POST CONSTRUCTION MANUAL PROJECT UPDATE Terri Fashing,
Terri Fashing, MCSTOPPP Program Manager Presentation to the North Bay Watershed Association Board, July 11, 2014 POST CONSTRUCTION MANUAL PROJECT UPDATE Project Partners North Bay Watershed Association Board North Bay Watershed Association Joint Technical Committee Bay Area Stormwater Agencies Association (BASMAA) Phase II Committee Marin County Stormwater Pollution Prevention Program Napa County Stormwater Pollution Prevention Program Phase II Municipalities in Sonoma (and SCWA!) Phase II Municipalities in Solano Dan Cloak Environmental Consulting Thanks to NBWA! 2011-2013 State Water Board worked on reissuing the NPDES Phase II Permit Compliance Collaboration: North Bay municipal permittees New post construction stormwater treatment and control requirements February 2013 – NPDES Phase II Municipal Stormwater Permit adopted Update existing MCSTOPPP Post Construction Manual Early 2013: North Bay Watershed Association (NBWA) Joint Technical Committee reviewed/approved the proposed project 2013: NBWA Board approved the project funds NBWA Executive Director and MMWD executed a contract with Dan Cloak Environmental Consulting August 2013: Post Construction Project kickoff meeting in Project Description Planning meetings Develop guidance manual to support compliance with Section E.12 of the Phase II Permit for: Applicants for Development Approvals North Bay Municipal Staff Hold three half-day workshops for development professionals and municipal staff in North Bay How to use the manual What are the E.12 Post Construction requirements? Project Status November 2013 – Dan Cloak delivered 1st Draft March 2014 – Draft 2 July 2014 – Final Draft October 2014 – three workshops scheduled Marin, Sonoma, and Napa Interspersed… many BASMAA Phase II Committee Meetings BASMAA in the title Marin Napa Sonoma Solano Stormwater Association (MNSSSA) is now the BASMAA Phase II Committee The BASMAA Phase II Committee wanted to name the manual the ―BASMAA Post Construction Manual‖ ―Prepared for the Bay Area Stormwater Management Agencies Association (BASMAA) Phase II Committee with funding from the North Bay Watershed Association‖ E.12 in a nutshell Site Design Runoff Treatment Peak Runoff Controls (Hydromodification Management) Facility Maintenance Let’s Look Inside the Manual! Types of Projects Table 1-1. Requirements at a Glance Type of Project Single-Family Homes* Create or replace 2,500 square feet or more of impervious surface Small Projects All projects besides singlefamily homes* that create or replace 2,500 – 4,999 square feet or more of impervious surface Requirements Incorporate Site Design Measures 1. Limit clearing, grading, and soil compaction. 2. Minimize impervious surfaces. 3. Reduce runoff, for example by dispersing runoff to landscape or using pervious pavements. 4. Conserve natural areas of the site as much as possible consistent with local General Plan policies. 5. Comply with stream setback ordinances/requirements. 6. Protect slopes and channels against erosion. Complete and submit a Stormwater Control Plan for Small Projects/Single-Family Homes. Types of Projects Continued Regulated Projects Same site design measures requirements as above, plus: Projects, other than single- 1. Route runoff to bioretention or other facilities sized and designed family homes,* that create according to the criteria in Chapter 4.** or replace 5,000 square feet or more of impervious 2. Identify potential sources of pollutants and implement corresponding source control measures in Appendix A. surface 3. Provide for ongoing maintenance of bioretention facilities. 4. Follow instructions in the Manual to complete a Stormwater Control Plan. Advantages of LID Filtration and pollutant sequestration Biological processing Attractive landscape amenity No mosquito problems Mimic natural hydrology Low maintenance Easy to inspect Slide provided by Dan Cloak Environmental Consulting Page 1-2 Bioretention evapotranspiration infiltration Slide provided by Dan Cloak Environmental Consulting Page 1-2 Path to Compliance 1. 2. 3. 4. 5. 6. 7. Pre-application meeting Follow the Manual. Stormwater Control Plan Draft O&M Plan Detailed project design Construction Transfer maintenance responsibility Slide provided by Dan Cloak Environmental Consulting Page 2-1 Development Review Process Pre-Application Meeting Completed Application ―Deemed Complete‖ Section Review Planning Commission Conditions of Approval CEQA Review Detailed Design Plan Set and Permit Application Slide provided by Dan Cloak Environmental Construction Discuss Development Review Process design, O&M responsibility Pre-Application Meeting Lay out the site and stormwater facilities Planning Commission Incorporate facilities in plans and specifications Detailed Design Completed Application ―Deemed Complete‖ Respond to questions and revise plan Prepare and submit a Stormwater Control Plan Section Review Conditions of Approval CEQAfacilities. Submit Construct Stormwater FinalReview O&M Plan prior to end requirements are of construction attached to COAs Plan Set and Permit Application Slide provided by Dan Cloak Environmental Construction Transfer Maintenance Responsibility Guidance 1. Step-by-step instructions in the Post Construction Manual 2. Checklist (page 3-2) 3. Template 4. Example Stormwater Control Plan(s) (to come) Slide provided by Dan Cloak Environmental Consulting Page 3-1 Stormwater Control Plan 1. 2. 3. 4. 5. 6. 7. 8. 9. Project Information Opportunities and Constraints Conceptual Site Design Calculations and Documentation Design Details Source Controls Maintenance Construction Checklist Certification Slide provided by Dan Cloak Environmental Consulting Page 3-1 Analyze Your Project for LID Page 3-3 Optimize the Site Layout Define the development envelope Minimize grading Set back from creeks, wetlands, and riparian areas Preserve significant trees Slide provided by Dan Cloak Environmental Page 3-3 Optimize the Site Layout Limit roofs and paving Preserve and use permeable soils Detain and retain runoff throughout the site Use drainage as a design element Slide provided by Dan Cloak Environmental Page 3-4 Use Pervious Surfaces Permeable pavements Green roofs Design criteria on page 4-6 Slide provided by Dan Cloak Environmental Page 3-4 Disperse Runoff Slide provided by Dan Cloak Environmental Consulting Page 3-4 Direct Runoff to Facilities Slide provided by Dan Cloak Environmental Page 3-4 7. Maintenance of Facilities Operation and maintenance plan required O&M Plan is referenced in an agreement that ―runs with the land‖ Stormwater Control Plan must: Acknowledge and summarize maintenance requirements Include a statement accepting maintenance responsibility Page 3-6 Most significant for subdivisions Slide provided by Dan Cloak Environmental Consulting Drainage Management AreasPage 4-2 Follow roof ridges and grade breaks Different DMA for each surface type Slide provided by Dan Cloak Environmental DMA Types Pervious DMAs Page 4-2 Use a curb to avoid run-on from self-treating areas Self-treating Self-retaining Impervious DMAs Drains to self-retaining Max 2:1 ratio impervious:pervious Drains to LID facility Slide provided by Dan Cloak Environmental Consulting To storm drain Grade self-retaining areas to drain inward. Set any area drains to pond 3"-4" Example DMA-1 DMA-2 DMA-3 DMA-4 DMA-5 DMA-6 DMA-7 Total Slide provided by Dan Cloak Environmental Consulting 3200 3200 3700 12400 500 8500 4200 35700 Sizing DMA Name DMA-1 PostDMA project Area surface (SF) type 3200 Roof DMA-2 3200 Roof 1.0 3200 DMA-4 12400 Paved 1.0 12400 Facility Sizing factor 18800 0.04 Total> Slide provided by Dan Cloak Environmental Consulting DMA Runoff factor 1.0 DMA Area Facility Name runoff factor 3200 Minimum Facility Size Proposed Facility Size 752 900 DMA-1 DMA-2 DMA-3 DMA-4 DMA-5 DMA-6 DMA-7 Total 3200 3200 3700 12400 500 8500 4200 35700 Make This Happen Page 4-5 Bioretention facilities are level so they ―fill up like a bathtub.‖ Slide provided by Dan Cloak Environmental Consulting Page 4-7 Slide provided by Dan Cloak Environmental Consulting Planting Soil 60-70% Sand ASTM C33 for fine aggregate 30-40% Compost Certified through US Composting Council Seal of Testing Assurance Program Install in 8"-12" lifts Do not compact Do not overfill Leave room for mulch Slide provided by Dan Cloak Environmental Consulting Page 4-7 Landscaping Select plants for fast-draining soils Select for facility location Avoid problem conditions Overly dense plantings Aggressive roots Invasive weeds Need for irrigation or fertilization Slide provided by Dan Cloak Environmental Consulting Page 4-7 Landscaping—O&M issues No fertilizer No pesticides Clean up as needed and annually Add mulch if needed annually Compost Page 5-2 mulch (aged mulch) recommended Avoid filling in or re-grading Slide provided by Dan Cloak Environmental Consulting MCSTOPPP’s Bioretention Facility Plant Matrix BASMAA Post Construction Manual Slide provided by WRA Environmental Consultants (Megan Stromberg) Role of Plants • Drought Tolerant • Native or adapted to • Tolerate well-drained CA climate soils AND flooding • No fertilizer • Irrigation Slide provided by WRA Environmental Consultants (Megan Stromberg) Biotreatment Soil is Not Soil! • • • • Concrete Sand and Compost Very fast draining Low water holding capacity Very different from native soil Slide provided by WRA Environmental Consultants (Megan Stromberg) Matrix Headings & Definitions • • • • • Plant Categories Light Preference (sun, part, shade) Size (height and width, in feet) Watering Preference Tolerances: Heat, Coast, Wind • Zone 1 Hydrology - wetter • Zone 2 Hydrology - drier • High Performers • Origin (Ca. Native or not) Slide provided by WRA Environmental Consultants (Megan Stromberg)
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