Stormwater Management Regulation Update

1
Stormwater Management Regulation Update

• UDC Update Project
• Agricultural Advisory Board
• November 13, 2007

Snohomish County Planning Development Services
2
UDC Life, Health Safety Pillar
3
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

4
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

5
Project Managers
6
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

7
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

8
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

9
Code Revisions

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

10
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

11
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

12
Permit Exemptions

• 30.63A.020  Exemptions. (draft code in progress)
•    (1)  The following commercial agricultural
  production activities conducted outside
  ((critical)) wetlands, lakes, marine waters, and
  fish and wildlife habitat conservation areas and
  on land designated riverway commercial farmland,
  upland commercial farmland, or local commercial
  farmland by the comprehensive plan are exempt
  from the requirements of this chapter      (a) 
  Tilling, soil preparation, and maintenance and 
     (b)  Fallow rotation, planting, and harvesting
  except
• (i) Conversions from
  timberland to agriculture and
• (ii) Construction of
  impervious surfaces, including but not limited to
  roads.   

13
Permit Exemptions

•   
• (2)  The following commercial agricultural
  production activities conducted outside
  ((critical)) wetlands, lakes, marine waters and
  fish and wildlife habitat conservation areas and
  on land designated riverway commercial farmland,
  upland commercial farmland, or local commercial
  farmland by the comprehensive plan are exempt
  from all other requirements of this title except
  that they shall comply with the stormwater
  pollution prevention plan (SWPPP) requirements of
  SCC 30.63A.220(1)(a)-(g), and     

14
Permit Exemptions

• (a)  Maintenance and repair except the
  creation of any new impervious surface on private
  property of existing commercial agricultural
  facilities, which may include drainage
  facilities, ponds, animal stock flood
  sanctuaries, animal waste management facilities,
  agricultural buildings, fences, roads, and
  bridges
•      (b)  New construction (((including
  enlargement))) of drainage ditches that are less
  than 500 cubic yards or less of land disturbing
  activity of 2,000 square feet or less, which does
  not adversely impact ((critical areas, lakes,))
  wetlands, lakes, marine waters and fish and
  wildlife habitat conservation areas or upstream
  or downstream properties, when such ditches do
  not have a surface connection within 100 feet of
  wetlands, lakes, marine waters and fish and
  wildlife habitat conservation areas or which
  contain water on-site for retention, infiltration
  or evaporation pursuant to chapter 30.62 SCC.

15
Right to Farm (RTF)

• DOE and FEMA exemptions
• De minimus ag activities that do not alter
  contours including tilling, plowing, harvesting,
  soil amendments and farm ditch digging if the
  originally constructed ditch configuration is not
  altered spoils are removed or tilled as a soil
  amendment.
• Exempt activities also include farm road
  construction or maintenance which does not alter
  contours, use culverts and is lt 6 inches above
  grade.

16
Permit vs. RTF

• Federal CWA mandate trumps local initiative
• Not allowed Construction of
• Roads
• Impervious Surfaces

17
Countys Strategy

• Discuss de-minimus RTF activity with DOE
• Provide de-minimus RTF justifications
• Send draft code to DOE including existing right
  to farm provisions

18
Right to Farm Justification

• DOE allows de minimus construction that does not
  alter contours
• Water infiltrates into outwash soils
• Roads typically generate lt 0.1 cfs threshold
• DOE regulates stormwater on farmlands
• Drainage plans and development reg by NRCS
• Farm plans address stormwater management
• Farm roads typically do not impact stormwater
  systems

19
Alternatives

• Amend code to match permit and include options if
  DOE will not allow RTF
• Porous pavement on roads
• Quarry spalls access roads

20
Related Non-Exemptions

• Conversion from timberland to agriculture not
  exempt

21
Agricultural Advisory Board Input

• Your comments and suggestions on RTF
  justification and options

22
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

23
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

24
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

25
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