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New Hampshire Department of Environmental Services

Pollution Source Investigations

There are three types of pollution source investigations currently being done by the NHDES Watershed Assistance Section.

Illicit Discharge Detection Investigations

In 1996, NHDES initiated illicit discharge detection investigations in an effort to identify pollution discharges to storm drainage systems. An illicit discharge is any discharge to a municipal storm drainage system that is not composed entirely of stormwater. Examples of illicit discharges commonly seen in urban communities in New Hampshire include sanitary wastewater piping that is directly connected from a home into a storm drainage pipe or a cross-connection between the municipal sewer to the storm sewer systems.

The Coastal watershed communities were the first to undergo these investigations, beginning in 1996. Since then, over 30 illicit discharges have been identified and removed in this watershed. Illicit discharge detection investigations were initiated in the Merrimack watershed in 2001. Approximately 100 miles of shoreline were investigated by the end of 2002 with the majority of work completed in Nashua, the Winnipesauke River corridor, and along the Merrimack River corridor from the Massachusetts border, north to the confluence with the Souhegan River. In 2003, initial investigations continued in Nashua and along the corridors of the Souhegan and Winnipesaukee Rivers. In 2004, NHDES completed the initial investigations for surface waters in Nashua and continued to investigate the shorelines of the Souhegan and Winnipesaukee Rivers.

The typical procedure for conducting illicit discharge investigations includes the following steps.

  1. Illicit discharge investigations begin with a meeting between the NHDES staff and the department of public works (DPW) personnel in the municipality where the survey will take place. Storm drainage infrastructure maps are a good starting point for a discussion.
  2. NHDES and DPW staff identify hot spots and prioritize survey areas.
  3. NHDES staff conduct dry-weather field screening to look for non-stormwater discharges in the storm drain outfalls.
  4. Water quality tests are conducted to see if the non-stormwater discharges are illicit charges.
  5. NHDES and DPW staff team up again to track down the source and remove the illicit discharges.
  6. Where pollution sources are found, staff work with appropriate parties on remediation, which often requires technical and financial assistance. In some cases, regulatory compliance and enforcement is warranted. The New Hampshire Estuaries Project has been providing grant funds to coastal communities to eliminate illicit discharges since 2000.

The New England Interstate Water Pollution Control Commission published a useful manual for communities titled Illicit Discharge Detection and Elimination Manual: A Handbook for Municipalities. Copies of this document may be downloaded from

For more information in the coastal watershed contact:
Rob Livingston at
or (603)271-3398
Sally Soule at
or (603) 559-0032

For more information in the Merrimack River watershed contact

Steve Landry at
or (603)271-2969

Stream Morphology Assessments and Surveys

The NHDES Watershed Management Bureau staff has spent considerable time learning and applying the methods of assessing stream and river channel restoration principals. The NHDES Watershed Assistance Section awarded restoration grants for projects that focus on the identification and assessment of factors causing stream and river channel instability and the design of channel restoration plans. All of the funded projects employ the principals of fluvial geomorphology and natural channel design to accomplish specific restoration goals related to channel disturbances and instability. These projects will also demonstrate that addressing river-related problems yields greater benefits when compared to treating symptoms with costly, bank-armoring techniques.

The Watershed Assistance Section staff are excited to see this trend in natural channel design-based stream and river restoration continue to increase as more project collaborators take advantage of the Generic Quality Assurance Project Plan for Stream Morphology Data Collection and the continued efforts and outputs of the New Hampshire Stream Team (NHST). The NHST’s mission is to advance the use of science in river restoration and streambank stabilization efforts, and provide a venue for communication among river management stakeholders. In order to meet its mission, the NHST has established goals to develop a Regional Hydraulic Geometry Reference Curve, provide and/or promote education, training, and technical assistance regarding natural stream channel design (NSCD) and fluvial geomorphic principles, incorporate NSCD methods in the New Hampshire wetlands permitting process, and collaborate with other New England states and academia regarding NSCD and regional hydrologic curve development.

The successful implementation of these 319-funded river and stream restoration projects will demonstrate the necessity for watershed based assessments designed to reveal underlying problems, yielding the information necessary to develop appropriate, cost effective solutions. This is a trend that NHDES personnel responsible for permitting and grants management will continue to encourage and/or require when applicable.

For more information about stream and channel restoration contact

Steve Landry at
or (603)271-2969

Microbial Source Tracking

Lab technician processes samples for Ribotyping In the late 1990s, the NHDES Watershed Assistance Section (WAS) staff teamed up with researchers at the University of New Hampshire to find better tools for tracking down sources of fecal-borne bacteria. These bacteria can be found in lakes, streams and marine waters when sanitary wastewater flows untreated into surface water. This happens during situations such as failing septic systems, leaking sewer pipes, overflows at wastewater treatment plants, or when stormwater washes animal waste into a waterbody.

Researchers found that a bacterial source tracking tool called Ribotyping is an effective and innovative way to identify the actual sources of bacterial pollution present in surface waters. Instead of just knowing how much bacteria is in the water, this technology can tell us if the bacteria came from a specific species such as a dog, cow, or human. The US Environmental Protection Agency and the NH Department of Environmental Services supported the start up costs of establishing a Ribotyping laboratory at the UNH Jackson Estuarine Laboratory located on the shore of the Great Bay Estuary. Several Ribotyping studies have been completed in the coastal watersheds, showing promising uses for this technology statewide. For example, residents in the Hampton/Seabrook Harbor watershed suspected that birds were the primary source of bacterial pollution, but the Ribotyping study results indicated that humans were responsible for a larger portion of the bacteria rather than birds. As a result, NHDES supported a pumpout boat to encourage frequent and proper disposal of boat sanitary waste and the Town of Hampton is conducting a major sewer replacement project in the beach area of the town. More recently, UNH purchased a RiboPrinter that allows for automated processing for Ribotyping analysis. This greatly increases the consistency and accuracy of the results.

NHDES and UNH have conducted Ribotyping studies in Varney Brook and the Bellamy River in Dover; Hampton/Seabrook Harbor in Hampton, Hampton Falls, and Seabrook; Little Harbor in Portsmouth, New Castle and Rye; Parsons Creek in Rye; Bass Beach Brook in Rye; and Chapel Brook and Little River in North Hampton.

If you are interested in the reports for any of these studies contact Natalie Landry (NHDES) at (603) 559-1507. If you are interested in the research aspects of ribotyping contact Dr. Steve Jones (UNH) at (603 )862-5124 or

NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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