Historical News
Nutrients Sampling
Ten river stations were sampled for nutrients on Wednesday, March 15, 2017, a day after a significant snow and rain storm. 1.6 inches of precipitation were recorded on March 14th. The highest nutrient concentrations were observed on the Ten Mile River at Central Avenue, where the total nitrogen (TN) averaged 2505 ppb, the total dissolved nitrogen (TDN) averaged 2295 ppb, and dissolved inorganic nitrogen (DIN) averaged 2063 ppb. The lowest nutrient concentrations were measured on the Coles River at Milford Road, where concentrations of 863 ppb TN, 789 ppb TDN, and 348 ppb DIN were measured.
Results from nutrient sampling done on March 29th and April 12th are pending analysis from the NBC Laboratory. The next anticipated sampling date for nutrients is April 26th.
Surface Mapping
Data was collected on April 19, 2017 while the R/V Monitor was underway collecting bacteria samples and performing vertical profiles in the Providence and Seekonk River estuaries. The chlorophyll concentrations were variable in areas surveyed with evidence of a north-south gradient. The lowest average chlorophyll concentrations were observed in the Seekonk River (9.29 µg/l) and Upper Providence River (9.38 µg/l). The highest average concentrations were seen in the Pawtuxet Cove area (12.23 µg/l) and the Lower Providence River (20.77 µg/l). Pockets of high chlorophyll concentrations were present in the Crook Point region in the Seekonk River and Collier Point Park area in the Providence River. Overall, chlorophyll ranged between non-detectable and 105.7 µg/l with an overall average of 12.59 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 April 19, 2017. Five of these stations were also sampled for Enterococci bacteria. Sampling occurred after five days of relatively dry weather, with only 0.05 inches recorded over the course of a few scattered showers. Bacteria counts in both rivers were generally low this week, and were within state primary contact standards; the results from the Providence River were also within shellfishing standards. The geometric mean fecal coliform count in the Seekonk River was 15 MPN/100 mL and in the Providence River was 8 MPN/100 mL. The maximum fecal coliform concentration was 93 MPN/100 mL, measured at the Point St. Bridge location. The overall fecal coliform geometric mean for both rivers was 10 MPN/100 mL.
Enterococci results were similarly low. The geometric mean for all sites was 11 MPN/100 mL, while the maximum result was 20 MPN/100 mL, also measured at Point St. Bridge.
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.
Bacteria Sampling
Twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers on April 5, 2017. Five of these stations were also sampled for Enterococci bacteria. Sampling occurred after five days of heavy rain, totaling 3.44 inches; the day before sampling included 1.51 inches of rainfall. These heavy rains led to elevated bacteria counts in both rivers. The geometric mean fecal coliform count in the Seekonk River was 191 MPN/100 mL and in the Providence River was 415 MPN/100 mL. The maximum fecal coliform concentration was 1,500 MPN/100 mL, measured at the Off FP Outfall location in the Providence River. The overall fecal coliform geometric mean for both rivers was 324 MPN/100 mL.
Enterococci results were also elevated following the heavy rains. The geometric mean of Enterococci concentrations was 88 MPN/100 mL, while the maximum result was 160 MPN/100 mL, measured at Phillipsdale Landing.
The elevated results in both rivers exceeded primary contact and shellfishing standards.
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.
R/V Monitor's Blog
On Wednesday, April 19th, the crew of the R/V Monitor was out on the upper Bay collecting bacteria 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. Jeffrey captained the boat while monitoring professionals Fern and Michael collected the samples and data. It was a partly sunny and brisk day with light winds. The below photo of a cargo ship was taken at the Port of Providence this day.
