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Water Quality Program

Construction Stormwater General Permit

Construction site operators are required to be covered by a Construction Stormwater General Permit if they are engaged in clearing, grading, and excavating activities that disturb one or more acres and discharge stormwater to surface waters of the state. Smaller sites may also require coverage if they are part of a larger common plan of development that will ultimately disturb one acre or more. Operators of regulated construction sites are required to:

  1. Develop stormwater pollution prevention plans.
  2. Implement sediment, erosion, and pollution prevention control measures.
  3. Obtain coverage under this permit.

NEW 11/18/2015 Ecology reissued the Construction Stormwater General Permit on November 18, 2015. The Construction Stormwater General Permit (CSWGP) is effective January 1, 2016.

The current Construction Stormwater General Permit (CSWGP) will expire December 31, 2015. All Permittees must reapply per Section G8 of the current permit. Reapplication Instructions and Information

New Permit and Related Documents

Permit and Documents


Contact Us - Contact your Permit Administrator for permit assistance or your Regional Office for site specific questions.

Application and Forms - Permit, application, forms, and appeal information.

High Turbidity Reporting - Construction projects must report high stormwater turbidity results within 24 hours. If you get a high result, call your Ecology regional office.

Resources and Guidance - DMRs, Stormwater monitoring, manuals, 303(d) list information, CESCL.

Historical Information - Pollution Control Hearing Board information, public comments.

Get Ecology updates about the Construction Stormwater General Permit - Sign up for the Construction Stormwater General Permit email listserv

Questions? Contact Amy Moon at 360-407-6467 or amy.moon@ecy.wa.gov


It’s Time to Reapply
All Permittees must reapply by July 3, 2015. Permittees can now reapply online.

Erosivity Waiver Calculator

Construction Stormwater Site Inspection Form

Online Application (eNOI) Now Available

Sampling Frequently Asked Questions

Construction Stormwater General Permit Application Status - Check the status of your application.

Stormwater Pollution Prevention Plan Template - To use this template, save to your computer.

Sign up for the Construction Stormwater General Permit email list