Water Quality Status In the North and South Rivers
The North and South Rivers are both National Park Service National Natural Landmarks and are classified by the state as Class SA, or “Outstanding Resource” waters. Both are impaired for fecal coliform bacteria according to the Massachusetts 2012 Integrated List of Waters; the North River is also impaired for mercury in fish tissue in its headwaters. The primary source for bacteria and other contaminants entering our rivers is stormwater runoff, particularly since wastewater has been more tightly controlled and better treated in the watershed over the past few decades. We monitor bacteria and other water quality parameters like temperature and dissolved oxygen each summer through our Riverwatch program and work with our watershed communities to implement stormwater management techniques with a goal of swimmable waters and shellfish beds that are open year-round.
History of Water Quality Restoration
Our initial efforts to restore water quality in the watershed focused on reducing wastewater inputs to our rivers. The NSRWA is known for its work to eliminate polluted discharges from the Scituate Wastewater Treatment Plant in the late 1980’s. We supported sewering of a portion of Marshfield along the South River in the early 2000’s that resulted in a dramatic decrease in bacterial counts, and continue to ensure that wastewater in our watershed is being managed properly.
More recently our focus has shifted to eliminating stormwater pollution discharges to our rivers. We have worked on multiple projects with communities such as Pembroke and Marshfield to monitor and track down sources of stormwater bacteria and construct appropriate stormwater best management practices (a.k.a. green infrastructure) to remove bacteria and other pollutants from stormwater and help replenish the groundwater. We have also used our Greenscapes program to educate homeowners about stormwater pollution and actions they can take personally to reduce it.
Water Quality Goals
We have two primary water quality goals:
1) We want our shellfish beds in the lower reaches open year round. Currently, they are only open during the cooler months, when bacterial counts are lower, and at the shoulders of that season they are still vulnerable to rain-induced closures.
2) We want the entire reach of both rivers to be fishable and swimmable. We know from our Riverwatch testing that some of the most persistently high bacterial counts are in the upper reaches, and we want to work with our communities to assess and remediate that issue.