skip navigation
New Hampshire Department of Environmental Services

Media Center

DATE: April 26, 2017
CONTACT: Chris Nash, NHDES 603-568-6741

Oyster River Dye Study at Durham, NH Scheduled for May 2-3

Durham, NH – The New Hampshire Department of Environmental Services (DES), the U.S. Food and Drug Administration (U.S. FDA), the U.S. Environmental Protection Agency’s (USEPA) New England Regional Laboratory, and the Town of Durham will begin conducting a dye tracing study on Tuesday, May 2, into Wednesday, May 3. They will be tracking the flow and dispersion of water in the Oyster River from the Durham Wastewater Treatment Facility. Dye tracking will continue into Little Bay, Great Bay, and nearby tidal rivers including the Bellamy River.

Information from this study will be used by NHDES to update and revise a previous dye study conducted by NHDES and USEPA in 2003, to incorporate new guidelines on how to assess public health risks of shellfish harvesting near wastewater treatment facility discharges. The study will provide information on which areas are suitable for recreational shellfish harvest and for commercial shellfish aquaculture, while still protecting public health. Rhodamine WT dye will be released late in the evening of May 2 from the Durham Wastewater Treatment Facility for a period of approximately 12 hours. As a result of the injection, portions of the Oyster River and Little Bay may turn reddish in color for a brief time through the communities of Durham, Madbury, Dover, and Newington; however, the dye is not harmful to people or the ecosystem.

The addition of dye to the treated wastewater effluent is intended to simulate conditions that may result in the rare instance of a treatment breakdown at the facility. Measurements of dye dilution and transport in the river can then be used to identify areas that may be at a higher level of risk for contamination. Similar studies have been conducted previously at the wastewater treatment facilities in Dover, Portsmouth, Exeter, Newmarket, Hampton, Seabrook, Newfields, and Kittery, Maine. For more information about the study, please contact Chris Nash, NHDES Shellfish Program at 603-568-6741.

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

copyright 2017. State of New Hampshire