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Wyoming

The stormwater permit for construction in Wyoming

Wyoming runs its own NPDES programme, so a state issued construction general permit governs. Below is what our engine can say about it, and where we have not read that permit, what it will not say.

Governing permit

Large Construction General Permit to Discharge Storm Water Associated with Large Construction Activity Under the Wyoming Pollutant Discharge Elimination System (WYPDES), Permit Number WYR100000

Issued by
Wyoming Department of Environmental Quality (WDEQ), Water Quality Division
Permit number
WYR100000
Version determined against
as published by the state agency
Expires
2025-08-01

Who may prepare the plan

No preparer credential found

No preparer credential was found for Wyoming. 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.

No credential, license, certification, or PE stamp is required to prepare the SWPPP for the Large CGP, at any acreage — the permit states this twice in identical terms (Parts 7.2 and 9.1.1). The only personnel requirements are a named 'SWPPP administrator' (Part 9.2.1) and 'qualified person(s)' for inspections (Part 10.4), both defined only as individuals knowledgeable and experienced in erosion/sediment control BMPs — a competency standard, not a credential. The only signature requirement (Part 9.2.7/11.7) is that the SWPPP/NOI be signed by a 'Legally Responsible Person' — a corporate officer, general partner/proprietor, or public-agency official — a signatory/liability role tied to project ownership, not a technical-preparer qualification. Stated expiration was August 1, 2025; per the permit's own Part 3.10.8 it is administratively continued past that date until reissued, and no reissued text could be located, so this should be rechecked once WDEQ publishes a new LCGP. Wyoming's companion Small CGP (WYR10-A000) appears structurally similar but was not independently confirmed to carry the same open preparer language.

Verified2020 Wyoming Large Construction General Permit (WYR100000 / WYR10-0000), Parts 7.2, 9.1.1, 9.2.1, and 10.4Source

Does a site in Wyoming need coverage

Worked for a one acre site as a reference point. Change the acreage in the tool below and the answer, and its reasoning, change with it.

Coverage

Permit coverage required

Verified

The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.

Determined against dataset version 2026-07-19.

Read these before you act on the answer

  • Requirements below are what we have read and cited directly from Large Construction General Permit to Discharge Storm Water Associated with Large Construction Activity Under the Wyoming Pollutant Discharge Elimination System (WYPDES), Permit Number WYR100000, not the federal CGP. A category we have not yet transcribed from this permit is omitted here rather than assumed to match EPA's rule.
  • Wyoming DEQ's live storm water permitting page now hosts the LCGP/SCGP PDFs inside Google Drive folders that could not be crawled for direct file links. The full permit text was instead read from the Wayback Machine's archived copy of DEQ's own prior direct-download URL, cross-checked against the companion 2020 Small Construction General Permit (SCGP, WYR10A000). The permit text states its master expiration date is August 1, 2025 (Part 3.9.1); per Part 3.10.8, if not reissued by that date it is administratively continued in force until a replacement permit is issued. No archived or live copy of a newer (post-2025) reissuance was found, so this is treated as the current operative, administratively-continued permit text. No explicit textual effective-date statement was located, so permit.effectiveDate is left null rather than inferred from PDF metadata. inspection.increased.sensitiveWaters, inspection.reduced.aridSemiAridDrought, and a numeric inspection.report.deadline were omitted -- no such provisions exist in this permit's actual text; Wyoming's only reduced-frequency provisions are for inactive sites, winter/frozen-ground conditions, and remote-site access delays, none framed around aridity or drought.
  • No preparer credential was found for Wyoming. 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.
  • Basinwise does not perform the physical site inspections the permit requires. Those must be carried out on site by a qualified person.
How this answer was reached, step by step
  1. 1

    Coverage threshold

    The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.

    VerifiedPart 1.1.2Source
  2. 2

    Permitting authority

    Wyoming. The state runs its own programme under WYR100000.

  3. 3

    Preparer credential

    No preparer credential was found for Wyoming. 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.

    Verified2020 Wyoming Large Construction General Permit (WYR100000 / WYR10-0000), Parts 7.2, 9.1.1, 9.2.1, and 10.4Source

What to do next

  1. 1. Confirm the governing permit. Read Large Construction General Permit to Discharge Storm Water Associated with Large Construction Activity Under the Wyoming Pollutant Discharge Elimination System (WYPDES), Permit Number WYR100000 directly. It is linked above, and it is the document an inspector will hold you to. Wyoming Department of Environmental Quality (WDEQ), Water Quality Division
  2. 2. Settle the preparer question before you draft. Getting this wrong costs a redraft at best. The detail is on the credential page for this state. Preparer credential in Wyoming
  3. 3. Screen the site. Run the real acreage and receiving water facts through the tool below. You get the inspection frequency, the stabilisation deadlines and the filing path with the permit section behind each.
  4. 4. Read the requirements in full. SWPPP requirements in Wyoming

Screen a Wyoming site now

Runs in your browser. Nothing about the site is transmitted.

Screen your site

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Total land disturbance over the whole project, including staging and access. This decides whether you need a permit at all.

Optional. If you phase the work, the most that will be disturbed at once. Leave blank if the whole site is open together. The stabilisation deadline turns on this figure, not the total.

A half acre lot inside a 40 acre subdivision is covered even though the lot alone is under the threshold. This is the most commonly missed trigger in the permit.

Receiving water and site conditions(optional, but they change the inspection frequency)

May allow a reduced inspection frequency during the seasonally dry period.

EPA keeps permitting authority in Indian country even inside a state that runs its own programme.

No account, no card, nothing transmitted.

What people ask about the Wyoming construction stormwater permit

Do I need a stormwater permit for a construction site in Wyoming?

Permit coverage is triggered at one acre of land disturbance, and below one acre if the project is part of a larger common plan of development or sale that will ultimately disturb an acre or more. The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.

Who issues the construction stormwater permit in Wyoming?

Wyoming Department of Environmental Quality (WDEQ), Water Quality Division issues Large Construction General Permit to Discharge Storm Water Associated with Large Construction Activity Under the Wyoming Pollutant Discharge Elimination System (WYPDES), Permit Number WYR100000.

Does Wyoming require a qualified preparer for the plan?

No preparer credential was found for Wyoming. 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.

Keep the record Wyoming will ask you for

The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.