City Posts Stormwater Pollution Prevention and Management Plan for Review

Posted on  06/30/2014 12:03 pm

To more efficiently address issues of storm water runoff requirements, the City recently adopted an integrated Wet Weather Management Program, Clean Waterways Wilmington (CWW). The vision of Clean Waterways Wilmington seeks to create a safe, clean and sustainable water environment to support a thriving community in Wilmington. The City will post a draft of the Stormwater Pollution Prevention and Management Plan for public review and comment.

The programs’ mission states:

  • We will improve surface water quality by reducing stormwater runoff and pollutants entering our waterways.
  • We’ll accomplish this by integrating green stormwater infrastructure while contributing to livable neighborhoods and a healthy community.
  • We are committed to fostering a coordinated watershed-based approach to protect our water environment in the most cost effective manner.


Discharges of storm runoff from Combined Sewer Overflows (CSO) and municipal separate storm sewer systems (MS4's) are regulated under the federal Clean Water Act, through the National Pollutant Discharge Elimination System (NPDES) program. In Delaware, the Department of Natural Resources and Environmental Control (DNREC) is delegated by the U.S. Environmental Protection Agency (EPA) to issue NPDES permits for both CSO discharges and storm water discharge. Under these separate permits, the City must implement a collective series of programs to reduce the discharge of pollutants from the CSO outfalls and the storm sewer system to the maximum extent practicable in a manner that protects the water quality of nearby streams, rivers, wetlands and bays.

MS4 Permit

On May 7, 2013, DNREC issued a five-year, Phase I MS4 permit for the City of Wilmington (NPDES Permit DE 0051071/State Permit WPCC 3063A/96). The permit requires the permittees to prepare a Stormwater Pollution Prevention and Management Plan (SWPP&MP) that describes how the quality of stormwater discharged from the MS4 will be controlled. A draft SWPP&MP was submitted to DNREC on May 7, 2014 and a public review process will follow with a final version of the plan to be submitted on August 7, 2014.


The draft SWPP&MP posted here for public review describes the programs and practices proposed by the City to fulfill the permit requirements. Under the permit the City must develop, implement and enforce a program that includes the following elements:

  • Public education and public involvement
  • Illicit discharge detection and elimination
  • Stormwater management during construction
  • Post-construction stormwater management
  • Pollution prevention/good housekeeping
  • Inspection of industrial facilities
  • Wet weather performance monitoring
  • Pollutant Minimization Plan (PMP) for polychlorinated biphenyls (PCBs)
  • A Watershed Priority List for development of Water Quality Improvement Plans


Documents pertaining to the draft SWPP&MP can be found at the links below:

Submission of Comments

All comments must be submitted by July 25, 2014 via email to:
or via mail to: Clean Waterways, Department of Public Works, 800 French Street, Wilmington, Delaware 19801.