Washington’s Construction Stormwater General Permit application is submitted through Ecology’s WQWebPortal using a SecureAccess Washington (SAW) account, at least 60 days before stormwater discharge begins. That lead time is not padding. Every application runs a public comment period of at least 30 days before Ecology grants coverage.
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How do you apply for the Washington construction stormwater permit?
- Set up a SecureAccess Washington (SAW) account and add Ecology’s Water Quality Permitting Portal (WQWebPortal) to it.
- Prepare the SWPPP. Washington’s is a detailed, element-by-element plan, and it is what the application is judged against.
- Complete the Notice of Intent in the WQWebPortal: site location, disturbed acreage, receiving waters, discharge points and construction dates.
- Submit at least 60 days before discharge begins.
- Ecology runs the required public notice period — a minimum of 30 days.
- Coverage is issued after the comment period closes and Ecology completes its review.
Ecology’s stated target is 45 days from a complete application, and the public notice period runs inside that. The 60-day rule is what you build the schedule around.
How long does coverage actually take?
Plan on 60 days, and longer on a contaminated site.
Ecology asks for 90 to 120 days of lead time where the project involves a contaminated site, because the review is more involved. Redevelopment work on former industrial or fuel-handling property falls into this category more often than contractors expect, and finding out at week eight is expensive.
The application clock does not start until the application is administratively complete. An NOI missing the SWPPP detail Ecology asks for gets returned, and the 30-day notice period starts over from the corrected submittal. Getting it right the first time is the whole timeline.
Who needs the permit in Washington?
Any project disturbing one acre or more, and any project disturbing less than an acre that is part of a larger common plan of development or sale that will ultimately disturb one acre or more. See when a SWPPP is required.
Washington adds a third trigger that catches people: a site of any size that discharges to waters of the state and is a significant contributor of pollutants can be required to obtain coverage. Acreage is the usual test, not the only one.
What changed in the 2026 permit?
Ecology reissued the Construction Stormwater General Permit on November 19, 2025. It took effect January 1, 2026 and runs through December 31, 2030. Two changes matter on the ground, and both remove an exemption small sites used to rely on:
Every site now needs a CESCL. Under the previous permit, sub-acre sites were exempt from having a Certified Erosion and Sediment Control Lead. Under the 2026 permit, every site regardless of size must use a CESCL for weekly and rainfall-triggered inspections.
Every site now samples. Weekly turbidity sampling applies to all sites, where previously sites under one acre were not required to sample. pH sampling applies where significant concrete work or engineered soils are present, and it must be done with a calibrated pH meter rather than strips.
Turbidity of 250 NTU or more has to be reported to Ecology within 24 hours of becoming aware of it. If your Washington compliance routine was built under the old permit, the sampling and CESCL lines are the two to check first. See Washington CESCL certification requirements.
Get your Washington SWPPP prepared by a CPESC and it goes into the portal ready for review.
What delays a Washington application?
Four things account for most of it.
Applying too late. Sixty days is a permit requirement, not a suggestion, and the public notice period cannot be compressed.
An incomplete SWPPP. Washington’s plan elements are prescriptive. A generic plan gets flagged and the clock restarts.
Unrecognized contamination. If the site has a history, say so at the start and give Ecology the 90 to 120 days it asks for.
Wrong or missing discharge information. Receiving waters and discharge points drive the review. Guessing here guarantees a request for more information.
Pro SWPPP writes the plan, files the permit, performs the inspections and keeps the records. Your crews install and maintain the controls; we document that they were there and that they worked. Get a Washington SWPPP estimate.
Frequently asked questions about the Washington CSWGP
How do I apply for Washington’s Construction Stormwater General Permit?
Through Ecology’s WQWebPortal using a SecureAccess Washington (SAW) account. Submit the Notice of Intent with your SWPPP and site details at least 60 days before stormwater discharge begins.
How long does it take to get coverage in Washington?
Plan on 60 days. Every application goes through a public comment period of at least 30 days, and Ecology targets 45 days from a complete application. Contaminated sites need 90 to 120 days.
When did the current Washington permit take effect?
Ecology reissued the permit on November 19, 2025. It became effective January 1, 2026 and expires December 31, 2030.
Do small sites need a CESCL under the 2026 permit?
Yes. The 2026 permit requires every site, regardless of size, to use a Certified Erosion and Sediment Control Lead for weekly and rainfall-triggered inspections. Sub-acre sites were exempt under the prior permit.
Is turbidity sampling required on every site now?
Yes. All sites must conduct weekly turbidity sampling under the 2026 permit, and turbidity of 250 NTU or more must be reported to Ecology within 24 hours of becoming aware of it.
What size project needs a permit in Washington?
One acre or more of disturbance, or less than an acre where it is part of a larger common plan. A site of any size discharging to state waters can also be required to obtain coverage if it is a significant contributor of pollutants.
Ready to get started? Order your SWPPP now or schedule a free consultation.
By Derek E. Chinners, CPESC — Founder & Stormwater Consultant, Pro SWPPP, LLC