Post on 27-Jan-2019
Overview of Regulatory Requirements: Ventura MS4 Stormwater PermitBIA/GLAV, AGC, APWA Ventura Stormwater (MS4) Seminar
December 8, 2009
Mary Lynn Coffee, Partner
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MS4 Stormwater PermitsPublic Storm Drain Stormwater Permits (MS4 Permits)
33 U.S.C. §§ 1342(p)(3)(B)
Cal. Water Code § 13263
Like regional water quality regulations for runoff from municipal storm drains
Effluent Control Standard: Maximum Extent Practicable (MEP)
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Construction Stormwater PermitConstruction Stormwater Permit
33 U.S.C. §§ 1342(p)(3)(A); 1311Cal. Water Code § 13263Like statewide water quality regulations for runoff from construction sites 1 acre or largerNow includes Linear, Utility Project and Oil and Gas Production construction sitesEffluent Control Standard: Best Achievable Technology (toxics) /Best Conventional Technology for (sediment)
33 U.S.C. § 1314(b)(2)(B); 40 C.F.R. § 124.3(d)
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Stormwater PermitsMS4 Permits Also Contain Construction Site Runoff Control Requirements
Most Stringent Requirements Control
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MS4 Permit —New Requirements
Limited Grandfathering for New Development/RedevelopmentMultiple LID Design Compliance Standards for New Development/ RedevelopmentLID Limited to Percolation/ReusePost-Construction Treatment BMP Performance CriteriaMandatory and Permissive Alternative Compliance Programs
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MS4 Permit —New Requirements
Overlapping Construction Site RequirementsTMDL Related RequirementsNew CEQA requirementsInterdepartmental MOUs?
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MS4 Permit —New Requirements
MALs EliminatedMeasured at MS4 outfalls“Upset” valuesTrigger iterative BMP action: study, pollutant identification, implementation of new control measures to prevent pollutant discharge
No MALs; Instead New Development/ Redevelopment LID RequirementsRetrofitting Existing v. Changing Standards for New Development
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MS4 Permit —New Requirements New Development/Significant Redevelopment
Creation of 5,000 sq. ft. or more of impervious surface (Redevelopment)All developments adjacent (within 200 feet of), or discharging directly to (flows are predominantly from subject site) environmentally sensitive areas (Pub. Res. Code 30107.5) Parking lots, restaurants, Gas stations auto service facilities adding of 5,000 sq. ft. or more
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MS4 Permits —New Requirements New Development/Significant Redevelopment
Streets, Highways, Freeways constructing 10,000 or more of impervious surfaceExempt routine maintenance that doesn’t change original line or grade or hydraulic capacityHighways/Freeways? Caltrans PermitNew Development Redevelopment Standards or USEPA Guidance re: Green Infrastructure/Green Streets?
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MS4 Permits —New Requirements New Development/Significant Redevelopment
Single Family Homes that add or replace 10,000 Square feet or impervious surfaceNew Development Redevelopment Standards or solely Site Design BMPs and BMPs that divert runoff to vegetation?
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MS4 Permit —New Requirements New Development/Significant Redevelopment
New Development Redevelopment Requirements effective 90 calendar days after RWQCB approval of Permittee’s Technical Guidance Manual (due to RWQCB May 7, 2010)Projects (not applications?) deemed complete, and vested projects are grandfathered
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MS4 Permit—New RequirementsLID Onsite Retention Standards
Limit of 5% Effective Impervious Area (EIA) for all New Development sites unless technically infeasibleAll Redevelopment and New Development for which 5% EIA limit is infeasible, must limit EIA to 30% of total project area and treat remainderRetain without runoff (percolate, evapotranspirate, or capture, store and reuse) 100% of the full design treatment volume
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MS4 Permit—New RequirementsLID Onsite Retention Standards
Separate but supplementary EIA and retention standardsNo exemption from 30% maximum EIA for technical infeasibilityBiofiltration BMPs, though extremely effective, are not permitted unless retention standard is fully met, and 30% maximum EIA is met: Biofiltration = other conventional treatment BMPs
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MS4 Permit—New RequirementsLID Onsite Retention Standards
Supplementary standards require treatment of a greater volume of water than the design volume—Disadvantages projects:
Onsite retention to achieve at least 30% maximum EIA; plusOnsite treatment for runoff from 65% of the site that is Directly Connected Impervious Area (DCIA); plusOnsite retention for full design volume/flow;Offsite mitigation for volume of runoff from 65% of the site that is DCIA
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MS4 Permit—New RequirementsLID Onsite Retention Standards
Project Scale Mandate Creates
Tremendous Storage/Reuse Constraint
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MS4 Permit—New RequirementsLID Onsite Retention StandardsRequires Percolation Regardless of Site
Characteristics and Soils Conditions
Potential Subsidence Related Liability for All
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MS4 Permit—New RequirementsLID Onsite Retention Standards
Onsite percolation/reuse standards (rain barrels on steroids) may create issues for reclaimed water market demandOnsite percolation/ reuse standards may water rights issues
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MS4 Permit—New Requirements
Treatment BMP Performance StandardsSpecified for Ponds, Basins, Bio and Media Filters, Hydrodynamic Devices OnlyEffective immediatelyDesign Standards, or Treatment Standards?Must Track and inspect by May 2010Who is responsible for compliance of post-construction effluent concentrations
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MS4 Permit—New RequirementsHydromod Control
Permittees must complete study and impose standardsInterim standards no longer specifiedBut several provisions require hydromod control BMP reporting and inspections immediately
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MS4 Permit—New RequirementsAlternative Compliance Programs
Mandatory: Offsite Mitigation for Projects where LID is Technically InfeasiblePermissive: RedevelopmentProject Area Master Plan(RPAMP)
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MS4 Permit—New RequirementsMandatory Alternative Compliance:
Prove Technical Infeasibility of LIDStill create EIA of at least 30%Provide $ to public or private offsite LID project:
In same subwatershedDemonstrate equivalent volume and load reduction for subwatershedList of eligible projects must be maintained
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MS4 Permit—New Requirements
RPAMP—New hurdles for Regional Stormwater Mitigation ProgramDesignated Redevelopment OnlyOnly local agencies can proposeRWQCB approval requiredLocal Govt Commission approvalReduce EIA to 5%--no equivalenceComplete construction by May 7, 2013
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MS4 Permit—New Requirements Retrofit existing storm drains, easement areas, parks and rec. areas, commercial and residential common areas, private property when possibleComplete offsite LID projects asap, at least within 4 years of Cert. of Occupancy for 1st project contributing fundsEIA achieved in offsite LID project is 5% max
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MS4 Permit—Construction Requirements
Local SWPPP prepared and reviewed in addition to GCP SWPPPDifferent factors determine riskMinimum BMPs for each risk levelSpecial Street Project requirements—different than LUP requirementsEffective NOW
Overlapping, but different requirements than Statewide Permit:
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MS4 Permit—New Planning Requirements
Permittees required to have completed updates to CEQA guidelines:Must analyze potential stormwater quality impacts—new thresholds of significance?CEQA mandate applies to projects that may otherwise be grandfathered; conflict may limit grandfathering
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MS4 Permit—New Planning Requirements
General Plan Update to incorporate stormwater policies required:Land use elementHousing elementConservation elementOpen Space elementProvide to RWQCB when noticed
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MS4 Permit—New Planning Requirements
Permittees must develop:Established structure for communication
and delineated authority among municipal departments with jurisdiction over project review, plan approval and project construction through MOUs
But timing and substance of requirements conflicts, and makes an integrated and timely water quality policy difficult to develop
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MS4 Permit—New TMDL Requirements
Incorporated WLAs for TMDLsFor TMDLs with implementation plans, some protection from interpretation of WLAs as NELs, but not clearly MEP discharge standard or iterative BMPs compliance schemeFor TMDLs with implementation plans, unclear protection from use of WLAs as NELs
Increased Public and Private Compliance Costs, Including Development Costs of Private
and Public Works Projects