Stormwater Monitoring

Phase I NPDES Municipal Stormwater Permittee Monitoring  Requirements and Information

The Phase I National Pollutant Discharge and Elimination System (NPDES) Municipal Stormwater Permit (Phase I permit) requires permittees to collect and analyze stormwater quality and quantity data. Additionally, Phase I permittees are required to develop Quality Assurance Project Plans (QAPPs) for review and approval by Ecology. The QAPPs contain detailed information about each permittee’s monitoring program. The monitoring described in Special Condition S8 of the Phase I permit include three monitoring components: Stormwater Monitoring (S8.D) Targeted Stormwater Program Effectiveness Monitoring (S8.E) Stormwater Treatment and Hydrologic Management Best Management Practice (BMP) Evaluation Monitoring (S8.F)

Phase I permittees are also required to develop and submit a Stormwater Monitoring Report as an attachment to the Annual Report. Permittee Annual Reports can be found on individual permittee websites.

Washington State Department of Transportation Monitoring Requirements and Information

The Washington State Department of Transportation (WSDOT) (NPDES) Municipal Stormwater Permit requires WSDOT to collect and analyze stormwater quality and quantity data. The monitoring described in Special Condition S7 of the WSDOT permit include four monitoring components:

1. Baseline Monitoring of WSDOT Highways (S7.B)
2. Seasonal First Flush Toxicity Testing (S7.C)
3. Baseline Monitoring of Rest Areas, Maintenance Facilities and Ferry Terminals (S7.D)
4. Monitoring the Effectiveness of Stormwater Treatment and Hydrologic Best Management Practices (S7.E)

WSDOT is required to develop and submit a Stormwater Monitoring Report as an attachment to the Annual Report. Annual Reports can be found on WSDOTs web site.

Detailed information about WSDOT’s monitoring program and QAPPs can be found on the following page:

Washington State Department of Transportation (WSDOT) Municipal Stormwater Monitoring Requirements and Information

Specific requirements for monitoring can be found in Special Condition S7 of the WSDOT Permit: http://www.ecy.wa.gov/programs/wq/stormwater/municipal/WSDOTpermitdocs.html

Phase II NPDES Municipal Stormwater Permittee Monitoring Requirements and Information

The Phase II permits for eastern and western Washington require permittees to report information in preparation for future monitoring in their jurisdictions. The Phase II eastern and western Monitoring Program described in Special Condition S8.C of the permit include a report for three types of monitoring:

• Stormwater Monitoring (S8.C.1.a) requires permittees to identify sites suitable for monitoring stormwater discharges based on jurisdictional size and land use types, and to set priorities based on stormwater-related pollution problems.
• Targeted Stormwater Management Program (SWMP) Effectiveness Monitoring (S8.C.1.b) requires permittees to identify questions monitoring could answer to determine the effectiveness of specific components of the SWMP.
• Runoff Treatment Best Management Program (BMP) Effectiveness Monitoring (S8.C.1.c) requires eastern Washington permittees to prepare to monitor BMPs.

By March 31, 2011, Phase II permittees are required to develop and submit a Monitoring Plan as an attachment to the Annual Report. Annual Reports are posted on individual permittee websites.

Specific requirements for Phase II monitoring can be found in Special Condition S8 of the western Washington and eastern Washington Phase II Municipal Stormwater Permits. Ecology staff also prepared Phase II Monitoring Report Guidance to assist permittees. For questions, contact your Ecology Municipal Stormwater specialist.

Monitoring Resources from Permittees

The City of Seattle developed software to help verify and validate analytical chemistry data. This Electronic Data Deliverable (EDD) Processing Tool was developed to support Phase I stormwater monitoring programs conducted under S8.D of the Phase I Municipal Stormwater Permit. You can review the User’s Guide for additional information. To obtain the software, contact your Ecology regional permit specialist. Please note that due to licensing limitations this tool is only available to NPDES permit holders in Washington State. Funded by an Ecology Stormwater Grant of Regional or Statewide Significance.