Construction Site Runoff

This section applies to activities which disturb one or more acres of land. The goal is to minimize erosion and prevent stormwater from carrying sediment into waterways via MS4 infrastructure over the course of the construction project.


Most of the requirements for this section go into effect on July 1, 2017 for all MS4s but more time is provided for the legal authority component.


Construction Site Runoff Requirement


Current MS4s

New MS4s

Interdepartmental Coordination Plan



Consider stormwater controls during site plan reviews & inspections



Procedure to receive & review public comments



State permit notification



Legal authority to regulate construction site stormwater runoff



Local Regulations/Legal Authorities

MS4s will need to revise or establish new legal authorities to cover the permit requirements listed below. We will post example legal authority language in the Legal Authorities section of this website if any towns or institutions share them with us.

  • Require developers, construction site operators, or contractors to be consistent with the 2002 Guidelines for Soil Erosion and Sedimentation Control, 2004 CT Stormwater Quality Manual, and all issued CT DEEP stormwater discharge permits;
  • Implement additional measures to protect or improve water quality;
  • Inspect and monitor construction sites to ensure compliance with MS4 requirements and to inventory the number of privately-owned retention ponds, detention ponds and other basins that discharge into (or receive water from) the MS4;
  • Require land owners seeking development approval to provide and comply with a long-term maintenance plan to ensure the performance of any retention ponds, detention ponds and other basins; and
  • Control the contribution of pollutants between MS4s through inter-agency/jurisdictional agreements.