire flow of 2,000 gpm is satisfied.

Sincerely,
WISS, JANNEY, ELSTNER ASSOCIATES, INC.

Jim Madden Garner A. Palenske, P.E.

Senior Associate Associate Principal

Page 389 of 585 ends

SIMULATED FIRE HYDRANT FLOW TEST

TESTED: June 1, 2021
FIRE HYDRANT LOCATION: 8125 Fletcher Pkwy, La Mesa

FIRE HYDRANT ID#: 501110
PROPERTY ADDRESS: 8125 Fletcher Pkwy, La Mesa

*This simulated fire flow was calculated on a fire hydrant located at 8125 Fletcher Pkwy, La Mesa, CA. Helix Water District cannot guarantee a minimum fire flow under all operating conditions at all times and assumes no responsibility for flows less than indicated above, due to but not limited to power outages, earthquakes, acts of nature, system malfunction or failures, and/or maintenance of the facilities. Simulated fire flow analysis performed by Aneld Anub, Associate Engineer.

Page 390 of 585 ends

HELIX WATER DISTRICT

SIMULATED HYDRANT FLOW TEST
Date: June 1, 2021 PERFORMED BY: Aneld Anub
Location F.H. #
PSI F.H.

FH
Size
Test
Orifice
Size
Discharge-G.P.M
Static Residual Model Observed
20 Lbs.
8125 Fletcher Pkwy.,
La Mesa 5011100 77 68
Clow
(2)2.5"x(1)4” 6" 2.5" 1,062 2,905

THE FIGURES SHOWN ABOVE WERE GENERATED USING A COMPUTER MODELING PROGRAM BASED ON MAXIMUM DAY DEMAND CONDITIONS.
*Helix Water District cannot guarantee a minimum fire flow under all operating conditions at all times and assumes no responsibility for flows less than indicated above, due to but not limited to power outages, earthquakes, acts of nature, system malfunction or failures, and/or maintenance of the facilities.

Page 391 of 585 ends

16'-0"
25'-0"
19'-0"
19'-0"
63'-0"
63'-0"
63'-0" EXISTING TRANSFORMER 14'-0"
SAN DIEGO TROLLEY 12'-0" EXISTING RECEIVINGEXISTING COMPACTOR EXISTING DOCK LOADING 25'-0" FLETCHER PARKWAY EXISTING UTILITY EASEMENT LA MESA, CA #469 ACCESSIBILITY ENTRANCE SIGN, TYP OF 3 BUILDING ADDITION 16,032 SF 15 15 13 40 6 9 6 34 5 34 C B A 12 D FEV FEV FEV FEV FEV FEV CLEAN AIR / VANPOOL VAN VAN DAIRY COOLER ADDITION 1,717 SF 2628 16 15 12 8 CLEAN AIR / VANPOOL ADA 2 ADA 1 ADA 2 ADA 1 6 FEV 2 9 26 1 31 9 11 46 40 4835 2 16 4 4 4 2 4 9 EXISTING ELECT. EXISTING ELECT. PANELS 10 40 VAN ADA 1 NO PARKING ADA 1 34 NO PARKING ADA 4 18 NO PARKING VAN VAN 5 ADA 2 6 ADA 2 ADA 9 NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING GAS VAN SERVICE 16' 24' 6'
17' 24' 5'
23'
3' 15'-5 5/8" 29'-7 1/2" 17' 17'-8"
4' 12' THIS AREA IS UNDER SEPARATE ADA UPGRADE PERMIT #B22-051 NEW REFRIGERATION EQUIPMENT NEW 8'-0" H. CHAIN LINK FENCE NEW PAIR OF 3'-0" W. CHAIN LINK GATES WITH KNOX LOCK FOR FIRE ACCESS NEW UNDERGROUND BIOFILTRATION SYTEM FLETCHER PARKWAY PROJECT DATA VICINITY MAP EXISTING TOTAL BUILDING EXISTING SITE AREA: EXISTING FOOD SERVICE EXISTING TIRE CENTER EXISTING BUILDING AREA EXISTING BUILDING DATA: PROJECT ADDRESS: CLIENT: 133,472 SF JACKSON DRIVE 126,477 SF 4,893 SF 1,056 SF LA MESA, CA 91942 ISSAQUAH, WA 98027 999 LAKE DRIVE COSTCO WHOLESALE 8125 FLETCHER PKWY EL CAJON BLVDLA MESA COSTCOEAST 8 8 BALTIMORE DRIVE0 30' 60' 120' 1" = 60'-0" ZONING: CM-F-D 14.26 ACRES (621,080 SF) PROPOSED BUILDING DATA: NEW BUILDING ADDITION 16,032 SF EXISTING BUILDING AREA 133,472 SF NEW TOTAL BUILDING AREA 152,805 SF # HC ACCESSIBLE STALLS (2% REQ.) TOTAL PARKING 10' WIDE STALLS 9' WIDE STALLS EXISTING PARKING: ## 20 STALLS 57 STALLS 666 STALLS 764 STALLS NOTES: EXISTING CONDITIONS TO BE FIELD VERIFIED. NO. OF STALLS PER 1000 S.F. OF BUILDING AREA: 5.46 STALLS REQUIRED PARKING SPACES 1 PER EACH 250 SF GLA 133,472 SF / 250 SF: 534 STALLS # HC ACCESSIBLE STALLS 5 STALLS (1 IN 6 VAN) ## 6 STALLS 1 STALLS FUTURE ELECTRICAL CAR CHARGING STATIONS (6% REQ'D) ACCESSIBLE FUTURE ELECTRICAL CAR CHARGING STATIONS # LOW EMISSION/VAN POOL ELECTRIC VEHICLE PARKING (8%REQ'D) 9 STALLS NEW DAIRY COOLER ADDITION 1,717 SF SCALE: SITE PLAN 1" = 60'-0" # HC ACCESSIBLE STALLS (2% REQ.) TOTAL PARKING 10' WIDE STALLS 9' WIDE STALLS ## 20 STALLS 49 STALLS 613 STALLS 703 STALLS NOTES: EXISTING CONDITIONS TO BE FIELD VERIFIED. NO. OF STALLS PER 1000 S.F. OF BUILDING AREA: 4.65 STALLS REQUIRED PARKING SPACES 1 PER EACH 250 SF GLA 152,805 SF / 250 SF: 612 STALLS # HC ACCESSIBLE STALLS 5 STALLS (1 IN 6 VAN) ## 6 STALLS 1 STALLS FUTURE ELECTRICAL CAR CHARGING STATIONS (6% REQ'D) ACCESSIBLE FUTURE ELECTRICAL CAR CHARGING STATIONS # LOW EMISSION/VAN POOL ELECTRIC VEHICLE PARKING (8%REQ'D) 9 STALLS PROPOSED PARKING PROVIDED WITH ADDITION: © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE CONCEPT SITE PLAN L A M E S A, C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PKWY. LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 CONCEPT SITE PLAN DD11-19 LA MESA, CA #469 EXISTING LOCKER RM. MEZZ. 1,046 SF NEW LOCKER RM. MEZZ. ADDITION 1,584 SF ATTACHMENT H Page 392 of 585 16'-0"
25'-0"
19'-0"
19'-0"
63'-0"
63'-0"
63'-0" EXISTING TRANSFORMER 14'-0"
SAN DIEGO TROLLEY 12'-0" EXISTING RECEIVINGEXISTING COMPACTOR EXISTING DOCK LOADING 25'-0" FLETCHER PARKWAY EXISTING UTILITY EASEMENT LA MESA, CA #469 24 30 12 37 15 13 17 40 6 9 6 4 5 34 C B A 12 D FEV FEV FEV FEV FEV FEV CLEAN AIR / VANPOOL VAN VAN EXISTING ELECT. EXISTING ELECT. PANELS 10 40 NO VAN PARKING NO PARKING 18 NO PARKING VAN VAN 5 NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING NO PARKING VAN THIS AREA IS UNDER SEPARATE ADA UPGRADE PERMIT #B22-051 FLETCHER PARKWAY VICINITY MAP JACKSON DRIVE

EL CAJON BLVD
LA MESA COSTCOEAST 8
BALTIMORE DRIVE 8 0 30' 60' 120' 1" = 60'-0" LA MESA, CA #469 © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE DEMOLITION SITE PLAN L A M E S A, C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PKWY. LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 DEMOLITION SITE PLAN DD12-19 Page 393 of 585 DO NOT MIRROR DO NOT MIRROR DO NOT MIRROR DO NOT MIRROR DO NOT MIRROR 12 10 8 7 6 5 4 2 1 12 11 9 7 6 5 4 3 1.1 1 9.9 GFEDCBA 10.6 11 10.2 9.3 8.8 7.9 7.4 6.7 5.9 5.5 5.1 4.6 4.2 3.2 8.1 7.1 6.3 5.4 4.8 4.3 AA.1 AA AA.9 A.5 B.5 C.5 D.5 DD.9 2.9 TALL PRODUCE COOLER 107 TALL DAIRY COOLER 105 TALL DELI / MEAT COOLER 116 DELI / DISH PREP 110 ROTISSERIE 111 ROTISSERIE PREP 112 MEAT PREP 115 TALL BAKERY FREEZER 119 BAKERY 117 BAKERY COOLER 118 RTV 106 DEMO ROOM 159 ANTE ROOM 150 VAULT 148 MPU 154 OFFICE 151 MANAGER 152 EXIST. EDP EXIST. JANITOR MIMO RECEPTION ROOM 173 OPTICAL SALES 172 MEMBERSHIP COUNTER 109 RETURNS COUNTER 108 EXIST. QUIET EXIST. EMPLOYEE LOCKER ROOM WOMEN RR MEN RR EXIST. TIRE INSTALLATION EXIST. TIRE SALES EXIST. FOOD SERVICE EXIST. PHARMACY SCRUBBER PIT 123 UNISEX RESTROOM 124 POS FREEZER 103 POS SUB-ZERO FREEZER 104 CONVERT POS COOLER CONVERT AND EXPAND 16'-0" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 36'-3" 3'-0" 9'-9" 26'-6" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 36'-3" 3'-0" 3'-0" 16'-0" 3'-0"3'-0" 16'-0" 3'-0" 16'-0" 3'-0" 15'-0" 4'-0" 16'-0" 3'-0" 16'-0" 3'-0" 64'-0" 26'-10" 10'-8" 72'-0" EXIST. HEARING CENTER EXIST. ELECT. 1'-8" 3'-4"
1'-0"
3'-0"
1'-8"
1'-8" 2'-0" 2'-0" 1'-8"
26' D-2 CASE (SIO) 8' HED 12' D-2 8' D-2
8' CAKE

DISPLAY
(SIO)
22' M-1 CASE (SIO) 56' M-1 CASE (SIO)
28' D-5 CASE (SIO) 56' D-5 CASE (SIO) 56' D-5 CASE (SIO) 56' M-1 CASE (SIO) 56' D-5 CASE (SIO) MOVABLE BAKERY RACKS (NIC) 34' M-1 CASE (SIO) DT 8' D-5
CASE
(SIO) 57'-4" 36'-0" 36'-0" 54'-0" 54'-0" 350'-0"
1'-8" 3'-0" 53'-4" 91'-6" 8'-8" 67'-2" 8'-8" 37'-4" COMPACTOR UP 15' STEEL
15' STEEL
15' STEEL TRANSFORMER 95'-3"
5'-1" 6'-7" 10'-9"
3'-8" 3'-10" 9'-8" 6'-0" 1'-5" 20'-1" 20'-1" 15'-6" 27'-9" 11'-8" 8' D-2 OFFICE 153 6'-2 1/2" 23'-10 1/2" EXISTING PLANTER EXISTING CONCRETE
23'-0"
166'-6" GREASE INTERCEPTOR CONFERENCE ROOM MEZZANINE LOCKER ROOMELECTRICAL ROOM DN PROPOSED RACK COUNT: GROCERY RACKS (15 ft) CENTER SECTION HARDLINE RACKS (15 ft) 212 19,150 SF44 PROPOSED BUILDING DATA EXISTING BUILDING DATA TOTAL BUILDING EXISTING RACK COUNT: GROCERY RACKS (15 ft) CENTER SECTION HARDLINE RACKS (15 ft) EXIST. FOOD SERVICE EXIST. TIRE CENTER 4,893 SF 1,056 SF 133,472 SF 224 16,497 SF 140 NOTES: EXISTING CONDITIONS TO BE FIELD VERIFIED. EXIST. BUILDING AREA 126,477 SF GROCERY PALLETS HARDLINE PALLETS 4020 HARDLINE PALLETS 127 GROCERY PALLETS 60 MASTER BUILDING DATA BUILDING DATA: 5,318 SF 154,431 SF BUILDING AREA 149,113 SF TIRE CENTER TOTAL BUILDING RACK COUNT: GROCERY RACKS (15 ft) CENTER SECTION HARDLINE RACKS (15 ft) 276 19,808 SF HARDLINE PALLETS 36 170 GROCERY PALLETS 134 NEW BUILDING ADDITION 16,032 SF EXISTING BUILDING AREA 133,472 SF NEW TOTAL BUILDING AREA 152,805 SF NEW DAIRY COOLER ADDITION 1,717 SF EXIST. LOCKER RM. MEZZ. 1,046 SF LOCKER RM. MEZZ. ADDITION 1,584 SF LEGEND EXISTING NEW SCALE: EQUIPMENT PLATFORM 1/16" = 1'-0" © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE CONCEPT FLOOR PLAN L A M E S A , C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PARKWAY LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 CONCEPT FLOOR PLAN DD21-19 LA MESA, CA #469 SCALE: CONCEPT MEZZANINE LOCKER ROOM 1/16" = 1'-0" 0 4' 8' 16' 1/8" = 1'-0" NET AREA BREAKDOWN 1,046 SF MEZZ. LOCKER ROOM 895 SF TOTAL MEZZANINE MASTER PROPOSED EXISTING - CONFERENCE ROOM -- 2,055 SF 408 SF - SF 2,630 SF ELECTRICAL ROOM - 167 SF 151 SF Page 394 of 585 12 10 8 7 6 5 4 2 1 12 11 9 7 6 5 4 3 1.1 1 9.9 GFEDCBA 56' D-5 ISLAND ENTRANCE EXIT MEMBERSHIP COUNTER 335 SF BATTERY CHARGERS COMPACTOR STORAGE 94 SF JANITOR 55 SF R.R. DRESSING R.R. R.T.V. CAGE 286 SF PRODUCE COOLER 1,486 SF MEAT COOLER 1,096 SF MEAT PREP. 1,254 SF FREEZER 360 SF COOLER 197 SF BAKERY 2256 SF OPTICAL KIOSK 554 SF FOOD SERVICE 1,056 SF RECEPT 161 SF EXAM 136 SF TIRE SALES 2,569 SF JAN. 33 SF R.R. 99 SF TIRE INSTALLATION 2,324 SF 40' D-5 CASES 16' D-5 CASES CAKE
90'-0" 12'-3" 5'-2" 10'-10" 10'-11" 10'-0" 10'-0" 12'-10" 10'-0" 12'-9" 68'-0" 72'-0" 36'-0" 36'-0" 54'-0" 54'-0" 54'-0" 60'-0" 434'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 37'-0"
217'-0"
37'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 36'-0" 31'-0" 320'-0" 57'-6" 47'-0" 36'-0" 54'-0" 54'-0" 45'-0" 21'-0" 48'-0" 434'-0" EYEWASH 8' HED GREASE INTERCEPTOR ROTISSERIE PREP 105 SF UP 56' D-5 ISLAND P.O.S. DAIRY 21'-6" HT. 8' D-5
CASE
8' M-1 CASE 60' M-1 CASE 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 10'-0" 15' STEEL
15' STEEL
15' STEEL
15' STEEL BALER COMPACTOR TRANSFORMER EYEWASH GREASE INTERCEPTOR 56' D-5 ISLAND 56' M-1 ISLAND 48' M-1 ISLAND WOMEN

RESTROOM
395 SF
MEN

RESTROOM
395 SF EDP 171 SF EMPLOYEE LOCKER ROOM 370 SF P.O.S. FREEZER 21'-6" HT. ROTISSERIE 341 SF POS SALES COOLER RELOCATE CENTER SECTION 7'-8" TOWARD RECEIVING 5' STEEL RECEIVING LAB PHARMACY PROFESSIONAL SERVICES 15' STEEL 15' STEEL
15' STEEL 15' STEEL 15' STEEL 15' STEEL FIRE SPRINKLER RISERS 15' STEEL 15' STEEL 15' STEEL OUTDOOR FOOD SERVICE SEATING AREA POS SALES COOLER 5' STEEL 5' STEEL 5' STEEL 5' STEEL 5' STEEL 71'-6" M.P.U. 177 SF MGR. 173 SF OFFICE 415 SF VAULT 140 SF 1,425 SF DELI / DISH PREP 563 SF 1,226 SF 1,397SF 1,000 SF HEARING CENTER 413 SFDEMO QUIET MEZZANINE LOCKER ROOMELECTRICAL ROOM DN LEGEND EXISTING NEW © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE CONCEPT DEMOLITION PLAN L A M E S A , C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PARKWAY LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 CONCEPT DEMOLITION PLAN DD22-19 LA MESA, CA #469 SCALE: DEMOLITION MEZZANINE 1/16" = 1'-0" 0 8' 16' 32' 1/16" = 1'-0" Page 395 of 585 6 7 0'-0" A.F.F. E.I.F.S. FINISH, TYP. EXPANSION JOINTS, TYP. STANDING SEAM MTL. ROOF 11 12 10 1 2 4 5 8 30'-8" A.F.F. 19'-4" A.F.F. SCORED SPLIT FACE BLOCK WALL (1 SIDE ONLY) PRECISION CMU & PAINTED MTL. CAP E.I.F.S. FINISH A B C D H J 0'-0" A.F.F. 10'-0" 10'-0" RECEIVING PRECISION CMU & SPLIT FACE CMU PAINTED MTL. CAP STANDING SEAM MTL. ROOF CONC. WALL E F G K 30'-8" A.F.F. 19'-4" A.F.F. 10'-0" A.F.F. 2'-0"
6'-0"
1'-4"
1'-4" PAINTED GALV. SHT. METAL TYP. E.I.F.S. FINISH PRECISION CMU E.I.F.S. FINISH TYP. SCORED SPLIT FACE CMU 10 12 1 2 4 8 19'-4" A.F.F. PAINTED GALV. SHT. METAL TYP. TO MATCH EXISTING SEISMIC JOINT TO MATCH EXISTING 11 TYP. 3 TYP. 3TYP. TYP. 4 TYP. 8TYP. 5 6 7 30'-8" A.F.F. 0'-0" A.F.F. SCORED SPLIT FACE BLOCK WALL (1 SIDE ONLY) DECORATIVE LIGHT FIXTURE TYP. TO MATCH EXISTING TYP. E.I.F.S. FINISH, TYP. PRECISION CMU & PAINTED MTL. CAP EXPANSION JOINTS, TYP. STANDING SEAM MTL. ROOF E.I.F.S. FINISH REVEALS TYP. TO MATCH EXISTING 1 4 TYP. 2 4 TYP. 3TYP. TYP. 3 5 9 TYP. TYP. 2 8 TYP. 10 2 DD34-19 1 DD34-19 D F G 0'-0" A.F.F. 19'-4" A.F.F. 2'-0"
6'-0"
1'-4"
1'-4" RECEIVING SPLIT FACE CMU PRECISION CMU SCORED SPLIT FACE CMU CONC. WALL 8" CMU BLOCK WITH CENTER SCORE BIOFILTRATION PLANTER TYP. 3TYP. TYP. 1 5 TYP. 2 TYP. TYP. 8TYP. AA B C E H J K 30'-8" A.F.F. 10'-0" A.F.F. 10'-0" 10'-0" PAINTED GALV. SHT. METAL TYP. E.I.F.S. FINISH A 3TYP. 4 REVEALS TYP. TO MATCH EXISTING4 TYP. 3 25'-3 1/2" 10 9 TYP. 9 TYP. 3 DD34-19 2 DD34-19 SIM. 12 6 5 4 30'-8" A.F.F. 0'-0" A.F.F. 10'-0" 10'-0" 23'-4" A.F.F. SCORED SPLIT FACE CMU 24'-8" A.F.F. 25'-0" A.F.F. 11 9 7 3 1 2'-0"
6'-0"
1'-4"
1'-4" 26'-0" A.F.F. PRECISION CMU & PAINTED MTL. CAP PAINTED GALV. SHT. METAL TYP. SPLIT FACE CMU LIGHT FIXTURE TYP. PRECISION CMU EMBOSSED METAL REFRIGERATION PANELS, COLOR - WHITE 10'-0" A.F.F. 9TYP. LA MESA, CA #469 1 SCALE: NORTH DEMOLITION ELEVATION 1/16" = 1'-0" 3 SCALE: WEST DEMOLITION ELEVATION 1/16" = 1'-0" © MG2. All rights reserved. No part of this document may be reproduced in any form or by any means without permission in writing from MG2. COSTCO WHOLESALE CONCEPT ELEVATIONS L A M E S A , C A L I F O R N I A A U G U S T 3 0 , 2 0 2 2 8125 FLETCHER PARKWAY LA MESA, CA 91942 91-1400-33 AUGUST 30, 2022 CONCEPT ELEVATIONS DD31-19 0 8' 16' 32' 1/16" = 1'-0" 2 SCALE: NORTH CONCEPT ELEVATION 1/16" = 1'-0" 4 SCALE: WEST CONCEPT ELEVATION 1/16" = 1'-0" 5 SCALE: SOUTH CONCEPT ELEVATION 1/16" = 1'-0" LEGEND EXISTING DEMOLITION NEW 4 PILASTER E.I.F.S SYSTEM SW #6015 DIVINE WHITE TO MATCH EXISTING 3 CMU 4" CMU VENEER SPLIT FACE CENTER SCORE NATURAL GRAY TO MATCH EXISTING 2 CMU (3) 8" H. COURSES OFF-WHITE PRECISION NATURAL GRAY TO MATCH EXISTING # MATERIAL FINISH COLOR WALL MATERIALS EXTERIOR FINISH SCHEDULE 1 CMU SPLIT FACE NATURAL GRAY TO MATCH EXISTING 5 FASCIA PRE-FINISHED SW COSTCO SAFETY RED 6 COSTCO SIGN SW COSTCO SAFETY RED 7 WHOLESALE SIGN SW 1805 LAPIS LAZULI 8 TRIM PRECAST CONCRETE BULLNOSE CAP TO MATCH EXISTING 9 SECURITY WALL PACK TO MATCH EXISTING 10 NEW STANDING SEAM METAL ROOF COSTCO SAFETY RED TO MATCH EXISTING 11 CMU (3) 8" H. COURSES PRECISION BLOCK PAINTED COSTCO RED Page 396 of 585 AUGUST 30, 2022 A U G U S T 3 0 , 2 0 2 2

Page 397 of 585 ends

La Mesa City CouncilMarch 28, 2023

La Mesa City Council
March 28, 2023