SWPPP Requirements in Delaware

Who needs a SWPPP in Delaware?

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 Delaware permit DE0051268.

Delaware runs its own delegated stormwater program. Operators obtain coverage from Delaware Department of Natural Resources and Environmental Control (DNREC), Sediment and Stormwater Program under Delaware NPDES Construction General Permit (2026) (DE0051268), not directly from the EPA. A small subdivision, a solar pad, and a road-widening project all clear the same one-acre line.

Delaware adds requirements worth flagging early: Approved Sediment and Stormwater Management Plan (the equivalent of the SWPPP) under 7 DE Admin. Code 5101, designed by a licensed professional and approved by the appropriate plan approval agency before construction; valid five years from approval (Parts 1.A, 1.B.b, 1.E.1); Plan revisions are submitted to and approved by the plan approval agency before erosion and sediment control or stormwater measures are built or modified (Part 1.E.1); Responsible Personnel trained through the DNREC Contractor Training Program provide daily oversight of land disturbance (Part 1.B.c); Preconstruction meeting, attended by the person(s) responsible for construction reviews, unless waived by the plan approval agency (Part 1.E.6.1); No more than 20 acres disturbed at any one time without a case-by-case exception; a second 20-acre section waits for stabilization of the first (Part 1.D.2.1.d); Post a notice of permit coverage with the NOI number, contacts, and the DNREC spill hotline statement, visible from the nearest public road (Part 1.C.11); Annual NOI renewal fee while coverage is active (Part 1.C.7).

What the plan must contain

A Delaware 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 Notice of Intent through DNREC’s Electronic Notice of Intent System and obtain Sediment and Stormwater Management Plan approval before construction; coverage begins when DNREC accepts the NOI and the Plan is approved (Parts 1.C, 1.C.1, 1.F.1).

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 7 calendar days (by Responsible Personnel or a Certified Construction Reviewer, from the first earth disturbance through the end of permit coverage, whether the site is active or inactive) (DE CGP (DE0051268) Parts 1.E.2 and 1.E.6.2). The Secretary may require additional monitoring on a site following written notification (DE CGP (DE0051268) Part 1.E.2). Every inspection is dated and signed, and any failed control is corrected before the next storm.

How Delaware differs from the federal permit

Because Delaware 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