Note: These results are from July 29 & 30. Water quality can change over time, especially with rainfall.
The purpose of the RiverWatch Water Quality surveys are to determine whether or not sites along the North and South Rivers have exceeded bacteria concentrations for Massachusetts’ swimming and shellfishing standards. Water samples were collected at ten sites along the North and South Rivers. All ten of these samples were analyzed for Enterococcus concentrations, and a subset of five sites in shellfish growing areas (none of which are open at the moment for harvest) were analyzed for fecal coliform concentrations. 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 samples collected on July 29, water at the Washington Street Bridge, Cornhill Lane, the Union Street Bridge, and the Keville Footbridge exceeded the Massachusetts’ swimming standard for enterococcus.
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, Damon’s Point, the North River Mouth, and the Julian Street Bridge.
Compared to the week of July 11th, the enterococcus levels at most of the locations dropped. The enterococcus level at the Washington Street Bridge had the largest decrease, dropping to almost half of its previous levels. Alternatively, many fecal coliform levels increased, most likely due to increased rainfall. Fecal coliform levels at the Julian Street Bridge had the largest increase, doubling in concentration.
July 30, 2024 Rapid Response Results
Additionally, the Scituate sewer supervisor called the NSRWA to notify us that at approximately 10 pm Monday night, July 29th, Scituate’s wastewater treatment plant had a power issue and there was a discharge into the Herring River, a tributary of the North River, of an estimated 50,000 gallons of wastewater that may not have undergone the final ultraviolet treatment stage. This is the last stage of disinfection of wastewater. At approximately 9:30 am Tuesday morning we were notified that the town had fixed the power issue and brought the wastewater treatment plant back online. Given the relatively small amount of partially treated wastewater and that there had been some tidal flushing since the event took place we believed that the contamination risk was low from the event. In order to account for the event at the Scituate Wastewater Treatment Plant, we conducted a rapid response survey the following morning at ~10:30 am (July 30th) to resample the water at Driftway Park and to add a sample from the Spit. Our results indicated that enterococci levels were within the Massachusetts swimming standards. At Driftway, the enterococci level was 41 cfu per 100 mL and at the Spit the level was 10 cfu per 100 mL.
Please note that all shellfish beds in the North and South Rivers are closed from May 31 until November 1. The next round of sampling will be conducted on Wednesday, August 14.
Thank you to this week’s RiverWatch volunteers: Kathy Harrington, Christine Harris, and Suzanne Moore.