By Endurance Laryea, LRWP Summer Research Intern and J.M. Meyer.

The final pathogen monitoring session of the month took place on Thursday, July 30th. Each week during the summer, from May to October, the Lower Raritan Watershed Partnership and Rutgers Cooperative Extension of Middlesex County run a volunteer-based monitoring program along the Raritan River. We collect water quality samples at six non-bathing public access beach sites, provide our samples to the Interstate Environmental Commission for analysis in their laboratory, and report the results to the public. Our mission is to share this data with the community and partners to ensure the safe use of the Raritan River for all.

Our lab results for water quality samples taken on Thursday, July 30th, 2026, show Enterococcus bacteria levels exceeding the EPA federal water quality standard of 104 cfu/100mL at four of our regular monitoring sites this week. The problem sites are indicated by the red frown on the map and chart and include Riverside Park (Piscataway), Rutgers Boathouse (New Brunswick), Edison Boat Basin (Edison), Ken Buchanan Waterfront Park (Sayreville).

This was the worst result since May 21st, and the high failure rate is largely attributable to the rainfall we received in the previous 24 hours.

Green smiles on the chart and map indicate the sites with bacteria levels safe for recreation and include the following: 2nd Street Park (Perth Amboy), and South Amboy Waterfront Park.

We tested just after high tide on Thursday; if not for the tidal flush of Raritan Bay, Perth Amboy would have also likely failed to meet the EPA standard for safe primary contact.

Pathogens/Enterococci levels are used as indicators of the possible presence of disease-causing bacteria in recreational waters. Such pathogens may pose health risks to people coming in primary contact with the water (touching) through recreational activities like fishing, kayaking or swimming in a water body. Possible sources of bacteria include Combined Sewer Overflows (CSOs), improperly functioning wastewater treatment plants, stormwater runoff, leaking septic systems, animal carcasses, pet waste, wildlife waste, and runoff from manure storage areas.

In order to better understand why Riverside Park, Piscataway has been our worst performing site over the past six years, we have started sampling further upstream. On July 30thj, we sampled the canal at Five Mile Lock, Easton Avenue, a third time since we started pathogens monitoring this season. The lab analysis produced 50 enterococci cfu per 100mL which passes the EPA federal water quality standard of 104 cfu/100mL. Again, this site passed the test, as it has every week that we’ve tested it.

Our goal in reporting these results is to give residents a better understanding of the potential health risks related to primary contact during water-based recreation. If you are planning on recreating on the Raritan this weekend, make sure to stay safe and wash up after any activities!