ML16048A205

Storm Water Pollution Prevention Plan

ML16048A205
Person / Time
Site:	Diablo Canyon
Issue date:	06/30/2015
From:	Pacific Gas & Electric Co
To:	Office of Nuclear Reactor Regulation
Shared Package
ML16048A230	List: DCL-15-142, Pacific Gas & Electric 230kV Electrical Switchyard Voltage Support Project DCL-2011-512, 2010 Annual Report on Discharge Monitoring DCL-2014-500, 2013 Annual Report on Discharge Monitoring ML16048A204 ML16048A205 ML16048A206 ML16048A207 ML16048A208 ML16048A210 ML16048A211 ML16048A212 ML16048A213 ML16048A214 ML16048A215 ML16048A218 ML16048A219 ML16048A284 ML16048A286 ML16050A178 ML16050A180 ML16050A291 ML16050A292 ML16050A294 ML16050A296 ML16050A297
References
DCL-15-142, CAC MF4019, CAC MF4020
Download: ML16048A205 (49)

Text

i \'1 SWR-03 STORM WATER POLLUTION PREVENTION PLAN Pacific Gas & Electric Company -Diablo Canyon Power Plant 9 Miles NW of Avila Beach, California June 30, 2015 EXECUTIVE

SUMMARY

This storm water pollution prevention plan (SWPPP) was prepared in accordance with the requirements of the California State Water Resources Control Board (SWRCB) Industrial Storm Water Permit for Discharges Associated with Industrial Activity (Order No. 2014-0057-DWQ) which was adopted on April 1, 2014. This permit replaces Order No. 97-03-DWQ which had been in effect from August 1, 1997 through June 30, 2015.This SWPPP identifies and evaluates all sources of pollutants that may affect the quality of industrial storm water discharges and authorized non-storm water discharges, identifies and describes the minimum best management practices (BMPs) and any advanced BMPs implemented to reduce or prevent pollutants in industrial storm water discharges and authorized non-storm water discharges.

Pacific Gas and Electric Company shall implement this updated SWPPP commencing July 01, 2015.The SWPPP will be revised whenever necessary, and will be certified and submitted electronically to the SWRCB via the Storm Water Multi-Application and Tracking System (SMARTS).

TAJ3LE OF CONTENTS Page EXECUTIVE

SUMMARY

i LIST OF TABLES iv LIST OF FIGURES (insert site map and other figures here -see permit section X.E.) iv 1. INTRODUCTION1

1.1 Background

and Requirements 1 1.2 SWPPP Performance Standards 2 1.3 SWPPP Implementation and Revisions 2 1.4 General Facility Information 2 1.5 Pollution Prevention Team 3 2. SITE LAYOUT AND EXISTING FACILITY PLANS (PERMIT SECTION X.E)5 3. LIST OF INDUSTRIAL MATERIALS (PERMIT SECTION X.F) 7 3.1 List of Industrial Materials Handled at the Facility 7 4. DESCRIPTION OF POTENTIAL POLLUTANT SOURCES (PERMIT SECTION X.G) 8 4.1 Industrial Processes 8 4.2 Material Receiving, Shipping and Handling '8 4.3 Dust and Particle Generating Activities 8 4.4 Significant Spills and Leaks 9 4.5 Non-Storm Water Discharges 9 4.6 Erodible Surfaces 10 5. ASSESSMENT OF POTENTIAL POLLUTANT SOURCES (PERMIT SECTION X.G.2) 11 5.1 Narrative Assessment of Likely Pollutants Present in Storm Water Discharges 11 5.2 Identification of Additional BMPs 11 5.3 Identification of Drainage Areas with No Exposure 11 5.4 Identification of Additional Parameters 11 6. STORM WATER BEST MANAGEMENT PRACTICES (PERMIT SECTION X.Hl) 12 6.1 Minimum BMPs (Permit Section X.H. 1) 12 6.1.1 Good Housekeeping 12 6.1.2 Preventative Maintenance 13 6.1.3 Spill and Leak Prevention and Response 13 6.1.4 Material Handling and Waste Management 14 6.1.5 Erosion and Sediment Controls 14 6.1.6 Employee Training Program 15 6.1.7 Quality Assurance and Record-Keeping 15 6.2 Advanced BMPs (Permit Section X.H.2) 15 6.2.1 Exposure Minimization BMPs 15 6.2.2 Storm Water Containment and Discharge Reduction BMPs 16 6.2.3 Treatment Control BMPs 16 ii TABLE OF CONTENTS Page 6.2.4 Other Advanced BMPs 16 7. TEMPORARY SUSPENSION OF ACTIVITIES (PERMIT SECTION X.H.3) 16 BMP

SUMMARY

(PERMIT SECTIONS X.H.4 AND X.H.5) 17 8. MONITORING IMPLEMENTATION PLAN (PERMIT SECTION X.I) 19 9. ANNUAL REPORTING (PERMIT SECTIONS XV AND XVI) 27 REFERENCES 28 TABLES FIGURES Appendix A -General Permit for Discharges Associated with Industrial Activities Appendix B -Permit Registration Documents Appendix C -SWPPP Amendment Form Appendix D -Training Log Appendix E -Industrial Facility Iuspection and Visual Observation Form Appendix F -Sample Collection and Handling and Example Chain of Custody Form Appendix G -Annual Reports I11 LIST OF TABLES Table No. Title I Pollution Prevention Team II Industrial Materials Handled at the Facility III Best Management Practices Summary IV Numeric Action Level Values V Summary Table for DCPP Ocean Plan Storm Water Monitoring Compliance LIST OF FIGURES Figure No. Title 1 Site Plan 2 Site Storm Water Drainage System 3 Site Storm Water Sampling Locations iv ACRONYMS AND ABBREVIATIONS BMP CFR COG CWA ELAP ERA HMBP General Permit mg/L NAL NEC NOI NOT NPDES NSWD PG&E PPT PRDs QISP QSE RQWCB SIC SMARTS SPCC SWPPP SWRCB SWRO WDID WHAT uG/L UST Best Management Practice Code of Federal Regulations Chain of Custody Clean Water Act Environmental Laboratory Accreditation Program Exceedance Response Action Hazardous Materials Business Plan Industrial Storm Water Permit for Discharges Associated with Industrial Activity Milligrams per liter Numeric Action Level No Exposure Certification Notice of Intent Notice of Termination National Pollutant Discharge Elimination System Non-Storm Water Discharge pacific Gas and Electric Company Pollution Prevention Team Permit Registration Documents Qualified Industrial Storm Water Practitioner Qualifying Storm Event Regional Water Quality Control Board Standard Industrial Classification Storm Water Multi-Application and Tracking System Spill Prevention Control and Countermeasure Storm Water Pollution Prevention Plan State Water Resources Control Board Sea Water Reverse Osmosis Waste Discharge Identification Waste Holding and Treatment Facility Micrograms per liter Underground Storage Tank V STORM WATER POLLUTION PREVENTION PLAN SIGNATURE AND CERTIFICATION I am duly authorized to sign reports required by the California State Water Resources Control Board Industrial Storm Water Permit for Discharges Associated with industrial Activity.

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to ensure that qualified personnel gather and evaluate 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 for knowing violations.

Date Kenneth Cortese -Manager, Chemistry and Environmental Operations vi

1. INTRODUCTION This industrial storm water pollution prevention plan (SWPPP) for Pacific Gas and Electric Company' s (PG&E) Diablo Canyon Power Plant (Facility) was prepared in accordance with the requirements of the California State Water Resources Control Board (SWRCB) Industrial Storm Water Permit for Discharges Associated with Industrial Activity ("General Permit," Order NPDES No. CAS000001).

A copy of the General Permit (Order No. 2014-0057-DWQ) dated April 1, 2014, is attached as Appendix A. This updated SWPPP supersedes the Industrial General Permit SWPPP associated with Order 97-03-DWQ.This SWPPP will be modified whenever there is a relevant change in operation, maintenance or construction at the facility which may affect the discharge of pollutants to surface water. It will also be amended if it is found ineffective in achieving the objectives listed in the General Permit.1.1 Background and Requirements The Federal Clean Water Act (CWA) prohibits discharges from point sources to waters of the United States, unless the discharges are in compliance with a National Pollutant Discharge Elimination System (NPDES) permit. In 1987, the CWA was amended to establish a framework for regulating municipal storm water discharges and discharges associated with industrial activity under the NDPES program.Industrial storm water discharges, are regulated pursuant to CWA section 402(p)(3)(A).

This provision requires NPDES permits for industrial storm water discharges to comply with technology-based effluent limitations and water quality-based limitations, as well as implement best management practices (BMPs).On April 17, 1997, the SWRCB issued NPDES General Permit for Industrial Storm Water Discharges, Excluding Construction Activities, Water Quality Order 97-03-DWQ.

The current General Permit, Order 2014-0057-DWQ, supersedes the previous permit, and serves as the statewide general permit for industrial storm water discharges.

The General Permit requires dischargers to:* Eliminate unauthorized non-storm water discharges (NSWDs);* Develop and implement SWPPPs that include BMPs;* Implement minimum BMPs, and advanced BMPs as necessary, to achieve compliance with the effluent and receiving water limitations of this General Permit;* Conduct monitoring, including visual observations and analytical storm water monitoring for indicator parameters;

• Compare monitoring results for monitored parameters to applicable numeric action levels (NALs) derived from the U.S. EPA 2008 Multi-Sector General Permit for Storm Water Discharges Associated with Industrial Activity (2008 MSGP), and other industrial storm water discharge monitoring data collected in California;

• Perform the appropriate Exceedance Response Actions (ERAs) when there are exceedances of the NALs; and* Certify and submit all permit-related compliance documents via the Storm Water Multiple Application and Report Tracking System (SMARTS).

Dischargers shall certify and submit these documents which include, but are not limited to, Permit Registration Documents (PRDs)including Notices of Intent (NOIs), No Exposure Certifications (NECs), and SWPPPs, as well 1 as Annual Reports, Notices of Termination (NOTs), Level 1 ERA Reports, and Level 2 ERA Technical Reports.1.2 SWPPP Performance Standards This SWPPP identifies and evaluates all sources of pollutants from the Facility that may affect the quality of industrial storm water discharges and authorized NSWDs. Additionally, this SWPPP identifies and describes the minimum BMPs and any advanced BMPs implemented to reduce or prevent pollutants in industrial storm water discharges and authorized NSWDs. BMPs will be selected to facilitate compliance with the objectives of the General Permit and will identify and describe conditions or circumstances which may require future revisions to be made to the SWPPP. A copy of the current SWPPP shall be maintained at the Facility.1.3 SWPPP Implementation and Revisions PG&E Diablo Canyon shall implement this SWPPP effective July 01, 2015. The SWPPP shall be revised whenever necessary and will be certified and submitted electronically to the SWRCB via SMARTS within 30 days whenever the SWPPP contains significant revisions.

Minor. revisions are not required to be entered into SMARTS more than once every three months within a given reporting year.1.4 General Facility Information Facility Name: Diablo Canyon Power Plant (DCPP)Facility Address: 9 miles NW of Avila Beach, Avila Beach, CA 93424 Telephone Number: (805) 545-4888 Standard Industrial Classification (SIC) Code: 4911 (Electric Power Generating Facility)Waste Discharge Identification (WDID) Number: 340108248 Scheduled Facility Operating Hours: 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s/7 days Size of Facility:

Industrial Facility Zone Approximately 585 Acres The Facility is located on a remote ocean cove approximately 9 miles west northwest of Avila Beach, San Luis Obispo, County, California (Figure 1). The industrial operating portion of the site area where the Facility is located is approximately 585 acres, and is currently owned by PG&E. The Facility is a two unit pressurized water reactor power generating facility with a combined output of approximately

.2,300 megawatts.

The Facility includes the following major buildings, facilities, structures and areas:* Turbine Building* Containment Building(s)

• Auxiliary/Fuel Handling Building* Rad Waste Facility* Administration Building* Cold Machine Shop 2 a Intake Structure* Training Building* Maintenance Shop Building* NPG Main Warehouse* Turbine Generator Equipment Storage* Hazardous Waste Storage Unit* Fabrication Shop* Blast /Paint Application Facility* Security Training Shooting Range* Sea Water Reverse Osmosis Facility* Makeup Water Facility* Vehicle Maintenance Shop* Building 113* Old Steam Generator Storage Facility Percent Impervious:

Approximately 25 % of 585 Acres Facility Contact: Name: Trevor Rebel Title: Senior Environmental Coordinator Company: Pacific Gas and Electric Company Phone: (805) 545-3607 Email: tdr5@pge.com Street Address: P.O. Box 56 City: Avila Beach State: CA Zip Code: 93424 1.5 Pollution Prevention Team A Pollution Prevention Team (PPT) responsible for assisting with the implementation of this SWPPP and for conducting all monitoring required under the General Permit has been identified.

The specific individuals (and job titles) that are responsible for developing, implementing, revising this SWPPP, and conducting compliance monitoring are identified in Table I.3 Table I Pollution Prevention Team Name of Person Title/Position Responsibilities, Duties, and Activities Supervise SWPPP development and implementation; provide support and PG&EUtilty Wter training to the Environmental PG&EUtilty Wter Coordinator and Plant Staff; review Jeremy Laurin Quality Subject Matter douetupaedoSMR

Expert Interface with the Regional and/or State Water Quality Control Boards when______________________necessary as related to storm water.Facility lead for storm water permit compliance, monitoring; and reporting; conduct employee training; supervise and/or conduct inspections and sampling, Trevor Rebel DCPPo nvroin mental record and report maintenance; record Coordnatorand report spills and leaks; file documents in SMARTS; BMP implementation; emergency response coordination; spill cleanup coordination.

DCPP Manager Designated Legally Responsible Person KnehCreeCEmvisometand (LRP); responsible for certification of Envionmetaldocuments within SMARTS_______________________Operations Stevn PngileySenior Scientist Tenera Secondary contact for storm water Stve PngllyInc.

Environmental inspections and sampling.Research Assistant Tessa Lange Tenera Inc. Secondary contact for storm water Environmental inspections and sampling.Bryn unnngamDCPP Environmental Provide management oversight and Bryn unnngamOperations Supervisor support including LRP designee.In the event that the Environmental Coordinator or other positions responsible for SWPPP implementation are temporarily unavailable to conduct storm water activities due to vacation, illness, out of town business, or other absences, secondary personnel will implement the SWPPP and conduct required monitoring.

PG&E will train, as applicable, all backup personnel so they are familiar with storm water requirements.

PG&E will ensure that this SWPPP is implemented and revised as necessary to be consistent with applicable municipal, state, and federal requirements that pertain to the requirements in the General Permit.4

2. SITE LAYOUT AND EXISTING FACILITY PLANS (PERMIT SECTION X.E)PG&E has prepared figures illustrating the information required by the General Permit. These include: Figure 1, Site Plan; Figure 2, Site Storm Water Drainage System; Figure 3 Storm Water Sampling Locations.

The maps present the following information where applicable:

• Site location;* North arrow;* Facility boundary;* Drainage areas;* Portions of any drainage area impacted by discharges from surrounding areas;* Direction of flow within each drainage area;* On-Facility surface water bodies;* Areas of soil erosion;* Nearby water bodies (e.g., rivers, lakes, wetlands);

• Municipal storm drain inlets;* Location of storm water collection and conveyance systems;* Points of discharge;

• Sampling locations;

• Structural control measures;N Impervious areas;* Locations of directly exposed materials;

• Locations of significant spills and leaks;* Areas of industrial activity;* Industrial storage areas/storage tanks;* Shipping and receiving areas;* Fueling areas;* Vehicle and equipment storage/maintenance areas;* Material handling/processing areas;* Waste treatment and disposal areas;* Dust or particulate generating areas;* Cleaning and material reuse areas; and* Other areas of industrial activity.5 Facility details are shown on Figure 2, Site Storm Water Drainage System. All runoff from the site is collected in gravity-driven culverts and inlets, and discharged either to Diablo Creek or the Pacific Ocean.Two retention basins serve to settle and infiltrate storm water for minor to moderate storm events prior to any possible discharge.

Minor to moderate events will not result in a discharge from the following described paths; Storm water path 012 collects water from Diablo Creek Road, Tni-Bar Flats, and the Northern section of the 500 kV switchyard.

If the retention basin fills to capacity, storm water path 012 discharges to Diablo Creek. Storm water path 004 retention basin collects water from approximately 25 % of the plant power block areas, and the Area 10 industrial facilities.

If the retention basin fills to capacity, storm water path 004 discharges to the Pacific Ocean at the Diablo Canyon Intake Cove following commingling with other non-storm water discharges.

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3. LIST OF INDUSTRIAL MATERIALS (PERMIT SECTION X.F)3.1 List of Industrial Materials Handled at the Facility The following table lists significant industrial materials handled at the Facility, the locations where the materials are stored, received, shipped, handled, and the typical quantities and handling frequency.

The DCPP Environmental Emergency Plan contains pertinent information for all hazardous materials stored at DCPP, including specific storage locations and quantities.

Additionally, DCPP maintains a Spill Prevention Control and Countermeasure Plan (SPCC) in accordance with 40 CFR parts 112 and 761.Table II Bulk Industrial Materials/Chemicals Handled at the Facility RecevingShipingTypical Material Reevng/SHipping How Storage Quantifites an HnligStored Location (~Frequency (Gallons)____

Aboveground Itk tutr ,0 Sodium Bromide Monthly Tank Itk tutr ,0 Sodium Bisulfite Quarterly Aboveground Adjacent Turbine 6,0__________

Tanks Building6,0 Adjacent Turbine#2 DeselFue-OilBimothl USTAST Bld, Fleet#2 iesl FelOilBimntly ST/ST Fueling, Marine 102,250 Fueling EthaolaineMonhlyAboveground Inside Turbine Etaoamn onhyTanks Buttress Building 4,000 Gasoline Monthly Aboveground Fleet & Marine2,5________________Tanks Refueling Stations 2,5 Hydraine onthl Porable anks Inside Turbine60 Hydraine onthl Porable anks Buttress Building 60 Sodium Hydroxide Weekly Aboveground Inside Turbine. 7,0 Tank Buttress Building 7,0 SufrcAi ekyAboveground Inside Turbine7,0 Sufrc cdWekyTank Buttress Building 7,0 Sodium Hypochlorite Weekly Aboveground Intake Structure

.9,500 Tanks Lurcain i AnalyAboveground Multiple Power 14,6 LurctinOlAnulYTanks Block Locations 14,6 Mineral Oil (Electrical Operating Mlil oe Equipment)

Annually Electric Multple2owe Transformers Block Locations 21,9 7

4. DESCRIPTION OF POTENTIAL POLLUTANT SOURCES (PERMIT SECTION X.G)4.1 Industrial Processes PG&E's Diablo Canyon Power Plant (DCPP) is a pressurized water reactor nuclear steam electric generating station. The primary industrial process is electrical power generation.

Secondary industrial processes include the use of ancillary support machinery and equipment.

The materials and areas of usage are described below.4.2 Material Receiving, Shipping and Handling Trash and recyclable materials are accumulated in dumpsters and/or roll-off containers located throughout the Facility.

Dumpsters have integral lids which are closed when the dumpsters are not being actively used. Metals and wood for recycling are accumulated in roll-off bins located east of the power block in a laydown area.All hazardous wastes generated by the Facility are protected (no exposure) from storm water. The Central Hazardous Waste Management Area (CHWMA) processes and stores industrial process generated hazardous waste (solids and liquids) inside of a secure (locked) warehouse.

Receiving The Facility receives regular deliveries Of the liquid industrial chemicals and materials listed in Table II. The materials stored in larger tanks are delivered by vendor service trucks and are directly loaded into the respective storage vessels. Receiving and loading of materials is performed directly adjacent to storage areas. Other materials include those listed in volume 2 of the DCPP Environmental Emergency Plan used in miscellaneous equipment and machines.

None of these materials are directly exposed to storm water.Shipping Shipping materials, oils, and wastes at the Facility occurs within the waste storage area indicated on Figure 2. Shipping generally occurs Monday through Friday from 0800 to 1700, during normal business hours.Material Handling Materials and wastes are moved using service vehicles.

Hazardous waste is picked up and shipped offsite for processing by a waste disposal vendor (PSC Industrial Services) during normal business hours.4.3 Dust and Particle Generating Activities The Facility operates an outdoor shooting range. All range activities direct rounds into engineered bullet trap enclosures.

Both structural and non-structural BMP are used to control potential particulate release.The Facility infrequently utilizes an outdoor abrasive blast yard. All blast material is captured and contained during abrasive blasting operations.

All blast materials are cleaned up and disposed of in sealed containers after each blasting activity.8

4.4 Significant

Spills and Leaks There have been two significant spills or leaks at the Facility in its operating history.In 1995, a transformer failure released 3,400 gallons of mineral oil to the Unit 1 transformer yard. An unknown quantity of oil reached Diablo Creek and the Pacific Ocean. The oil spill was cleaned up and/or dissipated.

In 2008 a transformer failure and fire released mineral oil to the Unit 2 transformer yard. A majority of the oil was consumed in the fire. No oil reached a discharge point from the facility.

Some biodegradable fire fighting foam used during the fire response reached Waters of the State at the Diablo Canyon Intake Cove.Significant spills and leaks include any toxic chemicals identified in 40 Code of Federal Regulations (CFR) Section 302 that are discharged into the Facility's storm water conveyance system as reported on U.S. EPA Form R, as well as spills or leaks of oil and hazardous substances in excess of reportable quantities (40 CFR §§ 110, 117, and 302). PG&E contracts with PSC Industrial Services to respond to any significant spills of fuels, oil or other materials.

During routine monthly inspections, PG&E evaluates the areas where spills and leaks could potentially occur during material delivery., unloading, loading, transport, storage/containment, or use.In accordance with the Facility SPCC Plan and the General Permit, in the event that significant spills or leaks occur in the future,- for each potential discharge PG&E will record and document the following information:

the location, characteristics, and approximate quantity of the materials spilled or leaked;approximate quantity of the materials discharged from the Facility's storm water conveyance system;the cleanup or remedial actions that have occurred or are planned; the approximate remaining quantity of materials that have the potential to be discharged; and the preventive measures taken to ensure spills or leaks of the material do not reoccur.4.5 Non-Storm Water Discharges A NSWD is any water discharged through a dedicated or shared storm water conveyance system at the Facility which is not the direct result of a rain event. Examples include process water, cooling water, and wash water. When non-storm water enters a storm water collection system, it may introduce pollutants into the system. Per the requirements of the General Permit, these NSWDs are considered illicit discharges and must be eliminated.

Certain limited categories of NSWDs are considered to be authorized (as long as they are not in violation of any Region Basin Plan, municipal agency ordinance, or other statewide water quality control plans or policy requirements), including:

• Fire hydrant flushing;* Potable water sources;* Drinking fountain water;* Refrigeration, air conditioning, dehumidifier, continuous emissions monitoring system, or compressor condensate;

• Irrigation drainage and landscape watering, provided that all pesticides, herbicides and fertilizer have been applied in accordance with manufacturers' recommendations; 9

• Uncontaminated natural springs, groundwater, and foundation/footing drainage;* Seawater infiltration where seawaters are discharged back into the sea; and* Incidental windblown mist from cooling towers.The NSWDs listed above are authorized by the General Permit if all of the following conditions are met:* The NSWDs are in compliance with Regional Water Quality Control Board (RWQCB)requirements.

• The NSWDs are in compliance with local agency ordinances and/or requirements.

• BMPs are specifically included in the SWPPP to (1) prevent or reduce the contact of NSWDs with significant materials or equipment and (2) minimize, to the extent practicable, the flow or volume of NSWDs.* The NSWDs do not contain significant quantities of pollutants.

• The monitoring program includes quarterly visual observations of each NSWD and its sources to ensure that BMPs are being implemented and are effective.

• The NSWDs are reported and described annually as part of the Annual Report.As part of the routine monthly site inspections, trained personnel will conduct an evaluation of the Facility to identify any NSWDs, sources, and drainage areas. The inspection will include an evaluation of all storm drain inlets to identify connections to the storm water conveyance system; and a description of any NSWDs that have occurred and how they have been eliminated.

In the event that NSWDs are discovered,they will be described on the inspection form located in Appendix E of the SWPPP. This description will include the source, quantity, frequency, and characteristics of the NSWDs, associated drainage area, and whether it is an authorized or unauthorized NSWD.NPDES Permit Number CA00375 1, Order 90-09 allows for the discharge of stored water from power block discharge points 004, 005, 008, 009.4.6 Erodible Surfaces The Facility experiences some erosion due to extensive ground squirrel/wildlife activity in native soils and road cut toe slopes. Eroded material is controlled with non-structural BMP to include: removing eroded material with sweeping and/or vacuuming, installing waddles or check dams as appropriate.

Erosion generally does not occur due to industrial activities.

Approximately 25 % of the Facility is developed and/or impermeable.

Larger unpaved portions of the in use industrial site include Parking Lot 1 and the Old Steam Generator Storage Facility laydown area.Both of these locations have minimal slope, and are not subject to erosion. The remaining unpaved areas of the Facility are covered with varying densities of natural coastal vegetation.

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5. ASSESSMENT OF POTENTIAL POLLUTANT SOURCES (PERMIT SECTION X.G.2)5.1 Narrative Assessment of Likely Pollutants Present in Storm Water Discharges Plant staff conduct frequent preventive maintenance and inspection to ensure power block and supporting structure plant machinery, equipment and storage vessels are in good working order. The most likely potential pollutants in storm water discharges are the materials listed in Table II.Approximately 19 storm water paths drain the industrial site, and are located throughout the Facility.PG&E has implemented BMPs, section 6, to control the offsite migration of potential pollutants.

5.2 Identification

of Additional BMPs The storm water retention basins at storm water paths 004 and 012 are advanced BMPs at the Facility constructed by PG&E. PG&E will consider identifying additional BMPs to address any significant changes to the Facility that may affect storm water discharges, or if any monitoring results indicate significant increases in concentrations of constituents of concern.5.3 Identification of Drainage Areas with No Exposure Three drainage discharge areas within the Facility meet the requirements of zero industrial exposure.All three drainages drain only coastal slope areas. Those areas are identified on the Site Storm Water Drainage System, Figure 2, as paths 007, 024 and 025.5.4 Identification of Additional Parameters In addition to the standard parameters required for all industrial facilities (pH, oil and grease, and total suspended solids), PG&E will continue to analyze for iron, as per the SIC code 4911 requirements of Table 1 and Attachment A of the General Permit.11

6. STORM WATER BEST MANAGEMENT PRACTICES (PERMIT SECTION X.H)6.1 Minimum BMPs (Permit Section X.H. 1)6.1.1 Good Housekeeping

• Monthly Visual Inspections.

Once per calendar month, personel inspect all outdoor areas associated with industrial activity, including storm water discharge locations, drainage areas, conveyance systems, waste handling/disposal areas, vehicle rinse areas, and perimeter areas impacted by off-Facility materials or storm water run-on to determine housekeeping needs. Any identified debris, waste, spills, tracked materials, or leaked materials identified during the inspections are cleaned and disposed of properly.* Tracking Control. There is a low potential for tracking of sediment at the Facility.

If tracking is discovered during routine inspection, then sediments are removed and associated area cleaned as practicable.

• Sweeping.

Comprehensive site street sweeping is performed on a semi-annual basis for all accessible paved areas. Note: Some site areas are not accessible due to nuclear security infrastructure, barriers, and limits to access. Additional concentrated street sweeping is performed as needed based on monthly site inspections.

• Dust Control. The power generation process does not generate dust; however., dust* suppression is implemented during excavation activities or minor construction.

• Industrial Materials Storage Control. The Facility appropriately stores all materials and performs all activities that involve hazardous materials under' roofed areas*(buildings or storage containers) to the maximum extent practicable, within secondary containment, or during dry weather, if possible.* Control of Non-Solid Industrial Materials/Wastes.

The Facility contains all stored non-solid industrial materials or wastes (e.g., waste oil) that can be transported or dispersed by wind or contact with storm water. Spill kits are maintained and allow for immediate response to spills. These materials are also stored indoors or within secondary containment to prevent any spilled or leaked material from being transported by storm water.* Control of Rinse/Wash Water Disposal.

No wash water impacts the sites storm water conveyance system. Rinse water from vehicle rinsing is directed to the 004 pathway retention basin. Soaps are not~used.

Rinse areas and the 004 retention basin are inspected monthly.* Spill Response.

The Facility prevents the disposal of any industrial materials into the storm water conveyance system by responding immediately to any spills and maintaining spill kits in good order. See additional information in section 6.1.3.* Minimize Storm Water Discharges from Non-Industrial Areas. Non-industrial areas exist within the facility.

The non-industrial areas (coastal slopes, employee parking areas, etc.) are observed and inspected to ensure there is no impact on industrial storm water discharges.

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6.1.2 Preventative

Maintenance

• The Facility implements the following preventative maintenance measures:* PG&E has identified the following outdoor equipment at the Facility which may spill or leak pollutants, as follows:-Containment areas, tanks and containers storing hazardous materials or wastes;-Oil-filled electrical equipment and oil-filled operating equipment; and-Service vehicles (pickup trucks, forklifts, and scissor lifts) used to load or transport materials such as fuels or drums of waste oil* Monthly observations of containment areas, tanks, equipment and systems are conducted to detect leaks, or identify conditions that may result in the development of leaks.* The Facility maintains a schedule for conducting routine maintenance of identified equipment and systems. There is daily inspection of service vehicles, and periodic servicing.

Services vehicles are maintained at the Facility in a covered garage.* The Facility has defined procedures for prompt maintenance and repair of equipment, and maintenance of systems when conditions exist that may result in the development of spills or leaks.6.1.3 Spill and Leak Prevention and Response PG&E has established the following protocols to respond to spills and leaks:* The Facility has developed procedures to minimize spills and leaks. The Facility has an SPCC Plan and a HMBP that address storage of materials and wastes.* The Facility has established spill and leak response procedures to prevent industrial materials from discharging through the storm water conveyance system. Spilled or leaked industrial materials are cleaned up promptly and disposed of properly.* The Facility has identified and described all necessary and appropriate spill and leak response equipment, locations of spill and leak response equipment, and spill/leak response equipment maintenance procedures in the Facility's SPCC plan and/or HMBP. Spill kits are maintained throughout the Facility.* The Facility maintains a full time Fire Department and emergency response team to respond to any leaks or spills. Designated personnel are trained in hazardous materials cleanup (HAZWOPER).

Spill and leak response personnel are trained annually, at a minimum. PG&E maintains a contract vendor (PSC Industrial Services) to respond and assist with any significant spill cleanup activities.

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6.1.4 Material

Handling and Waste Management PG&E has a robust program for addressing material handling and waste management, as follows:* The Facility minimizes the handling of industrial materials or wastes that can be readily mobilized by contact with storm water during storm events.* The Facility appropriately contains stored non-solid industrial materials or wastes (e.g., lubricant oil) that can be transported or dispersed by the wind or contact with storm water by storing these materials within equipment housings, in tanks surrounded by secondary containment, or in drums equipped with water-tight lids and/or staged inside enclosed secondary containers.

• Industrial waste disposal containers (waste/recycling roll-off and metal waste recycling bins) and industrial material storage containers are covered with lids or tarps to the extent practicable during inclement weather. Note: Predicted or potential high wind conditions may require tarp or lid removal to protect the safety and integrity of site energized high voltage transmission lines and system.* Site run-on and storm water generated from within the Facility is diverted away from material storage areas.* Spills of industrial materials or wastes that occur during handling are cleaned up in accordance with the site spill response requirements and Facility procedure CP M-9A.Outdoor material or waste handling equipment or containers that can be contaminated by contact with industrial materials or wastes are inspected and cleaned, as appropriate.

6.1.5 Erosion

and Sediment Controls The Facility experiences some erosion due to ground squirrel/wildlife activity and road cut toe slopes. Eroded material is controlled with non-structural BMP to include: removing eroded material with sweeping and/or vacuuming, waddles, and check dams where appropriate.

Erosion does not occur due to any industrial activities.

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6.1.6 Employee

Training Program Personnel responsible for implementing the storm water program at the Facility will receive annual storm water training.

The Facility has identified which personnel require training (Section 1.5), their responsibilities, and the type of training they will receive, and will prepare or acquire appropriate training materials and establish a schedule for providing the training.All participants will sign a Training Log that will be kept on file with the Facility's storm water compliance records. An example of this log is included in Appendix D. This documentation will be maintained with the SWPPP. At a minimum, training will cover the following topics:* BMP implementation;

• BMP effectiveness evaluations;

• Visual observations; and* Monitoring activities.

In the event the Facility enters Level 1 status (Section 9), appropriate team members will be trained by a Qualified Industrial SWPPP Practitioner (QISP). A QISP must complete a SWRCB-approved training course and assist in the preparation of ERAs for Level 1 and 2 status designations which are described in further detail in Section 9.6.1.7 Quality Assurance and Record-Keeping Facility staff has done, and will continue to perform, the following to retain proper quality assurance and record-keeping:

• Staff has developed and implemented management procedures to ensure that appropriate staff implements all elements of the SWPPP, including the Monitoring Implementation Plan.* The Facility has developed a method of tracking and recording the implementation of BMPs identified in the SWPPP, through the monthly inspection process.* The Facility will maintain the BMP implementation records, training records and records related to any spills and clean-up related response activities for a minimum of five years.6.2 Advanced BMPs (Permit Section X.H.2)In addition to the minimum BMPs described in Section X.H. 1 of the General Permit, the Facility will, to the extent feasible and/or practicable, implement and maintain any advanced BMPs necessary to reduce or prevent discharges of pollutants in storm water discharge in a manner that reflects best industry practice considering technological availability and economic practicability and achievability

6.2.1 Exposure

Minmiation BMPs The Facility has installed engineered bullet trap structures designed to retain and capture spent ammunition from the PG&E Diablo Canyon shooting range. The trap structures are periodically mined and the spent ammnnition is sent to a certified recycling facility.15

6.2.2 Storm

Water Containment and Discharge Reduction BMPs The Facility maintains two storm water retention basins for storing and infiltrating storm water, specifically paths 004 and 012. The retention basins only discharge when filled to capacity.

The basins are inspected on a monthly basis.6.2.3 Treatment Control BMPs Storm water from the outdoor firing range employs sediment trapping to reduce any particulate material associated with range activities.

6.2.4 Other

Advanced BMPs In the event that conditions change or monitoring results indicate an exceedance of one or more numeric action levels (NAL) listed in Table IV (Section 9), the Facility will consider additional advanced BMPs to address the changed conditions or constituents of concern.7. TEMPORARY SUSPENSION OF ACTIVITIES (PERMIT SECTION X.HI.3)PG&E's Diablo Canyon Power Plant operates 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day, 7 days a week. The Facility does not have any plans to suspend industrial activities for ten or more consecutive calendar days in any given year. Therefore, this section of the General Permit is not applicable.

16 BMP

SUMMARY

(PERMIT SECTIONS X.H.4 AND X.H.5)The following table summarizes each identified area of industrial activity, the associated industrial pollutant sources, the industrial pollutants, and the BMPs implemented.

The PPT identified in Section 1.5 is responsible for implementing all BMPs at the site. Some of the BMPs described below require the use of mechanical equipment, such as forklifts; in order to perform maintenance activities on the BMPs. PPT members are authorized to use the required equipment or to obtain the help of other Facility staff to maintain the BMPs onsite. The Facility's mechanics are responsible for maintaining the mechanical equipment throughout the Facility.To retain effectiveness during and after significant weather conditions, certain BMPs must be inspected more frequently than monthly. These BMPs will be informally inspected by PPT members during large rain events or following rain events, as applicable.

Table ml BMP Summary Potential Frequency of Area of Industrial Associated Industrial inutilBMPsBM Activity Pollutant Sources Pol~sImplemented Ipeetto Petroleum Active OWS Turbine HydocabonStoage Hydrocarbons At all times BuildingffoadSump Diversion to Cheicl OfladProcess Chemicals (WHAT) Facility Hydrazine SilKt Sulfuric Acid S~lKt Turin Butrss Cheicl OfladSodium Hydroxide Secondary Turin Butrss Cheicl ffladEtanoamneContainmefit, At all times EthanoamineFloor Drains SSodium Bisulfite adup Resin adup*, Engineered and Trnsformer Yards Eqimn2alr Petroleum Graded basin flows TrnsorerYads Eqipen FilreHydrocarbons to passive OWS with At all times 17,000 gal capacity Sodium Hypochlorite Secondary and Intake Facility Outdoor Tanks (Bleach) Tertiary Daily Inspection Containment, Water Sodium Bromide Test Prior to Release__________

Hazardous Waste Site Generated Engineered Integral Daily and Weekly Facility Potential Spills Hazardous Waste Containment Inspections Fabrication Shop Fabrication Metals, Paint, Oils Indoor Activity At all times High Level Alarm, Sewage Treatment Waste Water Treatment Sewage Potential Overflow At all times_________________to Retention Basin Indoor Storage, SWRO desalinization Process Chemicals Secondary At all times Containment Makep Waer'Indoor Storage, Facili Wty r' Water distribution Process Chemicals Secondary At all times FacilityContainment WHAT Facility (Industrial Waste EupetFirePotentially Oily Waste Engineered Facility A l ie Water Storage and Water with Containment Treatment)______________

____________

17 OilsIndoor Activity, Vehicle Maintenance Spills Solvents, HospilleKit g At all times MetalsSplKi Spill Kit, FletVeice uein Ptetil uein Sils Gasoline, Secondary FleDVhceeulng PtntaeueigSplsContainment, At all times DieselRetention Basin with 38,000 gal capacity Main Rfulng Poenia uein Sils Gasoline, Spill Kit, MrnReuln PoetaFulnSpls Diesel Secondary At all times Containment Engineered Bullet Shooting Range Shooting Range Metals, Sediment Traps, Sediment At all times Boxes, Filtration Paved and Graded 50kSwtyrd Oil Filled Operating Petroleum Collection System, At all times 50kSwthad Electrical Equipment Hydrocarbons Passive OWS with________________

__________________13,000 gal capacity Paved and Graded 230 kV Switchyard Oil Filled Operating Petroleum Collection System, At all times Electrical Equipment Hydirocarbons Passive OWS with 17,000 gal capacity Remote 12 kV Oil Filled Operating Petroleum Transformers Electrical Equipment Hydr~ocarbons Inspection Monthly Warehouse Material Handling Spills Multiple IndoorlStorage

____________and or Incidents Graded and Paved A l ie Petroleum Area 10 Rotor Storage Oil Filled Equipment Hydrocarbons Passive OWS At all times Outdoor Abrasive AbaieBatn ad eaPit Graded and Paved, Ec s Blast Facility AbrasiveBlasting_

Sand, MeaPit Housekeeping

.. Ec s Trash and Scrap Trash, Metals Trash, Metals Covered when not in At all times Dumpsters use as practicable Inspections, FcltWieSoil and SoilsentSweeping, Check At all times Facility Widedisruption/deposition SisDmVcuig Waddles 18

8. MONITORING IMPLEMENTATION PLAN (PERMIT SECTION X.i)As described above in Section 1.5, Facility staff has assembled a PPT that includes members assigned to conduct storm water monitoring.

Analytical monitoring will be conducted at eight sampling locations shown on Figure 3.Procedures for Monthly Visual Observations Facility staff will conduct visual observations within the drainage area at the Facility at least once per calendar month, which will include an evaluation of:* Presence or indications of prior, current, or potential unauthorized NSWDs and their sources;* Authorized NSWDs, sources, and associated BMPs; and* Outdoor industrial equipment and storage areas, outdoor industrial activities areas, BMPs, and all other potential source of industrial pollutants Monthly visual observations will be conducted during daylight hours without precipitation.

Note: The Facility operates 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> each day. Visual observations will be recorded on the form provided in Appendix E. Information to be recorded will include the date, approximate time, locations observed, presence and probable source of any observed pollutants, name of person(s) that conducted the observations, and any response actions and/or additional SWPPP revisions necessary in response to the visual observations.

If a monthly visual observation is not conducted, staff will provide an explanation in the Annual Report.Procedures for Sampling Event Visual Observations Facility staff will conduct visual observations at the same time sampling occurs at a discharge location.At each discharge location where a sample is obtained, Personnel will observe the discharge of storm water associated with industrial activity and record these observations on the form provided in Appendix E. The same types of information will be recorded as for the monthly inspections.

The following items will be observed and recorded:* The appearance of storm water discharged from containment sources (e.g., secondary containment or sumps) at the time that the discharge is sampled.* The presence or absence of floating and suspended materials, oil and grease, discolorations, turbidity, odors, trash/debris, and source(s) of any discharged pollutants.

In the event that a discharge location is not visually observed during a sampling event, personnel will record which discharge locations were not observed during sampling or that there was no discharge from the discharge location and will provide an explanation in the Annual Report for uncompleted sampling event visual observations, personnel will revise BMPs as necessary if the visual observations indicate pollutant sources have not been adequately addressed in the SWPPP.19 Representative Samples Industrial storm water at the PG&E Diablo Canyon Facility is representatively sampled from eight discharge locations on the site. Sample point reduction, performed in accordance with XI.C.4 of the General Permit is described.

Intake Area Sample Reduction Identification

-Intake areas drain through the following discharge locations:

003, 018, 020, 021, 023.Description of Drainage Locations

-Location 003 drains areas surrounding the Intake Structure building and shop areas before comingling with screen wash system seawater prior to discharge.

Location 018 drains areas south of the Intake Structure building.

Drain 020 drains storm water from a limited area west of the Intake structure deck prior to discharge directly in front of circulating water pump fore-bays.

Drain 021 discharges storm water from a limited area adjacent to the seawater travelling screen deck. Discharge location 023 drains areas south of the Intake Structure including an equipment laydown area and the chemical offload station.Industrial Activities

-Industrial activities associated with Intake area paths include the storage and offloading of bulk process chemicals (bleach and sodium bromide) that are protected by secondary and tertiary containment.

Additional ancillary activities associated with operating large electrically powered pumping systems and a screen wash system occur at the Intake area.BMP -BMP for the Intake area is inspection and good housekeeping practices.

Physical Characteristics-All drainages listed for Intake include storm water culverts and inlets draining asphalt and concrete surfaces.Sample Point and Rationale

-Sample point 023 is the most representative sample for the area as well as capturing a large surface area of the Intake. Point 003 drains to a comingled storm water and seawater pipe before discharging overboard.

Additionally, location 003 is not accessible due to heightened security requirements for the location and does not allow safe access during inclement weather. Drain 018 has intermittent flow based on drain valve (normally shut) position.

The drain valve for 018 is only opened as necessary to remove accumulated storm water. Location 020 drains to a location directly in front of circulating water pump fore-bays and is substantially identical in character 1o point 023. Drain 021 only drains a limited area storm water near the intake travelling screens, and is not representative of the industrial activities for Intake. Drainage location 023 adequately represents the overall industrial processes associated with Intake activities.

Drainage Locations South end of Facility Identification

-Drainage points in the southern portion of the Facility include 007, 024, 025A, 025B Description of Drainage Locations

-Zero industrial activity occurs within the listed drain paths.Industrial Activities

-Zero industrial activity occurs with listed drainages and are therefore, not sampled.BMP -Inspection only.20 Physical Characteristics

-Coastal range land drainage only via natural slopes to concrete inlets.Sample Point and Rationale

-Adjacent discharge location 006 is sampled to adequately represent industrial activities.

Drainage Locations North end of Facility Identifications

-Drainage points at North end of Facility include 008 and 009.Description of Drainage Locations

-Location 008 drains areas adjacent to the Turbine Building, Turbine Buttress Building, and an indoor maintenance shop. Drainage location 009 drains the Unit Transformer Yard and adjacent Turbine Building areas.IndustrialActivities

-Industrial activities in these areas include chemical tank storage and oil filled operating electrical transformers.

BMP -BMP for these areas include inspection, housekeeping, secondary containment for chemical storage and an oily water separator system for the transformer yard.Physical Characteristics

-All drainages listed for 008 and 009 are paved surfaces.Sample Point and Rationale

-Sample point 009 is the most representative sample for the area. Sample point 008 is not readily accessible due to enhanced security measures.

Additionally, sample points 004 and 005 have identical (mirror image) industrial activity and are sampled as part of the MIP.Drainage Locations East of Facility Identilfcations

-Drainage points at East of the Facility include 010, 011, 012, 013, 014, 015.Description of Drainage Locations

-Drainage 010 drains areas adjacent to the makeup water demineralization Facility, 011 primarily drains natural coastal slopes and a road, 012 drains the overflow outlet of an engineered storm water retention basin, 013 drains areas adjacent to an industrial Waste Water Treatment Facility (WHAT) and a large laydown area, 014 drains a laydown yard and the abrasive blast facility, 015 drains areas adjacent to the vehicle maintenance and equipment staging area.Industrial Activities

-Industrial activities in these areas include electrical transmission, water treatment, laydown and storage, vehicle maintenance, intermittent abrasive blast.BMP -BMP for these areas include inspection, housekeeping, secondary containment, storm water retention basin, switchyard retention basins.Physical Characteristics

-All drainages listed for this area drain asphalt or graded soil areas. All listed drainages flow to Diablo Creek.Sample Point and Rationale

-Sample points 013, 014, 015 adequately capture the industrial activities within the overall area. Path 010 is a minor discharge path that flows to adjacent hillsides.

Path 0 11 primarily drains native coastal slopes and a road. Path 012 has intermittent flow due to a large storm water retention basin, and is not safely accessible in wet weather.21 Summary of Sample Areas Representative samples of industrial areas are obtained by sampling 8 outfall locations located throughout the Facility.

All discharge locations are indicated on Figure 2 (Site Storm Water Drainage System) and sampled locations are indicated on Figure 3 '(Site Storm Water Sampling Locations).

Sampling and Analysis Samples will be collected during Qualifying Storm Events (QSE). A QSE is defined as a precipitation event that produces a discharge for at least one drainage area and is preceded by 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> with no discharge from any Facility drainage area. Responsible staff will collect and analyze storm water samples from two QSEs within the first half of each reporting year (July 1 to December 31), and two QSEs within the second half of each reporting year (January 1 to June 30), as practicable.

The occurrence of QSEs is dependent on natural conditions and QSEs may not occur in a periods of drought or prolonged low precipitation conditions.

Samples will be collected within four hours of the start of discharge at the locations shown on Figure 3.Sampling will be performed in accordance with requirements of the General Permit. Samples will be collected and analyzed for pH, oil and grease, and total suspended solids, as well as iron (based on the Facility's SIC code listed in Table 1 of the General Permit for additional analytical parameters).

Sampling results will be compared to two types of NAL values based on the specific parameter to determine whether either type of NAL has been exceeded for each applicable parameter.

Annual NAL exceedances are based on analytical results for the entire Facility for the reporting year, while Instantaneous Maximum NAL exceedances are based on analytical results from each distinct sample.The table below describes test methods, reporting units, and NAL values: Table IV -NAL Values Parameter Test Method Reporting Annul1 NAL InsaxntaneNAL UnitsMaiuNA Portable pH instrument*

pH units N/A < 6.0 or > 9.0 Oil and Grease EPA 1664A mg/L 15 25 Total Suspended Solids SM 2540-D mg/L 100 400 Iron EPA 200.7 mg/L 1.0 N/A*The pH screen will be performed as soon as practicable, but no later than 15 minutes after the sample is collected, and will be analyzed using a calibrated portable instrument for pH.All instruments used for pH measurement will be properly calibrated in accordance with the manufacturer's instructions and recommended

'frequency, and copies of the calibration records will be maintained onsite. Samples for iron, total suspended solids and oil and grease will be analyzed by an analytical laboratory that is Environmental Laboratory Accreditation Program (ELAP) certified.

All samples will be collected in accordance with Attachment H of the General Permit ("Sample Collection and Handling Instructions")

and handled under proper chain-of-custody (CCC) protocols.

General Permit Attachment H and an example COC are included in Appendix F.22 California Ocean Plan Monitoring On April 01, 2014 the State Water Board adopted Order 2014-0057-DWQ NPDES General Permit for Storm Water Discharges associated with Industrial Activities.

The order requires applicable industrial facilities to comply with requirements set forth in the California Ocean Plan 2012 (Ocean Plan) for storm water discharges to ocean receiving waters.DCPP has multiple storm water discharges that may discharge directly to ocean receiving waters during precipitation events. These facility discharges are indicated on the site storm water sampling locations map provided (Enclosure 1). The key storm water outfall locations which may directly discharge to ocean receiving waters include SW04, SW05, SW06, and SW23.For discharge location SW04, minor to moderate precipitation runoff is captured and infiltrated in a large retention basin located in the drainage pathway prior to outfall. The retention basin will only overflow during significant storm events after filling. Additionally, the outfall conveyance infrastructure leading from the basin (basin overflow riser and underground piping) cannot safely be accessed for sampling when the basin is filled. The basin discharge will also routinely comingle with non-storm water effluent (NPDES Order 90-09 Discharge 004) prior to final outfall to receiving waters. The infrequent, nature of discharge from the retention basin, and likely dilution of the basin effluent with other process water prior to outfall, limits the potential for obtaining a representative storm water sample from this pathway for Ocean Plan compliance monitoring.

Therefore, DCPP will utilize discharge points SW05, SW06, and SW23 as the site industrial storm water sampling points for the Ocean Plan MIP.As set forth in the Ocean Plan, industrial facilities must sample applicable discharges, on an annual basis, during two qualifying" storm events for the following chemical constituents; Total Suspended Solids (TSS), Oil and Grease (O&G), Total Organic Carbon (TOC), pH, Biochemical Oxygen Demand (BOD), Temperature, Turbidity, Table 1 Metals, and Polynuclear Aromatic Hydrocarbons (PAF~s).Discharge locations SW05, SW06, and SW23 will be sampled and analyzed for these constituents twice annually; as achievable dependent on natural patterns of precipitation and associated site storm water runoff activity.Core toxicity monitoring is also required for industrial facilities at least once per year for a minimum of 10% of applicable discharges exceeding 36-inches in diameter.

Only one site storm water discharge location, SW05, meets the infrastructure configuration and/or maximum potential flow definition of a discharge greater than 36-inches in diameter.

This discharge will be sampled for chronic toxicity testing at least once annually; as achievable dependent on natural patterns of precipitation and associated site storm water runoff activity.

However, this location cannot be sampled at the point of discharge in the surf zone (where runoff meets ocean water) due to lack of accessibility and significant safety concerns.

Therefore, this sample will be obtained in the discharge pathway inmmediately prior to the final piping that leads to the point of runoff entry into the surf zone.I Core toxicity monitoring will be conducted for Table 1 critical life stage toxicity using Tier 1 invertebrate species selected from the Ocean Plan Table-IIl-i

[Approved Tests -Chronic Toxicity (TUc)]. The preferential test species will be Red Abalone (Haliotis rufescens) or Sea Urchin (Strongylocentrotus purpuratus) dependent on availability of the respective chronic toxicity testing protocols at qualified analytical laboratories during the time period storm water sampling is completed.

Additionally, due to the often emergent and imperfect predictability of timing for sampling from qualified storm events, as well as resource and test preparation limitations of qualified analytical laboratories, there is potential the general protocol for a 36-hour maximum sample hold time prior to start of chronic toxicity analysis may be exceeded for this monitoring.

23 Sediment monitoring, bioaccumulation monitoring, and receiving water characteristics monitoring, as outlined in the Ocean Plan for storm water discharges, is only required for applicable Phase 1 MS4 permittees, and therefore not applicable to DCPP.Table V -Summary Table for DCPP Ocean Plan Requirements Storm Water MIP Sampling Points Discharge TS G&O TOC pH BOD Tm. Trity Table 1 Ppils Core Point TSI___{Tm 1 Trit 1 Metals ____ Toxicity SWO5 2X 2X -2X 2X 2X 2X_ 2X 2X 2X 1 X SW06 -.2X -2X -2X 2X 2X 2X_ 2X 2X 2X -_SW23 -2X 2X 2X 2X j2X 2X_ 2X 2X 2X -__Where iX and 2X equal annual sample frequency (sample once annually and twice annually respectively).

24 Exceedance Response Actions ERAs are required when an NAL value for any parameter is exceeded.

At the beginning of NOI coverage, PG&E will enter as a Baseline status for all parameters designated in Table IV above. If sampling results indicate an NAL exceedance (either annual or instantaneous) for any parameter listed in Table IV, the status will move up to Level 1 for that parameter on July ist following the reporting year during which the exceedance occurred (i.e. if there was an instantaneous exceedance on September 30, 2015, Level 1 would begin on July 1, 2016). Moving to Level 1 status triggers two actions: a Level 1 ERA Evaluation and a Level 1 ERA Report, both prepared with assistance of a QISP.* A Level 1 ERA Evaluation, due by October 1 following commencement of Level 1 status, consists of completing an evaluation of the industrial pollutant sources at the Facility that may be related to the NAL exceedance and evaluate all BMPs to determine if revisions are necessary to prevent future NAL exceedances.

• A Level 1 ERA Report, due by January 1 following commencement of Level 1 stats, is prepared after the Level 1 ERA Evaluation and consists of revising the SWPPP as necessary to implement any additional BMPs identified in the Evaluation and submitting via SMARTS the Level 1 ERA Report with details regarding SWPPP revisions and the results of the Evaluation.

A Level 1 status for any exceeded parameter will return to Baseline status once the Level 1 ERA Report has been completed, additional BMPs have been implemented, and results from four consecutive QSEs indicate no additional NAL exceedances for that parameter.

The status for any exceeded parameter will change to Level 2 if sampling results indicate an NAL exceedance for that same parameter while in Level 1 (i.e. if Level 1 was implemented on July 1, 2015 and an exceedance occurred on December 1, 2015, Level 2 would be triggered on July 1, 2016).Moving to Level 2 status triggers two actions: a Level 2 ERA Action Plan and a Level 2 ERA Technical Report, both prepared with assistance of a QISP.* A Level 2 ERA Action Plan, due by January 1 following the reporting year during which the NAL exceedance occurred, consists of a schedule and description of implementing a particular demonstration, as described in the Level 2 Technical Report, in response to the NAL exceedance.

-A Level 2 ERA Technical Report, due by January 1 of the reporting year following the submittal of the Level 2 ERA ActionPlan, describes one or more of the demonstrations in response to the NAL exceedance:

Industrial Activity BMPs Demonstration, Non-Industrial Pollutant Source Demonstration, and/or Natural Background Pollutant Source Demonstration (as described in the General Permit Section XII. D.2).-A Level 2 ERA Technical Report may be prepared and submitted at any time, whether or not the Facility is required to submit such a report.* A new Level 2 NAL exceedance is any Level 2 NAL exceedance for 1) a new parameter in any drainage area, or 2) the same parameter that is being addressed in an existing Level 2 ERA Action Plan in a different drainage area.* NAL exceedances, in and of themselves, are not violations of the General Permit. Failure to comply with the Level 1 status and/or Level 2 status ERA requirements is a violation of the General Permit.25 Plant staff will submit all sampling and analytical results via SMARTS within 30 days of obtaining all results for each sampling event. In the event a sample's analytical result is reported by the laboratory as naon-detect or less than the method detection limit, the method detection limit will be provided.

A value of zero will not be reported.Plant staff will provide the sample analytical results reported by the laboratory as below the minimum level (often referred to as the reporting limit) but above the method detection limit. Reported analytical results from multiple discharge points will be averaged automatically by SMARTS. For any calculations required by this General Permit, SMARTS will assign a value of zero for all results less than the minimum level as reported by the laboratory.

26

9. ANNUAL REPORTING (PERMIT SECTIONS XV AND XVI)Plant staff will conduct an Annual Comprehensive Facility Compliance Evaluation (Annual Evaluation) each reporting year (July 1 to June 30). If the Annual Evaluation is conducted fewer than eight months or more than sixteen months after the previous Annual Evaluation, the Facility will document the justification for doing so. Within 90 days of the Annual Evaluation, PG&E will revise the SWPPP as appropriate and implement the revisions.

At a minimum, the Annual Evaluations will cover the following:

• Review of all sampling, visual observation, and inspection records conducted during the previous reporting year;* Inspection of all areas of industrial activity and associated potential pollutant sources for evidence of, or the potential for, pollutants entering the storm water conveyance system;* Inspection of all drainage areas previously identified as having no exposure to industrial activities and materials in accordance with the definitions in Section XVII;* Inspection of equipment needed to implement the BMPs;* Inspection of all site BMPs;* Review and effectiveness assessment of all BMPs for each area of industrial activity and associated potential pollutant sources to determine if the BMPs are properly designed, implemented, and are effective in reducing and preventing pollutants in industrial storm water discharges and authorized NSWDs; and* Assessment of any other factors needed to comply with the requirements in Section XVI .B.Information gathered during the Annual Evaluation will be recorded, on the form provided in Appendix E, Annual Report Plant staff will certify and submit via SMARTS an Annual Report no later than July 15th following each year, and certified by the Legally Responsible Person. The Annual Report will include the following:

• A Compliance Checklist that indicates compliance with all applicable requirements of the General Permit;* An explanation for any non-compliance of requirements within the reporting year;* Identification of all revisions made to the SWPPP within the reporting year; and* The date of the Annual Evaluation.

Copies of the Annual Report are included in Appendix G.27 REFERENCES

1. California State Water Resources Control Board, 2014. Industrial Storm Water Permit for Discharges Associated with Industrial Activity (Order No. 2014-0057-DWQ).

2. Storm Water Pollution Prevention Plan ((97-03-DWQ), Revision 2, 2011.3. Waste Discharge Requirements for PG&E Diablo Canyon Power Plant Units 1 and 2, Order 90-09, NPDES No. CA0003751.

4. PG&E Diablo Canyon Power Plant Spill Prevention Control and Countermeasure Plan (SPCC), 2014.5. PG&E Diablo Canyon Power Plant Environmental Emergency Plan (Hazardous Materials Business Plan), Revision 21, February 2015.28 APPENDIX A General Permit for Storm Water Discharges Associated with Industrial Activities (State Water Resources Control Board Order 2014-0057-DWQ)

APPENDIX B Permit Registration Documents APPENDIX C SWPPP Amendment Form ecinadSummary of WPAmn etso Revision s DEampe Form) i Section and Summary of Revision Date Name / Title Page ____________________________________

t +

APPENDIX D Training Log SWPPP Training Log (Example Form)Name of Trainer:___________________

Date of Training:___________________

Location of Training:

________________

Topics covered:[] SWPPP compliance responsibilities

[] BMP implementation

[] BMP effectiveness evaluations

[] Visual observations

[] Monitoring activities

• ] SMARTS reporting Name Tidle Company Signature APPENDIX E Industrial Storm Water Facility Inspection and Visual Observation Form Industrial Storm Water Facility Inspection and Visual Observation Form (Example Form)General Inormation

...Facility Name WDID No.Date of Inspection Start/End Time Inspector's Name(s)Inspector's Title(s)Inspector's Contact Information Inspector's Qualifications Inspector's Signature

__________________________________

Type of Inspection*

El Monthly Visual Observation El Sampling Event Visual Observation

', :,..- , " ~~Weathier Infofrmation i ' ."-Weather at time of this inspection?

El Clear 0 Cloudy El Rain [] Sleet El Fog El Snow [] High Winds[] Other: Temperature:

If this is a sampling event visual observation, fill in storm event information:

Date Storm Began: Rain Gauge Level: Rain Gauge ID: " " ' ' .~~Visual

"' " .'Are there any spills/leaks observed at the time of inspection?

ElYes ElNo If yes, describe: Have any previously unidentified discharges of pollutants occurred since the last inspection?

ElYes ElNo If yes, describe: Are there any discharges occurring at the time of inspection.?

ElYes ElNo If yes, note the presence of any of the following:

El Floating Materials ElSheen El Discoloration El Turbidity El Odor El Trash/Debris El Other: Describe all checked above: , ' ,: .....

Observations

f : :,i",....Outfall Observations Is NSWD Potential Corrective Action Person Date Corrective No. Present? Source(s) of Contacted Action____NSWD Completed ElYes ElNo E]Yes ElNo El yes El]No*Mont~hly visual observations will be conducted during daylight hours of normally scheduled Facility operation and on days without precipitation.

Sampling event visual observations will be recorded at the same time sampling occurs at a discharge location.

BMP Control Measures* Describe corrective actions initiated, date completed, and note the person that completed the work in the Corrective Action Log.S Structual Conitt61 If No, Ii, Need of Correctfive Action Needid and Measure :" Measureis

°Maintenane, (identify needed maintenance and repairs, or any SOperating Repair,, or

• failed* control measures that need replacement)

' ' .... ':' " Effectively?, R ... aceme..nt.....

1 ElYes ElNo El Maintenance El Repair____ El Replacement 2 EYes E--No El Maintenance El Repair El Replacement 3 LIYes ElNo El Maintenance El Repair El Replacement 4 EYes ElNo El Maintenance El Repair El Replacement 5 EYes ElNo El Maintenance El Repair El Replacement 6 EYes ElNo El Maintenance El Repair El Replacement 7 EYes ElNo El Maintenance El Repair El Replacement 8 EYes ElNo El Maintenance El Repair____ El Replacement 9 Eyes ElNo El Maintenance El Repair El Replacement

________________________

10 ElYes ElNo El Maintenance El Repair____ El Replacement 37 Areas of Industrial Materials or Activities exposed to storm water Below is a list of areas that should be assessed during routine inspections[r Customize this list as needed for the"specific types of industrial materials or activities at your Facility.S Area/Activity

,Inspeted?

.. Corrective Action Needed and Notes'..... ... .... ~(appropriate,'

: .... .... " :: " : i' , ; : effective, and :: ..1 Material LiYes LiNo Li N/A LiYes LiNo loading/unloading and storage areas 2 Equipment operations and LIyes []No Li N/A LiYes LiNo maintenance areas 3 Fueling areas LiYes LINo Di N/A LiYes LiNo 4 Outdoor vehicle and LiYes LiNo Li N/A LiYes LiNo equipment washing areas 5 Waste handling and LiYes LiNo Li N/A LiYes LiNo disposal areas 6 Erodible LiYes LiNo Li N/A LiYes LiNo areas/construction 7 Non-storm water/ ilicit LiYes LiNo Li N/A LiYes LiNo connections*

8 Dut tgeneration and LiYes LiNo Li N/A LiYes LiNo vehicle tracking 9 General Housekeeping LiYes LiNo Li N/A LiYes LiNo 10 LiYes LiNo Li N/A LiYes LiNo*Include a description of the source, quantity, freq uency, and characteristics of the non-storm water discharges, associated drainage area, and whether it is an authorized or unauthorized non-storm water*discharge.

Non-Compliance Describe any incidents of non-compliance observed and not described above:

Additional ControlMeasures**

Describe any additional control measures needed to comply with the permit requirements:

• • Additional Control Measures include the following categories as described in the General Permit: Minimum BMPs: Good Housekeeping," Preventaa've Maintenance;" Spill and Leak Protection;" Material Han dung and Waste Management;" Erosion and Sediment Controls;" Employee Training," and Quality Assurance and Record Keeping Advanced BMPs: Exposure Minimiztion," Storm Water Containment and Discharge Reduction,'

and Treatment Control Notes Use this space for any additional notes or observations from the inspection:

APPENDIX F General Permit Attachment H "Sample Collection and Handling Instructions" and (Example Chain of Custody Form)

APPENDIX G Annual Reports