Based on data from the watershed watchdog’s stream monitoring program in Hunterdon, Somerset and Morris counties, local waterways got a “C” grade on the 2018 water quality report card.
When rain falls onto surfaces impervious to water, it carries contaminants into storm drains and then into streams, including road salt and motor oil from roadways, and fertilizers, pesticides and animal waste from farms and homes.
Testing the waters Cindy Ehrenclou, executive director of Raritan Headwaters, said compiling the annual stream quality report card is one way the nonprofit works to educate local residents about issues affecting their water quality.
The upper Raritan River watershed includes the North and South Branches of the Raritan, and numerous tributary rivers and streams.
Every year in June, RHA staff members and volunteer citizen scientists conduct biological monitoring at 64 stream sites in the watershed.
Certain macroinvertebrates are very sensitive to pollution, making their presence an indicator of good stream health.
In addition to biological monitoring, Raritan Headwaters also conducts chemical, bacterial and habitat monitoring.
Stream sites ranked good include most of the North Branch from Mendham to the confluence of the South Branch in Branchburg.
Also rated good were several locations along the South Branch and its tributaries that were not rated excellent.
Other sites ranked fair include sections of the North Branch near Natirar Park in Peapack-Gladstone, the Spruce Run in Union Township, the Beaver Brook in Clinton Township, the Rockaway Creek in Readington Township, the Cold Brook in Tewksbury Township, and the Middle Brook in Bedminster.