Water Quality Monitoring

Eb at the helm

Emma at the charts

Don Williams and Jack Kedian, Co-chairs

12 Years of Data

HPWA has  collected water samples from Great Herring Pond since 2008, several times a year. When we started out, we were trained in use of EPA approved sampling procedures by Environmental Management (Kim Michaelis) of the Town of Plymouth. We collected water samples from several sites,  all about 50 ft from shore at storm drain discharge locations. The following year we began including sampling sites on Little Herring Pond and Carter's River. Samples were collected when there had been no rain for at least two days. They were immediately delivered to state certified Envirotech Laboratory in Sandwich for analysis. The laboratory tested for parameters typically used to analyze drinking water (click to see early data in side bar). Sampling locations are marked on the two maps:

Our sampling has evolved since. Details of our procedures can be found in our approved 2011 Quality Assurance Project Plan (QAPP). Our water sampling was supported between 2009 and 2012 by a three year grant from Massachusetts Environmental Trust and by the Town of Plymouth as well as our association members. It continues to be supported partially by the Town.

For several years we collected water samples at 9 locations on Great and Little Herring Ponds, and on Carter’s River, as marked on the two maps. Two of these locations are away from shore at the deepest points of Great Herring Pond, where samples are drawn from near the pond bottom as well as from the surface. The other locations we sampled surface water only. They are identical to  locations used in the earlier tests. One sampling location is in the middle of Little Herring Pond. Two additional locations are at the beginning and end of Carter's River, the stream connecting the two ponds.

During each sampling event, we also collect a duplicate sample, as required by EPA procedures, to assure analysis integrity. 

Based on results, sampling sites and laboratory analyses have changed over time. At present, the laboratory analyzes for e-coli, total phosphorus, nitrates, nitrites, Kjeldahl (organic) nitrogen and total nitrogen, pH, electrical conductance, chlorophyll A, and turbidity.