rfb_13199_for_info_only_2-RWQCB_draft_NOI_memo.pdf

Form 200 (10/97) 1

State of California Regional Water Quality Control Board

APPLICATION/REPORT OF WASTE DISCHARGE

GENERAL INFORMATION FORM FOR

WASTE DISCHARGE REQUIREMENTS OR NPDES PERMIT

I. FACILITY INFORMATION

A. FACILITY:

Name Address City/County/State/Zip Code Contact Person Telephone Number Email

B. FACILITY OWNER:

Name Address City/State/Zip Code Contact Person Telephone Number Email Federal Tax ID Owner Type (Mark one):

Individual Corporation Governmental Agency Partnership Other:

C. FACILITY OPERATOR (The agency or business, not the person):

Name Address City/State/Zip Code Contact Person Telephone Number Email Operator Type (Mark one):

Individual Corporation Governmental Agency Partnership Other:

Cole Grade Road Widening Phase 1

Cole Grade Road at Cool Valley Ranch Road Unincorporated community of Valley Center, San Diego County, CA 92082

Marisa Barrie

858-694-2212 marisa.barrie@sdcounty.ca.gov

County of San Diego Department of Public Works 5510 Overland Avenue, Suite 410

San Diego, CA 92123 Marisa Barrie

858-694-2212 marisa.barrie@sdcounty.ca.gov

Same as Owner

Form 200 (10/97) 2

D. OWNER OF THE LAND

Name Address City/State/Zip Code Contact Person Telephone Number Email Owner Type (Mark one):

Individual Corporation Governmental Agency Partnership Other:

E. ADDRESS WHERE LEGAL NOTICE MAY BE SERVED

Address City/State/Zip Code Contact Person Telephone Number Email

F. BILLING ADDRESS

Address City/State/Zip Code Contact Person Telephone Number Email

II. TYPE OF DISCHARGE

Check Type of Discharge(s) Described in this Application:

Waste Discharge to Land Waste Discharge to Surface Water

Check all that apply:

Animal or Aquacultural Wastewater Land Treatment Unit Animal Waste Solids Landfill (see instructions) Biosolids/Residual Mining Cooling Water Storm Water Domestic/ Municipal Wastewater Surface Impoundment Treatment and Disposal Dredge Material Disposal Waste Pile Hazardous Waste (see instructions) Wastewater Reclamation Industrial Process Wastewater Other, please describe

Same as owner

Same as owner

Same as owner

Construction Dewatering

Form 200 (10/97) 3

III. LOCATION OF THE FACILITY

Describe the physical location of the facility:

1. Assessor’s Parcel Number(s) Facility:

Discharge Point:

2. Latitude Facility:

Discharge Point:

3. Longitude Facility:

Discharge Point:

IV. REASON FOR FILING

Check all that apply:

New Discharge or Facility Change in Design or Operation Change in Quantity/Type of Discharge Changes in Ownership/Operator (see instructions) Waste Discharge Requirements Update or NPDES Permit Reissuance Other:

V. CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA)

Name of Lead Agency Has a public agency determined that the proposed project is exempt from CEQA?

Yes No If yes, state the basis for the exemption and the name of the agency supplying the exemption on the line below:

Has a “Notice of Determination” been filed under CEQA?

Yes No

If Yes, enclose a copy of the CEQA document, Environmental Impact Report (EIR), or Negative Declaration. If No, identify the expected type of CEQA document and expected date of completion.

Expected CEQA Documents: EIR Negative Declaration Expected CEQA Completion Date:

N/A. Project located in Cole Grade Road Right-of-Way, See page No. 27

Discharge into the center of the creek bed under existing bridge

33.268530

-117.023471

County of San Diego

2/11/26

Form 200 (10/97) 4

VI. OTHER REQUIRED INFORMATION

Please provide a COMPLETE characterization of your discharge. A complete characterization includes, but is not limited to, design and actual flows, a list of constituents and the discharge concentration of each constituent, a list of other appropriate waste discharge characteristics, a description and schematic drawing of all treatment processes, a description of any Best Management Practices (BMPs) used, and a description of disposal methods.

Also include a site map showing the location of the facility and, if you are submitting this application for an NPDES permit, identify the surface water to which you propose to discharge. Please try to limit your maps to a scale of 1:24,000 (7.5' USGS Quadrangle) or a street map, if more appropriate.

VII. OTHER

Attach additional sheets to explain any responses which need clarification. List attachments with titles and dates below:

You will be notified by a representative of the RWQCB within 30 days of receipt of your application. The notice will state if your application is complete or if there is additional information you must submit to complete your Application/Report of Waste Discharge, pursuant to Division 7, Section 13260 of the California Water Code.

VIII. CERTIFICATION

"I certify under penalty of law that this document, including all attachments and supplemental information, were prepared under my direction and supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment."

Print Name Title Signature Date

FOR OFFICE USE ONLY

Date Form 200 Received:

Letter to Discharger:

Fee Amount Received:

Check #:

CEQA Notice of Determination - see pages 125 -131

Cole Grade Road Improvement Project Final Environmental Impact Report - see pages 132 - 531

CWA 410 Permit - see pages 532 - 561

Marisa Barrie Director of Public Works

County of San Diego Department of Public Works

5510 Overland Avenue, Suite 410 San Diego, CA 92123

4/24/26

Marisa.Barrie@sdcounty.ca.gov

Construction Dewatering

See attached

No contamination sites are located within 1/2 miles of the site Reference: https://geotracker.waterboards.ca.gov/

Keys Creek (tributary to the San Luis Rey River [903.11 HA]) months

November 2026

Fresh water creek

See attached tables

Inland surface water creek, 3.12

N/A

One

Keys Creek (tributary to the San Luis Rey River [903.11 HA])

0.017 MGD

0.036 MGD

NPDES Permit Order No. R9-2015-0013 - NOI Section II.B: Disposal Alternative Analysis

Cole Grade Road Bridge Replacement, Valley Center, CA Project

II.B) Alternative disposal options

A) Irrigation: The preferred method for discharge is reuse for irrigation/watering of oak trees or natural vegetation adjacent to the creek in the project area. Discharge to Keys Creek under the NPDES permit will be performed if the preferred reuse option is not practicable (e.g., adequate or excessive precipitation, saturated soil).

B) Sewer discharge permit: This is not a feasible disposal option based off the lack of sewer infrastructure in the proposed project vicinity.

C) Off-site disposal: The proposed project has an estimated flow rate of 12 GPM or 17,280 gallons per day which would equate to 4 tank truckloads per day, leading to an increase in vehicular traffic volume, associated air pollutants, and carbon emissions. The local residents also do not support exporting/disposing of discharge from the immediate area. Therefore, this is not practical or feasible disposal option.

D) Land disposal: This is not a feasible option due to the limited project footprint and rights for disposal.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | June 21, 2023 16

Potential Analysis

Units Sample Result Water Quality

Objective/Criteria Trigger Value

Reasonable Potential (yes/no) mg/L 1050 50 Presumptive - yes mL/L 6.5 0.2 Presumptive - yes NTU 96.6 20 Presumptive - yes s.u. 7.24 6.5 - 8.5 Presumptive - yes mg/L * 500 Presumptive - yes

Notes:

EPA = United States Environmental Protection Agency ID = identification mL/L = milliliters per liter mg/L = milligrams per liter ND = not detected above the laboratory reporting limit NL = not listed NTU - Nephelometric Turbidity Units s.u. = standard units F = field parameter TDS = Total Dissolved Solids

* Based on Notice of Applicability TL6926 Keys Creek, Cole Grade Road near Cool Valley Road, Valley Center, CA (Project), dated July 5, 2022.

Settleable Solids

TDS

Table G-1 - Parameters with Presumptive Reasonable Potential for all Discharges

Parameter

Total Suspended Solids

Turbidity F pH F

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | 6/23 1 of 1

Less than 200 200 – 300 Greater than 300

Cadmium μg/L ND<0.142 4.3 5.8 7.3 no Copper μg/L 14.7 16.9 23.9 30.5 no Lead μg/L 1.65 7.7 12.9 18.6 no Nickel μg/L 2.81 94 132 169 no Silver μg/L ND<0.170 13.4 26.9 44.1 no Zinc μg/L 117 216 304 388 no

Notes:

[1] All metals are expressed as total recoverable.

[2] Hardness from Keys Creek sample = 1,110 mg/L < = not detected above the laboratory reporting limit mg/L = milligrams per liter μg/L = micrograms per liter water quality objective based on greater than 300 mg/L receiving water total hardness

Table G-2 - RPA for Discharges to Freshwater Inland Surface Waters

Reasonable Potential (yes/no)

Parameter Units Sample Result

Water Quality Objective/Criteria Trigger Value Receiving Water Total Hardness (mg/L) [2]

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | 6/23 1 of 1

Parameter Units Sample Result

Objective/Criteria Trigger Value

Reasonable Potential (yes/no)

Hydrogen Sulfide F ug/L ND<100 2.0 no [6]

Xylene ug/L ND<0.17 5.0 no Chlorinated Phenolics ug/L ND<44.7 10 no [6]

Remaining Base/Neutral Compounds[1] ug/L ND 10 no Total Petroleum Hydrocarbons mg/L 0.043 J 0.5 no Percent Sodium % 0.0177 60 no Total Nitrogen mg/L 10 1.0 yes Total Phosphorus mg/L ND<0.0182 0.1 no Methylene Blue Active Substances (MBAS) mg/L 0.0505 J 0.5 no Fluoride mg/L ND<0.40 1.0 no Total Residual Chlorine [2] ug/L ND<53.3 2.0 no [6]

Dissolved Oxygen F mg/L 7.5 5.0/6.0 [3] no Iron, Total Recoverable mg/L 6.5 0.3 yes Manganese, Total Recoverable mg/L 0.177 0.05 yes Total Coliform[4] MPN/100 mL 26 1,000 no Fecal Coliform[4] MPN/100 mL ND<2 200 no Dibromochloropropane ug/L ND<0.51 0.2 no [6]

Ethylene Dibromide ug/L ND<0.19 0.02 no [6]

Antimony, Total Recoverable ug/L ND<0.263 4,300 no Arsenic, Total Recoverable ug/L 3.13 150 no Chromium (III) , Total Recoverable ug/L 6.41 410 no Chromium (VI) , Total Recoverable ug/L ND<0.250 11 no Mercury, Total Recoverable ug/L ND<0.000124 0.051 no Selenium, Total Recoverable ug/L 5.09 5.0 yes Thallium, Total Recoverable ug/L ND<0.117 6.3 no Cyanide, Total ug/L ND<2.50 5.2 no 2,3,7,8 TCDD ug/L ND<9.3E-08 1.4E-08 no [6]

TCDD Equivalents [5] ug/L 1.6E-07 J I 1.4E-08 yes Acrolein ug/L ND<4.6 780 no Acrylonitrile ug/L ND<1.4 0.66 no Benzene ug/L ND<0.28 71 no Bromoform ug/L ND<0.25 360 no Carbon Tetrachloride ug/L ND<0.28 4.4 no Chlorobenzene ug/L ND<0.19 21,000 no Chlorodibromomethane ug/L ND<0.15 34 no Dichlorobromomethane ug/L ND<0.19 46 no 1,2-Dichloroethane ug/L ND<0.15 99 no 1,1-Dichloroethylene ug/L ND<0.33 3.2 no 1,2-Dichloropropane ug/L ND<0.17 39 no 1,3-Dichloropropylene ug/L ND<0.30 1,700 no Ethylbenzene ug/L ND<0.25 29,000 no Methyl Bromide ug/L ND<0.22 4,000 no Methylene Chloride ug/L ND<0.57 1,600 no 1,1,2,2-Tetrachloroethane ug/L ND<0.20 11 no Tetrachloroethylene ug/L ND<0.21 8.9 no Toluene ug/L ND<0.23 200,000 no 1,2-Trans-Dichloroethylene ug/L ND<0.24 140,000 no 1,1,2-Trichloroethane ug/L ND<0.17 42 no Trichloroethylene ug/L ND<0.17 81 no Vinyl Chloride ug/L ND<0.47 530 no 2-Chlorophenol ug/L ND<0.078 400 no

Table G-3 - RPA for Discharges to Freshwater Receiving Waters Not Designated MUN

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | 6/23 1 of 4

Objective/Criteria Trigger Value

Reasonable Potential (yes/no)

Table G-3 - RPA for Discharges to Freshwater Receiving Waters Not Designated MUN

2,4-Dichlorophenol ug/L ND<0.092 790 no 2,4-Dimethylphenol ug/L ND<0.12 2,300 no 4,6-dinitro-o-cresol ug/L ND<3.8 765 no 2,4-Dinitrophenol ug/L ND<4.4 14,000 no Pentachlorophenol ug/L ND<0.10 6.7 no Phenol ug/L ND<0.76 4,600,000 no 2,4,6-Trichlorophenol ug/L ND<0.15 6.5 no Acenaphthene ug/L ND<0.082 2,700 no Anthracene ug/L ND<0.069 110,000 no Benzidine ug/L ND<2.2 0.00054 no [6]

Benzo(a)Anthracene ug/L ND<0.066 0.049 no [6]

Benzo(a)Pyrene ug/L ND<0.19 0.049 no [6]

Benzo(b)Fluoranthene ug/L ND<0.098 0.049 no [6]

Benzo(k)Fluoranthene ug/L ND<0.073 0.049 no [6]

Bis(2-Chloroethyl)Ether ug/L ND<0.093 1.4 no Bis(2-Chloroisopropyl)Ether ug/L ND<0.087 170,000 no Bis(2-Ethylhexyl)Phthalate ug/L ND<1.7 5.9 no Butylbenzyl Phthalate ug/L ND<0.93 5,200 no 2-Chloronaphthalene ug/L ND<0.13 4,300 no Chrysene ug/L ND<0.055 0.049 no [6]

Dibenzo(a,h)Anthracene ug/L ND<0.13 0.049 no [6]

1,2-Dichlorobenzene ug/L ND<0.13 17,000 no 1,3-Dichlorobenzene ug/L ND<0.12 2,600 no 1,4-Dichlorobenzene ug/L ND<0.12 2,600 no 3,3 Dichlorobenzidine ug/L ND<1.5 0.08 no [6]

Diethyl Phthalate ug/L ND<0.13 120,000 no Dimethyl Phthalate ug/L ND<0.069 2,900,000 no Di-n-Butyl Phthalate ug/L ND<1.8 12,000 no 2,4-Dinitrotoluene ug/L ND<0.10 9.1 no 1,2-Diphenylhydrazine ug/L ND<0.066 0.54 no [6]

Fluoranthene ug/L ND<0.092 370 no Fluorene ug/L ND<0.076 14,000 no Hexachlorobenzene ug/L ND<0.089 0.00077 no [6]

Hexachlorobutadiene ug/L ND<0.16 50 no Hexachlorocyclopentadiene ug/L ND<0.093 17,000 no Hexachloroethane ug/L ND<0.14 8.9 no Indeno(1,2,3-cd)Pyrene ug/L ND<0.12 0.049 no [6]

Isophorone ug/L ND<0.084 600 no Nitrobenzene ug/L ND<0.092 1,900 no N-Nitrosodimethylamine ug/L ND<0.13 8.1 no N-Nitrosodi-n-Propylamine ug/L ND<0.16 1.4 no Pyrene ug/L ND<0.076 11,000 no Aldrin ug/L ND<0.0031 0.00014 no [6] alpha-BHC ug/L ND<0.0012 0.013 no beta-BHC ug/L ND<0.0039 0.046 no gamma-BHC ug/L ND<0.00066 0.063 no Chlordane ug/L ND<0.026 0.00059 no [6]

4,4'-DDT ug/L ND<0.0016 0.00059 no [6]

4,4'-DDE ug/L ND<0.0019 0.00059 no [6]

4,4'-DDD ug/L ND<0.0044 0.00084 no [6]

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | 6/23 2 of 4

Objective/Criteria Trigger Value

Reasonable Potential (yes/no)

Table G-3 - RPA for Discharges to Freshwater Receiving Waters Not Designated MUN

Dieldrin ug/L ND<0.0013 0.00014 no [6] alpha-Endosulfan ug/L ND<0.0013 0.056 no beta-Endosulfan ug/L ND<0.0041 0.056 no Endosulfan Sulfate ug/L ND<0.0014 240 no Endrin ug/L ND<0.0023 0.036 no Endrin Aldehyde ug/L ND<0.024 0.81 no Heptachlor ug/L ND<0.0012 0.0002 no [6]

Heptachlor Epoxide ug/L ND<0.0039 0.00011 no [6]

PCBs sum [7] ug/L ND<0.052 0.00017 no [6]

Toxaphene ug/L ND<0.054 0.0002 no [6]

Notes:

Isomer Group 2,3,7,8-tetra CDD 2,3,7,8-penta CDD 2,3,7,8-hexa CDDs 2,3,7,8-hepta CDD

Octa CDD 2,3,7,8-tetra CDF

1,2,3,7,8-penta CDF 2,3,4,7,8-penta CDF 2,3,7,8-hexa CDFs 2,3,7,8-hepta CDFs

Octa CDF

% = percent mg/L = milligram per liter ug/L = microgram per liter mL/L = milliliters per liter s.u. = standard unit NTU = nephelometric turbidity unit

NA = Not analyzed F = field parameter

0.001

0.5

0.01

0.1 0.05

0.1 0.01

Toxicity Equivalence Factor

MPN/100 mL = most probable number per milliliter

[1] As defined using Method 625.1 SIM [2] Reasonable potential for total residual chlorine shall be “Presumptive-yes”, regardless of effluent sample results if the effluent is disinfected or otherwise chlorinated prior to discharge.

[3] Shall not be less than 5.0 at any time in waters with designated warm fresh-water habitat beneficial use or less than 6.0 in waters with cold fresh-water habitat beneficial use.

[4] Monitoring for total coliform, fecal coliform and enterococcus is only required if the groundwater extraction activity is associated with sewage collection or treatment.

[5] TCDD Equivalents shall mean the sum of the concentrations of chlorinated dibenzodioxins (2,3,7,8-CDDs) and chlorinated dibenzofurans (2,3,7,8-CDFs) multiplied by their respective toxicity factors, as shown in the table below:

[6] The parameter was not detected above the method detection limit; however, the method detection limit was above the Water Quality Objective / Criteria Trigger Value. The analytical method used was a United States Environmental Protection Agency accepted method for drinking water analysis and is accepted by the Water Board.

[7] PCBs sum shall mean the sum of chlorinated biphenyls whose analytical characteristics resemble those of aroclor-1221, aroclor-1232, aroclor- 12342, aroclor-1248, aroclor-1254, and aroclor-1260.

1.0 0.5 0.1

0.001

Result exceeds Water Quality Objective / Criteria Trigger Value

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | 6/23 3 of 4

Objective/Criteria Trigger Value

Reasonable Potential (yes/no)

Table G-3 - RPA for Discharges to Freshwater Receiving Waters Not Designated MUN

I = value is estimated maximum possible concentration.

J = the result is less than the laboratory reporting limit, but greater than the method detection limit and the concentration is an approximated value.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | 6/23 4 of 4

5710 Ruffin Road, San Diego, California 92123 Phone 858/576-1000 Fax 858/576-9600 www.ninyoandmoore.com

San Diego Irvine Los Angeles Fontana Oakland San Jose San Francisco Sacramento Las Vegas Phoenix Tucson Prescott Valley Salt Lake City Denver Broomfield Houston

TECHNICAL MEMORANDUM

To: Mr. E. David Gasaway, Senior Civil Engineer (Public Works) Date: October 18, 2023

Firm: County of San Diego Department of Public Works Fax No:

Address: 5510 Overland Avenue, Suite 410, San Diego, California 92123 Telephone No: (858) 560-2125

From: Stephan A. Beck, PG 4375, CEG 1512, CHG 126 Total Pages

Including Transmittal:

Subject: Groundwater Quality Characterization Data, Cole Grade Road Bridge Over Keys Creek Project, Valley Center, California, Oracle No. 1003046 Project No: 108611016

Urgent For Approval For Your Use Please Reply As Requested Original Document: Will Not Follow Will Follow By U.S. Mail By Other

Background/Purpose Ninyo & Moore was retained to perform a Groundwater Dewatering Study for the County of San Diego, Department of Public Works (DPW) Cole Grade Road Bridge over Keys Creek Project (Project). The Project is located in the unincorporated community of Valley Center in the County of San Diego, along Cole Grade Road where it crosses Keys Creek, approximately 130 feet south of the intersection with Cool Valley Ranch Road, see attached figures. In anticipation of the need for construction dewatering and permitting, in December 2021, Ninyo & Moore installed and developed one 4-inch diameter test well and two 2-inch diameter observation wells to 30 feet below ground surface, and performed aquifer testing to evaluate hydraulic properties of the aquifer and to calculate estimated dewatering rates for the Project.

Subsequent to aquifer testing, Ninyo & Moore collected a grab groundwater sample and submitted it to a state-certified laboratory for analytical testing. The purpose of the groundwater sampling and analysis was to collect water quality data to perform a Reasonable Potential Analysis according to the requirements for Groundwater Extraction Discharges to Waters of the United States within the San Diego Region (Order No. R9-2015-0013) for discharges to freshwater receiving waters that are not designated with municipal beneficial uses. The groundwater analytical reports are dated March 2 and 9, 2022.

This technical memorandum is being prepared for the San Diego Regional Water Quality Control Board (RWQCB) to certify that the groundwater characterization has not changed since the date of sampling.

Findings In June 2023, Ninyo & Moore submitted a Groundwater Resources Investigation Report (GRIR) report for the Cole Grade Road Bridge Project to the DPW. The purpose of the GRIR was to evaluate the potential effects of temporary, localized dewatering of groundwater during the construction phase of the Project. The GRIR revealed that the adjacent properties were zoned as rural residential, vacant or undeveloped land, and field crops. The surrounding community generally consisted of semi-rural residential land uses (e.g., low density residential, recreational, agricultural).

To supplement the findings of the 2023 GRIR, on October 11, 2023, Ninyo & Moore accessed the Department of Toxic Substances Control EnviroStor and State Water Resources Control Board GeoTracker online regulatory databases.

Neither the Project site nor properties within 0.5 miles of the Project site were listed on either database as properties of potential environmental concern.

Ninyo & Moore | 5510 Overland Avenue, Suite 410, San Diego, California | 108611016 | October 18, 2023 2

Conclusions Based on the weight of evidence, i.e., findings of the 2023 GRIR, the lack of listings for the Project site and properties within 0.5 miles of the Project site in the EnviroStor and GeoTracker databases, and the rural nature of the Project site and surrounding properties, it is our professional opinion that the groundwater characterization performed in March 2022 at the subject Project site has not changed.

This technical memo will accompany the March 2 and 9, 2022 groundwater analytical reports, as part of the NOI application for the Project.

Stephan A. Beck, PG 4375, CEG 1512, CHG 126 Principal Geologist

GAH/SB

Attachments: Figure 1 – Site Location Figure 2 – Well Locations

Distribution: (1) Addressee (via e-mail)

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5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com

October 18, 2023 Project No. 108611016

Mr. E. David Gasaway, P.E.

County of San Diego Department of Public Works 5510 Overland Avenue, Suite 410 San Diego, California 92123

Subject: Groundwater Treatment System for Construction Dewatering Activities Cole Grade Road Bridge over Keys Creek Project Valley Center, CA 92082

Ninyo & Moore was retained by the County of San Diego (County), Department of Public Works

(DPW) to prepare groundwater treatment system specifications for the Cole Grade Road Bridge

Over Keys Creek Project (Project). The Project is located in the unincorporated community of Valley

Center in the County of San Diego on Cole Grade Road where it crosses Keys Creek between Cool

Valley Ranch Road and Cool Valley Road (Figure 1).

PROJECT OVERVIEW

The Project will provide a new bridge crossing of Cole Grade Road over Keys Creek intended to meet current roadway and bridge standards and accommodate the planned road widening. The

County anticipates temporary dewatering for installation of articulated concrete block (ACB) for scour protection in Keys Creek channel. During the construction process, areas of the site will require excavation and dewatering below the groundwater level, generating groundwater that will need treatment prior to storm drain discharge into Keys Creek, a tributary to the San Luis Rey River

(903.11 HA).

This summary describes the dewatering activity and is made as an attachment to a General Permit

Authorization Application for Groundwater Extraction Discharges to Surface Waters within the San

Diego Region: R9-2015-0013 with the California Regional Water Quality Control Board, San Diego

Region (RWQCB).

In February of 2022, Ninyo & Moore personnel collected grab groundwater samples for characterization and groundwater treatment system design and engineering. The groundwater sample collected from the site was analyzed for chemical constituents as required by the National

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | October 18, 2023 2

Pollutant Discharge Elimination System (NPDES) application. Based on the results, the following groundwater parameters exceeded the RWQCB Order trigger values: total nitrogen, total recoverable iron, total recoverable manganese, total recoverable selenium, and chlorinated dibenzodioxins and dibenzofurans isomers (TCDD Equivalents). The tabulated results of the

Reasonable Potential Analysis (RPA) are included as attachment to NPDES application.

HALF-MILE RADIUS STUDY

Ninyo & Moore performed a half mile radius review of the area as required in the RWQCB Order to determine if there are any other contaminated groundwater plumes that may migrate into this site during the construction dewatering activities. The search was conducted using the State Water

Resources Control Board (SWRCB) GeoTracker online database. A map identifying the site and radius area is attached to this report.

The result of the review indicates that there are no open cases in the Half Mile Radius Area of this project under the Cleanup Program Site and no permitted underground storage tanks (USTs). The treatment process installed at the site will successfully treat the groundwater and the effluent will meet the discharge requirements in Order R9-2015-0013, if the system is properly operated and maintained by the owner/operator.

Based on the results of the influent groundwater laboratory report, the groundwater at the site will require treatment prior to discharge for the following compounds: total recoverable iron, total recoverable manganese, total recoverable selenium, and TCDD Equivalents. Additional contaminants listed in Attachment C of the NPDES Permit Order No. 2015-0013 as automatic reasonable potential contaminants (pH and chronic toxicity) will also require treatment.

The laboratory analytical reports for this site will serve as the baseline for establishing groundwater treatment objectives. Based on the laboratory results presented, the Project will require a 25-gallons per minute maximum (GPM) groundwater treatment system, with a maximum capacity to treat up to

36,000 gallons per day of recovered groundwater.

METHOD OF TREATMENT

The target treatment constituents are: total recoverable iron, total recoverable manganese, total recoverable selenium, and TCDD Equivalents. The 25-GPM proposed treatment system incorporates eight primary methods of treatment to control these constituents:

Retention of the influent raw groundwater in holding/settling tanks, provides for suspended materials settling and removal.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | October 18, 2023 3

Aeration in the primary tank to boost dissolved oxygen levels.

Disinfectant (e.g., chlorine) injection system into the first holding tank.

Polymer injection system into the second holding tank.

Multi-chamber bag filter systems, for removal of suspended materials and fine particles.

Adsorption system (e.g., granular activated carbon media), for removal of organics.

Ion exchange resin filtration media, for removal of inorganics.

Chemical injection and polishing mechanical filter.

BEST MANAGEMENT PRACTICES

Ninyo & Moore, the DPW, and the general contractor for this construction project will exercise best management practices at all times during the course of the construction dewatering and discharge.

The recommended maintenance program includes a weekly site visit to confirm that all treatment system components are operating as designed. Emergency personnel should be available 24 hours per day, 7 days per week and be able to respond within 1 hour of being notified.

All operating and maintenance manuals are to be provided to the owner/operator of the treatment system and two days of operations and training are administered to the project manager/staff, general contractor, and operator of the treatment system, prior to full scale operations.

MATERIALS

For the 25-GPM proposed treatment system, the following components are recommended at a minimum to meet the discharge requirements:

Holding tanks: two 18,000-gallon capacity weir-type holding tank, with the appropriate fittings and valves.

200-cubic feet per minute (CFM) atmospheric air blower in the first tank, with a particulate filter.

Disinfectant (e.g., chlorine) injection system and 4-inch static in-line mixer into first holding tank.

Polymer injection into second weir holding tank.

Electric motor-powered process pump, 10 horsepower, 25-gallons per minute flow design, with electric control panel and automatic liquid level switches to control: pump on, pump off automatic, high liquid level system shut off, including groundwater pumps to prevent accidental tank overflow.

Multi-chamber bag filtration system: two by four chamber units installed in parallel series with high performance bag filters.

Ninyo & Moore | Cole Grade Road Bridge Project Over Keys Creek, San Diego County, California | 108611016 | October 18, 2023 4

Two adsorption process vessels (e.g., granular activated carbon media); each vessel filled with a minimum of 65-cubic feet of granular activated carbon.

Two ion exchange resin process vessels; each vessel filled with a minimum of 65-cubic feet of ion exchange resin.

Flow meter and totalizer (paddle type, non-resettable) capable of 5 to 200 GPM in line at the discharge with an accuracy of ± 2%.

Sample ports and pressure gauges: one stainless steel sample port at the effluent of the system before the discharge line.

All connections are 2-inch flexible hoses or rigid piping, including the discharge line.

Electrical requirements: 220/240 volts, 3-phase power, and approximately 100-amp service.

EQUIPMENT TESTING AND MAINTENANCE

The DPW and general contractor for the project will exercise best management practices at all times and perform all maintenance, including servicing the suspended solids removal system. Filtration media services will be performed as required to meet the discharge requirements.

EFFLUENT WATER TESTING AND REPORTING

Ninyo & Moore perform all water testing and reporting as required by the RWQCB under the NPDES permit requirements for the Project under a separate scope and fee.

Respectfully submitted, NINYO & MOORE

Stephan A. Beck, PG 4375, CHG 126 Principal Geologist

GAH/SB

Attachments: Figure 1 – Site Location Figure 2 – Well Locations Attachments: Project Dewatering Treatment Plans

GeoTracker Half-Mile Radius Study RWQCB Beneficial Uses and Water Quality Objectives Hydrologic Sub-Area Boundary Map Analytical Reports

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3, ANALYTICAL REPORT

Eurofins Calscience 2841 Dow Avenue, Suite 100 Tustin, CA 92780 Tel: (714)895-5494

Laboratory Job ID: 570-83286-1 Client Project/Site: Cole Grade Rd NPDES Revision: 2

For:

Ninyo & Moore 5710 Ruffin Road San Diego, California 92123

Attn: Adrian Olivares

Authorized for release by:

3/9/2022 9:57:40 AM

Virendra Patel, Project Manager I (714)895-5494 Virendra.Patel@eurofinset.com

The test results in this report meet all 2003 NELAC, 2009 TNI, and 2016 TNI requirements for accredited parameters, exceptions are noted in this report. This report may not be reproduced except in full, and with written approval from the laboratory. For questions please contact the Project Manager at the e-mail address or telephone number listed on this page.

This report has been electronically signed and authorized by the signatory. Electronic signature is intended to be the legally binding equivalent of a traditionally handwritten signature.

Results relate only to the items tested and the sample(s) as received by the laboratory.

Table of Contents Client: Ninyo & Moore Project/Site: Cole Grade Rd NPDES

Laboratory Job ID: 570-83286-1

Eurofins Calscience

3/9/2022 (Rev. 2)

Cover Page Table of Contents Definitions/Glossary Case Narrative Detection Summary Client Sample Results Toxicity Summary Surrogate Summary Isotope Dilution Summary QC Sample Results QC Association Summary Lab Chronicle Certification Summary Method Summary Sample Summary Chain of Custody Receipt Checklists

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Patel, Virendra

From: Adrian Olivares <aolivares@ninyoandmoore.com> Sent: Friday, February 4, 2022 8:41 AM To: Patel, Virendra Subject: RE: Eurofins Environment Testing Southwest, LLC sample confirmation files from

570-83286-1 Cole Grade Rd NPDES

EXTERNAL EMAIL*

Virendra, Is it too late to remove the total hardness analysis? The sample was mistakenly taken from the well and not the creek.

Thanks, Adrian Olivares, CIH Senior Environmental Scientist Ninyo & Moore

858.576.1000 (x11257)

From: Virendra Patel [mailto:Virendra.Patel@eurofinset.com] Sent:Wednesday, February 2, 2022 10:31 AM To: Adrian Olivares <aolivares@ninyoandmoore.com>; Patel Virendra <Virendra.Patel@eurofinset.com> Subject: Eurofins Environment Testing Southwest, LLC sample confirmation files from 570 83286 1 Cole Grade Rd NPDES

Hello, Attached please find the sample confirmation files for job 570-83286-1; Cole Grade Rd NPDES

Please feel free to contact me if you have any questions.

Thank you.

Virendra Patel Project Manager

Eurofins Calscience Phone: 714-895-5494 Ext: 218

E-mail: Virendra.Patel@eurofinset.com www.eurofinsus.com/env

Page 65 of 79 3/9/2022 (Rev. 2)

Reference: [570-285362] Attachments: 3

> > Bank information has changed, please refer to remittance information on invoice. < <

* WARNING EXTERNAL: This email originated from outside of Eurofins Environment Testing America. Do not click any links or open any attachments unless you trust the sender and know that the content is safe!

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FINAL ENVIRONMENTAL IMPACT REPORT

COLE GRADE ROAD IMPROVEMENT PROJECT

SCH# 2015121090

Lead Agency:

County of San Diego Department of Public Works Environmental Services Unit

5510 Overland Avenue, Suite 410 San Diego, California 92123

September 2019

County of San Diego, Department of Public Works Cole Grade Road Improvement Project – Final EIR September 2019

EXECUTIVE SUMMARY

ES.1 Project Synopsis

The County of San Diego (County), Department of Public Works (DPW) is proposing to widen a segment of Cole Grade Road between the signalized intersections of Cole Grade Road with Fruitvale Road and Pauma Heights Road/West Oak Glen Road. The new road would provide improved traffic flow and safety, and would also include the installation of bicycle and pedestrian facilities to improve pedestrian and bicycle access along the roadway. The Project also proposes replacement and improvements to the existing tributary crossings traversing Cole Grade Road, undergrounding of utilities, and installation of additional drainage features adjacent to the existing roadway alignment.

ES.1.1 Location and Existing Conditions

The Project site is located in the unincorporated community of Valley Center, along Cole Grade Road, from its signalized intersection with Fruitvale Road to its intersection with Pauma Heights Road/West Oak Glen Road. Currently, vehicles traveling along the two-lane road must repeatedly slow down for motorists making left-turns on crossroads or driveways. Cole Grade Road also lacks bicycle and pedestrian bicycle facilities along this segment, which leaves limited space for such users due to narrow road shoulders.

ES.1.2 Project Components and Construction Activities

Under the proposed Project, the 2.83-mile-long segment of Cole Grade Road between Fruitvale Road and Pauma Heights Road/West Oak Glen Road would be widened within a proposed 84-foot right-of-way. As currently designed, implementation of the proposed Project would include the acquisition of right-of-way easements from approximately 50 property owners along the proposed segment of Cole Grade Road (see Section 1.4.2.5, Right-of-Way Acquisition) in order to widen Cole Grade Road for the purpose of providing:

12-foot-wide northbound travel lane;

12-foot-wide southbound travel lane;

12-foot wide two-way left-turn lane;

Three left-turn pockets at the intersections of Cole Grade Road with Cool Valley Road, Cool Valley Ranch Road, and Hilldale Road;

Replacement of three box culverts at Keys Creek and unnamed tributary undercrossings of Cole Grade Road;

5-foot-wide bike lanes on both sides of the roadway;

3-foot-wide graded road shoulders and 7-foot-wide vegetated drainage swales adjacent to the bike lanes on both sides of the roadway;

6-foot-wide graded parkway east of the drainage swale on the east side of the roadway;

and

Page ES-1

September 2019

12-foot-wide decomposed granite pathway west of the drainage swale on the west side of the roadway with fencing on both sides of the proposed pathway to enhance pedestrian and equestrian safety.

Although design changes have reduced impacts to trees, the proposed Project would require the removal of existing vegetation (including up to 177 oak trees greater than 5 inches in diameter breast height). In addition, Project construction would require removal and relocation of structures (e.g., fences, mailboxes, power poles, etc.), minor compaction and grading of the roadway and associated drainage swales, removal and undergrounding of existing utilities, relocation of stoplights, stop signs, and other roadway signage.

Total grading associated with the proposed Project would include excavation of approximately 74,000 cubic yards, 26,000 cubic yards of which would be used on-site during construction as fill.

Heavy haul trucks would be used to relocate excavated soils to areas where they are needed for fill. Additionally, approximately 2,400 double-trailer haul truck trips would be required to export 48,000 cubic yards of soil from the site. Additional heavy haul truck trips would also be required to import road base, asphalt, and decomposed granite to the site. Cement trucks would be used to haul in cement for construction of the new box culverts, bridge, retaining structures, and potentially for utility work. Project construction would also include the installation of two retaining walls as well as a soil nail wall proposed for the east side of the road south of Cool Valley Road.

The soil nail wall would be up to 20 feet in height and would be composed of sculpted shotcrete (i.e., concrete conveyed through a hose) which would be textured and colored to appear as a natural rock finish.

Standard daytime construction operating hours would be observed (7:00am-7:00pm) consistent with the County’s Noise Ordinance (County Code of Regulatory Ordinances Section 36.423). A Traffic Control Plan would be prepared and implemented during the entire construction period.

During construction, traffic patterns would shift, but will provide for two-way traffic along Cole Grade Road. Bridge construction just north of Cool Valley Road is anticipated to take approximately 18 months to complete, during which time traffic on the bridge would be reduced to one lane for approximately 9 months. A temporary traffic signal would be used to assign right-of-way across the one lane bridge. While not anticipated, night work may be necessary on occasion to avoid daytime traffic impacts during construction. If night work is required, the County would issue a variance for construction work to include all appropriate avoidance and minimization measures (e.g., sound barrier) to avoid impacts to nearby sensitive receptors. Public noticing would occur prior to night work, if necessary.

All blasting activity would be carried out in accordance with County Ordinance Number 9044 Title 3, Division 5, Fire Protection and Explosives. County DPW staff would obtain all appropriate permits from the Sheriff or Chief Office of the fire department pursuant to Section 12000 et seq.

of the California Health and Safety Code and Article 77 Uniform Fire Code. Blasting activities would occur between the hours of 7:00am and 6:00pm (or 30 minutes before sunset, whichever occurs first) Monday through Saturday. Additionally, County DPW would give notice in writing to all residences and businesses within 600 feet of any potential major blast location, or 300 feet from any minor blast location.

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September 2019

ES.2 Summary of Significant Effects and Mitigation Measures That Reduce or Avoid the Significant Effects

Table ES.1 provides a brief summary of each potentially significant environmental effect associated with the proposed Project. Additionally, this table presents the mitigation measures that would be implemented to reduce or avoid that effect to the maximum extent practicable.

Additional complete descriptions of potential impacts and associated mitigation measures is provided in Section 2.0, Significant Environmental Effects of the Proposed Project.

ES.3 Areas of Controversy

The California Environmental Quality Act (CEQA) Guidelines Section 15123(b)(2) states that an Environmental Impact Report (EIR) shall identify areas of controversy known to the Lead Agency, including issues raised by agencies and the public. The County issued a Notice of Preparation (NOP) for the Cole Grade Road Improvement Project on December 17, 2015, held a public meeting in the community, and received 15 written communications from area residents, agencies, and organizations during the NOP comment period (see Appendix A). The majority of comments received were regarding the number of trees required for removal to support the road improvement. The preliminary project design was determined to result in significant impacts to the environment due to removal of approximately 234 oak trees (including 188 mature oak trees with diameters of greater than 5 inches). These trees are concentrated at the two crossings of Keys Creek where culvert replacement and extension would impact riparian and oak forest growing along this creek corridor (see Section ES.5.1, Alternative 1: Original Project Design).

NOP comments described that the removal of this many oak trees had the potential to result in significant impacts to biological resources, aesthetics, and could be considered contrary to the goal of the Valley Center Community Plan to “preserve Valley Center’s unique natural and cultural resources while supporting its traditional semi-rural lifestyle.” Consequently, County DPW prepared and presented four alternatives to the project to the Valley Center Community Planning Group (VCCPG). At the conclusion of the meeting, the VCCPG recommended that the design of the roadway improvements be modified to include the originally proposed culverts replacements, but only to a width of two vehicle lanes, and that the County employ innovative techniques to optimize preservation of oak trees during construction. , reducing the overall scale of tree removal to 177 oak trees greater than 5 inches in diameter breast height. County DPW staff reviewed these comments and developed a new alternative (i.e., the proposed Project), which would still remove and replace the existing culverts at creek crossings, but with substantially reduced culvert and bridge widths.

ES.4 Issues to Be Resolved by the Decision-Making Body

Issues to be resolved by the County Board of Supervisors whether or how to mitigate the potentially significant environmental effects to aesthetics and visual quality, biological resources, land use and planning, and traffic and circulation.

Significant impacts to aesthetics and visual quality associated with the removal of mature oak trees could not be reduced to less than significant, even with the implementation of mitigation measures. Therefore, the County Board of Supervisors would need to decide whether any of the

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September 2019 project alternatives would substantially reduce significant impacts, while still meeting the key Project objectives, or whether to adopt a Statement of Overriding Considerations in order to approve the Project.

ES.5 Project Alternatives

Alternatives are required to be identified and evaluated to determine if they would reduce or avoid significant impacts. The following four alternatives are compared in this EIR to the proposed Project and are summarized below in order of environmental superiority based on the detailed analysis in Section 4.0, Project Alternatives:

Alternative 1: Original Project Design Alternative 2: Two Lane Roadway and Pedestrian Bridges Alternative 3: Two Lane Roadway and Gapped Pedestrian Pathway No Project Alternative

ES.5.1 Alternative 1: Original Project Design

EIR Alternative 1 (i.e., the original project design presented in December 2015) would replace the existing double box culvert crossing south of Cool Valley Ranch Road with a 72-foot-wide bridge, and would improve the existing box culvert crossing north of Cool Valley Ranch Road.

Additionally, the alternative would include improvements to pedestrian facilities included an 11-foot wide pathway on the west side of the road north of Horse Creek Road as well as a 6-foot graded parkway on the east side of the road.

ES.5.2 Alternative 2: Two Lane Roadway and Pedestrian Bridges

Under EIR Alternative 2, a continuous two-way left-turn lane would not be established. Instead, the 2.83-mile-long segment of roadway would remain a two-lane road with a northbound travel lane and a southbound travel lane as well as minimal…