Virginia Stormwater Management Program Regulations

DEQ is responsible for issuing individual and general permits that control stormwater discharges from municipal separate storm sewer systems (MS4s) and construction activities.  DEQ administers these programs through the Virginia Stormwater Management Program (VSMP) Regulations, which are authorized by the Virginia Stormwater Management Act.

Excess fertilizers; herbicides and insecticides from residential areas; oil, grease and toxic chemicals from roadways and parking lots; sediment from improperly managed construction sites; bacteria and nutrients from pet waste; failing sewers and faulty septic systems; as well as carelessly discarded trash, are among the pollutants found in stormwater runoff.  Once they enter nearby waterways, these pollutants can discourage recreational use, contaminate drinking water supplies, and interfere with aquatic wildlife habitats.

Polluted stormwater runoff is often collected and discharged through MS4s. These include road drainage systems, municipal streets, catch basins, curbs, gutters, ditches, constructed channels and storm drains designed to collect and convey stormwater – and which are owned or operated by a federal, state or local government entity. MS4s are not part of a 'publicly owned treatment works system' (sewage collection, transportation and treatment) or part of a combined sewer (a system designed to carry sewage and stormwater to a sewage treatment plant). Privately owned and operated drainage systems are not considered MS4s.

Discharges of Stormwater from Construction Activities

The following land-disturbing activities are covered by the construction general permit:

  • Construction activities resulting in land disturbance equal to or greater than one acre.
  • Construction activities resulting in land disturbance less than one acre that are part of a larger common plan of development or sale that ultimately disturbs one or more acres. A larger common plan of development or sale is a contiguous area where separate and distinct construction activities may be taking place at different times on different schedules. General permit coverage is required if one or more acres of land will be disturbed, regardless of the size of the individually owned or developed sites.

The construction general permit requires the operator to implement a site-specific stormwater pollution prevention plan (SWPPP).

The SWPPP outlines the steps that an operator must take to comply with the permit, including water quality and quantity requirements, to reduce pollutants in the stormwater runoff from the construction site. The SWPPP also specifies all potential pollutant sources that could enter stormwater leaving the construction site and covers methods used to reduce pollutants in stormwater runoff during and after construction.

Municipal Separate Storm Sewer Systems

Discharges from MS4s are regulated under the Virginia Stormwater Management Act and the Clean Water Act as point source discharges. MS4 regulations were developed in two phases. Implementation of the first phase began in the early 1990s and required that operators of MS4s serving populations of greater than 100,000 people obtain permits to discharge stormwater from their outfalls.

Stormwater discharges from Phase I municipal separate storm sewer systems are authorized under individual stormwater permits. Under these permits, the MS4 owner/operator must implement a series of programs to reduce the discharge of pollutants from the storm sewer system in a manner that protects the water quality of nearby streams, rivers, wetlands and bays.

The second phase of MS4 regulations became effective March 23, 2003, and requires that operators of small MS4s in 'urbanized areas' obtain permits for stormwater discharges.

Small MS4s include storm sewer systems operated by cities, counties, towns, and federal and state facilities. Discharges from small MS4s are regulated under a general permit.

Similar to the Phase I programs, small MS4 programs must be designed and implemented to control the discharge of pollutants from the storm sewer systems to the maximum extent practicable in a manner that protects the water quality in nearby waters.

Because of the wide variability of the amount of pollutants in stormwater and the difficulty in determining their impacts on water quality, MS4 permits are based on a “best management practice” strategy. For MS4s, the operator implements BMPs to reduce the amount of pollutants in the stormwater. These BMPs can include ordinances, inspections, and educational activities, as well as projects such as detention ponds and constructed wetlands.

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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000


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