Construction & Post Construction Construction & Post Construction Stormwater Quality Mitigation CIP Stormwater Quality Mitigation CIP

ProjectsProjects

Anita KuhlmanAnita KuhlmanCity of CamarilloCity of Camarillo

12/14/2009; revised 12/14/2009; revised 2/14/20112/14/2011

CIPs subject to Construction CIPs subject to Construction Requirements in Two NPDES Requirements in Two NPDES PermitsPermits• State General Construction NPDES Permit (GCP)

Order 09-0009-DWQ; Effective 7/1/2010*http://www.waterboards.ca.gov/water_issues/programs/stormwater/constpermits.shtml

• Ventura Countywide Municipal Stormwater NPDES Permit Order 2010-0108 (MS4); effective 7/1/2010 (Post-construction requirements effective approx. 5/2011)

* CIPs only subject to post-construction requirements in MS4 permit

GCP - GrandfatheringGCP - Grandfathering

• Projects under Orders 99-08-DWQ & 03-0007-DWQ are grandfathered as Risk Level 1 until 9/2/2011 (Reg Bd. exceptions)

• However, must have refiled application electronically by 7/1/2010 (SMARTS system).

https://smarts.waterboards.ca.gov/smarts/faces/SwSmartsLogin.jsp

GCP – Key ChangesGCP – Key Changes

• Risk Determination• Permit Registration Documents (PRDs)-electronic filing• Developing SWPPP (QSD)• Implementing SWPPP (QSP)• REAPs• Minimum BMPs• Numeric Effluent Limits & Action Levels• No longer allows emergency construction exemption• Increased Monitoring• Reporting• Combines LUP with GCP

• Operates as a zero risk level for small projects– Small projects = 1-5 acres– Waives permit requirements for projects with

an R-factor of 5 or less• Based on USEPA R-factor waiver in Phase II

stormwater rule; download calculator athttp://cfpub.epa.gov/npdes/stormwater/lew/lewcalculator.cfm

GCP - Rainfall Erosivity WaiverGCP - Rainfall Erosivity Waiver

GCP - Rainfall Erosivity WaiverGCP - Rainfall Erosivity Waiver

If you change construction dates to 5/2010 – 8/2010 – R Factor is 4.63

GCP – Two Part Risk GCP – Two Part Risk DeterminationDetermination

1. Sediment discharge risk (bare ground soil loss using factors from RUSLE – Revised Universal Soil Loss Equation)A = (R)(K)(LS)(C)(P)

A= soil loss from sheet and rill erosionR= rainfall-runoff erositivity factorK= soil erodibility factorLS= length-slope factorC= cover factor (erosion control) – not usedP= Management/support practices (sediment controls) – not used

2. Receiving water riskDrains to sediment sensitive water (directly or indirectly)

303(d) listed or TMDL for sedimentBeneficial Uses of COLD, SPAWN & Migratory

http://www.waterboards.ca.gov/water_issues/programs/stormwater/docs/constpermits/wqo_2009_0009_app_1.xls#Start!A1

Calleguas Creek Watershed ReachesSediment Impaired Reaches – 2-8 & 11COLD, Spawn, Migratory Beneficial Uses – Calleguas Creek & Conejo Creek

GCP - Risk AssessmentGCP - Risk Assessment

Traditional Project Risk

Sediment Risk

Receiving Water Risk

Low Med High

Low Level 1 Level 2

High Level 2 Level 3

Calleguas Creek reaches 2-8 & 11 are impaired by sediment and discharges within those reaches would be “high receiving water risk”

GCP requirements tied to risk levelsGCP requirements tied to risk levels

Level 1 Level 2 Level 3REAP X X

Minimum list of BMPs X X XAdditional erosion control BMPs to ensure soil loss </= preconstruction soil loss

X X

Narrative Effluent Standards (non-visible pollutants)

X X X

Numeric Action Levels

250 NTU(Turbidity) & 6.5-8.5 pHX X

Numeric Effluent Limits

500 NTU; 6.0-9.0 pHX

GCP - GCP - MonitoringMonitoring Requirements by Requirements by Risk LevelRisk Level

Level 1 Level 2 Level 3

Non-visible pollutant monitoring as necessary X X X

Stormwater discharge monitoring for pH and turbidity

X X

Non-stormwater discharges from site X X

Contained rainwater when discharged X X

Report all data within 5 days of storm event X

Bioassessment monitoring – if project larger than 30 acres & direct discharge to receiving water.

X

Receiving Water Monitoring – if project exceeds NEL (pH, turbidity, suspended sediment concentration) & discharges directly into receiving water.

X

GCP “Direct Discharge” Definition

• A discharge that is routed directly to waters of the United States by means of a pipe, channel, or ditch (including a municipal storm sewer system) or through surface runoff.

However, see GCP Fact Sheet for clarification. “Discharges from a construction site to a MS4 where commingling with upstream and/or downstream discharges can occur are not considered “direct discharges’.”

GCP - GCP - ReportingReporting Requirements by Requirements by Risk LevelRisk Level

Level 1 Level 2 Level 3

Annual Report Due electronically by Sept. 1 X X X

NAL report, if requested by Regional Board X X

When NAL exceeded, submit sample results within 10 days of storm event conclusion

X X

All Sample results within 5 days of storm event conclusion

X

When NEL exceeded, submit NEL violation Report within 5 days of storm event conclusion

X

GCP – New GCP – New TrainingTraining Requirements Requirements

• SWPPPs must be developed and revised by a Qualified SWPPP Developer (QSD) effective 7/1/2010.

• Each project must have an assigned Qualified SWPPP Practitioner (QSP). Effective 9/2011 QSP must meet certification requirements. QSP responsible for BMPs, inspections, sampling, REAPs.

• Both QSD & QSP must attend state-sponsored training & test by 9/2011.

Who can be a QSD?Who can be a QSD?

• Registered CA professional Engineer –civil

• Registered CA Professional Geologist or Engineering Geologist

• Registered CA landscape Architect

• Registered Professional Hydrologists (AIH)

• Certified Professional– Erosion & Sediment Control (CPSEC)(NICET)– Storm Water Quality (CPSWQ)

Who can be a QSP?Who can be a QSP?

• Qualified as a QSD

• Certified Inspection of Sediment & Erosion Control (CISEC)

• Certified Erosion, Sediment, Storm Water Inspector (CESSWI)

MS4 PermitMS4 PermitConstruction RequirementsConstruction Requirements

• Provide local SWPPP– Requires specific “certification” language– Requires local agency approval page

• Specific BMPs depending on project size

• Enhanced BMPs for high risk areasHillsides

303(d) listed for sediment or ESA (direct discharge)

MS4 Permit “Direct Discharge” definition – Means outflow from a drainage conveyance system that is composed entirely of flows from the subject property, development or industrial facility and not commingled with the flows from adjacent lands.

MS4 Permit Construction MS4 Permit Construction RequirementsRequirements

• Roadway paving/repaving - Specific sediment/erosion controls required

• CIP projects which disturb less than 1 acre soil disturbance require an SWPCP

• CIP projects which disturb 1 acre more of soil require coverage under GCP

• All city contractors & their employees on job site must be trained on SWPCP/SWPPP BMPs (must be documented in writing)

MS4 Permit Post Construction MS4 Permit Post Construction RequirementsRequirements

• Technical Guidance Manual revisions to include LID, Hydromodification submitted 11/2010

• New requirements effective 90 days after Regional Board Approval of Technical Guidance Manual – TGM (approx. 5/2011)

• CIPs – effective date shall be date the governing body or designee approves initiation of project design

MS4 Permit – CIP Projects MS4 Permit – CIP Projects Post-Construction RequirementsPost-Construction Requirements

• Projects 1+ acre of disturbed area and adding 10,000 SF impervious area

• Parking lot 5,000 SF or more of impervious area or 25 or more parking spaces

• Streets, roads, highway construction of 10,000 SF or more of impervious surface area (shall incorporate USEPA guidance-Managing Wet Weather w/Green Streets to MEP).

• Projects located in or directly adjacent to ESA• Redevelopment projects with land-disturbing activity that

results in creation, addition, or replacement of 5,000 SF or more of impervious surface area. Does not include routine maintenance activities that maintain original line and grade, hydraulic capacity, original purpose of facility or emergency redevelopment activity required to protect public health and safety.

MS4 Permit – CIP Projects MS4 Permit – CIP Projects Post-Construction RequirementsPost-Construction Requirements

• Streets, roads, highway construction of 10,000 SF or more of impervious surface area (shall incorporate USEPA guidance-Managing Wet Weather w/Green Streets to MEP).

Min requirements:• Provide retention or Biofiltration BMPs

• To the MEP minimize street width; use porous pavement, add tree canopy (see section 2.2 in TGM)

MS4 Permit – Post Construction MS4 Permit – Post Construction RequirementsRequirements

Fundamentally changes land development through use of retention BMPs

• Limit effective impervious area (EIA) to 5% by retaining the water quality volume (.75” storm depth) using infiltration, reuse, or evapotranspoiration BMPs (retention BMPs).

• Provide treatment for 5% EIA and developed pervious areas.

• If technically infeasible (see Section 3.2 of TGM) to reduce EIA to 5%, then biofilter 1.5 times the remaining volume.

• If project does not fall into “technically infeasible categories” (section 3.2 of TGM) then must redesign site to meet 5% EIA.

Effective Impervious Area?Effective Impervious Area?

• Portion of total project area that cannot absorb storm water runoff.

• Expressed as %• Impervious surfaces may

be rendered “ineffective” if stormwater runoff is full retained onsite.

• Impervious area can become effectively pervious that collects and fully retains design storm.

Alternative Compliance for Alternative Compliance for Technical InfeasibilityTechnical Infeasibility

• If retention or biofiltration BMPs have been used to MEP and 5% EIA can’t be met, then the following projects are eligible for alternative compliance– Redevelopment Projects– Infill projects– Smart Growth projects– Pedestrian/bike trail projects– Agencies’ flood control, drainage and wet utilities projects– Historical preservation projects– Low income housing projects

Alternative ComplianceAlternative Compliance

Alternative compliance may be met through two options:

• Offsite mitigation project or

• Offsite mitigation fee

Alternative Compliance for Alternative Compliance for Technical InfeasibilityTechnical Infeasibility

• The mitigation vol. is the difference btwn. The volume of runoff associated with 5% EIA and the volume of runoff associated with the actual EIA achieved onsite </=30%

• Office mitigation for EIA in excess of 30% is 1.5 times the amount of stormwater not managed on site

Offsite Mitigation/AlternativesOffsite Mitigation/Alternatives

• Cities shall identify LID projects (public and/or private) & funding mechanism that can be used to benefit local sub-watershed by increasing infiltration (groundwater recharge), reuse, and evapotranspiration. Measures can include bioretention, biofiltration, green streets, porous pavement or other BMPs.

• Mitigation alternative must be within same sub-area as the proposed project on the Basin Plan subareas.

• Must be completed within 4 years of Cert.of Occupancy for 1st project that contributed funds, unless RB grants extension

• Funds sufficient to offset the volume must be transferred to the City (public projects) or an escrow account (private projects) within one year of the initiation of construction.

Next StepsNext Steps• Conditions of Development & CIP special

provisions have been revised to include GCP & MS4 construction permit requirements (handout)

• COD & CIP Special Provisions will be updated to reflect post-construction requirements when they are finalized (approx. 5/2011)

• Countywide training on TGM to be provided once TGM has been approved.