Announcement: The City is seeking feedback on the Draft updated Bacteria and Sediment TMDL plans attached to the right. Please provide comments here

 MS4 Stormwater Management Program

The City of Manassas Park is an operator of a small Phase II Municipal Separate Storm Sewer (MS4) System and regulated under the General Permit issued by the Virginia Department of Environmental Quality (DEQ). This General Permit establishes a timeline for stormwater management program development over a five-year permit cycle. The City’s MS4 permit became effective on November 1, 2018 and will expire on October 31, 2023.

The City is required to develop, implement, and enforce a stormwater management program that addresses the six minimum control measures established by the MS4 permit and the Special Conditions for approved Total Maximum Daily Loads (TMDLs) for the Chesapeake Bay TMDL and non-Chesapeake Bay TMDLs (e.g. Bull Run).


 The six minimum control measures are:

  • Public Education and Outreach
  • Public Involvement and Participation
  • Illicit Discharge Detection and Elimination
  • Construction Site Stormwater Runoff Control
  • Post-Construction Stormwater Management for New Development and Development on Prior Developed Lands
  • Pollution Prevention and Good Housekeeping for Municipal Operations

Further information on the specific requirements to address each of these minimum control measures and the Special Conditions for the Chesapeake Bay TMDL and non-Chesapeake Bay TMDLs can be found in the General Permit available on the Virginia Department of Environmental Quality’s website.

What are illicit discharges and illicit connections?

An illicit discharge is an unlawful act of disposing dumping, spilling, emitting, or other discharge of any substance other than stormwater into the storm drain system; such as catch basins, yard inlet, or lakes and streams. Examples of illicit discharges:

  • Paint being poured into or near a storm structure
  • Changing oil or antifreeze over or near a storm structure
  • Discarding yard waste, e.g. leaves and brush, in or near a storm structure
  • Draining chlorinated swimming pool water in or near a storm structure
  • Water from a washing machine emptying in or near a storm structure

An illicit connection is an unlawful connection which allows the discharge of non-stormwater to the storm drain system or lakes and streams via pipe or other direct connection. Examples of illicit connections:

  • Floor drains going into the storm drain system
  • Wash water from laundromats or car washes tying into a storm drain system
  • Pipe from a washing machine tying into a storm drain structure
  • Sewer service pipe tying into a storm structure or emptying into Bull Run

If you see an illicit discharge, or have another stormwater pollution concern, report it! Use the online form, or:

In cases of a large spill or other emergency, call 911.

Land-disturbing Sites

To report construction concerns regarding erosion and sediment control problems or stormwater runoff, please call the Department of Public Works 703-393-0881.

What Else Can You Do?illicit discharge

Around Your Home or Business

  • Properly use and dispose of household chemicals
  • Keep streets and parks litter free
  • Avoid washing paintbrushes under outdoor water faucets, this washes harmful chemicals into streams
  • Do not dump used motor oil in the storm drain, take it to an appropriate recycling center
  • Check your car for leaks and fix leaks as soon as possible
  • Use nontoxic, biodegradable, recyclable products whenever possible

Lawn and Garden

  • Test your soil. Know how much fertilizer to use and never over fertilize.
  • Never fertilize before a rain storm.
  • Don’t blow grass clippings and leaves in the street or down a storm drain.
  • Pick up after your pets both in your yard and while on walks
  • Use pesticides and fertilizers sparingly
  • When planting shrubs and trees, consider native plants. Native plants often require less water, fertilizer, and pesticides