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| Stormwater Monitoring location to evaluate treatment facility effectiveness. |
The Stormwater and Watersheds Program provides guidance and technical support to planning, design, construction, and maintenance offices to help WSDOT enhance project delivery and achieve compliance with the Federal Clean Water Act, and State Water Quality Laws (RCW 90.48, WAC 173-201A, and WAC 173-270).
National Pollutant Discharge Elimination System (NPDES)
The 1987 amendments to the Clean Water Act (CWA) extended the NPDES program to include stormwater discharges. The primary objective of the Clean Water Act (CWA) is to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters. The NPDES permit program is the U.S. Environmental Protection Agency’s (EPA) primary enforcement mechanism to ensure compliance with the CWA’s provisions. EPA regulations require NPDES permits for discharges from four broad categories of stormwater discharges:
- Municipal separate storm sewer systems (MS4s)
- Construction activity
- Industrial activity
- Sand and gravel activity
WSDOT has permit coverage under all four of these categories.
More on WSDOT NPDES stormwater permits.
NPDES Annual Progress Reports
WSDOT submits annual reports to the Department of Ecology summarizing activities undertaken to meet obligations with its NPDES municipal stormwater permit and evaluate the performance of its stormwater management program. Previous reports are archived at WSDOT and can be made available upon request. For further information about report and data submittals contact WSDOT's municipal stormwater permit administrator at flab461@ecy.wa.gov.
Puget Sound Highway Runoff Program
In 1987, the Puget Sound Water Quality Authority issued the Puget Sound Water Quality Management Plan. This plan called for a Highway Runoff Program, which was subsequently developed by Ecology and codified in Chapter 173-270 of the Washington Administrative Code (WAC). This regulation established the basis for the management of stormwater runoff from transportation infrastructure to protect water quality in the Puget Sound basin.
Guidance, Procedures, & Tools
Stormwater Research
Stormwater management is a complex task with a variety of regulatory drivers and constraints, involving numerous technical disciplines including hydraulics, hydrology, geology, and water quality. The relatively narrow linear nature of the highway network further constrains the use of conventional stormwater management approaches while also requiring safe access for maintenance of stormwater facilities. To help meet these challenges, WSDOT relies on stormwater research to help identify state-of-the-art, cost-effective solutions for designing, constructing, and maintaining stormwater management systems.
More on WSDOT stormwater research.
Erosion & Sediment Control Program
The WSDOT Erosion Control Program prevents erosion-related cost overruns, project delays, and protects the environment by providing training, technical assistance, and guidance materials to WSDOT staff and contractors.
Stormwater Pollution Prevention Plans
The Water Quality Program can assist with the preparation and review of Stormwater Pollution Prevention Plans (SWPPPs) for Highway Construction, Ferries, Aviation, and Rail divisions.
Stormwater Facilities Inventory & Retrofits
Under WAC 173-270 (adopted in 1991), WSDOT is required to inventory, prioritize, and retrofit all stormwater outfalls. Work is currently under way to inventory over 20,000 outfalls around the state. Information will be gathered into a database and will include a thorough assessment of the conditions at each outfall. The database will then automatically generate a priority list of outfalls that require retrofit. Recommendations for retrofit best management practices (BMPs) are also included as part of the overall prioritization score for each outfall. Information from this inventory will simultaneously benefit several WSDOT operations such as Program Management, Design Offices, Maintenance, and Environmental Offices (NPDES and NEPA). Stormwater facility inventory and retrofit guidance is available, including:
Outfall information associated with Hydraulic Reports should be collected in accordance with the Hydraulic Staff Outfall Inventory Instructions (pdf 72 kb). Enter the information into the Hydraulic Staff Outfall Inventory Spreadsheet (.xls 12 kb) and e-mail it to Cory Simon. Any questions about this process should be addressed to Cory at 360-570-2589.
NEPA/SEPA Program Support
When staffing resources are available, the Stormwater and Watersheds Program provides the following services in support of National Environmental Policy Act (NEPA) and Washington State Environmental Policy Act (SEPA) environmental studies:
Surface Water Discipline Report preparation guidance and templates.
June, 2010 NEPA/SEPA Stormwater Design Documentation Checklist (docx 41 kb):
The NEPA SEPA Stormwater Design Documentation Checklist collects design information needed to describe pre-project conditions and compare them to proposed post-project conditions, as they relate to stormwater management. This checklist is used by the project's environmental documentation coordinator to gather pertinent stormwater design information for inclusion in the Surface Water Discipline Report. Completion of this checklist documents the level of design information available at the time of analysis for discipline report authors. Establishing this "snap-shot-in-time" can reduce review time and minimize rework by providing a clear record of the data available at the time of analysis.
The NEPA/SEPA Stormwater Design Documentation Checklist breaks down the analysis of stormwater management activities and impacts by areas draining to specific discharge points, also know as 'threshold discharge areas' (TDAs). The project's environmental documentation coordinator should ask the appropriate design team staff to fill out this checklist. Many of the answers can be found on the Stormwater Design Documentation Spreadsheet.
Prepare and review discipline reports in accordance with WSDOT Environmental Procedures Manual Section 430 and Exhibit 430-1.
Drinking Well Protection Agreement
WSDOT and the Washington State Department of Health have entered into a Drinking Well Protection Agreement to clarify expectations, establish screening criteria, and facilitate communication for projects that intersect the sanitary control area of a public water supply.
Illicit Discharge Detection and Elimination (IDDE)
Illicit discharges include spilling, dumping, or pumping pollutants or polluted water into drainage ditches or storm drains. WSDOT's Municipal Stormwater Permit requires us to identify and eliminate illicit discharges to prevent pollution of Washington’s waters.
Examples of illicit discharges include:
- Muddy water from construction sites draining into storm drains.
- Chemicals spilling into a storm drain.
- Industrial waste water being pumped into a drainage ditch.
- Sewage leaking into a storm drain.
- Farm animal wastes spilling into a drainage ditch.
For more information on the IDDE program, additional guidance on identifying illicit discharges or connections, or training opportunities, visit the Spills and Illicit Discharge Detection and Elimination (IDDE) webpage or contact Chris Gustafson (360) 709-8058.
Underground Injection Control
Infiltration is one of the preferred methods for disposing of excess stormwater. Subsurface infiltration is regulated by the Underground Injection Control (UIC) Rule, which is intended to protect underground sources of drinking water. The UIC Rule requires WSDOT to assess and register all underground injection facilities.
Project Offices in coordination with the Region Hydraulics Offices, shall download and complete the linked spreadsheet (xls 153 kb). Send completed forms to simonc@wsdot.wa.gov. Completed spreadsheet information will be used to register facilities.