5/22/2012. Low Impact Development through NPDES Permits TAKE AWAY MESSAGES. Municipal Stormwater NPDES Permits

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1 Low Impact Development through NPDES Permits Ed O Brien eobr461@ecy.wa.gov 360/ TAKE AWAY MESSAGES Municipal SW permits will require LID on new and redevelopment projects Site LID: necessary but insufficient to protect aquatic resources Follow endorsed design methods & local codes Use approved computer models & methods More training options on the way take advantage Municipal Stormwater NPDES Permits 7 Phase I primary permittees (cities & counties) 86 Phase II primary permittees in West. Wash All must develop SW Programs that meet permit requirements 1

2 Permit Requirements Legal Authority Public Education & Outreach Public Involvement & Participation System Mapping Illicit Discharge Elimination Construction Site Runoff Control New Dev. & Redev. Runoff Control Pollution Prevention & O & M Coordination Structural Controls (only Phase I) Existing Municipal SW Phase I & II Permits Regulations to control runoff from new and redevelopment during construction and postconstruction Site planning process and BMP selection and design criteria. Long-term O/M standards Allow for LID Inspections/enforcement Adopt Appendix I (or equivalent) Minimum Requirements Thresholds Definitions Exemptions, Adjustments, Variances Optional: Basin-specific plans (if equal in protection) Runoff Models Adopt 2005 SWMMWW or equivalent* Adopt 2005 SWMMWW or other*: *Other must document how meet MEP/AKART for water quality During & Post- Construction Requirements Phase I Permit Appeal Pollution Control Hearings Board (PCHB) Findings: LID for parcels and subdivisions is known and reasonable Permit must require LID and the flow control standard Lack of evidence re reasonableness of LID on a watershed scale 2

3 PCHB Mandated Permit Changes Modified Phase I permit to require: LID to minimize impervious surfaces & land disturbance where feasible Removal of barriers Annual reporting of basin planning ID areas where basin planning can incorporate development strategies to protect aquatic resources Footnote: Ecology to add details PCHB Mandated Phase II Permit Changes Report by March 2011: ID LID barriers and measures taken to remove them LID practices implementable this permit term LID practices planned Ways to promote and measure LID use Schedule to require LID more broadly Ecology discretion re LID requirements next permit term LID to the extent feasible What defines a low impact development? some minimum defining characteristics? a minimum performance standard? How do you decide feasibility? General criteria? Site-by-site? Implementation time frame? 3

4 LID Advisory Committees Technical Committee & Implementation Committee For background, agenda, minutes, handouts: stormwater/municipal/lidstandards.html Municipal Permits Reissuance Schedule Ecology Issues Draft Permits for Public Comment October 19, 2011 February 3, 2012 Workshops and Public Hearings December 2, 2011 February 3, 2012 Comments on Permits & WWA Manual 2,750 commenters on all the Permits 1,525 pages Western Washington Phase I & II Permits 300 pages on LID 80 pages on Appendix 1 other than LID Western WA Manual 58 commenters 608 pages 12 4

5 Process to Permits Issuance Consider all comments Revise texts/coordinate with related documents Target Issuance Date: August 2012 Subject area teams in Ecology to recommend/decide Develop response to comments Permit appeal deadline: 30 days later Big picture decisions need Management buy-in Consult legal counsel 13 Issuing Multiple Sets of Permits Reissue existing Permits Phase I w/ monitoring update: 8/12 8/13 West Wa Phase II: 8/12 8/13 East Wa Phase II: 8/12 8/14 Updated Phase I & West Wa Phase II Issue 8/12; But Effective 8/13 8/18 Updated East Wa Phase II Issue 8/12; But Effective 8/14 8/19 Updated West Wa Permits LID Overview Site & Subdivision Project Requirements Phase I: S5.C.5.b.i & ii, Appendix 1 Phase II: S5.C.4.a.i & ii, Appendix 1 Updates of Local Development Codes, Rules, & Standards Watershed-scale Stormwater Planning 5

6 Regulations to control runoff from new and redevelopment during construction and postconstruction Site planning process and BMP selection, design and feasibility criteria. Long-term O/M standards Allow for Require LID Inspections/enforcement Updated W Wa Permits Adopt Appendix I (or equivalent) Minimum Requirements Thresholds Definitions Exemptions, Adjustments, Variances Optional: Basin-specific plans (if equal in protection) Runoff Models Adopt 2012 SWMMWW equivalent* Adopt 2012 SWMMWW or other*: *Other must document how meet MEP/AKART for water quality Appendix 1 Changes Section 2: Definitions LID/ LID BMP s/ LID Principles Bioretention VS Rain Gardens Hard Surfaces Converted Vegetation Areas Section 3: Thresholds Remain same Hard surface replaces impervious Appendix 1 Changes Section 4: Minimum Requirements M.R. #1: Site Planning for LID M.R. #2: Construction ESC New Element for LID Protection M.R. #5: On-site Stormwater Management LID Requirements for projects subject to M.R. #1 - #5 LID Requirements for projects subject to M.R. #1 - #9 6

7 Minimum Requirement #5 2,000 sq ft > hard surfaces < 5,000 sq ft Use LID BMPs from List #1, where feasible Or Meet LID Performance Standard Cannot use Rain Gardens; can use Bioretention and any other BMPs Demonstrate compliance using approved models & methods 19 Lawn and landscaped areas: List #1 Soil Quality & Depth; BMP T5.13 Roofs: Consider in order listed; use first feasible 1. Full Dispersion or Downspout Full Infiltration 2. Rain Gardens or Bioretention; > 5% 3. Downspout Dispersion 4. Perforated Stub-out Connection Other Hard Surfaces (driveways, patios, walks, parking lot): Consider in order listed; use first feasible 1. Full Dispersion 2. Permeable pavement or Rain Garden/Bioretention > 5% 3. Sheet Flow Dispersion or Concentrated Flow Dispersion 20 Minimum Requirement #5 > 5,000 sq. ft. hard surface Project Type & Location Development (new or redevelopment) on any parcel inside the UGA, or development outside the UGA on a parcel less than 5 acres Requirement LID Performance Standard and BMP T5.13 OR List #2 (applicant option) Development (new or LID Performance Standard and redevelopment) outside the UGA BMP T on a parcel of 5 acres or larger 7

8 List #2 hard surfaces > 5,000 sq. ft. Lawn and Landscaped Areas Soil Quality & Depth; BMP T5.13 Roofs 1. Full Dispersion or Downspout Full Infiltration 2. Bioretention > 5% 3. Downspout Dispersion 4. Perforated Stub-out Connection Other Hard Surfaces 1. Full Dispersion 2. Permeable pavement 3. Bioretention > 5% 4. Sheet flow Dispersion/Concentrated Flow Dispersion 22 Feasibility Criteria Site/Engineering-based Conditions Listed within SW Manual for each LID BMP Competing Needs Listed in Chapter 5, Vol V of SW Manual Municipalities can use and cite; or adopt changes and be prepared to defend as AKART and MEP. LID Performance Standard Match post-development discharge durations to pre-developed (pre-european settlement) durations from 8% of the 2-year flow to 50% of the 2-year flow. 24 8

9 LID Std: Control durations from 8% of 2-yr through 50-year LID Standard MR #5 Flow Control Standard MR #7 25 SWMMWW: Vol V Chapter 5 BMP T5.10A Downspout Full Infiltration * BMP T5.10B Downspout Dispersion * BMP T5.10C Perforated Stub-out Connection * BMP T5.11 Concentrated Flow Dispersion BMP T5.12 Sheet Flow Dispersion BMP T5.13 Post-Construction Soil Quality and Depth BMP T5.14 Rain Gardens* BMP T7.30 Bioretention Cells, Swales, and Planter Boxes* BMP T5.15 Permeable Pavement* BMP T5.16 Tree Retention and Tree Planting BMP T5.17 Vegetated Roofs* BMP T5.30 Full Dispersion Guidance Documents Stormwater Manual for West. Wash. Volume 1: Chapters 2 (requirements) and 3 (site planning) Volume III: Chapter 3: Infiltration, Bioretention, & Permeable Pavement Volume V: Chapter 5: On-site BMPs expanded Chapter 7: Expanded for Bioretention LID Manual for Puget Sound Site Planning Guidance BMP design criteria and guidance West. Wash. Hydrology Model Updated LID Modeling Procedures Rain Garden Handbook for West. Wash. 9

10 Updated West Wa Permits LID Overview Site & Subdivision Project Requirements Updates of Local Development Codes, Rules, & Standards Phase I: S5.C.5.b.iii Low Impact Development Phase II: S5.C.4.a.iv Low Impact Development Watershed-scale Stormwater Planning Updated W Wa Permits Regulations to control runoff from new and redevelopment during construction and postconstruction Site planning process and BMP selection and design criteria. Long-term O/M standards Allow for Require LID Inspections/enforcement Adopt Appendix I (or equivalent) Minimum Requirements Thresholds Definitions Exemptions, Adjustments, Variances Optional: Basin-specific plans (if equal in protection) Runoff Models Adopt 2012 SWMMWW Chapt 4 Vol 5 or equivalent* Adopt 2012 SWMMWW or other*: Site Planning Process BMP selection & design criteria *Other must document how meet MEP/AKART for water quality Update Site Development Codes Update Site Development Codes Rules & Standards Incorporate LID Principles & BMP s to the MEP Revised Codes, etc., become standard operating procedure Need to justify not using them, rather than asking for allowance to use them 10

11 LID Local Development Codes Make LID the preferred and commonly used approach for site development Minimize impervious surface Minimize native vegetation loss PSP Integrating LID into Local Codes Guidebook 31 Update Site Development Codes Rules & Standards Engineering & Street Standards Clearing & Grading Ordinance & Standards Parking Requirements Individual Zoning District Bulk & Dimension Regulations Subdivision Standards Landscaping and Tree Standards LID- Timelines New site & subdivision stormwater codes effective Phase I: June 30, 2015 Phase II: December 31, 2016 Revise developmentrelated codes, rules & standards Phase I: June 30, 2015 Phase II: December 31,

12 Updated West Wa Permits LID Overview Site & Subdivision Project Requirements Updates of Local Development Codes, Rules, & Standards Watershed-scale Stormwater Planning Phase I S5.C.5.c Phase II S5.C.4.g LID Watershed Scale Planning Phase I County selects a watershed and leads a planning process Select watershed by Oct. 31, 2013 Begin process by April 1, 2014 Submit final plan by Oct. 1, 2016 Phase II: Participate in watershed-scale planning led by a Phase I County 35 Proposed watersheds Streams impacted by development & retain anadromous fish Targeted to accept significant growth Basins proposed in Phase I permit Planning Process Baseline assessment Model flow & pollutants; use best available science Beneficial use impact identification Plan to address impacts 36 12

13 Other Documents in Preparation Recommended O&M Standards and Procedures for LID BMPs Updated Cost Estimates for Example New Development Sites Future Training Inspection and Maintenance of LID BMPs WWHM Training to demo new features especially LID modeling examples New Legislation and Budget $1 Million/year for 5 years Free to phase II permittees and private development community Sequenced geographically and timely TAKE AWAY MESSAGES Municipal SW permits will require LID on new and redevelopment projects Site LID: necessary but insufficient to protect aquatic resources Follow endorsed design methods & local codes Use approved computer models & methods More training options on the way take advantage 13

14 Questions? 40 Go Forth, And Use Low Impact Development 14