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Stormwater Regulations that affect POTWs and Collection Systems NBWA Workshop Ray Goebel, EOA, Inc.

Stormwater Regulations that affect POTWs and Collection Systems NBWA Workshop Ray Goebel, EOA, Inc. June 23, 2009. Stormwater Perspective (Regulatory Drivers) . Clean Water Act & Federal Regulations Phase II General Stormwater Permit Phase I Permits / Draft Municipal Regional Permit

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Stormwater Regulations that affect POTWs and Collection Systems NBWA Workshop Ray Goebel, EOA, Inc.

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  1. Stormwater Regulations that affect POTWs and Collection SystemsNBWA WorkshopRay Goebel, EOA, Inc. June 23, 2009

  2. Stormwater Perspective(Regulatory Drivers) • Clean Water Act & Federal Regulations • Phase II General Stormwater Permit • Phase I Permits / Draft Municipal Regional Permit • Local Ordinances

  3. Phase II Stormwater Permit • State Water Board General Permit “Waste Discharge Requirements for Storm Water Dischargers from Small Municipal Separate Storm Sewers Systems (MS4s)” • Applicability: • High population density (>1000 residents/mi2) • High growth or growth potential • Significant contributor of pollutants or discharge to sensitive receiving water bodies • In Marin Co., all cities, towns, & county unincorporated area are regulated

  4. Phase II Permit Requirements(condensed) • Prohibits discharge of material other than storm water to waters of U.S., unless exempt or authorized by separate NPDES permit. • Implement best management practices (BMPs) to reduce pollutants in stormwater to maximum extent practicable (MEP) • Develop a Storm Water Management Program (SWMP), plus legal authority to implement and enforce • Annual reporting that includes assessment of BMP effectiveness

  5. Phase II Permit Requirements(condensed) • Supplemental provisions for MS4s serving a population > 50,000 • These MS4s are subject to more prescriptive design standards and run-off controls, some of which refer to diversion to sanitary sewer. • Examples: restaurant outdoor wash areas and automotive repair shop vehicle/equipment wash areas.

  6. SWMP Requirements • Must describe BMPs and associated measurable goals for six minimum control measures (MCMs): • Public Education and Outreach on Storm Water Impacts • Public Involvement / Participation • Illicit Discharge Detection and Elimination • Construction Site Storm Water Runoff Control • Post-Construction Storm Water Management in New Development and Redevelopment • Pollution Prevention/Good Housekeeping for Municipal Operations

  7. Illicit Discharge Detection and Elimination - 1 • “To the extent allowable under State or local law, effectively prohibit, through ordinance or other regulatory mechanism, non-storm water discharges into the MS4 and implement appropriate enforcement procedures and actions” • BMPs developed pursuant to this requirement may specify diversion of non-stormwater discharges to sanitary sewer.

  8. Illicit Discharge Detection and Elimination - 2 • This provision also contains 17 categories of non-storm discharges that can be exempt from the prohibition. Examples include: • Potable water line flushing • Uncontaminated pumped groundwater, foundation drains • Landscape irrigation • Individual residential car washing • However, a given agency’s BMP or local ordinance may not exempt a particular category

  9. Phase I Permits / Draft Municipal Regional Permit (MRP) • Larger jurisdictions fall under individual Phase I Permits (not general permit) • Regional Water Board is consolidating 6 Phase I municipal stormwater permits into one regional Bay Area permit (77 permittees) • MRP was developed to ensure consistent level of implementation and reporting • Does not include Marin, Sonoma, Napa County stormwater programs, but provides insight into possible future Phase II permit requirements.

  10. Draft MRP • More detailed and prescriptive requirements • Emphasis on specific pollutants, including trash • Diversion to sanitary sewer is cited as a potential control option in a number of cases • Defers to sanitary sewer agency authority to impose conditions or reject such discharges • Requirement for feasibility studies / pilot testing of “first flush” stormwater and dry season storm drain diversion to POTW (this provision specifically linked to PCB and mercury controls)

  11. Draft MRP • Examples where diversion to sanitary sewer is cited as a potential control option: • Municipal Maintenance Activities – asphalt cutting, sidewalk/pavement washing, Corp Yard vehicle/equip wash areas • Low Impact Development Provisions – dumpster drips, wash areas, swimming pool & fire sprinkler test water (if onsite discharge is not feasible) • Copper Control Measures – discharge from pools spas and fountains that contain copper-based chemicals

  12. Wastewater Perspective • Miscellaneous Thoughts • Benefits & Opportunities • Issues and Concerns - General • Issues and Concerns for Workshop Topics • Next Steps?

  13. Miscellaneous Thoughts • POTWs are accustomed to a high level of regulatory oversight; collection system agencies are not - but are getting there quickly! • Most POTWs are experienced in permitting/regulating discharges to their systems through Pretreatment & P2 Programs; this is generally not the case for collection-only agencies • In spite of their qualifications, most POTWs are not anxious to assume additional regulatory responsibilities and associated costs.

  14. Benefits & Opportunities • Environmental stewardship – improving the quality of water flowing to the Bay • Improved coordination between public agencies that have a similar missions • Potential for productive use of surplus POTW capacity • Potential resource value of increased effluent flow (dry weather)

  15. Issues & Concerns - General • Impact of increased flows • Sewer system capacity and operations; SSOs • Treatment plant capacity; conflicting regulatory mandates • Impact of increased pollutant loadings • Sewer system blockages & SSOs • Compliance with NPDES effluent limits • Other effluent quality issues (e.g. recycled water TDS) • Biosolids quality • Increased regulatory burden • Costs and cost recovery

  16. Workshop Topics • Swimming pools – draining, discharge of copper-based chemicals • Non-residential car washing • Construction groundwater – trench dewatering • Surface cleaning, including mobile businesses • Outdoor surface drains – refuse areas

  17. Swimming Pools • Flow Issues • Pool draining: Relatively infrequent and probably manageable during dry season. Highly problematic during wet season (impact on plant wet weather capacity, blending, and 85 % removal reqm’t) • Pool overflows during rainfall events: Discharge to sanitary sewer is highly problematic since it occurs at the worst possible time for collection system and POTW. Onsite discharge to vegetated area is not very practical during wet season. • Loss of dry weather flow capacity may be an issue for some POTWs

  18. Swimming Pools • Pollutant Loadings: • Pool draining: Slug loads of copper (if present) could result in NPDES permit violations. • Routine pool discharges (e.g. backwash water): Cumulative impact from these discharges is also a concern relative to compliance with copper limits. Filter backwash containing diatomaceous earth is potentially a problem for the collection system. • TSD from pools using salt systems for disinfection will degrade recycled water quality.

  19. Swimming Pools • Regulatory & Other • Can the desired regulatory outcome be achieved through public education/outreach only, or will a permit system be needed? • Costs for administering a permit system with a large number of pool owners will be high. Can costs (including POTW capacity charges) be recovered through fees?

  20. Non-residential Car Washing(Auto dealerships, etc) • Flow Issues • Increased wet weather flow from rainfall entering wash area drains is contrary to I&I reduction efforts and must be prevented (roofing required). • Loss of dry weather flow capacity may be an issue for some POTWs • Pollutant Loadings • Sand and debris are a problem for both the collection system and POTW

  21. Non-residential Car Washing(Auto dealerships, etc) • Regulatory Issues • If POTWs accept these discharges, pretreatment, permitting and inspections will likely be needed. • Permitting burden should be manageable due to relatively low number of dischargers and fixed locations. • Cost Recovery • Can permitting fees cover actual program costs?

  22. Construction Groundwater –Trench dewatering • Flow Issues • Increased wet weather flow from these sources is contrary to I&I reduction efforts. • Loss of dry weather flow capacity may also be an issue. • Pollutant Loadings • Solids present in groundwater may can create problems for both collection systems and POTWs • A POTW may not be able to remove specific pollutants from contaminated groundwater

  23. Construction Groundwater –Trench dewatering • Regulatory Issues • POTWs should insist that other disposal options have been considered first • For clean or brackish groundwater, discharge to storm drain under Phase II exemption or NPDES general permit, or storage & reuse for irrigation • For contaminated groundwater, discharge under NPDES general permit for VOC or fuel leak sites

  24. Surface Cleaning, including Mobile Sources • Flow Issues • Loss of dry weather flow capacity may be an issue for some POTWs. • Pollutant Loadings • Sand and other solids create problems for both collection systems and POTWs • Grease and other non-traditional pollutants may also pose problems

  25. Surface Cleaning, including Mobile Sources • Regulatory & Other Issues • Water collection and access to sanitary sewer • Are pretreatment requirements practical? • Are mobile sources more difficult to permit and monitor?

  26. Outdoor Surface Drains – Refuse Areas • Flow Issues • Increased wet weather flow from rainfall entering outdoor surface drains is contrary to I&I reduction efforts • Pollutant Loadings • Potential for grease from food service refuse and grease containment areas • Regulatory & Other Issues • Pretreatment may be needed but difficult to implement • Large number of facilities to be identified and regulated Which agency will be responsible?

  27. Next Steps? • Create process for ongoing coordination between stormwater and wastewater agencies • Regional efforts – BACWA Feasibility of Stormwater Diversion White Paper • POTWs should assess which flows they are willing to accept, and under what conditions • Address POTW cost recovery issues • Discussion with Water Board regarding possible pollutant credits / protection from diversion- induced effluent violations

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