Public Works and Environmental Services

Fairfax County, Virginia

CONTACT INFORMATION: Our administrative offices are open to the public by appointment only at this time. Please call or email 8 a.m. – 4:30 p.m., Monday - Friday

703-324-5500
TTY 711

12000 Government Center Parkway
Suite 449, Fairfax, Va 22035

Craig Carinci,
Director, Stormwater Planning

Polluted Runoff Inspections

Illicit Discharge and Improper Disposal (IDID) Program

Fairfax County's Municipal Separate Storm Sewer System (MS4) permit requires the county to implement an illicit discharge and improper disposal (IDID) program to prohibit any individual non-stormwater discharge to the county MS4 and to state waters. The MS4, also known as the storm drainage system, was designed to convey runoff from rain and snowmelt from the land to surface waters such as streams and rivers. Material that enters Fairfax County's MS4 does not go to a wastewater treatment plant. Therefore, chemicals and waste materials must not be disposed of in the MS4.

What is an IDID?

What is an IDID?

Improper greasy water disposalFairfax County defines an IDID as the intentional or unintentional release of non-stormwater materials that may enter the storm drainage system, streams or ponds by dumping, pouring, throwing, spilling, abandoning, negligent storage or through an illicit connection.

Fairfax County defines an illicit connection as a pipe that is improperly connected to the storm drainage system and transports non-stormwater materials into a storm drainage system. For example, sometimes a sanitary sewer or wastewater pipe is improperly connected to an open channel or stream and transports non-stormwater materials directly to a body of water.

Some discharges are not considered illicit because they are authorized by the MS4 permit. These include discharges that have a Virginia Pollutant Discharge Elimination System (VPDES) permit as well as some specific discharges that are not considered to be a significant source of pollutants such as dechlorinated swimming pool water and irrigation water.

Examples of IDID?

Examples of IDID

Examples of IDID include, but are not limited to:

  • Improper disposal of vehicle fluids and toxic wastes including motor oil, household hazardous wastes, and pesticides.
  • Fats, oils and grease (FOG) from food service establishments.
  • Inappropriate disposal of grass clippings, leaf litter and pet wastes.
  • Liquid wastes such as oil, paint, and process wastewater (such as radiator flushing wastewater, plating bath wastewater, etc.).
  • Saltwater and chlorinated swimming pool water.
  • Gray Water - residential and commercial laundry wastewater, commercial carwash wastewater, fleet washing wastewater and floor washing wastewater.
  • Sewage and septic tank effluent.
  • Floatable debris including but not limited to street litter, medical items, debris from industrial activities, sewage-related items, waste from boats, and fishing equipment.
  • Unpermitted non-contact cooling tower discharge.
  • Discharge from improper outdoor material storage (e.g., sand, dirt, mulch, salt, and other chemicals, etc.).
Unpermitted Non-Contact Cooling Tower Discharge
Unpermitted Non-Contact Cooling Tower Discharge
Cleaning Detergents and Chemicals
Cleaning Detergents and Chemicals
Unpermitted Vehicle Washing Discharge
Unpermitted Vehicle Washing Discharge
Grease and Litter
Grease and Litter
Outdoor Salt Pile Storage
Outdoor Salt Pile Storage
Litter in the Storm Drainage System
Litter in the Storm Drainage System
How to Report an IDID?

How to Report an IDID

If you are reporting an emergency situation that could result in imminent or substantial danger to the health and safety of persons, call 911.

If you are reporting a "fish kill", contact Virginia DEQ through the 24/7 Virginia Emergency Operations Center at 800-468-8892.

For all other IDIDs, call the Stormwater Planning Division, 703-324-5500, TTY 711 or complete the Report Illicit Discharges online form.

Requested Information

When reporting an IDID, provide the following information:

  • What you observed.
  • Location of the discharge or improper disposal.
  • Date and time that the discharge/disposal was discovered.
  • Whether the discharge/disposal is ongoing.
  • The suspected cause of the discharge/disposal.
  • Your contact information. Reports may also be made anonymously, however staff will not be able to inform you of the outcome of an investigation.
  • Photographs of the incident, if available.
How is the IDID Eliminated?
Other Dumpings?

Other Illegal Dumping

What about dumping that does not involved the storm drainage system or waterways?

Please report illegal dumpsites to the Department of Code Compliance (DCC) at 703-324-1300, TTY 711. For more information about DCC’s handling of illegal dumping reports, please visit DCC’s Illegal Dumping website.

Swimming in Natural Waters

Is it safe for me or my pet to swim or consume water in streams?

Based on the levels of E. coli found, we discourage swimming in natural waters. See Health Department Advisory.

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