DEEP: Links to Best Management Practices to Address Waters Impaired by High Indicator Bacteria

Best Management Practices for Reducing Bacterial Pathogens and other Nonpoint Source Pollutants

A great deal of work has been done since to passage of the Clean Water Act to reduce the input of pathogens and other pollutants into our State's waters. Wastewater treatment plant, industrial, and commercial plant discharges have been subjected to rigorous permit requirements and leachate from landfills and other illegal dumping sites have been addressed with best available technology where identified. Still many of our rivers lakes and beaches do not meet goals for drinking and swimming water quality, especially after rainstorms that produce runoff from impervious surfaces. CT DEP considers developing and implementing plans to restore impaired waters to be one of it's highest priorities. CT DEP is actively developing Total Maximum Daily Load Analyses (TMDL) to help restore water quality in waterbodies on the Impaired Waters List. We also enourage and assist stakeholders with development of Watershed Based Plans.

Nonpoint source pollution from stormwater has been shown to contribute significant quantities of pathogens and other pollutants to our waters. Connecticut DEP's Nonpoint Source Pollution Program and NPDES Stormwater Permitting Program are actively working with commercial and industrial businesses, developers, municipalities, watershed stakeholders, ConnDOT, and other institutions, to implement permits and plans to reduce stormwater pollution. Several species of "Indicator bacteria": E. Coli in freshwater, Enterococcus in Salt Water, and Fecal Coliform near shellfish beds are used to predict the presence of other pathogens that can be harmful to human health.  Indicator bacteria counts that are above CT Water Quality Standards can result in impairment of designated uses like recreation and shellfish harvesting in those waterbodies.

Not all of the bacterial pollution comes from human sources: pet waste, nuisance animal populations, such as excess numbers of non-native resident geese, swans, and ducks, as well as pigeons roosting under bridges, and animals like racoons and rodents inhabiting stormdrains can result in elevated bacteria levels in waters.  This is one of the reasons why feeding of waterfowl should be discouraged.

Much work has also been done to indentify and correct areas where combined sewer overflows exist as a result of too much stormwater infiltrating into sanitary sewer lines. Many older stormdrain systems drained directly to sanitary sewers resulting in higher flows than could be effectively treated at Publicly Owned Sewage Treatment Works (POTWs). Basement sumps discharging to sanitary sewers also exascerbate the problem of too much flow at wastewater treatment plants during major storms.

Unidentified illicit wastewater discharges still exist especially in some urban areas where infrastructure is old and underground pipes were installed without careful survey and planning. The CT Municipal Separate Storm Sewer System (MS4) Phase 2 Stormwater General Permit, implemented in 2004, places new emphasis and authority to require owners of stormwater collection systems to identify and correct illicit discharges. Difficulties arise because of the intermittent nature of some discharges, old and interconnected infrastucture, clogs from grease discharged into sanitary and storm sewers, location in areas where tidal waters fill drain pipes, and lack of funding for maintenance and upkeep of problems that have sometimes been out of sight and out of mind.

Public education and outreach toward pollution prevention can help to significantly improve stormwater quality. DEP's Office of Long Island Sound Programs has a no-cost Storm Drain Marker Program to help raise awareness about the impacts of stormwater on the waterways of Connecticut. Street and driveway sweeping can have dramatic benefits to reduce bacteria in stormwater that runs off of pavement.  An ounce of prevention is often worth more than a pound of cure.  

Solving the problem of polluted stormwater requires increasing awareness that the problem exists, and that small changes in people's everyday activities can make a difference. Proper management of pet and domestic animal waste, lawn care, car washing, boating waste, and other outdoor activities can all add up to make a difference. Wetlands and watercourses are not places to dispose of unwanted leaves and grass clippings. Use a broom instead of a hose to clean the driveway. Countless small inputs like these can make waters unsafe for swimming and other recreational activities. Most people just don't comprehend the nature of the problem.

The following is a listing of internet resources that are available to aid in reduction of bacteria and pathogen inputs into stormdrains and water bodies. This page will be updated as new sources of information become available.

Information on Illicit Discharges and Illegal Connections to Storm Sewers

NEIWPCC Illicit Discharge Manual; New England Interstate Water Pollution Control Commission

EPA Guidance for Illicit Discharge Detection and Elimination

Center for Watershed Protection's Illicit Discharge Detection and Elimination Manual

Detection method: Optical Brightener Handbook

Model Ordinances for Municipalities to Control Nonpoint Source Pollution compiled by Rivers Alliance of Connecticut

Model Ordinances for Illicit Discharge Detection and Elimination from Stormwater Center 


Onsite Wastewater Treatment and Septic System Guidance

NEIWPCC Wastewater and Onsite Systems

National Small Flows Clearinghouse

Onsite Wastewater Training Program: University of Rhode Island

System Owner's Guide: University of Minnesota

Septic Systems and Their Maintenance: University of Maryland


Stormwater and Construction Best Management Practices including information for municipalities, homeowners, and small farms

2004 CT Stormwater Manual

2002 CT Guidelines for Soil Erosion and Sediment Control

CT DEP's MS4 Stormwater General Permit Outreach Materials

EPA National Management Measures to Control Nonpoint Source Pollution from Urban Areas


University of New Hampshire Stormwater Center

University of New Hampshire Cooperative Institute for Coastal and Estuarine Environmental Technology

Water Quality and Home Landscape: UConn Cooperative Extension Service

New England Regional Water Program

Guidance for Lawncare and Domestic Animal Pollution Prevention: UCONN Cooperative Extension Service

CT NOFA Organic Landcare Program

Environment and Human Health

NRCS: Horse Environmental Awareness Program - HEAP

Environmental Impacts of Intensive Lawn Maintenance, Connecticut College

EPA Pollution Prevention Measures for Nonpoint Source Pollution see especially Chapters 2 & 4

Nonstructural Urban BMP Handbook, Northern Virginia Planning District Commission