Construction Stormwater General Permit

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Coronavirus (COVID-19) status update

To expedite application processing please scan or take a photo of all forms and email them to us at ecyrewqianoi@ecy.wa.gov. When you are able, please still mail us signed original documents.

We continue to process permit related documents, but we may have extended turnaround times. We are currently emailing coverage letters and other documents to the permittee on file.

If you have any questions, contact us at the email addresses below.

Stormwater runoff from construction sites can carry muddy water, debris, and chemicals into local waterways. Sediments, chemicals, and debris can harm aquatic life and reduce water quality.

We require regulated construction sites to get coverage under the Construction Stormwater General Permit (CSWGP). Following the requirements in this permit helps control and reduce water pollution. If water on your construction site is contaminated see this guidance for contaminated water on construction sites.  

Operators of regulated construction sites are required to:

  1. Develop stormwater pollution prevention plans.
  2. Implement sediment, erosion, and pollution prevention control measures.
  3. Obtain coverage under this permit.

The current permit went into effect on Jan. 1, 2021, and expires on Dec. 31, 2025.

To receive updates about this permit, sign up for our email list.

Applications and forms

I've got permit coverage. Now what?

Check out our eCoverage packet for more information about your requirements.

Need help implementing the permit?

What do I do with contaminated water?

See contaminated water on construction sites for guidance.

Not finding what you're looking for?

See our regional contacts page to help find a person to answer to your questions.