To gauge the health of our waterways, a dedicated crew of volunteers performs monthly testing at 19 sites (see “documents” below for the sites) on the Taunton River and tributaries, measuring levels of nitrate, total phosphorus, fecal coliform bacteria, dissolved oxygen, total suspended solids, pH and temperature (click on the picture of the sample bottles below to see the 2016 data).
The TRWA has been testing some of these sites for over 28 years. This citizen collected data helps form a picture of the watershed’s health and keeps the spot light on areas and actions needed for further improvement. Our citizen monitors and photography volunteers also take periodic pictures (click on the picture of the green algae bloom below).
TRWA monitors the main stem of the Taunton River at four locations Berkley to Bridgewater along with critical tributaries feeding the river at fifteen additional locations during the early morning hours the second Tuesday of each month March to November. The reason we do this is to provide the watershed a regular check-up essential to continue the focus on correction of previously identified problems and to identify new issues. We monitor nitrate, total phosphorus, fecal coliform bacteria, total suspended solids, dissolved oxygen, pH, and temperature.
Currently the biggest TRWA monitored water quality problem pollutant in the watershed is excess nitrogen loading by wastewater treatment plants (66% of load) and other sources including stormwater runoff, excess lawn/turf/crop fertilization (and sloppy application of fertilizer i.e. on sidewalks, roads and driveways), pet wastes, stream bank erosion, stream buffer loss, and poor manure management from farming areas (34% of load). A comprehensive state sponsored 2004 to 2006 study throughout the Taunton River Estuary and Mount Hope Bay documented high algae and depressed dissolved oxygen attributed to high nitrogen loads. TRWA monitoring continues to measure nitrate (a portion of total nitrogen) in the main stem of the river at levels 2 to 5 times the in-stream target total nitrogen level 0.45 milligrams/liter (mg/l) MassDEP, EPA and RI say is needed to protect the estuary. Our monitoring indicates that action to remove nitrogen from wastewater treatment plants is necessary. As the plants are upgraded to remove nitrogen (a requirement of new discharge permits) our monitoring is important to track progress as nitrogen levels (and water quality) improves and to identify sources other than treatment plants in need of remediation.
The next most critical parameter we measure is total phosphorus important in the upper fresh waters of the watershed (main stem upstream of the Route 24 Bridge just south of route 44 in Raynham) and the tributary freshwater rivers/streams/lakes/ponds. Just as nitrogen is the limiting nutrient in the estuarine portion of the watershed, phosphorus is the algae growth limiting nutrient in the freshwaters upstream. Monitoring has measured total phosphorus levels near the riverine target of 0.10 mg/l (0.05 mg/l is the target for lakes/ponds/impoundments) at a number of locations along with criteria exceedance on tributaries such as the Town and Three Mile Rivers. The treatment plants generally have total phosphorus limits which are being adjusted upon renewal as needed. Phosphorus is an important pollutant in stormwater but since it attaches itself to particulates it can be filtered out by soil infiltration Best Management Practices (BMPs). Phosphorus is less mobile than nitrogen which can pass through soils and travel with groundwater. Total phosphorus in stormwater can be effectively removed by infiltration of first flush flows. During blooms algae can use up total phosphorus so quickly measurement of instream total phosphorus alone can give artificially low values. For this reason TRWA in 2016 added photographic monitoring to document the widespread algae blooms and excess rooted aquatic plant growth in the upper watershed to supplement its chemical monitoring (click on the first picture (of the green algae bloom) above to view some photos).
The third most critical parameter we measure is fecal coliform bacteria level (excess of 400 colonies/100 milliliters) indicate the potential presence of disease causing organisms (usually gastro-intestinal) for swimmers or kayakers. The three sites on the Mill River in Taunton and the Chuckamucksett Brook in Berkley sometimes had elevated levels in the 500 to 1000 colonies range. Our monitoring helps assure the locations we monitor are safe for recreation.
Over the last several years other parameters tested have generally not exhibited unusual levels observable by monthly grab sampling collected from the free flowing main stem of the Taunton River and the main flow from its tributaries.
Sampling Locations (PDF)
Stormwater Fact Sheet (PDF)