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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.

Find the types of facilities that require coverage under the ISGP in Table 1 of the current permit.

The current permit went into effect Jan. 2, 2015 and expires Dec. 31, 2019.

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Current permit and related documents

Permit applications and forms


Make changes

Implement & comply


Online tools

Guidance & Manuals

Contacts for assistance

Central Region

Joyce Smith
Permit Administrator

Eastern Region Northwest Region Southwest Region