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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 (CSWGP) on November 18, 2015. The new CSWGP went into effect on January 1, 2016. Ecology received one appeal. Although the CSWGP has been appealed, the new permit is current effective January 1, 2016.

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 by phone or electronically. 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


Reapplications were due July 3, 2015 - Reapply online to maintain permit coverage

Online Application (eNOI) Now Available

Erosivity Waiver Calculator | Fact Sheet

Site Inspection Form

Request for Chemical Treatment Form

Sampling Frequently Asked Questions

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 listserv