Guidance for contaminated water on construction sites

Our Construction Stormwater Permits require permittees to prevent water pollution by managing water that may be contaminated from their construction sites.

Learn how to handle your contaminated construction stormwater safely and properly. Find helpful documents, links, and frequently asked questions. 

Documents and helpful links

Treatment Systems for Contaminated Construction Runoff (TSCCR)

This spreadsheet shows treatment systems that may be effective in treating specific contaminants. Users should evaluate the effectiveness of any treatment system they plan to implement and confirm that the chosen treatment system does not cause or contribute to a violation of the water quality standards.

EPA's Drinking Water Treatability Database

This database from the U.S. EPA outlines different types of treatment processes. We do not guarantee or endorse any of the listed treatment systems.

Technology Assessment Protocol - Ecology (TAPE) database

The TAPE program provides a peer-reviewed regulatory certification process for emerging stormwater treatment technologies. This database is a collection of assessed treatment technologies. 

Effluent Characterization for Permit Application (Attachment A)

Our preferred lab methods for stormwater discharge monitoring.

Permit Calculator Workbook

This is our Water Quality Standards calculator.

EPA Effluent Limitations Guidelines

Effluent guidelines are national standards based on the performance of treatment and control technologies for wastewater discharges to surface waters and municipal sewage treatment plants. Your local jurisdiction may have different guidelines, so check with them before discharging from your site.

RCW 70.105.010 — definitions

Definitions from the Washington State legislature regarding dangerous wastes and hazardous substances

Frequently asked questions

I answered "yes" on my NOI that contaminated soils will be disturbed/contaminated groundwater will be discharged because of the proposed construction activity. What do I report to Ecology? Is there a database of contaminated sites? Do I have to test for other contaminants on my construction site to receive a permit? Can I discharge my treated runoff into waters of the state? Can I infiltrate contaminated dewatering water back into contaminated soil? Can treatment systems be grouped together? Do I have to include the contaminant concentrations found in the construction stormwater in my WQWebDMR reports? What do I do if I have a breach in my contaminant containment system? If I have a flow-through treatment system, do I need to have secondary containment for 110% containment of the total volume? If my site has a No Further Action (NFA) letter, is it automatically considered clean? If my site meets MTCA, is it clean? Do I have to control my stormwater runoff if my soil is contaminated? When can I expect to hear back from Ecology regarding my Notice of Intent (NOI) form? Where do I dispose of my pollutant refuse? Where do I find BMPs for managing and containing contaminants? Where do I find the contaminant concentration levels I need to treat to?