Overview of Municipal Regional Permit

Provision C.3 Requirements and Upcoming ChangesJill C. Bicknell, P.E., EOA, Inc.

Assistant Program ManagerSanta Clara Valley Urban Runoff Pollution Prevention Program

Presentation OverviewSF Bay Area Municipal Regional Permit (MRP)

RequirementsRegulated ProjectsLID RequirementsAlternative ComplianceSummary of 12/1/11 Changes

Special StudiesSpecial Projects ProposalLID Feasibility EvaluationBiotreatment Soil SpecificationsGreen Roof SpecificationsGreen Street Pilot Projects

Grass pavers in parking lot of Stevens

Creek Corridor Park, Cupertino

Bay Area Municipal Regional PermitConsolidates 6 Phase 1 municipal permits into 1 regional permit (76 permittees):

San Mateo, Santa Clara,Alameda, and Contra CostaCounties, Fairfield-Suisun, and Vallejo

Adopted: October 14, 2009Effective date: December 1, 2009Provision C.3 includes new, more prescriptive Low Impact Development (LID) requirements for new and redevelopment projects which will take effect December 1, 2011

C.3 – New Development/RedevelopmentRegulated Projects

Most Development Projects – 10,000 sq.ft. impervious surface threshold; “50 % rule” applies to redevelopment

Special Land Uses (auto facilities, gas stations, restaurants, uncovered parking lots) –Threshold drops to 5,000 sq.ft. on 12/1/11

Single Family Homes (not part of common plan) – treatment requirements do not apply

≥ 10,000 sq.ft.: site design and source control>2,500 – <10,000 sq.ft.: must include one of six site design measures, beginning 12/1/12

C.3 – New Development/Redevelopment

Regulated ProjectsRoad and Trail Projects – 10,000 sq.ft. threshold (contiguous impervious surface) applies to:

New roads, and sidewalks and bike lanes built as part of new roadsWidening of existing roads with traffic lane(s)Trails >10 ft wide or < 50 ft from creek bankRequirements for road widening with traffic lanes and trails take effect 12/1/11 for private projectsand 12/1/12 for public projects

C.3 – New Development/Redevelopment

NOT Regulated ProjectsDetached single family home;Roadway reconstruction;Road widening that does not add a travel lane;Sidewalks and bike lanes along existing roads;Impervious trails <10’ wide and >50’ from creek;Sidewalks, bike lanes and trails that drain to vegetated areas or made of permeable paving;Interior remodels;Routine maintenance and repair;Pavement resurfacing within existing footprint.

C.3 – New Development/RedevelopmentLID Requirements

Source Control Measures:Minimize pollutants in runoff using appropriate controls including plumbing non-stormwater discharges to sanitary sewer, if feasible and allowedRequires “appropriate sustainable landscaping practices” such as Bay-Friendly Landscaping

Site Design Measures:Minimize disturbance of natural drainage systems, conserve natural areas, minimize impervious surfaceImplement at least one of six measures to direct runoff to landscaping/reuse or permeable paving

Site Design ConceptsDefine Development Envelope

Minimize land disturbanceProtect native vegetationPreserve open space

Minimize Impervious AreaReduce building footprintUse pervious paving

Use Drainage as aDesign Element

Reduce speed of, detain, infiltrate runoff in landscaping

C.3 – New Development/RedevelopmentLID Requirements, continued

LID Treatment required for 100% of water quality design flow or volume

“LID Treatment” = harvesting/reuse, infiltration, evapotranspiration, or biotreatmentBiotreatment only allowed if others infeasibleImplementation date: December 1, 2011

Sizing criteria (no change)Flow: 2 X 85th percentile rainfall intensity, or 0.2 in/hrVolume: 85th percentile 24-hr runoff event, or 80% of annual runoff

C.3 – New Development/Redevelopment

LID Technique CategoryRainwater cisterns Harvest and use

Green roofs Evapotranspiration

Landscaped detention, street trees

Evapotranspiration, infiltration

Pervious paving Infiltration

Infiltration trenches Infiltration

Bioretention areas (unlined, no underdrain)

Evapotranspiration, infiltration

Bioretention areas (lined, with underdrain)

Biotreatment

Planter boxes Biotreatment

C.3 – New Development/RedevelopmentAlternative Compliance Options

Can apply to any Regulated ProjectOption 1: A portion of LID Treatment onsite and the rest at offsite location in same watershedOption 2: A portion of LID Treatment onsite and payment of in-lieu fees to treat equivalent amount of runoff at Regional Project in same watershed Hitachi HM Detention

Basin, San Jose

C.3 – New Development/RedevelopmentSummary – What Takes Effect Dec. 1, 2011?

LID source control, site design and treatment requirements take effect for all regulated private projectsThreshold drops to 5,000 sq.ft. for privatespecial land use projects (auto facilities, gas stations, restaurants, uncovered parking lots)Private road widening with traffic lanes and creek-side paved trails >10’ wide become regulated projects

C.3 – New Development/Redevelopment

Summary – What Takes Effect Dec. 1, 2012? LID source control, site design and treatment requirements take effect for all regulated publicprojectsThreshold drops to 5,000 sq.ft. for publicspecial land use projects (auto facilities, gas stations, restaurants, uncovered parking lots)Public road widening with traffic lane and creek-side paved trails >10’ wide become regulated projectsSingle family homes >2,500 sq.ft. and <10,000 sq.ft. must include one of six site design measures

C.3 – New Development/RedevelopmentWhat if my project is already “in the pipeline”?

Projects in the review process are exempt from requirements for LID treatment, 5,000 sq.ft. threshold, and road/trail project applicability if:Private Projects –Deemed complete before 12/1/09 and project applicant is “diligently pursuing the project” (i.e., some action between 12/1/09 and 12/1/11)Deemed complete after 12/1/09 and project applicant receives final discretionary approval before 12/1/11

Public Projects –If funding committed and construction scheduled to begin by December 1, 2012

C.3 Requirements: Hydromodification

Management

Hydromodification:The change in the runoff hydrograph from an area due to developmentCan cause increased creek/channel erosion downstream

HydromodificationEffects of land development on the site runoff hydrograph:

Less infiltration / evapotranspirationMore surface runoff (increased volume)Runoff leaves the site faster (increased peak flows)Runoff occurs moreoften (increased duration)More runoff conveyed directly to creek

C.3 Hydromodification Management (HM) Requirements

Increases in runoff peak flow, volume, and duration must be managed for projects that create or replace 1 acre or more of impervious area, where increased flows may cause increased erosion in streamsFlow controls are required to limit post-project peak flows, volumes and durations to pre-project condition, for a specified range of flows Does not apply to projects that will not cause erosion downstream (e.g., if project drains to hardened channel or tidal zone, or does not increase impervious surface above pre-project condition)

HMApplicability

Map

C.3 – New Development/RedevelopmentBMP O&M Verification

Municipalities are required to inspect and verify that treatment and HM measures are being maintained (including LID measures)Municipalities must maintain a database of Regulated Project treatment measures installed and report inspections annuallyInspection requirements:

Inspect new BMPs within 45 days of installationAnnually inspect at least 20% of all BMPs installed and at least 20% of vault-based or proprietary systemsInspect all BMPs at least once every 5 years

LID Special StudiesSpecial Projects Proposal

Permit recognizes that smart growth, high density, and transit-oriented development have inherent environmental benefitsCertain projects may be allowed to use “non-LID” treatment measuresProposal for “LID Credits”submitted to Water Board on December 1, 2010Approval process includes public reviewDiscussions with WaterBoard/EPA staff ongoing

LID Special StudiesFeasibility/Infeasibility Criteria Report

Literature and case study review of feasibility of infiltration, rainwater harvest & use, and ETProposed criteria and procedures for determining where biotreatment can be usedReport submitted to Water Board on May 1, 2011Report on experience with LID and procedures due Dec. 1, 2013

Bioretention areas, VMware, Palo Alto

LID Special StudiesBiotreatment Soil Media Specification

CriteriaLong term infiltration rate of 5-10 in/hrSustain plant growthMaximize runoff retention and pollutant removal

ApproachBased on Contra Costa soil specificationConvened Roundtable of expertsDeveloped soil mix and installation guidance Submitted to Water Boardon December 1, 2010 Daly City Library

Bioretention Area

LID Special StudiesGreen Roof Specifications

RequirementsPropose minimum design specificationsProvide literature and field data on feasibility, pollutant removal, barriers, and lessons learnedDevelop guidance to permittees

ApproachFocus on specs relatedto water qualitySpecify soil media depthto provide storage forwater quality volumeCredit as “self-retaining”Submitted to Water Boardon May 1, 2011 Casa Feliz Green Roof, San Jose

LID Special Studies“Green Street” Pilot Projects

Must complete 10 in Bay Area (≥ 2 in each permitted county) by December 2014

Can’t be Regulated Projects(typically retrofits)

Must comply with C.3.d. (numeric sizing criteria)

Must incorporate LID features

Summary of all projectsin 2013 Annual Report Belle Air/Third Ave Street

Creek, San Bruno

Design for Holly Road, Belmont

Challenges Ahead Projects may have difficulty achieving 100% LID treatment

Space-limited projects, retrofitsRoad projects with limited ROW

New approaches have limited track recordUncertainty for projects currently in the review processPermittees will need to update ordinances and procedures in a short time period

Rainwater Sculpture, Mills

College, Oakland

For More Information:Go to www.scvurppp.org

Municipal Regional Permitand all submittals to date(OR Google “SF Bay Municipal

Regional Permit”)

SCVURPPP Site Design Guidebook

Updates to C.3 Handbook(Click on Program Components/New Development and Redevelopment/Reports and Work Products)

Roosevelt Community Center, San Jose