WSDOT expands its stormwater management program to protect our environment

A WSDOT Maintenance worker clears debris from a drain.

Stormwater runoff can pick up pollutants and carry them into rivers and lakes.

In February 2009, WSDOT obtained a new stormwater permit from the Department of Ecology. The new permit expands WSDOT’s current stormwater management program over a larger geographic area and increases monitoring and reporting efforts.

The permit requires that highways and other transportation facilities be designed and maintained to help reduce pollutants in our waterways, and reduce downstream flooding and erosion. When rest areas, maintenance yards and shops, ferry terminals and park and ride lots are included, WSDOT’s paved surfaces cover more than 40,000 acres.

More about stormwater runoff and why it’s a problem
Stormwater runoff occurs when rain and snowmelt flow off the landscape and man-made surfaces. Impervious surfaces – such as sidewalks, driveways and roadways – prevent stormwater runoff from soaking naturally into the ground. For every inch of rain that falls on an acre of pavement, about 27,000 gallons of stormwater are produced.

Stormwater running off these impervious surfaces can pick up oil, grease, metals, and other pollutants and carry them downstream into lakes, rivers and marine waters. Uncontrolled stormwater runoff can also add to the erosion of soil and stream channels, producing muddy water that can suffocate fish and their egg nests, as well as increase the risk of flooding.

Doing our part to protect the environment
Managing stormwater that runs off of highways, ferry terminals, rest area parking lots, and other transportation facilities is one of the ways WSDOT is meeting its commitment to environmental stewardship and regulatory requirements.
Managing stormwater generated from WSDOT’s transportation facilities helps:

• reduce pollutants in Washington’s streams and rivers
• contributes to Puget Sound and salmon recovery
• reduce downstream flooding and erosion

 
Working cooperatively with federal, state and local agencies, WSDOT has developed a stormwater program that is among the most comprehensive and stringent in the nation.

Managing stormwater is not new to WSDOT

• WSDOT has had a stormwater permit since 1995, which covered the state’s most populated areas in King, Snohomish and Pierce counties and the Seattle and Tacoma urban areas.
• In 1997, WSDOT prepared its own Stormwater Management Plan that outlined a strategy for protecting water quality and complying with federal and state laws.
• In 2009, the Department of Ecology issued a new permit to WSDOT, which was challenged in court. A settlement was reached in January 2010 and a modified permit was issued in May 2010.

 

Comparing the 1995 permit to the new 2009/modified 2010 permit
WSDOT’s new stormwater permit comes with added responsibilities over a wider statewide area:

• Coverage area - In 1995 the coverage area included three counties and two urban areas (Seattle and Tacoma). The new permit expands coverage to four counties and 100 urban areas across the state, including some in eastern Washington.
  
  The permit also includes an increase in the state highway centerline miles, from 1,140 miles in 1995 to 1,600 miles in 2009, a 40 percent increase.
  
• Maintenance – Although WSDOT was required to maintain and inspect stormwater facilities in the 1995 permit, no frequency was prescribed. The 2009 permit requires annual inspections for each of more than 2,100 existing stormwater facilities; and that number continues to grow.
  
  Previously, inspection and maintenance of catch basins was not required. Those are now required annually for the more than 25,000 (and growing) catch basins covered by the 2009 permit.
  
  Also new in the 2009 permit – Stormwater Pollution Prevention Plans must be created for maintenance areas, park and ride lots, and ferry terminals.
  
• Monitoring – Comparing the 1995 permit to the 2009 permit, monitoring requirements are substantially increased at more locations (6 versus 20) and for the number of samples analyzed (830 versus 4,620+). The 2009 permit also adds the requirement for sediment and toxicology evaluations.
  
• Mapping – This requirement has been greatly expanded in the 2009 permit. WSDOT must develop a database and inventory and map its existing stormwater facilities and add new facilities and outfalls that are created. This includes the documentation of:
• Drainage areas
• Catch basins
• Conveyances, such as ditches and storm sewer pipelines
• Outfalls (where the runoff enters streams, rivers, ponds, etc.)
• Runoff treatment and flow control facilities
• Connection from and into WSDOT’s stormwater system
  
• Tracking and reporting - Similar to the 1995 permit, WSDOT

  WSDOT employees test water quality near the Ebbey Slough bridge.

  must submit an annual progress report to the Department of Ecology. However, the new permit expands the reporting requirements and ties them to more stringent performance indicators including:

• Status of water cleanup plan implementation
• Barriers to implementation of low-impact development approaches that are intended to treat runoff at its source and infiltrate runoff into the soil
• Actions taken to remove these barrier
• Budget requests for resources needed for permit compliance
  
• Stormwater standards and retrofits – The 1995 permit required WSDOT to build stormwater systems to current design standards. The 2009 permit includes more stringent standards. It also adds a new requirement that WSDOT retrofit existing highways that have non-existent or substandard runoff treatment and control.
  

Key elements of the 2010 settlement agreement

The Puget Soundkeeper Alliance filed a legal challenge to WSDOT’s 2009 permit and a settlement was negotiated with the Department of Ecology and WSDOT. This settlement left a majority of the permit intact, but added substantive language in four areas:

• Illicit discharge detection and elimination – This provision relates to water coming from sources outside of WSDOT’s right-of-way. WSDOT agreed to increase our monitoring and identification of illicit discharges, and modified what actions we will take when we find them.
  
• Water body cleanup plans (also called Total Maximum Daily Loads) – Ecology will evaluate cleanup plans every 18 months, and if those plans include pollutants from state highway stormwater runoff, Ecology will add those plans to WSDOT’s permit and we will implement requirements specified in the cleanup plans.
  
• Consultation with the US Fish and Wildlife Service and National Marine Fisheries Service (Services) – Enlists the Services’ review of non-federally funded transportation projects when they have potential impacts in areas where Endangered Species Act-listed species may be affected.
  
• Stormwater retrofit for existing highways – Within the Puget Sound basin, WSDOT will retrofit existing highway pavement when a project adds new pavement and stormwater treatment. These retrofits are subject to engineering feasibility and cost-effectiveness thresholds. Retrofits will occur when the cost to do so does not exceed 20 percent of the cost for treating the new pavement.
  
  Since most of the state’s highway infrastructure, including drainage systems, was built long before the 1980’s enactment of the Clean Water Act and other environmental protection laws, this requirement could have significant cost impacts.

 

WSDOT’s progress and next steps

Stormwater facilities, like this one along SR 500 in Clark County, allow pollutants to settle out as water slowly soaks into the ground.

Some of WSDOT’s achievements to reduce the effects of stormwater’s water quality and quantity include:

• To date, WSDOT has constructed more than 2,100 stormwater treatment facilities statewide. That number is expected each year as new highway projects are funded and built.
• In the permit area, 333 stormwater facilities were constructed since the permit was reissued in 2009
• Approximately 20 discharge points were retrofitted as stand-alone projects between 2007 and 2009
• Field work has begun to prioritize additional highway segments in Puget Sound for stand-along stormwater retrofit.
• More than 90 percent of our stormwater erosion assessment measures in 2009 received an “excellent” or “good” rating
   

WSDOT’s next steps to implement the 2009 permit include:

• By March 2011, complete the stormwater features inventory database and begin inventorying stormwater facilities
• Complete stormwater pollution prevention plans for all maintenance facilities, ferry terminals, rest areas, and WSDOT-maintained park and ride lots in the permit area by March 2011
• Establish routine catch basin and permanent stormwater facility inspection program in the permit area by March 2011
• Begin full implementation of stormwater monitoring program by September 2011.

What you can do to help

Fixing drips and leaks helps keep oil and other pollutants out of stormwater runoff.

Pollutants that may run off the highways and other paved surfaces are generated from motor vehicle “wear and tear,” emissions, and litter. You can do your part by:

• Keeping your vehicle properly maintained and fixing drips and leaks
• Leaving your vehicle at home – by sharing the ride you reduce the amount of emissions and idling caused by congestion
• Using a vehicle trash bag and secure loads – trash that falls on the roadway can end up in our waterways
• Consider purchasing a low-emission vehicle when it comes time to replace your existing car
• Picking up after your pet at rest areas and along roadways – pet waste contributes to runoff pollution

For more information:
For more information about WSDOT’s Municipal Stormwater Permit, contact Larry Schaffner, NPDES Municipal Stormwater Permit Coordinator, at 360-570-6657, or by e-mail at: SchaffL@wsdot.wa.gov
 
More detailed information about WSDOT’s Stormwater and Watershed Program can be found at: www.wsdot.wa.gov/Environment/WaterQuality