WSDOT Stormwater Monitoring

Science Center Objects

The Washington State Department of Transportation, or WSDOT, monitors the water quality of runoff from state highways and other transportation facilities under their National Pollution Discharge Elimination System (NPDES) permit. The NPDES permit requires WSDOT to make sure that the stormwater meets Clean Water Act and other regulations designed to restore and protect our country's water resources.

To help WSDOT meet new as well as existing NPDES permit requirements and look for ways to improve their performance, the USGS will provide a scientific assessment of the WSDOT stormwater monitoring program.

9722-DTM - Assessment of Washington State Department of Transportation Stormater Monitoring Program - Completed FY2009

Problem - The Washington State Department of Transportation (WSDOT) stormwater monitoring program, in operation for about 8 years, has never been subject to an external, objective assessment. In addition, WSDOT would like to know what monitoring program standard operating procedures and quality-assurance protocols are necessary to meet their NPDES permit requirements. As a result, in March 2009, the U.S. Geological Survey (USGS) was approached by WSDOT to conduct an assessment of their current stormwater monitoring program.

Objectives - The objective of this proposal is to evaluate the current WSDOT stormwater monitoring program and develop recommendations to enable WSDOT to meet new permit requirements and regional/national stormwater monitoring standards, while ensuring that adequate processes and procedures are identified to collect high-quality, scientifically defensible stormwater monitoring data.

Relevance and Benefits - This project addresses high priorities of the USGS Cooperative Water Program ( by (1) conducting activities that support Federal, State, or local efforts to improve water quality and stream ecosystems, and (2) conducting activities related to the effects of land use and population increases on the water resources in the coastal zone.

In addition, this study addresses several priority water-resource issues as outlined in the Strategic Plan for the Water Resources Division for 1998-2008 ( Specifically these issues are related to:

  1. Effects of urbanization and suburbanization on water resources
  2. Effects of land use and population increases on water resources
  3. Suitability of aquatic habitat for biota


Approach - District personnel will monitor the outfalls using automatic samplers and grab samplers. The data will be interpreted and used to prepare a Stormwater Prevention Plan, develop Best Management Practices, and prepare the permit application for Vancouver Barracks.

  1. Review existing monitoring program procedures;
  2. Compare WSDOT’s monitoring program procedures against any applicable national, EPA, industry, and state standards for stormwater monitoring;
  3. Compare WSDOT’s existing monitoring program against those of other NPDES Phase 1 Municipal permittees (City of Tacoma and King County); and
  4. Summarize findings for improving the WSDOT stormwater monitoring program as a USGS Open-File Report (OFR) published online.