Stormwater Management Regulation Update

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Stormwater Management Regulation Update

• UDC Update Project
• Utilities Stakeholder Group
• November 13, 2007

Snohomish County Planning Development Services
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UDC Life, Health Safety Pillar
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Why Are We Doing This Update?

• Protect health and safety
• Prevent/minimize degradation of water quality and
  slope instability
• Preserve WQ for aquatic habitats, recreation, and
  drinking water
• Comply with CWA and DOE NPDES Permit

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Phase 1 Municipal Stormwater Permit Requirements

• Adopt Appendix 1 Minimum Technical Requirements
  for New Development and Redevelopment
• Adopt 2005 DOE Stormwater Manual for Western
  Washington with a Snohomish County Addendum

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Project Managers
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How is Stormwater Managed?

• Construction Stormwater Pollution Prevention Plan
  (SWPPP)
• Control water flow, install sediment controls,
  stabilize soils, protect slopes, wetlands, drain
  inlets, channels and outlets
• Control pollutants with Best Management Practices
  (BMPs), source control, runoff treatment, and
  treatment facility sizing

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Whats New?

• More restrictive exemptions
• Applies to development and redevelopment
• Applies to Class IV FP conversions - stormwater
  calculations required
• More analysis is required for discharges to
  wetlands and a different baseline is used for the
  analysis in the 2005 DOE Manual

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Whats New? (continued)

• Larger detention and retention ponds
• Pre LDA site inspection
• Reporting and inspections existing facilities
  and upgrades
• New pollution source control rules
• Permit has several less restrictive provisions
  than existing code

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Code Revisions

• Revisions to drainage grading codes
• - Exemptions
• - Development redevelopment thresholds
• - Minimum requirements

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DOE 2005 Manual

• Adopt 2005 DOE Manual with addendum and ref to
  drainage and grading
• Change to reflect Snohomish County business
  practices
• Modify for clarity
• Change to make user friendly

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Engineering Design Development Standards (EDDS)

• Revisions to address LID design standards
• Review other standards (roads, drainage, etc.)
  for appropriate revisions
• Modify for consistency with code and Drainage
  Manual
• Adopted per rulemaking process

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Permit Utility Exemption

• (f) Underground utility projects located outside
  of a critical area that replace ground surfaces
  with in-kind materials or materials with similar
  runoff characteristics are exempt from all
  minimum requirements in SCC 30.63A.XXX except for
  minimum requirement 2 Construction Stormwater
  Pollution Prevention Plan pursuant to SCC
  30.63A.XXX.

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Existing Utility Exemptions

• (3)  Utility construction and maintenance.   
   (a)  Minor utility activities in improved county
  rights-of-way which, pursuant to Title 13 SCC, do
  not require a Type D permit are exempt from the
  requirements of this chapter (Note items b-e
  below not clearly exempt in permit)     (b) 
  Utility construction outside critical areas and
  within county rights-of-way conducted under a
  Type D7 blanket utility permit pursuant to Title
  13 SCC which does not adversely impact critical
  areas ((, lakes)), or upstream or downstream
  properties shall comply with the erosion control
  requirements of SCC 30.63A.220(1), and is exempt
  from all other requirements of this chapter. 
  Utilities applying for a blanket utility
  construction permit shall propose erosion and
  sedimentation control best management practices
  for all permitted activities at the time of
  project application. 

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Existing Utility Exemptions

• (d)  Utility construction within impervious
  surface areas, including trenching or other
  utility installation or maintenance which cuts
  and subsequently repairs existing impervious
  surface outside critical areas and outside of
  public rights-of-way, which does not adversely
  impact critical areas and their buffers ((,
  lakes, )) Keep and their buffers -old CAR or
  upstream or downstream properties, shall comply
  with the erosion control requirements of SCC
  30.63A.220(1), and is exempt from all other
  requirements of this chapter.  Utilities
  proposing installation or maintenance which is
  subject to a county permit, approval or
  authorization shall propose erosion and
  sedimentation control best management practices
  for the utility construction at the time of
  application.

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Existing Utility Exemptions

• (e)  Utility maintenance outside critical areas
  and outside of public rights-of-way which does
  not add impervious surface and does not adversely
  impact critical areas, lakes, or upstream or
  downstream properties shall comply with the
  erosion control requirements of SCC
  30.63A.220(1), and is exempt from all other
  requirements of this chapter.

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Existing Utility Exemptions

• (c)  Major utility construction within impervious
  surface areas, including trenching or other
  utility installation or maintenance which cuts
  and subsequently repairs existing impervious
  surface outside critical areas within public
  rights-of-way conducted under a Type D8 major
  utility construction permit pursuant to Title 13
  SCC, which does not adversely impact critical
  areas ((,lakes,)) or upstream or downstream
  properties, shall comply with the erosion control
  requirements of SCC 30.63A.220(1), is exempt
  from all other requirements of this
  chapter. Utilities applying for a major utility
  construction permit shall propose erosion and
  sedimentation control best management practices
  for the utility construction at the time of
  application.

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County Strategy

• Discuss existing exemptions with DOE
• Update requirements for exemptions
• - CESCL to manage project
• - Blanket SWPPPs
• - other ideas?

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General Project Schedule

• SEP Draft codes and DOE Manual
• OCT DEC Draft documents and public outreach
• DEC Review drafts
• FEB Transmit codes and manual to DOE for 60-day
  review
• APR JUL 2008 PC and Council Public Hearings
• AUG/SEP 2008 Adoption for NPDES permit compliance

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Keep in Touch

• Status updates and drafts available on the UDC
  Update Project homepage at www.snoco.org (search
  UDC Update)
• Public can submit comments on the project page

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Staff Contacts

• Bill Leif, Environmental Program Compliance
  Specialist, 425-388-3148
• Randy Sleight, Chief Engineering Officer,
  425-388-3311, x2014
• Arthur Lee, Project Specialist, 425-388-3812
• Bob McEwen, Transportation Specialist,
  425-388-3488, x4578
• Linda Kuller, Chief Planning Officer,
  425-388-3412

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Acronyms

• BMP Best Management Practices
• CESCL Certified Erosion-Soil Control Lead
• CWA Clean Water Act
• DOE Department of Ecology
• DOE Manual 2005 Stormwater Manual for Western
  WA
• EDDS Engineering Design Development Standards
• LID Low Impact Development
• NPDES National Pollutant Discharge Elimination
  Permit
• SWPPP Stormwater Pollution Prevention Plan
• WWHM Western WA Hydrology Model