Industrial Stormwater General Permit

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Submitting an application

We have transitioned to a modern work environment. To expedite application processing, please scan or take a photo of all permit forms and email them to our resource mailbox at: Also, you must mail the original, signed documents to:

Water Quality Program
PO Box 47696
Olympia, WA 98504-7696

We are currently emailing all coverage documents and permit related information to the permittee on file. 

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

Stormwater can pick up pollution from factories and businesses. Those contaminants are carried into waterways and harm fish and other aquatic life. The Industrial Stormwater General Permit (ISGP) helps industrial facilities comply with federal regulations that reduce pollution. We require most industrial sites in Washington to monitor, measure, and reduce stormwater pollution leaving their site.

The current permit went into effect on Jan. 1, 2020, and expires Dec. 31, 2024.

Join our email list to receive updates about this permit.

Permit reissuance

We are pleased to announce that the draft Industrial Stormwater General Permit is available for public comment. In respose to requests, we have extended the comment period from 45 days to 60 days. We invite comments on the draft permit documents May 15, 2024 until Monday, July 15 at 11:59 p.m. The comment period originally closed on Friday, June 28. After the close of the comment period, we will publish a Response to Comments as an appendix to the fact sheet to address comments submitted during the public comment period.

Read our focus sheet for more information. 

Changes to the permit we are proposing include:

  • A new definition for transportation facilities to make it clear that the permit applies to all areas of industrial activity, not just in areas where vehicle maintenance, equipment cleaning, and airport deicing occur.
  • Clarifying the definition of “industrial activity” to ensure transportation facilities apply the permit, sampling, and best management practices (BMPs) facility-wide, including areas where material is handled and stored.
  • Adding PFAS sampling requirements for airports and landfills, since these operations are more likely to have PFAS contamination.
  • Adding 6PPD-quinone (from tire wear) sampling for larger transportation facilities, where we expect increased tire wear particles and likelihood for 6PPD pollution, starting in year three of the permit. 
  • Adding flexibility to allow facilities to apply for a waiver to adjust where they sample their stormwater discharge. This is intended to help with safety and logistical issues of sampling wharves and piers at marine cargo handling facilities. 

  • Increase inspection oversight by removing the automatic approval for areas not exposed to rain, also called Conditional ‘No Exposure’ exemptions.

Transportation facility

Draft permit documents

How to provide comments

We will accept comments from May 15, 2024 until July 15, 2024, 11:59 p.m.

You may submit comments:

  • Online: Submit your comments through our online comment form (preferred)
  • By Mail: Lucienne Banning
                   Washington State Department of Ecology
                   PO Box 47696
                   Olympia, WA 98504-7696
  • Verbal Comments: Comments are accepted during any of our public hearings.

Workshops and hearings 

During the workshop, we will explain the proposed changes to the permit and answer questions. The hearing will begin after the public workshop and will end when public testimony is complete. During the hearing, you may give verbal testimony and written comments on the proposed changes. Written comments will receive the same consideration as verbal testimony.

Online workshops and hearings

View the workshop presentation


Fall 2023: Informal listening sessions
May 15 - July 15, 2024: Formal public comment period on the draft permit
December 2024: Decision on reissuance
Dec. 31, 2024: Current permit expires

Current applications and forms and historic permit documents