Washington
Washington issues its own construction general permit. We have read Construction Stormwater General Permit (CSWGP), issued November 19, 2025, effective January 1, 2026 and list below the requirements we could cite to it, with the scope limits stated plainly. Screen your own acreage further down.
Who may prepare the plan
No preparer credential foundNo preparer credential was found for Washington. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
CSWGP Section 9 contains no professional-engineer or licensure requirement. CESCL is inspection-scoped under S4.B.
No permit section cited. Confirm this with your permitting authority.
Coverage trigger
The project disturbs 3 acres, at or above the 1 acre threshold, so it needs permit coverage.
The trigger people miss is the second one. A half acre lot inside a 40 acre subdivision is covered, because the larger common plan of development or sale is what counts, not the lot.
Worked for a three acre site with the receiving water unconfirmed. Each line says why it attached to this site rather than in general. Check the notes above for the site sizes this permit does not cover.
The Permittee must prepare and properly implement an adequate Stormwater Pollution Prevention Plan (SWPPP) for construction activity beginning with initial soil disturbance and until final stabilization.
The Permittee must prepare and properly implement an adequate Stormwater Pollution Prevention Plan (SWPPP) for construction activity in accordance with the requirements of this permit beginning with initial soil disturbance and until final stabilization.
Operator must submit the NOI at least 60 days before discharging stormwater from construction activities and prior to the first public notice; absent a written Ecology response, coverage automatically commences on the 31st day after Ecology receives a complete NOI (or the permit issuance date, whichever is later).
Why this applies here: This is the deadline for a new site. A transfer to a new operator or an emergency related project has a different deadline.
The operator must submit the NOI at least 60 days before discharging stormwater from construction activities and must submit it prior to the date of the first public notice ... Unless Ecology responds to the complete application in writing, coverage under the general permit will automatically commence on the 31st day following receipt by Ecology of a completed NOI, or the issuance date of this permit, whichever is later...
The CESCL must inspect all areas disturbed by construction activities, all BMPs, and all stormwater discharge points at least once every calendar week and within 24 hours of any discharge from the site.
Why this applies here: You have not confirmed whether the site discharges to an impaired or high quality water. If it does, the increased frequency applies instead and this answer changes.
The CESCL must inspect all areas disturbed by construction activities, all BMPs, and all stormwater discharge points at least once every calendar week and within 24 hours of any discharge from the site.
Certified Erosion and Sediment Control Lead (CESCL) — a person who has current certification through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology
Why this applies here: This is why Basinwise cannot perform your inspections. The permit requires a trained person physically on the site.
All Permittees must have site inspections conducted by a Certified Erosion and Sediment Control Lead (CESCL). ... Certified Erosion and Sediment Control Lead (CESCL) means a person who has current certification through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (See BMP C160 in the SWMM).
The Permittee must not allow soils and stockpiles to remain exposed and unworked longer than: West of the Cascade Mountains Crest — 7 days in the dry season (May 1–Sept 30), 2 days in the wet season (Oct 1–Apr 30). East of the Cascade Mountains Crest (except Central Basin) — 10 days dry season (July 1–Sept 30), 5 days wet season (Oct 1–June 30). Central Basin (East of Cascades, <12 in. mean annual precipitation) — 30 days dry season (July 1–Sept 30), 15 days wet season (Oct 1–June 30). Soils must also be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast.
Why this applies here: This applies at both land disturbance amounts.
Depending on the geographic location of the project, the Permittee must not allow soils and stockpiles to remain exposed and unworked for more than the time periods set forth below to prevent erosion. • West of the Cascade Mountains Crest: During the dry season (May 1 - September 30): 7 days. During the wet season (October 1 - April 30): 2 days. • East of the Cascade Mountains Crest, except for Central Basin: During the dry season (July 1 - September 30): 10 days. During the wet season (October 1 - June 30): 5 days. • The Central Basin, East of the Cascade Mountains Crest: During the dry Season (July 1 - September 30): 30 days. During the wet season (October 1 - June 30): 15 days.
10 days
Immediately beginning the process of fully implementing and maintaining appropriate source control and/or treatment BMPs, within 10 days of the inspection. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when an extension is requested by a Permittee within the initial 10-day response period.
Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems within 10 days of the date the discharge exceeded the benchmark, and sample discharges daily until turbidity is 25 NTU or lower (or transparency 33 cm or greater, or compliance with the background water-quality standard is demonstrated, or discharge stops).
Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, addressing the problems within 10 days of the date the discharge exceeded the benchmark. ... Sample discharges daily until: a.) Turbidity is 25 NTUs (or lower); or b.) Transparency is 33 cm (or greater); or c.) The Permittee has demonstrated compliance with the water quality standard for turbidity...
Notify Ecology within 24 hours of becoming aware of a turbidity/transparency exceedance at or beyond the high-turbidity reporting level (≥250 NTU or ≤6 cm transparency), or of any other noncompliance that may threaten human health or the environment, by phone or electronic report to the applicable Ecology Region's ERTS number.
Anytime sampling performed in accordance with Special Condition S4.C indicates turbidity has reached the 250 NTUs or more (or transparency less than or equal to 6 cm), high turbidity reporting level, the Permittee must notify Ecology within 24 hours of becoming aware of a failure to comply either by calling the applicable Ecology Region's Environmental Report Tracking System (ERTS) number by phone or by submitting an electronic ERTS report...
The Permittee must retain records of all monitoring information (site logbook, sampling results, inspection reports/checklists, etc.), the SWPPP, permit coverage letter, and other compliance documentation for the entire life of the construction project and for a minimum of 5 years following termination of permit coverage; longer if litigation is unresolved or Ecology requests it.
Why this applies here: The clock runs from permit expiry or termination, not from when the record was written, so on a multi year project every record stays live for the whole project plus three years.
The Permittee must retain records of all monitoring information (site logbook, sampling results, inspection reports/checklists, etc.), Stormwater Pollution Prevention Plan, copy of the permit coverage letter (including Transfer of Coverage documentation) and any other documentation of compliance with permit requirements for the entire life of the construction project and for a minimum of five (5) years following the termination of permit coverage.
Your acreage, your receiving water, your answer. Runs in your browser, nothing is transmitted.
This is EPA's list, from the 2022 Construction General Permit. It does NOT govern in Washington, where the state issues its own permit and sets its own contents. It is here as a shape to expect, not as the requirement you will be held to.
Read the permit itself at the source document.
Washington issues its own construction general permit, and we have read Construction Stormwater General Permit (CSWGP), issued November 19, 2025, effective January 1, 2026. The requirements listed on this page, such as inspection frequency, who may inspect, stabilisation, corrective action and record retention, are cited to that permit rather than to EPA's. Anything we have not transcribed is left out instead of assumed to match the federal rule, and the scope note on this page says which sites the permit does not cover. Confirm the current permit and any site-size variant with Washington State Department of Ecology (Ecology).
No preparer credential was found for Washington. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
The inspection frequency is set by the Washington construction general permit, which we have not read. Confirm it with Washington State Department of Ecology (Ecology).
Screening is free. Pro generates the site specific plan document and retains the inspection and corrective action log.