Alton/New Durham Cyanobacteria Mitigation Steering Committee

New Durham Elementary School in New Durham on July 27, 2017 at 6:30PM.

The next meeting of the Alton/New Durham Cyanobacteria Mitigation Steering Committee will be held at the New Durham Elementary School in New Durham on July 27, 2017 at 6:30PM. Currently the levels of phosphorus are very high in the Merrymeeting River in New Durham and parts of Alton and cyanobacteria blooms have been documented there in each of the past two years. To address these water quality concerns Pat Tarpey, Exec. Director of the Lake Winnipesaukee Association, will give a brief presentation of watershed management planning, what it is, why it is important, and how residents and the communities will benefit from having one. This will be followed by a brief business meeting focusing on the recent activities of the various working groups. The working groups evaluating hatchery best management practices and the Merrymeeting River water quality testing working group will make presentations. The public is invited at attend.

Watershed Management Plans(WMPs)are comprehensive documents which describe the sources of pollution within the watershed and prescribe methods to remediate this pollution. In New Hampshire excessive nutrients, especially phosphorus, are responsible for overgrowth of algae and toxin-producing bacteria (cyanobacteria)in fresh waterbodies. WMPs which concentrate on phosphorus pollution take into consideration storm water runoff and especially erosion into waterbodies, since in New Hampshire soil particles bind high levels of phosphorus . Land topography and use each affect the storm water runoff, as does the soil type and natural barriers to runoff. Using the physical and chemical characteristics of the land and water, a WMP identifies the sources of excessive phosphorus and provides steps for its remediation.

Sources of phosphorus may be either point sources (clearly identified, such as a commercial enterprise) or nonpoint sources (more difficult to pin point such as agricultural runoff or runoff from lawns). Identifying each type of phosphorus source and reducing the phosphorus loads into the water, help reduce dangerous overgrowth of toxin-producing cyanobacteria.

Hopefully, the implementation of the WMP for the Merrymeeting River Watershed will reduce the phosphorus levels in water and the incidence of cyanobacteria blooms and continue to keep the receiving water, Lake Winnipesaukee, pristine.