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 on Jan. 1, 2020 and expires Dec. 31, 2024.

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Current permit and related documents

  Current applications, forms, and historic permit documents