Municipal Separate Storm Sewer Systems

The federal 1987 Water Quality Act (WQA) was an amendment to the Clean Water Act, requiring that EPA issue National Pollutant Discharge Elimination System (NPDES) permits for storm water discharges that were permitted prior to February 4, 1987, or associated with industrial activity, or from Municipal Separate Storm Sewer Systems (MS4s) serving a population of 100,000 or more, or judged by the permitting authority to be significant sources of pollutants or which contribute to a violation of a water quality standard.

The storm water program also includes a Phase II, which phased in regulation of some smaller dischargers than previously regulated. These regulations require storm water permits by March 10, 2003 for numerous small MS4s, construction sites of one to five acres, and industrial facilities owned or operated by small MS4s which were previously exempted under the Intermodal Surface Transportation Efficiency Act. Until now only a portion of the small MS4s have been regulated under Phase II.

The universe of small MS4s is quite large since it includes every storm water collection system in every community except for those medium and large MS4s regulated under the first phase of the storm water program. There are thousands of them. Only a portion of small MS4s have been regulated d by the Stormwater Phase II Final Rule, either by being located near an urban area having high population density or designation by the NPDES permitting authority because the MS4 or drainage ditch discharges to sensitive waters.

As was stated in Executive Order 13508 -Strategy for Restoring and Protecting the Chesapeake Bay Watershed Public Comment Response dated May 12, 2010: EPA will initiate rulemaking to increase coverage and raise standards for CAFOs, municipal stormwater, and new dischargers of pollution. The EPA representative at the Public Hearing in Annandale, VA stated that EPA expects that it will promulgate new Chesapeake Bay specific regulations expanding the reach of MS4 point source regulations to ensure compliance with the total maximum daily load, TMDL, numerical limit imposed by EPA.

Polluted stormwater runoff is commonly transported through Municipal Separate Storm Sewer Systems (MS4s), from which it is often discharged untreated into local water bodies. To prevent harmful pollutants from being washed or dumped into an MS4, operators must obtain a NPDES permit and develop a stormwater management program. In the smallest MS4s a stormwater management program consists of modest activities like education, best management practices, BMPs to control flow and run off.

On December 28, 2009, EPA issued a Federal Register Notice announcing EPA's initiation rulemaking to strengthen its stormwater program. EPA is now soliciting input on potential rules and regulations relating to the Chesapeake Bay watershed, with several public “listening sessions” to be held in October and November 2010, and an interactive Webcast scheduled for November 16, 2010, 1 p.m. to 4 p.m. EST, Visit http://www.epa.gov/npdes/stormwater/rulemaking to register to participate in the Webcast.

The intent of the new regulations is to control and manage stormwater discharges not currently regulated that are causing or contributing to water quality impairments in the Bay watershed. That is pretty much every drop of stormwater in the Chesapeake Bay watershed. This would require additional measures, such as BMPs and change in flow patterns targeting ( but not limited to) nitrogen, phosphorus, and sediment in the Chesapeake Bay Watershed, According to the Federal register these rules would require the retrofit of stormwater controls for existing developments; and applying specific performance standards to discharges from new and retrofitted stormwater systems within the watershed. EPA is also seeking input on whether to consider specific evaluation, tracking, or reporting elements.

That modest announcement will probably impact all homeowners throughout the Chesapeake Bay watershed. The success of any changes in stormwater regulations in protecting the environment will depend on notification of and the compliance of individual homeowners, homeowner associations and communities. For the individual homeowner the regulations will have to be clear, fair and easily understood by a layman reading them and county and community staff will have to be informed and informative. Compliance with the regulations will suffer if no one is ever aware of them, the building department will issue roadwork permits with out ensuring compliance with MS4 regulations or the regulations are, or are perceived, to be excessively costly or burdensome and without environmental benefit.