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

We accepted comments on draft permit documents from May 1, 2019, to June 29, 2019. We held six public workshops and hearings across the state, including an online webinar. During the workshops, we explained the proposed changes to the permit and answered questions. The public hearings provided the opportunity for the public to give formal comments on the draft permit.

We will publish a Response to Comments as an appendix to the fact sheet to address comments submitted during the public comment period.

You may view comments received on the draft permit.

You may still view the draft permit documents, but the public comment period is closed and are not accepting any new comments.


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

Previous permit documents

Permit applications and forms