Historical News
Nutrients Sampling
Seven local and border river stations and six bay stations (surface and bottom) were sampled for nutrients on December 19, 2018. In the five days before sampling, there was 0.16 in of recorded rainfall.
Among the river stations sampled, highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) values were measured in the Ten Mile River at Roger William Ave, with reported values of 1,990 ppb, 2,100 ppb, and 1,956 ppb, respectively. The Woonasquatucket River at Manton Ave had the lowest measured values with a TN of 762 ppb, a TDN of 778 ppb, and a DIN of 663 ppb.
For the bay sites, Phillipsdale Landing had the highest concentrations of surface TN, TDN and DIN with values of 1,170 ppb, 1,040 ppb, and 943 ppb respectively. Conimicut Point had the lowest nutrient concentrations with 593 ppb for TN, 502 ppb for TDN, and 413 ppb for DIN. Chlorophyll concentrations were very low throughout the bay with a maximum of 1.8 ug/L at Phillipsdale and an overall concentration average of 1.2 ug/L.
R/V Monitor's Blog
On Wednesday, March 20th, the crew of the R/V Monitor was out on the upper Bay collecting bacteria samples in an effort to document water quality improvements associated with NBC construction projects. Real-time surface mapping was not done this day as a result of computer issues. Jeff captained the boat while monitoring professionals Dan and Fern collected the samples and data. It was a sunny, brisk day with calm waters, warming up nicely by the afternoon. The photo below was taken within Pawtuxet Cove.
R/V Monitor's Blog
On Wednesday, March 13th, the crew of the R/V Monitor was out on the upper Bay collecting nutrients and plankton samples, taking Secchi Disk and Par sensor water clarity measurements, conducting water column profiles using the Seabird instrument, and conducting real-time surface mapping of water quality parameters, including dissolved oxygen, chlorophyll, water temperature, salinity, and pH, all in an effort to document water quality improvements associated with NBC construction projects. Sara captained the boat while monitoring professionals Fern, Steve and Mike collected the samples and data. It was a cool day with no wind and calm waters. It was sunny in the morning, becoming partly cloudy by the afternoon. The photo below was taken just east of the Port of Providence.
Surface Mapping
Data was collected on March 13, 2019 while the R/V Monitor was underway collecting nutrient samples and performing vertical profiles in the Providence River estuary. The chlorophyll concentrations were low to fair in areas surveyed. From north to south, average chlorophyll concentrations were as follows: Upper Providence River (11.94 µg/l), Edgewood Shoals area (5.09 µg/l), Pawtuxet River area (1.85 µg/l), and the Lower Providence River (29.55 µg/l). Overall, chlorophyll ranged between non-detectable and 137.50 µg/l with an overall average of 16.06 µg/l. The chlorophyll data from this date is presented in the map below:
Bacteria Sampling
Twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers on February 6, 2019. Five stations were also sampled for enterococci bacteria. Light rain (0.1 inches of precipitation) occurred the morning of sampling.
Fecal coliform geometric mean decreased from the previous sampling to 17 MPN/100 mL. The fecal coliform geomean was higher in the Seekonk River (29 MPN/100 mL) compared to the Providence River (13 MPN/100 mL). The maximum fecal coliform concentration (430 MPN/100 mL) was measured at Point Street Bridge in the Providence River. Fecal coliform bacteria results in both rivers met state guidelines for primary contact.
The enterococci geometric mean for the Seekonk and Providence Rivers decreased from the previous sampling to 13 MPN/100 mL. Enterococci concentrations ranged from below detection at three stations to 63 MPN/100 mL at Point Street Bridge. These results are within the state criteria for primary contact.
Please note: the results of NBC's fecal coliform and enterococci monitoring are for informational/research purposes only and are not intended to suggest official state compliance with bathing or shellfishing standards.
