When do I have to update my SWPPP?

Within seven days of a change in design, construction, operation or maintenance that affects discharges, or when an inspection or corrective action shows a control is not working (Part 7.4.1).

Source: EPA 2022 Construction General Permit (as modified), Part 7.4.1Verified

Modification is not an admission of error

An unmodified plan that no longer matches the site is the more common finding, not a plan with a mistake in it. Sites change: phases slip, controls get moved, a basin gets added. The permit expects the document to move with them.

Record the date of every modification and who authorised it (Part 7.4.2–7.4.3).

The cases that catch people

Adding dewatering after the plan was written is one: the turbidity monitoring section (Part 3.3) may become relevant, and the plan has seven days to say so. Discovering the receiving water is listed as impaired is another, because Part 4.3.1 can change the inspection frequency.

Questions people ask

Do I need a new plan or an amendment?
An amendment, recorded with its date and the person who authorised it. The generated document is a .docx so the plan can be edited rather than replaced.
Does a change of contractor need an update?
If it changes who controls an area of the site, yes — Part 7.2.1 asks for the operators and the area each one controls.

The states this question turns on

All 50 states, in one table

The documents this affects

Other questions

Check your state and build a draft
The questionnaire and the generator run in your browser. Checkout is not open, so nothing can be charged.

Source: EPA 2022 Construction General Permit (as modified), Part 7.4.1, read 2026-08-04. County and city rules are not covered.

What we are, and what stays your responsibility

  1. SwpppDraft is a document generation tool. It does not provide engineering services, legal services, or compliance consulting, and no engineer or attorney reviews what it produces.
  2. Everything in the document is built from the site facts you enter. Checking that those facts are right, and that the resulting plan fits your project, is yours to do.
  3. We do not file anything on your behalf, we do not certify or endorse your compliance, and we accept no liability for what happens when you use the document.
  4. State-level requirements carry the date we verified them. County and city rules are not covered — some local jurisdictions require a licensed preparer even where the state does not, and you have to check that yourself.
  5. When the product opens, our total liability will be capped at the amount you paid us. Today that amount is zero, because nothing is for sale.