Exhibit F. North Landfill Storm Water Management Plan.pdf

STORMWATER

MANAGEMENT PLAN

(SWMP)

Larimer County, Colorado

North Landfill

November 8, 2021

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STORMWATER MANAGEMENT PLAN (SWMP)

Larimer County North Landfill

November 8, 2021 | i

Table of Contents

1 PURPOSE

2 SWMP ADMINISTRATOR

3 FACILITY DESCRIPTION

4 FACILITY MAP

5 FACILITY INVENTORY

5.1 Inventory of Facility Activities and Equipment

5.2 Inventory of Materials

6 DESCRIPTION OF CONTROL MEASURES

6.1 Practice Based Effluent Limitations

6.2 Numeric Effluent Limitations

6.3 Water Quality Based Effluent Limits

7 ADDITIONAL CONTROL MEASURE REQUIREMENTS

8 INSPECTION PROCEDURES AND DOCUMENTATION

8.1 Inspection Frequency and Personnel

8.2 Inspection Scope

8.3 Inspection Documentation

8.4 Exception to Inspection Frequency for Inactive and Unstaffed Sites

8.5 Non-Compliance Discovered During Inspection

9 MONITORING PROCEDURES AND DOCUMENTATION

9.1 General Monitoring Requirements

9.1.1 Monitored Outfalls

9.1.2 Representative Sampling

9.1.3 Substantially Identical Outfalls

9.1.4 Measurable Storm Events

9.1.5 Storm Event Information

9.1.6 Sample Type and Requirements

9.1.7 Analytical Requirements

9.1.8 Adverse Weather Conditions

9.1.9 Climates with Irregular Stormwater Runoff

9.1.10 Monitoring Periods

9.1.11 Changes to Monitoring Requirements and Additional Monitoring

9.1.12 Monitoring for Allowable Non-Stormwater Discharges

9.1.13 Monitoring Exceptions for Inactive and Unstaffed Sites

9.2 Specif ic Monitoring Requirements

9.2.1 Visual Assessment Monitoring

9.2.2 Benchmark Monitoring

9.2.3 Effluent Limitations Guidelines (ELG) Monitoring

9.2.4 Water Quality Standards Monitoring

9.2.5 Additional Monitoring Required by the Division

10 CORRECTIVE ACTIONS

10.1 Conditions that Must be Eliminated

10.2 Conditions that Require Review and Modification

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10.3 Corrective Action Reports and Deadlines

10.4 Control Measure Modification

10.5 Substantially Identical Outfalls

11 REPORTING AND RECORDKEEPING

11.1 Routine Reporting of Data – Discharge Monitoring Report

11.2 Annual Report

11.3 Additional Reporting

11.4 SWMP Records

11.5 Sampling Records

11.6 Signatory and Certification Requirements

Attachments

Attachment A – General Permit COR900000

Attachment B – DMR Form (EPA form 3320-1)

Figures

Figure 1 – Location Map

Figure 2 – Existing Conditions

Figure 3 – Site Plan

Figure 4 – Units 1 and 2 Final Grades and Stormwater Control Plan

Figure 5 – Surface Water Map

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Acronyms and Abbreviations

BOD5 Biochemical Oxygen Demand

CDPHE Colorado Department of Public Health and Environment

CFR Code of Federal Regulations

County Larimer County

Division CDPHE Water Quality Control Division

DMR Discharge Monitoring Report

EDOP Engineering Design and Operations Plan

ELG Ef f luent Limitations Guidelines

HDR HDR Engineering, Inc.

LCNL Larimer County North Landf ill

LCRS Leachate Collection and Removal System

LFG Landf ill Gas

MSW Municipal Solid Waste

NAVD North American Vertical Datum

SPCC Spill Prevention, Control and Countermeasure

SWMP Stormwater Management Plan

TSS Total Suspended Solids

WAPA Western Area Power Administration

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1 PURPOSE

This Stormwater Management Plan (SWMP) was developed by HDR Engineering, Inc. (HDR) for

Larimer County (County) and describes how the Larimer County North Landf ill (LCNL) will be constructed, operated, and closed in accordance with the requirements of the Colorado Department of Public Health and Environment ’s (CDPHE) Water Quality Control Division’s (Division) Colorado

Discharge Permit System’s “General Permit COR900000 for Stormwater Discharges Associated with

Non-Extractive Industrial Activity” (General Permit), Sector L – Landf ills, Land Application Sites, and

Open Dumps . The General Permit is currently in the process of being reissued. This SWMP will be revised as needed to ref lect any changes required by the reissued General Permit.

This SWMP is arranged to be consistent with the order of elements listed in Part I, Paragraph F of the General Permit. Since the LCNL is in the process of being permitted, the SWMP is expected to be updated as details of the design and operation of the facility are formalized prior to the commencement of construction activities at the site.

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2 SWMP ADMINISTRATOR

The following individual, by name or title, will be responsible for development, implementation, maintenance, and modif ication of the SWMP:

Name:

Title:

Phone:

Cell:

Fax:

Email:

Address: 14855 N County Road 9

Wellington, Colorado 80549

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3 FACILITY DESCRIPTION

The legal description for the landf ill parcel is the whole of Section 29, Township 10 North, and Range

68 West in the County of Larimer. The landf ill site is bounded on the east by N County Road 9. The southeast corner of the landf ill site is at the intersection of N County Road 9 and Hackamore Road.

The southwest corner of the landf ill site is at the intersection of E County Road 76 and N County

Road 11. The site is approximately two miles west of Interstate 25 and seven miles north of the town of Wellington, Colorado. The general location of the facility is shown on Figure 1 and existing site conditions are shown on Figure 2.

The landf ill is comprised of two operating units; Unit 1 and Unit 2 located on the southwest and northeast side, respectively, of a Western Area Power Administration (WAPA) 345 kV transmission line that bisects the site northwest to southeast. The Site Plan provided on Figure 3 shows the location and general geometric conf iguration of the landf ill units on the site as well as the general layout of the facility. Unit 1 has a waste f ill footprint of 211 acres. Unit 2 has a waste f ill footprint of

105 acres.

The landf ill above existing ground will be formed by waste placement and f inal cover system to a f inish elevation of 5851 feet amsl (top of final cover) for Unit 1 and 5759 feet amsl (top of final cover) for Unit 2. The top deck at these elevations are approximately 5 acres in size and sloped a maximum of 5%. The outside slopes of the landf ill will be approximately 4H:1V with tack-on drainage berms constructed approximately every 40 vertical feet on the slopes . Thelandf ill f inal cover grades for both units are shown on Figure 4.

Once waste is placed to its maximum elevation, the waste will be covered with an engineered f inal cover system comprised of the following layers (top-to-bottom):

• 6-inch thick seedbed layer capable of supporting plant germination

• 18-inch thick rooting layer capable of supporting a root system and protecting the barrier layer

• 40-mil textured linear low-density polyethylene (LLDPE) geomembrane

The landf ill capacity is defined as the airspace between the bottom liner system and the f inal cover system. Based on the landf ill configurations as noted, the following available airspace for waste placement for Units 1 and 2 are estimated:

• Unit 1 - 51,074,700 cyds

• Unit 2 - 17,956,300 cyds

Other facilities that will be constructed on-site in support of landfilling activities include access roads, stormwater detention ponds, a stormwater run-on retention basin, stormwater ditches, scales and scale house, and leachate tanks. The Site Plan provided on Figure 3 of the EDOP drawings shows the proposed locations of some of these facilities. The locations of support facilities may change during the detailed design process.

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4 FACILITY MAP

This section addresses the Facility Map requirements as stipulated in Part I, Paragraph F.3. of the

General Permit:

• Surface Water Map – Attached Figure 5 shows the LCNL property and adjacent topography and surface water features. A north-south running ridgeline located near the western edge of the property provides a drainage divide where surface water west of the divide f lows through intermittent streams generally southwest to Boxelder Creek. Surface water east of the divide f lows through intermittent streams and ditches generally southeast to Coal Creek.

Boxelder Creek is located approximately 0.6 miles southwest f rom the southwest property corner. Coal Creek is located approximately 1.5 miles southeast f rom the southeast property corner. Figure 1 also shows a natural topographic depression primarily located within the northwest quadrant of the site. This depression intermittently ponds water within the lower elevations but has been determined to be non-jurisdictional. As shown in the Site Plan provided on Figure 3, the depression will largely be f illed during site development.

Stormwater retention provided by the depression will be compensated by construction of a run-on retention basin in the north central portion of the property as shown on the

Stormwater Control Plan provided on Figure 4.

• Signif icant Impervious Surfaces - The Site Plan provided on Figure 3 shows the proposed locations of significant impervious surfaces which are essentially limited to paved access roads and buildings. Impervious surfaces will comprise a minor portion of the developed site.

• Facility Stormwater Conveyances – The Stormwater Control Plan shown on Figure 4 shows the proposed locations of all facility stormwater conveyances including ditches, pipes, swales, and berms.

• Stormwater Inlets and Outfalls – The locations of proposed stormwater inlets and outfalls for the developed site are provided on the Stormwater Control Plan shown on Figure 4.

Essentially all stormwater collected f rom the proposed landfill areas and supporting inf rastructure will be directed to the four stormwater detention ponds. Monitored outfalls, labeled Outfalls 001 through 004, are proposed for the discharge associated with each of these ponds as shown on Figure 4.

• Directions of Stormwater Flow – The proposed directions of stormwater f low for the developed site are indicated by arrows provided on the Stormwater Control Plan shown on

Figure 4.

• Areas Where Industrial Activities are Conducted – Industrial activities at the site will primarily consist of municipal solid waste (MSW) unloading and disposal within the limits of waste as indicated on the Site Plan provided on Figure 3. Relatively minor industrial activities will occur within the vicinity of the leachate storage tanks that will be located along the perimeter berm at the leachate pump stations.

• Locations of All Pollutant Sources – Potential pollutant sources are primarily related to waste unloading and disposal within the limits of waste as indicated on the Site Plan provided on

Figure 3. Other potential pollutant sources include the leachate storage tank areas, and the access roads and parking areas if vehicle leaks occur, also shown on Figure 3.

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• Locations of Control Measures to Meet Ef fluent Limits – proposed structural and applicable non-structural control measures used to meet stormwater ef f luent limits include (see Figures

3 and 4 for reference):

o Lining the bottom of the waste disposal areas with a liner consisting of a 12-inch thick prepared subgrade overtopped by a geosynthetic clay liner and a 60-mil HDPE textured geomembrane to contain leachate generated f rom solid waste operations.

o Providing a leachate collection system within the waste disposal areas consisting of drainage composite placed over the liner to collect leachate and direct it to perforated leachate collection pipes. The pipes will f low by gravity to sumps where the leachate will be removed by submersible pumps and transferred to leachate storage tanks.

o Providing dual-contained leachate piping and secondary containment for the leachate pump stations and leachate storage f rac tanks.

o Maintaining separation of stormwater f rom solid waste by installing temporary and permanent diversion berms and ditches to divert run-on away f rom active f ill areas and to the stormwater management system. Stormwater that comes into contact with solid waste will be handled as leachate and segregated f rom the stormwater management system.

o Covering deposited waste with soil cover to isolate stormwater f rom contact with waste. The soil cover can be temporary during operations or permanent af ter closure of a portion of the landf ill. The soil cover also limits the amount of leachate that is generated.

o Constructing four extended detention ponds to capture and treat runof f f rom the landf ill prior to offsite discharge.

o Maintaining a supply of soil on site to construct containment berms as needed to contain spills or leaks.

o Maintaining a supply of absorbent booms or pads on-site to contain spills or leaks.

o Inspections and servicing of fleet vehicles will be performed to identify and correct leaks.

o Vegetation will be established on slopes as soon as practical to limit erosion and sedimentation.

o Measures such as silt fencing, sediment tubes, erosion control matting, pavement sweeping, etc. will be used to limit erosion and sedimentation.

o Treatment measures such as turbidity curtains, aeration, and polymer addition will be added to the extended detention ponds if required to meet ef fluent limitations.

• Locations of Significant Spills or Leaks – The landf ill site is currently undeveloped and no known signif icant spills or leaks have occurred on the property.

• Locations of Stormwater Monitoring Points – The proposed stormwater monitoring points for the landf ill are located at the discharge points f rom the four extended detention ponds just prior to f lowing off-site as shown on the Stormwater Control Plan on Figure 4.

• Location and Description of any Authorized Non-Stormwater Discharges – The only authorized non-stormwater discharges anticipated for the facility include uncontaminated

November 8, 2021 | 9 condensate f rom air conditioners, potential discharge f rom foundation or footing drains, and discharges f rom emergency f ire f ighting activities. The locations of the potential ai r conditioner and foundation drain discharges are limited to the scale house location as shown on Figure 3. The locations of discharges from emergency f ire f ighting activities can occur almost anywhere on site but would most likely occur within the limits of waste disposal in which case the discharges would be routed to one of the four extended detention ponds .

• Locations and Sources of Run-on f rom Adjacent Property - There are only two signif icant sources of run-on f rom adjacent property. These include two of fsite watersheds located north of the facility of approximately 155 acres and 390 acres as shown on the Stormwater

Control Plan on Figure 4. These watersheds are currently undeveloped and therefore the run-on is not anticipated to contain significant quantities of pollutants.

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5 FACILITY INVENTORY

This section provides information on proposed landf ill facility activities, equipment, and materials and an assessment of corresponding potential pollutant sources.

5.1 Inventory of Facility Activities and Equipment

The following table identifies all areas of the facility exposed to precipitation that are associated with industrial activities that may potentially be sources of pollutants that can impact stormwater:

Facility Activity or

Equipment

Potential in

SWMP Coverage

Area?

Description of Pollutant Sources and

General Comments

Yes No

Loading and Unloading of

Materials

X

Waste will be unloaded at the working face of the landf ill. Other uncovered materials that will be unloaded at the site include stone/rock and soil used during construction and operations.

Leachate generated within the waste disposal areas will be pumped to leachate storage tanks that will be regularly emptied by tanker trucks for treatment of f -site. Other materials may be temporarily unloaded at the site and exposed to precipitation during construction projects, such as geosynthetics and pipe, but do not represent a potential source of stormwater pollution.

Outside Storage of

Materials or Products

X

Materials that will be stored outside that could impact stormwater include stone/rock and soil used for construction and operations. Leachate will be stored in covered tanks with secondary containment.

Outdoor Manufacturing or

Processing X

There are no outdoor manufacturing or processing activities proposed for the facility.

On-Site Dust or

Particulate Generating

Processes, Including

Dust Collection Devices and Vents

X

Soil dust will be generated during landf illing activities and by traf f ic during dry periods.

On-Site Waste

Treatment, Storage, or

Disposal, Including

Waste Ponds and Solid

X

Once waste is placed at the working face of the landf ill it will be compacted and covered with soil or alternative cover materials in accordance with the solid waste permit requirements such that it will be exposed to precipitation for a

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Waste Management

Units limited time. Leachate generated f rom the waste will be temporarily stored in closed tanks with secondary containment. There is no waste treatment proposed for the site.

Vehicle and Equipment

Fueling, Maintenance, and/or Cleaning (includes washing) X

Heavy equipment used at the active face of the landf ill will primarily be fueled and maintained at the active face using maintenance trucks. Other vehicles and equipment used at the facility will primarily be fueled, maintained, and cleaned of f-site.

Immediate Access Roads and Rail Lines Used or Traveled by Carriers of Raw Materials, Manufactured Products, Waste Material, or Byproducts

Used or Created by the Facility.

X

Waste hauling vehicles will use the facility ’s temporary and permanent access roads to deliver the waste to the active face of the landf ill for disposal. These vehicles will be covered which will control the blowing or spilling of waste. There is a possibility of leakage of leachate f rom the waste in poorly maintained vehicles. The same roads will be used to haul leachate f rom the storage tanks to the lined landf ill areas for recirculation and to haul rock, soil, and other materials used for construction and operations.

Roofs or other Surfaces

Exposed to Air Emissions f rom a Manufacturing

Building or a Process

Area

X

Air emissions at the site will primarily be landf ill gas (LFG) generated by the decomposition of waste escaping through the waste and cover soils. Eventually, an LFG control system will be constructed to collect the gas and convey it to a f lare for combustion which will also generate air emissions. Vehicle emissions will also be generated at the site. It is unlikely that these sources of air emissions will produce significant quantities of particulates that can settle on roofs or other surfaces and impact stormwater.

Roofs and Associated

Surfaces Composed of

Galvanized Materials that may be Mobilized by

Stormwater (e.g., roofs, ducts, heating/air condition equipment, gutters and downspouts)

X

There are no signif icant exposed galvanized materials proposed for the facility.

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5.2 Inventory of Materials

The following table lists materials that have the potential to contribute pollutants to stormwater at the facility:

Material Source Location Transport Regime and

Outfall Location(s)

MSW Waste disposal areas within the lined landf ill and hauling trucks operating on the facility access roads.

Waste blown or spilled outside of the active face of the landf ill is normally collected and placed within the active face for disposal. Such waste that is not collected can be carried through the stormwater management system to any of the four detention ponds and the associated outfalls proposed for the facility.

Leachate Waste disposal areas, seeps f rom waste disposal areas, leachate hauling tankers, dual contained piping, and storage tanks.

Leachate escaping the lined landf ill area or leaked and spilled outside of it can be carried through the stormwater management system into any of the four detention ponds and the associated outfalls proposed for the facility.

Vehicle Fluids (fuel, oil, coolant, etc.)

Vehicle maintenance locations near the active face of the landf ill and along the facility access roads and parking lots.

Leaked or spilled vehicle f luids can be carried through the stormwater management system into any of the four detention ponds and the associated outfalls proposed for the facility

Landf ill Gas (LFG)

Condensate

Components of the LFG collection and removal system including wells, sumps, gas header and lateral pipes, forcemains, and f lare station.

LFG condensate can enter the environment through leaks or overf lows within the LFG collection and removal system where it can carried through the stormwater management system into any of the four detention ponds and the associated outfalls proposed for the facility.

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There are no known potential pollutant sources f rom past activities at the site.

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6 DESCRIPTION OF CONTROL MEASURES

This section documents the location and type of each non-structural and structural control measure implemented at the facility to achieve the ef f luent limitations contained in the General Permit.

6.1 Practice Based Effluent Limitations

Practice based ef f luent limitations required by the General Permit include the following:

• Minimize Exposure – MSW will primarily be delivered to the LCNL in covered vehicles and deposited immediately at the working face of the landf ill and covered with soil with six inches of earthen material at the end of each operating day in accordance with permit requirements to minimize exposure of the MSW to rain, snow, snowmelt, and runof f . Storage and processing of MSW will not occur at LCNL. Precipitation or run-on that comes into contact with MSW will be considered leachate and directed to the leachate collection system.

• Good Housekeeping – Litter will be regularly monitored and controlled at the site in accordance with the procedures described in the Litter Control Plan provided in Appendix E of the Engineering Design and Operations Plan (EDOP). Debris will be removed f rom the stormwater management system to avoid overflows and washouts. Regular sweeping will also occur on paved surfaces to limit materials entering the stormwater management system.

Maintenance f luids and materials will be kept in appropriate labeled containers under cover.

• Maintenance of Control Measures – LCNL will maintain all control measures used to achieve the ef f luent limits of the General Permit. Maintenance includes preventive and routine maintenance, modif ication, repair, replacement, or installation of new control measures.

Observations resulting in maintenance activities will be made during a site inspection, or during general observations of site conditions. Corrective actions associated with maintaining control measures will be conducted as soon as possible af ter the need is discovered. Corrective actions will be documented and the SWMP modif ied as needed to ref lect replacement or installation of new control measures.

• Spill Prevention and Response Procedures – A formal Spill Prevention, Control and

Countermeasure (SPCC) Plan will be developed for the LCNL prior to the beginning of operation and will be incorporated into this SWMP by reference. A copy of the latest version of the SPCC Plan will be maintained on-site within the administrative of fices. The SPCC

Plan will include procedures for regular inspections for potential releases to the stormwater system, procedures for labeling containers susceptible to leaks and spills, preventive measures for material storage and handling, procedures for rapid response to stop and contain leaks and spill, and procedures for notification of appropriate personnel and regulatory agencies.

• Erosion and Sediment Controls – Erosion and sedimentation will be controlled across the site by stabilizing disturbed areas as soon as practical with temporary or permanent vegetation based on the time of year planting occurs and whether the area will be disturbed again in the near future. Other erosion and sediment controls that may be used at the site include berms, letdowns, ditches, detention ponds, armored energy dissipation, erosion control mats, silt fence, check dams, sediment tubes, hay bales, and sediment traps. The general locations of erosion and sediment controls proposed for the LCNL are provided on the Stormwater Control Plan shown on Figure 4. Details of controls are provided on the

Stormwater Management Details of the EDOP (Figures 4-5, 4-6, and 4-7)

November 8, 2021 | 15

• Management of Runof f – The proposed stormwater management system at the LCNL is designed to minimize pollutants within the stormwater discharges f rom the site by promoting the establishment of vegetation at the site as well as incorporating the erosion and sediment controls previously described in the SWMP. Most proposed swales and berms for the facility are designed to be vegetated to promote stormwater inf iltration and pollutant removal.

Pollutant removal will also be achieved by promoting sheet f low or runof f across vegetated areas to the extent possible and by directing runoff to one of the four extended detention ponds for the facility. The extended detention ponds are designed to treat the contributing water quality volume determined for each pond.

• Salt Storage Piles or Piles Containing Salt - There are no salt storage piles proposed for the

LCNL.

• Sector Specif ic Practice-based Effluent Limits – The following specific practice-based limits are stipulated under Part III, Subsection L (Landf ills, Land Application Sites, and Open

Dumps) of the General Permit:

o Preventive Maintenance Program – Regular monthly inspections of the leachate collection and removal system (LCRS) will be performed at the LCNL to verify the system is operating properly to avoid the comingling of leachate with stormwater.

Leachate pumps will be tested to verify proper operation while dual contained piping and storage tanks will be visually observed for leaks. The integrity and ef fectiveness of intermediate and f inal cover will be verif ied by regular inspections and necessary repairs made to correct the ef fects of seeps, settlement, sinking, and erosion to limit leachate generation.

o Erosion and Sedimentation Control – Temporary stabilization consisting of seeding, mulching, erosion control matting, or other approved means will be provided over soil stockpiles, inactive areas of the landf ill, and f inal cover areas where vegetation has not yet been established.

o Unauthorized Discharge Test Certif ication – Each permitted outfall for the LCNL will be regularly tested for the unauthorized discharge of leachate and vehicle wash water by visual and analytical means as required by the General Permit. Operation of the pumps, piping, and tanks associated with the LCRS and any vehicle wash systems will also be observed for any unauthorized releases.

• Employee Training – The LCNL will develop and implement a training program for employees. The training will be conducted at least annually and will address site-specific control measures used to achieve the ef f luent limits, components and goals of the SWMP, monitoring and inspection procedures, and other app licable requirements of the General

Permit. At a minimum, the following individuals must be trained:

o Employee(s) overseeing implementation of , revising, and amending the SWMP.

o Employee(s) performing installation, inspection, maintenance, and repair of control measures.

o Employee(s) who work in areas of industrial activity subject to the General Permit.

o Employee(s) who conduct stormwater discharge monitoring.

• Non-Stormwater Discharges – This SWMP has been designed to control non-stormwater discharges f rom the LCNL stormwater management system. In accordance with the General

Permit, the only non-stormwater discharges anticipated for the facility include uncontaminated condensate f rom air conditioners, coolers, and other compressors;

landscape watering; uncontaminated spring water; foundation or footing drains; and discharges resulting f rom emergency f ire f ighting activities.

16 | November 8, 2021

• Waste, Garbage and Floatable Debris – Waste, garbage and f loatable debris will be kept f rom the LCNL stormwater management system by limiting waste disposal activities to the minimal practical active face and by covering exposed waste with soil. Regular policing of the facility to remove blown litter will be conducted as described in the Litter Control Plan provided in Appendix E of the EDOP. As a f inal measure, litter that is washed into the stormwater management system will be intercepted by the stormwater detention ponds where it can either settle out or be screened at the discharge structure to prevent of f-site discharge.

• Dust Generation and Vehicle Tracking of Industrial Materials – Dust generation will be minimized at the facility by wetting gravel and soil roadway surfaces with operational water stored on-site within a minimum 250,000 gallon earthen embankment supplied by an of f -site potable water source. Alternately, an approved commercially available dust suppressant may be used. Tracking of waste and mud deposited on the interior access road system will be controlled by regular sweeping of paved surfaces and manual removal as described in the

Litter Control Plan provided in Appendix E of the EDOP.

6.2 Numeric Effluent Limitations

The following numeric ef f luent limitations apply to runoff from non-hazardous waste landf ills and will be monitored annually (Industrial Sector L):

Parameter Effluent Limit

Biochemical Oxygen Demand (BOD5) 140 mg/L, daily maximum

37 mg/L, monthly avg. maximum

Total Suspended Solids (TSS) 88 mg/L, daily maximum

27 mg/L, monthly avg. maximum

Ammonia 10 mg/L, daily maximum

4.9 mg/L, monthly avg. maximum

Alpha Terpineol 0.033 mg/L, daily maximum

0.016 mg/L, monthly avg. maximum

Benzoic Acid 0.12 mg/L, daily maximum

0.071 mg/L, monthly avg. maximum p-Cresol 0.025 mg/L, daily maximum

0.014 mg/L, monthly avg. maximum

Phenol 0.026 mg/L, daily maximum

0.015 mg/L, monthly avg. maximum

November 8, 2021 | 17

Total Zinc 0.20 mg/L, daily maximum

0.11 mg/L, monthly avg. maximum pH Within the range of 6-9 standard pH units (s.u.)

6.3 Water Quality Based Effluent Limits

The following water quality based ef fluent Limits are required by the General Permit:

• Water Quality Standards – This SWMP is designed such that stormwater discharges f rom the site meet applicable water quality standards. If the authorized discharge causes or contributes to an exceedance of applicable water quality standards, LCNL will take corrective action as required by the general permit, document the corrective actions, and report the corrective actions to the Division. If information indicates that compliance with the terms and conditions of the General Permit will not control the discharge as necessary to meet applicable water quality standards, the Division may require site specif ic water quality based ef f luent limitations in the permit certif ication, or require LCNL to obtain coverage under an individual permit. The Division may also include a compliance schedule and additional terms and conditions in the permit certif ication.

• Additional Requirements for Discharges to Water Quality Impaired Waters – This is currently not applicable to the LCNL.

• Additional Requirements for Discharges to Waters Designated as Critical Habitat for

Threatened and Endangered Species - This is currently not applicable to the LCNL.

• Additional Requirements for New or Increased Discharges to Reviewable Waters - This is currently not applicable to the LCNL.

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7 ADDITIONAL CONTROL MEASURE

REQUIREMENTS

This section documents the schedules, procedures, and evaluation results for the following sub set of practice based ef f luent limitations:

Practice Based Effluent Limitation Minimum

Frequency

Good Housekeeping. A schedule for regular pickup and disposal of waste materials, along with routine inspections for leaks and conditions of drums, tanks and containers.

Daily for Litter

Quarterly for

Leaks and

Conditions

Maintenance. Preventative maintenance schedules for industrial equipment and systems; control measures; and any back-up practices in place should a runof f event occur while a control measure is of fline.

Quarterly

Spill Prevention and Response Procedures. Procedures for preventing, responding to, and reporting spills and leaks. LCNL may reference other plans

(e.g., a SPCC Plan) otherwise required by the permit, provided that a copy of the other plan is kept onsite with the SWMP, and made available for review.

Quarterly

Employee Training. A schedule for all types of training required by the permit, content of the training, and log of the dates on which specif ic employees received training.

Annually

Non-Stormwater Discharges. Documentation of the stormwater conveyance system evaluation for the presence of non-stormwater discharges not authorized by the permit, and the elimination of all unauthorized discharges. Documentation of the evaluation must include:

• The date of any evaluation;

• A description of the evaluation criteria used;

• A list of the outfalls or onsite drainage points that were directly observed during the evaluation;

• The dif ferent types of non-stormwater discharge(s) and source locations;

and

• The action(s) taken, such as a list of control measures used to eliminate unauthorized discharge(s), if any were identif ied.

As needed with each occurrence

November 8, 2021 | 19

8 INSPECTION PROCEDURES AND

DOCUMENTATION

LCNL will document inspection procedures and maintain such procedures and other documentation within the SWMP in accordance with requirements of the General Permit .

8.1 Inspection Frequency and Personnel

LCNL will conduct and document two separate visual inspections of the stormwater management system at the facility. These include inspections conducted at least quarterly (i.e., once each calendar quarter) at least 20 days apart and inspections conducted at least monthly. The scope of these two separate inspections are described in Sections 8.2 and 8.3 below.

LCNL will conduct a minimum of one (1) inspection per calendar year during a runof f event, which for a rain event means during or within 24 hours af ter the end of a measureable storm event resulting in discharge f rom the facility and for a snowmelt event means at a time when a measurable discharge occurs f rom the facility.

Inspections will be conducted by adequately trained qualif ied personnel.

8.2 Quarterly Inspection Scope

Each of the quarterly inspections described in Section 8.1 will include the following:

• Observations made at stormwater sampling locations and areas where stormwater associated with industrial activity is discharged off-site, or discharged to waters of the state, or to a storm sewer system that drains to waters of the state.

• Observations for the presence of f loating materials, visible oil sheen, discoloration, turbidity, odor, etc. in the stormwater discharge(s).

• Observations of the condition of and around stormwater outfalls, including flow dissipation measures to prevent scouring.

• Observations for the presence of illicit discharges or other non-permitted discharges such as domestic wastewater, noncontact cooling water, or process wastewater (including leachate).

• A verif ication that the descriptions of potential pollutant sources required under this permit are accurate.

• A verif ication that the site map in the SWMP ref lects current conditions.

• An assessment of all control measures used to comply with the ef f luent limits contained in this permit, noting all of the following:

o Ef fectiveness of control measures inspected.

o Locations of control measures that need maintenance or repair.

o Reason maintenance or repair is needed and a schedule for maintenance or repair.

o Locations where additional or dif ferent control measures are needed and the rationale for the additional or dif ferent control measures.

8.3 Monthly Inspection Scope

Each of the monthly inspections described in Section 8.1 will focus on the following:

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• Areas of landf ills that have not yet been f inally stabilized.

• Areas used for storage of materials.

• Wastes that are exposed to precipitation.

• Stabilization and structural control measures.

• Leachate collection systems.

• Locations where equipment and waste trucks enter and exit the site.

• Proper operation of sediment and erosion control measures.

The f requency of this inspection may be reduced to quarterly for areas that have been f inally stabilized.

8.4 Inspection Documentation

LCNL will document the f indings for each inspection in an inspection report or checklist and keep the record on-site with this SWMP. Each inspection report will document the observations, verif ications, and assessments required in Section 8.2 of this SWMP and will additionally include:

• The inspection date and time.

• Locations inspected.

• Weather information and a description of any discharges occurring at the time of the inspection.

• A statement that, in the judgement of the person conducting the site inspection and either the

Principal Executive Of f icer or senior elected official, the site is either in compliance or out of compliance with the terms and conditions of the General Permit, with respect to Section 8.2 of this SWMP.

• A summary report and a schedule of implementation of the corrective actions that LCNL has taken or plans to take if the site inspection indicates that the site is out of compliance.

• Name, title, and signature of the person conducting site inspection and the following statement: “I certify that this report is true, accurate, and complete, to the best of my knowledge and belief .”.

• Certif ication and signature of the Principal Executive Of f icer, senior elected official, or a duly authorized representative of LCNL.

8.5 Exception to Inspection Frequency for Inactive and

Unstaffed Sites

This exemption does not apply to LCNL.

8.6 Non-Compliance Discovered During Inspection

Any corrective action required as a result of a facility inspection will be performed consistent with the requirements described in Section 10.0 of this SWMP, Corrective Action Documentation.

November 8, 2021 | 21

9 MONITORING PROCEDURES AND

DOCUMENTATION

This section documents stormwater monitoring procedures that will be used at the LCNL.

9.1 General Monitoring Requirements

LCNL will collect and analyze stormwater samples and document monitoring activities consistent with the procedures within the General Permit and applicable to Sector L (Landf ills, Land Application

Sites, and Open Dumps). The results of such monitoring will be reported on the Discharge

Monitoring Report (DMR) form, to include reporting “No Discharge” on the DMR if no discharge occurs within the reporting period, and other reporting conventions.

9.1.1 Monitored Outfalls

There are four proposed outfalls proposed for monitoring at the LCNL, each associated with an extended detention basin which will be constructed to capture and treat runof f from the landf ill prior to of f-site discharge. The extended detention basins will be constructed in stages as needed as development of the landf ill progresses and therefore the number of outfalls to be monitored will vary based on the stage of landfill development. The Stormwater Control Plan shown on Figure 4 provides the locations of the proposed monitored outfalls at full buildout of the landf ill.

9.1.2 Representative Sampling

Samples and measurements taken at the proposed outfalls will be representative of the nature of the monitored discharge.

9.1.3 Substantially Identical Outfalls

Impacts to stormwater quality at the LCNL will largely be dependent on the extent and type of landf ill activities taking place within the contributing drainage areas f lowing to the extended detention basins and can vary over time. The LCNL therefore does not currently anticipate monitoring substantially identical outfalls. This SWMP will be revised in the future to include substantially identical outfall monitoring if proposed for LCNL.

9.1.4 Measurable Storm Events

Storm events associated with stormwater monitoring activities will meet the following requirements:

• Rain Event – LCNL will conduct all required monitoring on a storm event that results in an actual discharge f rom the facility (“measurable storm event”), and that follows the preceding measurable storm event by at least 72 hours (3 days).

• Snowmelt Event – LCNL will conduct snowmelt monitoring at a time when a measurable discharge occurs f rom the facility.

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9.1.5 Storm Event Information

The following information will be recorded to document monitored storm events:

• Rain Event – o The date, time of the start of the discharge, time of sampling, duration (in hours) of the rainfall event, and magnitude (in inches) of the storm event sampled.

o The duration between the storm event sampled and the end of the most recent storm event that produced a discharge.

• Snowmelt Monitoring – LCNL will document the date of the sampling event for each monitored snowmelt event.

9.1.6 Sample Type and Requirements

Stormwater sampling at LCNL will comply with the following requirements:

• Grab samples will be used for all monitoring and will not be combined.

• A minimum of one grab sample will be taken f rom a discharge resulting f rom a measurable storm event.

• Grab samples will be collected within the f irst 30 minutes of a measurable storm event. If it is not possible to collect the sample within the f irst 30 minutes of a measurable storm event, the sample must be collected as soon as practicable af ter the f irst 30 minutes, and documentation must be kept with this SWMP explaining why it was not possible to take samples within the f irst 30 minutes.

• Snowmelt samples will be taken during a period with a measurable discharge.

• All discharge samples at the LCNL will be taken during the same storm event, if feasible.

9.1.7 Analytical Requirements

All sampling will be performed by LCNL according to specified methods in 40 Code of Federal

Regulations (CFR) Part 136; methods approved by EPA pursuant to 40 CFR Part 136; or methods approved by the Division, in the absence of a method specified in or ap proved pursuant to 40 CFR

Part 136.

Additional analytical requirements of the General Permit, Part IH.7, will also be followed and are incorporated into this document by reference (see Attachment A).

9.1.8 Adverse Weather Conditions

When adverse weather conditions prevent sample collection according to the relevant monitoring schedule, LCNL will take a substitute sample during the next qualifying storm event. Adverse conditions are those that are dangerous or create inaccessibility for personnel, such as local f looding, high winds, or electrical storms.

Adverse weather does not exempt LCNL f rom having to f ile timely DMRs. LCNL will report any failure to monitor and indicate the basis for not sampling during the usual reporting period.

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9.1.9 Climates with Irregular Stormwater Runoff

The LCNL is located in an area where limited rainfall occurs during parts of the year and where f reezing conditions exist that prevent runof f f rom occurring for extended periods. The required monitoring events may therefore be distributed during seasons when precipitation occurs, or when snowmelt results in measurable discharge f rom the facility as described in Section 9.1.11 of this

SWMP. LCNL will still collect the required number of samples and will maintain the revised monitoring schedule within this SWMP.

9.1.10 Monitoring Periods

Monitoring requirements for the LCNL begin on the date of discharge authorization. Quarterly monitoring will be conducted at least once in each of the following 3-month intervals:

• January 1 – March 31;

• April 1 – June 30;

• July 1 – September 30; and

• October 1 – December 31.

This monitoring schedule may be modif ied in accordance with Section 9.1.11 below and the revised schedule documented within this SWMP.

9.1.11 Changes to Monitoring Requirements and Additional Monitoring

LCNL may request that the Division modify permit certification monitoring conditions. A justification for such modifications must accompany the request.

If LCNL, using an approved analytical method, monitors any parameter more f requently than required by the General Permit, the results of such monitoring will be included in the calculation and reporting of the values required in the DMRs or other forms required by the Division. Such increased f requency will also be indicated.

9.1.12 Monitoring for Allowable Non-Stormwater Discharges

LCNL is only required to monitor allowable non-stormwater discharges when they are commingled with stormwater discharges associated with industrial activity. The anticipated allowable non-stormwater discharges will not be commingled with f lows entering the monitored outfalls.

9.1.13 Monitoring Exceptions for Inactive and Unstaffed Sites

LCNL is intended to be an active and staf fed facility. If the status of the landf ill changes , this SWMP will be revised in accordance with the requirements of the General Permit to allow monitoring exceptions.

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9.2 Specific Monitoring Requirements

Five types of stormwater monitoring are discussed in the General Permit and described in the following subsections. The types of monitoring that will be required for the LCNLL are noted and will be identif ied in the permit certif ication.

When more than one type of monitoring for the same parameter at the same outfall applies, LCNL may use a single sample to satisfy the monitoring requirements.

9.2.1 Visual Assessment Monitoring

Visual assessment monitoring will be performed once each quarter for the entire permit term. LCNL will collect a stormwater sample f rom each outfall and conduct a visual assessment of each of these samples in accordance with the following procedures:

• Sample Collection - The samples will be collected in such a manner that the samples are representative of the stormwater discharge.

• Visual Assessment - The visual assessment will be sampled in a clean, clear glass, or plastic container and examined in a well-lit area. The sample will be visually inspected for the presence of the following water quality characteristics:

o Color;

o Odor;

o Clarity;

o Floating solids;

o Settled solids;

o Suspended solids;

o Foam;

o Oil sheen; and o Other obvious indicators of stormwater pollution.

• Quarterly Visual Assessment Documentation - LCNL will document the visual assessment results and maintain this documentation on-site and with the facility SWMP. LCNL is not required to submit visual assessment f indings to the Division unless specifically requested to do so. At a minimum, visual assessment documentation will include:

o Sample locations;

o Sample collection date and time, and visual assessment date and time for each sample;

o Personnel collecting the sample and performing visual assessment, and their signatures;

o Nature of the discharge (i.e., runof f or snowmelt);

o Results of observations of the stormwater discharge;

o Probable sources of any observed stormwater contamination; and

November 8, 2021 | 25 o If applicable, why it was not possible to take samples within the f irst 30 minutes.

• Quarterly Visual Assessment Corrective Actions – If the visual assessment indicates the control measures for the facility are inadequate or are not being properly operated and maintained, the permittee must conduct corrective actions as described under Sec tion 10.0 of this SWMP.

• Visual Monitoring Procedures – LCNL will maintain visual monitoring procedures within this

SWMP.

9.2.2 Benchmark Monitoring

The General Permit provides pollutant benchmark concentrations that may be applicable to the discharge authorized by the General Permit. The benchmark concentrations are not ef f luent limitations and therefore a benchmark exceedance is not a permit violation. If the discharge exceeds an applicable benchmark concentration, LCNL must conduct corrective actions consistent with the procedures in Section 10.0 of the SWMP. Failure to respond to benchmark value exceedances is a violation of the General Permit.

• Applicability of Benchmark Monitoring – LCNL will monitor at each benchmark sampling location for each benchmark parameter listed for the applicable industrial sector in the

General Permit. The Division may also include a site specif ic benchmark in a permit certif ication as appropriate to ensure that compliance with the other terms and conditions of the General Permit will control discharges as necessary to meet water quality based ef f luent limitations. The Sector L (Landf ills, Land Application Sites, and Open Dumps) benchmark monitoring includes TSS and Total Iron; however, the benchmark monitoring is only required for discharges not subject to effluent limitations. Since LCNL is subject to effluent limitations, benchmark monitoring is not required at the facility unless the Division requires site specific benchmarks.

• Benchmark Monitoring Schedule – Benchmark monitoring, if required by the Division, will be conducted quarterly for the f irst 4 full quarters of permit coverage. A modification to the quarterly schedule may be requested for facilities in climates with irregular stormwater runof f.

• Averaging Monitoring Values – If benchmark monitoring is required by the Division, the LCNL will calculate average concentrations in accordance with the requirements of the General

Permit.

• Benchmark Monitoring Actions (data not exceeding benchmarks) – Af ter collecting 4 benchmark samples, if the average of the monitoring values for any parameter, at a specif ic outfall, does not exceed the benchmark, LCNL may reduce benchmark monitoring f requency for that parameter to once per year, rotating through the monitoring periods such that 8 samples are collected every f ive years.

• Benchmark Monitoring Actions (data exceeding benchmarks) – o If the averaged monitoring values for any parameter, at a specif ic outfall, exceeds the benchmark as described below, LCNL must conduct corrective action in accordance with Section 10.0 of the SWMP:

▪ The average of the initial 4 quarterly sample monitoring values for any parameter exceeds the benchmark.

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▪ If less than 4 benchmark samples have been taken, but the sum of the quarterly sample results to date is more than 4 times the…