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 When you are safe and able, please still mail us signed original documents.

We continue to process electronic permit related documents, but we may have extended turnaround times. Also, at this time, we're unable to print documents and may have to provide printed items at a later date. Until we're able to print, we will email 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 modified permit went into effect May 5, 2017, and expires Dec. 31, 2020.

To receive updates about this permit, sign up for our listserv

Comment period on the draft permit

July 1 to Aug. 14, 2020

We invite you to comment on the draft reissuance of the Construction Stormwater General Permit.

How do I comment?

We will accept comments July 1 to  Aug. 14, 2020, at 11:59 p.m.:

  • Online via the online comment form (preferred method).
  • Orally at the following online hearings.
  • By mail (postmarked no later than July 14, 2020) to:

Noel Tamboer
Washington State Department of Ecology
PO Box 47696
Olympia, WA 98504-7696

Online workshops and hearings

We invite you to attend either of two public workshops, followed by formal hearings, to learn more about the changes to the permit, ask questions, and submit oral comments. We recommend registering before the workshop/hearing.  

Written comments receive the same consideration as oral testimony. We'll publish a Response to Comments as an appendix to the fact sheet to address comments submitted during the public comment period.

Current permit and 2016 modification


Summer 2020: Formal public comment period on the draft permit
Fall 2020: Decision on reissuance
December 2020: Current permit expires

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.