TEMPORAL AND SPATIAL TRACKING OF CONTAMINATION WITHIN THE FORT RIVER WATERSHED

The Fort River is the longest free-flowing tributary to the Connecticut River in Massachusetts. It provides habitat for many native species of fish and invertebrates and is used by the community for recreational activities. The Fearing Brook, a tributary to the Fort River, has been implicated as a source of pollution and recently (2021) a floodplain restoration project was undertaken to help mitigate the influx of contaminants. This brook, along with others in the Fort River watershed, have been periodically sampled over the past few decades, and over the past 3 years at a far higher resolution, including the use of in situ data loggers. This study examines both long term and high resolution shorter term water quality issues for these waterways.

One clear influx of contaminants is from the connection of the town’s storm water system to the sewage overflow outlets. Data logging in the Fort River, both above and below where the Fearing Brook enters, recorded one such sewage release event that occurred in August, 2022. Conductivity rose from a baseline of ~200 to over 600 μS/cm in a matter of hours and maintained that level over the next ~5-days. We estimate from the relative discharges of the Fearing Brook and Fort River that the Fearing Brook contained > 20,000 μS/cm during this period (typical background would be < 500 μS/cm). While these occurrences likely release large amounts of E coli and cause the suspension of recreational activities, more subtle background contamination has increased over the years as well with rising urbanization.

Conductivity measurements along the length of the Fearing Brook decrease from where Fearing Brook initially daylights, near the urban center of Amherst, to where it enters the Fort River. As it gains volume, mainly from groundwater, it dilutes the relatively high levels of conductivity coming from the town infrastructure. Data loggers placed above and below a 1914 sewage pipe suggest some leakage as well. Consistently lower conductivity values (approximately 100-200 μS/cm less) upstream and significant spikes (up to 16,000 μS/cm) downstream suggest discharge from the pipe.

The close monitoring of this important waterway has shown the need for more robust sampling and continuous monitoring of sites that are important for community access.