Home / Guides / What is a SWPPP?

What is a SWPPP?

A SWPPP (stormwater pollution prevention plan) is the written site plan a construction stormwater permit requires. It describes the work, maps where runoff goes, lists what could pollute it, and sets out the erosion, sediment and pollution prevention controls plus how they are inspected and fixed. Under EPA's 2022 Construction General Permit (CGP), every operator must write it before applying for coverage, and it covers sites that disturb 1 acre or more, or less than 1 acre within a larger common plan that will disturb 1 acre or more. EPA 2022 CGP Part 1.1.2, 1.4.1, 7.1

National guide. The rules cited are from EPA's 2022 Construction General Permit (as modified in 2025), checked October 20, 2026, which applies where EPA is the permitting authority. Most states issue their own permit with different details; check your state before relying on a number.

Last reviewed October 19, 2026. Prepared by our team led by Mohamed Elansary, PhD. We are not a licensed engineering firm and do not seal plans. General information, not legal advice; the permit text controls.

Who needs a SWPPP

Construction that disturbs 1 acre or more of land, or less than 1 acre when it is part of a common plan of development or sale that will disturb 1 acre or more, needs construction stormwater permit coverage. EPA 2022 CGP Part 1.1.2 EPA's permit covers every "operator": a party with control over the plans and specifications, or with day-to-day control of the activities needed to comply. Where a project has several operators, each needs coverage; subcontractors generally are not operators. EPA 2022 CGP Part 1.1.1 Several operators can share one group SWPPP, but each stays responsible for compliance. EPA 2022 CGP Part 7.1, footnote 84

Which permit applies to your site

EPA issues the Construction General Permit only where it is the permitting authority. Its Appendix B lists those areas: New Hampshire, Massachusetts (except Indian country), New Mexico (except Indian country), the District of Columbia and Puerto Rico, plus Indian country in many states and certain federal facilities. EPA 2022 CGP Appendix B Every other state issues its own construction general permit, and its rules can differ from EPA's in numbers that matter on site, such as the rain total that triggers an inspection. Of the EPA-permitted states, our checkout is open for New Hampshire and Massachusetts, with the conditions shown on coverage by state.

The 2022 CGP took effect February 17, 2022, was modified effective April 8, 2025 (June 10, 2025 in EPA Regions 1 and 3), and expires February 16, 2027. EPA 2022 CGP, cover pages EPA published a proposed 2027 CGP in the Federal Register on August 3, 2026, with comments due September 17, 2026. EPA

What a SWPPP contains

EPA's minimum list is Part 7.2 of the CGP:

All site operators and the areas each controls. EPA 2022 CGP Part 7.2.1
The stormwater team, by name and position, with proof of training, including inspector training. EPA 2022 CGP Part 7.2.2
The nature of the construction: property size, total and maximum disturbed area, support activities, a schedule for starting work, stopping work, stabilization and removing temporary controls, pollutant-generating activities, and business days and hours. EPA 2022 CGP Part 7.2.3
A site map with boundaries, disturbed areas and phasing, slopes before and after grading, stockpiles, receiving waters within the site and one mile downstream, drainage patterns, discharge points, pollutant-generating activities and all stormwater controls. EPA 2022 CGP Part 7.2.4
Authorized non-stormwater discharges. EPA 2022 CGP Part 7.2.5
A description of each stormwater control, its design specifications, maintenance and installation schedule. EPA 2022 CGP Part 7.2.6
Inspection, maintenance and corrective action procedures, including the inspection schedule and the rain gauge or weather station used. EPA 2022 CGP Part 7.2.7
Turbidity monitoring procedures for dewatering, where required; endangered species, historic property and underground injection documentation. EPA 2022 CGP Part 7.2.8-7.2.9
The signatory's signature and date, then, after authorization, the NOI, the acknowledgment letter and a copy of the permit. EPA 2022 CGP Part 7.2.10-7.2.11

The full list with site map items is on what goes in a SWPPP plan.

When it must be ready

Under EPA's permit the SWPPP comes before the Notice of Intent, and the NOI for a new site is due at least 14 calendar days before construction starts. Coverage begins 14 calendar days after EPA confirms it received a complete NOI, unless EPA delays or denies it. EPA 2022 CGP Part 1.4.1, 1.4.3 Table 1 A sign or notice of coverage must be posted where it is visible from the nearest public road. EPA 2022 CGP Part 1.5

Keeping it current and available

Keep a current copy at the site or an easily accessible place, available to EPA, state or local agencies, and the storm sewer operator; if no one is on site, post its location near the main entrance. An electronic SWPPP is allowed if it is readable like paper and immediately accessible. EPA 2022 CGP Part 7.3 Modify it, including the site map, within 7 days when operators, plans or controls change or an inspection shows a change is needed. EPA 2022 CGP Part 7.4.1

SWPPP, SWP3, SW3P

These are names for the same kind of plan. Texas uses SWP3 in its permit; see SW3P, SWP3 and SWPPP.

Who writes it and who signs

The permit does not require a particular preparer for the SWPPP itself; EPA notes that operators may use products or hire companies to help, and the choice is the operator's. EPA 2022 CGP Part 7.1, footnote 85 The operator's signatory signs it. EPA 2022 CGP Part 7.2.10 Some states and cities do require a licensed or certified preparer for the plan or part of it, which is why our coverage by state lists conditions.

How state permits differ: one example

Rule	EPA 2022 CGP	Texas TXR150000
Storm inspection trigger	0.25 inch of rain in 24 hours (or snowmelt from 3.25 inches of snow) on the 14-day schedule EPA 2022 CGP Part 4.2.2	0.5 inch of rain on the 14-day schedule TXR150000 Part III.F.8(c)
Who files a Notice of Intent	All operators, at least 14 calendar days before work EPA 2022 CGP Part 1.4.3	Primary operator of a large site (5 acres or more) before work; small sites post a site notice instead TXR150000 Part II.E.2-3
Filing system	EPA NeT EPA 2022 CGP Part 1.4.2	TCEQ STEERS TCEQ

State hubs with the permit, agency and inspection rules for each state we have checked: Alaska, Arizona, Arkansas, Colorado, Florida, Hawaii, Idaho, Illinois, Indiana, Iowa, Kentucky, Louisiana, Massachusetts, Michigan, Mississippi, Nebraska, Nevada, New Hampshire, New York, North Dakota, Ohio, Oklahoma, Oregon, South Carolina, South Dakota, Texas, Utah, Washington, West Virginia. Texas specifics are on the Texas hub.

What this page does not cover

Industrial facility SWPPPs, MS4 programs, oil and gas sites, and the full text of any permit. This page summarizes EPA's permit; your state's permit controls where the state is the permitting authority.

Have it written for you

SWPPP Desk prepares site-specific SWPPPs from your drawings for construction sites in the states we cover (coverage by state), for a fixed price, delivered the next business day after your inputs are complete. Small site (1 to under 5 acres): $449. Large site (5 acres or more): $749. Background: all guides.

Small site: $449 Large site: $749