This is not intended to be 100% complete. Please refer to the codified (final published) copy of the laws or rules.
Polluted stormwater runoff is a leading contributor to water pollution in the Puget Sound Region. When uncontrolled, it can cause or contribute to flooding. Stormwater runoff causes the destruction of fish, wildlife, aquatic habitat; loss of aesthetic values; and threats to public health due to contaminated food and drinking water supplies.
These new stormwater regulations require property owners to minimize land disturbance, prevent and control erosion, reduce pollutants and provide treatment of pollutants. The new regulations are required to comply with federal requirements of the Clean Water Act (CWA) via a NPDES (National Pollution Discharge Elimination System) permit, a federal regulation mandating the regulation of Stormwater. The Federal Clean Water Act prohibits anybody from discharging pollutants through a point source into a water of the United States unless they have an NPDES Permit. The permit outlines water quality laws into specific code provisions. It limits what can be discharged, requires the use of best management practices (BMPs) for source control, treatment, and flow control and other provisions to ensure that discharges do not hurt water quality or public health.
What is Stormwater? Stormwater is the water from rain or snow which runs off yards, roofs, roadways and other developed land and flows into nearby lakes, rivers and Puget Sound. As stormwater runs downhill into low spots, ditches and storm drains, the water picks up soil, chemicals, oil, grease, bacteria and other pollutants and carries them into our lakes, rivers and marine waters.
What are “best management practices” (BMPs) with regard to drainage and land disturbing activities (LDA)? BMPs are the schedules of activities, prohibited practices, maintenance procedures, structural practices or managerial practices, that when used singly or in combination, prevent or reduce the release of pollutants and other adverse impacts to waters of Washington State. The types of BMPs are source control, treatment, and flow control.
The Washington Department of Ecology (Ecology) is the authority which oversees the county on compliance with the Clean Water Act and state water quality laws. Ecology issues the permit pursuant to the NPDES program of the Clean Water Act and the Water Pollution Control Act of Washington. The NPDES Permit regulates stormwater discharges from all new development, redevelopment and construction activities to prevent and control adverse impacts of drainage and stormwater on the public health, safety, and general welfare.
New stormwater management ordinances Effective September 30, 2010, as required by the NPDES Permit include: Regulations in the following ordinances will be incorporated into Snohomish County Code on September 30, 2010:
• Amended Ordinance No. 10-023 relating to land disturbing activities (requires a permit for clearing and grading/all LDA permits will trigger drainage review). • Ordinance No. 10-024 relating to Low Impact Development (Note: LID BMPs are specified in Appendix 1-A of Volume 1 of the proposed Snohomish County Drainage Manual currently in the rule making process). • Amended Ordinance No-025 relating to drainage and land disturbing activity fees. • Amended Ordinance No. 10-026 relating to drainage (stormwater) regulation.
New and amended definitions are located in the back sections of the ordinances, primarily Amended Ordinance No. 10-026 (Stormwater), in sections numbered 30.91-.
Snohomish County Code Title 30 regulate stormwater?
Title 30 SCC contains the development regulations. The main stormwater management regulations are found in: • Chapter 30.63A – Drainage • Chapter 30.63B – Land Disturbing Activity (Clearing and Grading) • Chapter 30.63C – Low Impact Development (LID)
The proposed regulations invoke standards in the following proposed rules which will be adopted by the Department of Public Works (DPW): • Snohomish County Drainage Manual (as an equivalent to Ecology’s 2005 stormwater Management Manual for Western Washington (2005 Ecology Manual)) • Chapters 1 (General Considerations), 4 (Road Elements and Features) and 5 (Drainage) of the Engineering Design and Development Standards (EDDS)
The Drainage Manual contains methods for achieving compliance with the stormwater requirements addressed in Chapters 30.63A, 30.63B, 30.63C and 7.53 SCC. Upon adoption, it shall be used in place of the 2005 Ecology Manual. The Drainage Manual’s five volumes include the following subject matter:
• Volume I: Introduction and stormwater site plans; • Volume II: BMPs for short-term stormwater management at construction sites; • Volume III: Hydrologic analysis and BMPs to control flow volumes from developed sites; • Volume IV: BMPs to minimize pollution generated by potential pollution sources at developed sites; and • Volume V: BMPs to treat runoff that contains sediment or other pollutants from developed sites.
The following Drainage Manual Appendices may be of special interest while reviewing the code:
• Appendix I-A: Low Impact Development BMPs • Appendix I-D: Wetlands and Stormwater Management • Appendix I-F: Stormwater Pollution Plan (SWPPP) Submittal Requirements for Small Projects, SCC 30.63A.810
The EDDS provides engineering standards for project design and construction. Proposed Chapters 1 (General Considerations), 4 (Road Elements and Features) and 5 (Drainage) of the EDDS provide updated standards and detailed specifications necessary to implement the proposed stormwater regulations and Drainage Manual. Work performed and materials installed pursuant to the requirements of Chapters 30.63A, 30.63B and 30.63C SCC shall conform to the EDDS. The updated EDDS has been updated to include standard Washington State Department of Transportation (WSDOT) plans and specifications wherever possible.
What are some of the major changes in the stormwater regulations?
The following bullets provide a small sample of the changes: • Exemptions from the proposed stormwater regulations are more limited. • The right to farm exemptions are now located in the exemption code sections in Chapters 30.63A (Drainage) and 30.63B (Land Disturbing Activity (LDA)) • LDA permits will be required for clearing and grading at NPDES Permit thresholds (unless the project is exempt) • Minimum stormwater control requirements (MRs) are required depending upon the new thresholds for new, replaced, or new plus replaced impervious surface or land disturbing activity. • There are new requirements for redevelopment (sites already with 35% impervious surface).
What is new about erosion control?
• New development or redevelopment must comply with Minimum Regulation (MR) 2: Stormwater Pollution Prevention Plans (SWPPPs for erosion control) unless exemption criteria are met
• Projects disturbing more than 1 acre must be managed by a Certified Erosion and Sediment Control Lead (CESCL).
• Small project SWPPPS are now required for projects with up to 2,000 square feet of new, replaced, or new plus replaced impervious surface (currently 200 sq. ft.) when the project meets the criteria in SCC 30.63A.810. In this case, an engineer may not be required to produce the SWPPP. Volume 1, Appendix 1-F provides small project SWPPP requirements.
When is a land disturbing activity permit is required? A permit is required if the project does not meet the exemptions. All projects which are exempt from the requirements are still required to utilize Best Management Practices.
Land Disturbance Activity permits are required if:
1. The project creates new, replaced, or new plus replaced impervious surface and exceeds 2,000 SF.
2. Clearing or grading of more than 7,000 SF of land?
3. Conversion of three-quarters of an acre or more of native vegetation to lawn or landscaped areas?
4. Conversion of 2.5 acres or more of native vegetation to pasture?
5. If the project creates more than: 100 cubic yards or less of grading on a site in any 18 consecutive months (except fills and associated compaction intended to support structures or private roads); 500 cubic yards or less of excavation in any 18 consecutive months for a basement foundation, or for improvements to a single-family dwelling and/or accessory structures, provided that excess excavated material shall be disposed of at a permitted site approved by the director and provided further that the activity shall only commence after a building permit is secured by the applicant; or 500 cubic yards or less of grading in any 18 consecutive months for construction of underground drainage systems, provided that the construction shall only commence after a right-of-way use, utility, single-family or commercial building permit is obtained by the applicant.
Note: Grading thresholds will remain the same as existing code. Any land disturbing activity that exceeds a minimum threshold above requires a LDA permit and compliance with the drainage regulations including submittal of a stormwater site plan. All new development and redevelopment must comply with soil erosion control requirements except for those activities that are exempt from all requirements.
Where can I find the exemptions and minimum project thresholds? Chapter 30.63A Drainage; 30.63A.200 General exemptions; 30.63A.300 Drainage review thresholds and requirements for new development.; 30.63A.310 Minimum drainage review thresholds and requirements for redevelopment.
Chapter 30.63B; Land Disturbing Activity; 30.63B.070 Land disturbing activity permit exemptions.
COUNTY NPDES WEBSITE: http://www1.co.snohomish.wa.us/Departments/PDS/Divisions/PlanningandTechnology/Code_Development/UDC/NPDES.htm
