2/27/2015. Polluted Runoff. Topics Covered. Approaches to Stormwater Management. Managing Stormwater. Traditional Stormwater Management

Transcription

1 Impending Stormwater Compliance for Contractors & Developers Presented dto: Humboldt Builder s Exchange February 27, Presented By: Streamline Planning Consultants Sam Polly, CPESC, QSD/QSP Bob Brown, AICP 2 Topics Covered Polluted Runoff Water Quality Regulation Overview The New MS4 Regulations Calculations LID Planning Lessons Learned Polluted Runoff is the #1 Water Quality Problem in California & the U.S. (U.S. EPA) MS4 = Municipal Separate Storm Sewer System (A municipality) 3 4 The only purpose of a street gutter/ storm drain is to put pollutants into our streams. Old School Managing Stormwater New School Approaches to Stormwater Management Traditional Stormwater Management = Gray Infrastructure Collection, Conveyance, Discharge Low Impact Development = Green Infrastructure 5 1

2 Today s Problem Today s Problem Bad Attitude? Working in the Rain? Sediment Cleaning his Sprayer at the Storm Drain Inlet? Water soluble? Downspout extension to curb hole 7 8 The Current Regulatory Climate: Avoid this scene The Current Regulatory Climate: Avoid this kind of mail 9 10 The Current Regulatory Climate: Stormwater CWA & Porter Cologne everyone is liable regardless of permit Agriculture dairies & now vineyards, livestock, lilies Industrial SIC Codes such as creameries, contractor yards, asphalt plants, wood workers Construction > 1 acre disturbed MS4 2,500 ft 2 will now have stormwater requirements July 1, 2015 What does this mean? Confusion for everyone: 289 pgs, 76 p. fact sheet Additional costs/ Potential development size reduction Increased building permit difficulties Transparency of municipalities to the whole world So municipalities MUST strictly enforce MS4 regulations Plans & projects MUST be in compliance for building permits, occupancy, profit & reputation

3 Practice Tip #1 Get you building permit approvals before July 1 st What happens if you submit an application on June 15 th and it gets turned back for corrections on June 30 th? After July 1 st, get pre application consultation After July 1 st, prepare SWCP (Storm Water Control Plan) Whose watching? California State Water Resources Control Board Regional Water Resources Control Board Local lmunicipality i (Permittee)( ) Neighbors 3 rd Party Watchdog Groups & Lawyers Whose in? Larger urban areas Cities: City Limits of: Fortuna, Eureka, Arcata Smaller polygon within city limits: Trinidad County: Unincorporated town: McKinleyville Resort Improvement District: Shelter Cove Communities surrounding Eureka: Bayview, Cutten, Ridgewood Heights, Humboldt Hill, Myrtletown Others: School Districts, HSU, State Parks, etc. Whose out? Smaller urban areas Towns: Manilla, Samoa, King Salmon, Fields Landing, Willow Creek, Rio Dell, Garberville Rural Neighborhoods & woods: Areas outside the MS4 Permit boundary maps SMARTS Webpage: Scroll down Click here! SMARTS Click Here

4 Figure 2- Drainage Basins & Stormwater Outfall Locations Legend Outfalls Storm Drain Sewer Mains City Boundary Drainage Basin Boundaries BASIN A B C D E F G H I J K L M O PALCOMARSH 2/27/2015 After clicking the SW Data box, Scroll down again to: After clicking the Search for Owners/Operators, use the dropdown menu for the Application Type and fill in the Owner, then click the Search box: Click View Attachments: Click Facility/Site Map: Humboldt Bay City of Eureka: MS4 Jurisdiction J I G H K E F L PALCOMARSH D C B A M O 23 County of Humboldt: MS4 Jurisdiction 24 4

5 City of Fortuna: MS4 Jurisdiction City of Arcata: MS4 Jurisdiction MS4 Permit Requirements Small Projects 2,500 to 5,000 ft 2 of replaced or created impervious surface Single family home projects 2,500 ft 2 Must use 1 or more Site Design Measure (SDM) Must quantify runoff reduction from SDMs City of Trinidad: MS4 Jurisdiction MS4 Permit Requirements Practice Tip #2 Keep your new or remodel projects (impermeable surfaces of building, driveways, parking, etc) to less than 2,500 s.f. Design so minimal impervious surfaces. Cut corners where you can. Regulated Projects 5,000 ft 2 of replaced or created impervious surface Single family home projects excluded Must use maximum Site Design Measures (SDMs) Must incorporate Source Controls Must use LID Design Standards for maximum runoff reduction and to treat remaining runoff Must quantify runoff reduction Annual reports demonstrating proper O&M

6 MS4 Permit Requirements Regulated Projects LID Design Standards 5,000 ft 2 of replaced or created impervious surface Perform Site Assessment quantify runoff reduction Map Drainage Management Areas (DMAs) Employ Numeric Sizing Criteria of the 85 th percentile, 24 hour runoff volume (0.65 ) Must use maximum Site Design Measures (SDMs) Must incorporate Source Controls Must treat the remaining 85 th percentile runoff using Bioretention MS4 Permit Requirements Regulated Projects Operation& Maintenance: Post Construction Storm Water Management Measures Project proponent s signed statement of responsibility for O&M until legally transferred or, Written conditions in sales/lease agreements/deeds requiring buyer or lessee responsibility until legally transferred Conditions of approval, etc. granting site access to Permittee for O&M inspections MS4 Permit Requirements Regulated Projects Condition Assessment: Post Construction Storm Water Management Measures Annual reports to jurisdictional Permittee Practice Tip #3 Keep your new or remodel projects (impermeable surfaces of building, driveways, parking, etc) to less than 5000 s.f. Design so minimal impervious surfaces. Cut corners where you can Municipal Stormwater Calculations Practice Tip #4 Design your new or remodel projects (impermeable surfaces of building, driveways, parking, etc) so that each DMA drains to large enough landscape area. This requires shifting project on lot, regrading driveway features, reconsider downspout locations Regulated Projects Runoff Calculation Requirement Increase >50% impervious on redevelopment then Ronoff from ALL (existing + new) impervious is included; <50% increase = only the new impervious is included in calculations

7 Municipal Stormwater Calculations Residential Methods Dictated by local jurisdiction Local LID Manual Cl Calculator lt Manual Each method has advantages and drawbacks 16,500 sf lot Residential Residential 16,500 sf lot Residence 4000 s.f. Concrete 4000 s.f. Imp. Surface: 8000 s.f. Landscaping 8500 s.f. Current Practice: Grade the lot so you can get all stormwater to driveway and out onto street MS4 Requirement Minimize Disturbed area Minimize Impervious surfaces Design Grading Plan Design roof downspouts Define DMA s Perform Calculations Add Site Design Measures Residential DMA s DMA Calculation DMA Roof (sf) Concrete (sf) Residential DMA s Landscape (sf) Total (sf) Total

8 Residential DMA s Residential DMA s DMA Calculation DMA Roof (sf) Concrete (sf) Landscape (sf) Total (sf) /2 (need 750) short /2 (need 1350) short extra 1700/2 (need 850) extra 2100/2 (need 1050) 2150 Site Design Measures Rain Garden Bioswale Permeable Pavement Trees Rain Barrels Etc total Bioretention Rain Gardens and Vegetated Swales Rain Gardens and Vegetated Swales Rain Garden By Timothy Lawrence 45 By Timothy Lawrence 46 Vegetated Bioswales Bioretention Area Cross-section Parking Lots Curb cuts drain roadways into landscaped LID By Timothy Lawrence 48 8

9 DMA s for Commercial or Multifamily Practice Tip #5 for Projects > 5000 sf (Regulated Projects) Bioretention may be worth it. 10,000 sf of impervious requires 400 sf bioretention. Bioretention requires recording of O&M agreement on deed and submittal of annual O&M reports. Bioretention may not be worth it Drainage Management Areas Step 1: Delineate the DMAs Step 2: Classify the DMAs Page Drainage Management Areas Tabulation and Calculations Areas draining to self retaining areas DMA Square Feet Surface Runoff Factor Product Receiving DMA Receiving DMA Area Ratio Roof DMA Roof DMA Roof DMA

10 Municipal Stormwater Calculator web1.saclink.csus.edu/lidtool/start.aspx Municipal Stormwater Calculator Municipal Stormwater Calculator 0.16 ac = 6,970 ft2 Practice Tip #6 for Projects > 5000 sf (Regulated Projects) If using a generalized web soil map, check your site s soil to avoid excess Site Design Measures Municipal Stormwater Calculator Practice Tip #7 for Projects > 5000 sf (Regulated Projects) Consider available space versus up front cost & long term maintenance One 55 gal rain barrel = 7.35 ft 3 so multiply by 4 barrels = 29.4 ft 3 = 22.4% reduction; Remaining 77.6% x 325ft 2 = 252.2ft 2 Amended Strip 18 deep (16 x16 or 5 x50 )

11 Interpretations Permit Goals vs. Manual Standards E.12.e.(ii)(f)3) minimum infiltration rate of 5 inches per hour E.12.e.(ii)(f)3) A mixture of sand (60% 70%) and compost (30% 40%) may be used. Really? Interpretations Permit Goals vs. Manual Standards What s really sustainable and what works on the ground E.12.e.(ii)(f) The facilities must be demonstrated to be at least as effective as a bioretention system with the following design parameters: Doesn t say must have the following parameters E.12.e.(ii)(f)8) Appropriate plant palette for the specified mix implies different mixes Flexibility Practice Tip #8 for Projects > 5000 sf (Regulated Projects) If the local jurisdiction allows, assess your soils before resorting to bioretention; an engineered soil mix and associated impacts may be unnecessary LID What s the Point Microbes eat toxins for breakfast! LID What s the Point LID Creating a toxin-eating ecosystem Microbes eat hydrocarbons for lunch!

12 Design Considerations and Requirements Considerations Irrigation? Soil, Compost/Mulch, Plant Type, Planting Season Design Considerations and Requirements Considerations Compaction Surrounding Project Construction/Engineering Equipment within LID feature Design Considerations and Requirements Considerations Follow local climate cycles Native plants have dormant cycles Brown is the New Green Cosumnes Elementary, Sloughouse, CA Photo Courtesy of Delta Bluegrass Practice Tip #9 Waterboard Intent = Development mimics natural landscape and ecosystem to reduce runoff and pollution Maximize soil plant microbial systems Questions?.No? Waterboard stormwater@waterboards.ca.gov (866) Streamline Planning bob@streamlineplanning.net spolly@streamlineplanning.net (707)

13 Bioretention Rain Gardens and Vegetated Swales Rain Garden Pervious Pavement Minimize stormwater runoff Reduce need for storm drain systems Provide filtration of pollutants Increase infiltration to groundwater Even eliminate i puddles! Pervious Concrete Permeable Pavers Reinforced Grass By Timothy Lawrence Rain Barrels/Cisterns Design Considerations and Requirements Soils and Plants Where are the Roots? Roots: Perennial vs. Annual 13