Industrial Stormwater General Permit

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 Jan. 2, 2015, and expires Dec. 31, 2019.

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Current permit and related documents

Permit reissuance — 2019

Reapplications for permit coverage are due July 3, 2019. For questions about permit fees, see our Permit Fees page.

We are pleased to announce that the draft Industrial Stormwater General Permit is available for public comment. We invite comments on the draft permit documents beginning May 1, 2019, until 11:59 p.m. on June 29, 2019. We will publish a Response to Comments as an appendix to the fact sheet to address comments submitted during the public comment period.

What's changing:

We are updating the current permit language to make the following changes:

  • Adding two new industry groups that require coverage:
    • Marine construction
    • Construction, transportation, and mining equipment rental and leasing
  • Changing the timing of first flush
  • Revising requirements for consistent attainment

How to provide comments

We will accept comments from May 1, 2019, until 11:59 p.m. on June 29, 2019.

You may submit comments:

Online:      Submit your comments through our online comments form (preferred option

By mail:     Travis Porter
                   Washington State Department of Ecology
                   PO Box 47696
                   Olympia, WA  98504-7696

In person:   You may provide comments during any of our public hearings.

Workshops and hearings

We will host a workshop immediately followed by a public hearing at the following dates and locations:

During each 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 oral testimony and written comments on the proposed changes. Written comments will receive the same consideration as oral testimony.


Spring 2019: Formal public comment period on the draft permit
Nov. 2019: Decision on permit issuance

Previous permit documents

Permit applications and forms

Contacts for assistance

Central Region

For permittees located in the following counties:

Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, and Yakima

Noel Tamboer
Permit Administrator

Eastern Region Northwest Region Southwest Region