Additional Documentation and Research

Pathogens in Urban Stormwater Systems

by The American Society of Civil Engineers Environmental and Water Resources Institute

The report is intended to help MS4 permit holders and watershed stakeholders develop effective and realistic goals and strategies for addressing pathogens. The report includes regulatory context for stormwater and pathogens, as well as chapters on pathogen sources, transport and fate, monitoring and source tracking, statistical analyses, source controls, structural controls, and bacteria TMDLs.

Read the full report.


The City of Spokane received a GRSS Grant from the Department of Ecology to test products that frequently come into contact with stormwater for PCBs.

The final report presents some very interesting findings from this study. As a follow up to this, the City of Spokane is working with the Spokane River Regional Toxics Task Force (SRRTTF) to further understand some of the major sources. In the short term, the SRRTTF plans to do more research on hydroseed. Additionally, the City recently passed a PCB-free purchasing ordinance similar to the state bill. The City will collect information from suppliers and perform a limited amount of sampling in an effort to find PCB-free (or at least lower-PCB) alternatives to products that we purchase.

To learn more, visit the Spokane River Regional Toxics Task Force website.


Contaminants in Western Washington Stormwater

The Department of Ecology has published a new report on stormwater pollution (with a quick summary of the data available as well).

From 2007 to 2013 eight municipal stormwater permittees (Clark, King, Pierce, and Snohomish Counties, the cities of Seattle and Tacoma, and the ports of Seattle and Tacoma) collected the most comprehensive data set of stormwater chemistry in western Washington. These data, collected at discharges from residential, commercial, and industrial areas across wet and dry seasons, provide a robust baseline of stormwater chemistry for western Washington to compare to future monitoring.