SWPPP Requirements in Maine

Who needs a SWPPP in Maine?

Any construction project that disturbs one acre or more — or is part of a larger common plan of development reaching one acre — needs a SWPPP under Maine permit MCGP.

Maine runs its own delegated stormwater program. Operators obtain coverage from Maine Department of Environmental Protection (DEP), Bureau of Land Resources under Maine Construction General Permit (MCGP) (MCGP), not directly from the EPA. A small subdivision, a solar pad, and a road-widening project all clear the same one-acre line.

Maine adds requirements worth flagging early: SWPPP meeting the Basic Performance Standards in Appendices A–D, submitted with the NOI: site plan, erosion and sedimentation control plan, inspection and maintenance plan, and housekeeping plan (Parts III.A and IV.A.1.e); SWPPP prepared by a professional with a Maine DEP erosion control certification (Part III.B); Large construction activities (5 acres or more): Appendix D sequencing and open-area limits, on-site mulch reserve, certified resident inspector and civil contractor, 100-foot and 50-foot buffers, and an Erosion Risk Assessment where buffers cannot be met (Part IV.A.1.e.v; Appendix D); Double perimeter sediment controls where disturbance within 50 feet of a protected natural resource drains toward it (Appendix A(1)(a)); Stabilize areas within 75 feet of a downgradient protected natural resource within 48 hours of initial disturbance or before any storm, whichever is first (Appendix A(9)); Winter construction (November 1–April 15): additional winter stabilization for areas not stabilized by November 15 (Appendix A(12)); Written approval from the Department of Inland Fisheries and Wildlife for activity in Essential Habitat (Part IV.A.1.b); File a Notice of Termination within 30 days of completing permanent stabilization (Part IV.B).

What the plan must contain

A Maine SWPPPis the site's compliance binder — the document an inspector opens first. It documents:

1. 1Site & project descriptionTotal and disturbed acreage, soils, slopes, and the sequence of construction.
2. 2Receiving waters & discharge pointsWhere stormwater leaves the site and the waterbodies it reaches.
3. 3Erosion & sediment control BMPsSilt fence, stabilized entrances, inlet protection, and stabilization measures.
4. 4Inspection schedule & recordsDated, signed inspection logs and the corrective actions taken.
5. 5Operator certificationThe SWPPP is signed by the legally responsible party before work begins.

Required and conditional BMPs

Filing your Notice of Intent

Submit the NOI, location map, photos, and SWPPP to the DEP electronically (Part IV.G); the NOI is deemed approved 14 calendar days after receipt unless the DEP finds it deficient first, and it must be approved before construction begins (Part IV.A.2).

A Notice of Termination closes coverage once the site reaches final stabilization. Keeping the SWPPP and its inspection records on site is what keeps a project clear of stop-work orders.

Inspection requirements

Inspect at least once every calendar week and before and within 24 hours after any storm event (rainfall) (disturbed areas, erosion control measures, materials storage areas exposed to precipitation, and vehicle entrances and exits; also prior to completing permanent stabilization measures; by a person with knowledge of erosion and stormwater control, including the permit’s standards and conditions) (MCGP Appendix B(1)). Every inspection is dated and signed, and any failed control is corrected before the next storm.

How Maine differs from the federal permit

Because Maine administers its own program, the federal EPA Construction General Permit does not apply directly here — the state permit governs. Sites inside a regulated municipal storm sewer system may carry additional local ordinance requirements on top of the state permit.

Frequently asked questions