The purpose of the RiverWatch Water Quality surveys is to determine whether or not sites along the North and South Rivers have exceeded colony concentration numbers for Massachusetts’ swimming and shellfishing standards. Enterococcus colonies were collected at all ten sites along the North and South Rivers, while fecal coliform samples were collected in shellfish growing areas (none of which are open at the moment for harvest). According to Massachusetts’ swimming standards, enterococcus levels may not exceed 104 cfu per 100mL of water sampled. The Mass. Division of Marine Fisheries shellfishing standard is 14 cfu per 100mL of fecal coliform.
For the week of June 26, water at Washington St. Bridge and Keville Footbridge exceeded the Massachusetts’ swimming standard for enterococcus. This occurred during the last round of sampling two weeks ago, meaning that these numbers are likely consistent and further investigation is required. The concentration of enterococcus is much higher than in recent years, likely due to rainfall in the area. This week’s sampling showed that not only do these two sites exceed the swimming standard, but they are increasing in concentration.
Shellfish beds are closed from May 31 until November 1 so the information presented in this section is purely for informational purposes. Concentrations of fecal coliform exceeded the shellfish standard at Driftway Park, North River Marine, and Julian Street Bridge. These levels are in fact lower than the past 2 years, meaning that improvements to the area have been beneficial. However, some caution must still be taken as many designated shellfish areas still exceed the standard for consumption per Massachusetts regulation.
In this round of sampling, both enterococcus and fecal coliform concentrations were consistently high at the same sites and increased compared to the last round. All locations that remained below the standards either had the same concentrations or decreased.