Week of April 29 - May 5, 2018
Water Column Profiles
Water column profiles were measured at eight sites in the Providence and Seekonk Rivers on May 2, 2018. Rainfall five days prior to the survey totaled 0.67 inches, and additional trace amounts were recorded in the days leading up to May 2. Stratification was observed at most sites, with warmer and fresher water at the surface and cooler, saline waters at depth. Surface temperatures ranged from 11°C (India Point Park and Conimicut Point) to 14-15°C (Pawtuxet Cove and Point St. Bridge). Temperatures at depth ranged from 7°C (India Point Park) to 11°C (Pawtuxet Cove). Surface salinity ranged from <5 PSU (Pawtuxet Cove) to 23 PSU (Bullock Reach). Salinity at depth ranged from 23 PSU (Pawtuxet Cove and Phillipsdale Landing) to 29 PSU (Pomham Rocks, India Point Park, Conimicut Point, and Bullock Reach).
Oxygen levels were high this week and no hypoxic readings were measured. Dissolved oxygen concentrations ranged from approximately 6 mg/L to 11 mg/L. Lastly, the maximum fluorescence, 9.7 mg/m3, was observed at a depth of 4 meters at Bullock Reach.
Week of May 6 – May 12, 2018
Bacteria Sampling
Twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers on May 9, 2018. A total of 0.15 inches of rain occurred during the five days prior to sampling.
Overall, the fecal coliform geometric mean was 67 MPN/100 mL for both rivers, an increase from the previous sample date. The fecal coliform geomean was higher in the Seekonk River (110 MPN/100 mL) compared to the Providence River (54 MPN/100 mL). The maximum fecal coliform concentration (930 MPN/100mL) was measured at Point Street Bridge in the Providence River. Fecal coliform concentration results for both rivers were above state guidelines for shellfishing and primary contact.
The Enterococci geometric mean for the Seekonk and Providence Rivers was 10 MPN/100 mL, a slight decrease from the previous sampling date. Enterococci concentrations ranged from below detection at three stations to 10 MPN/100 mL at the Point Street Bridge and Conimicut Point stations. 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.
Week of April 29 – May 5, 2018
Bacteria Sampling
Twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers on May 2, 2018. Five of these stations were additionally sampled for Enterococci bacteria. A total of 0.72 inches of rain occurred during the five days prior to sampling.
Overall, the fecal coliform geometric mean was 13 MPN/100 mL for both rivers, a slight increase from the previous sample date. The fecal coliform geomean was higher in the Seekonk River (55 MPN/100 mL) compared to the Providence River (6 MPN/100 mL). The maximum fecal coliform concentration (93 MPN/100mL) was measured in the Seekonk River at the Narragansett Community Boating Center, Off BP Outfall, and at Bishop Point. Fecal coliform concentrations in the Providence River were within state guidelines for shellfishing and primary contact.
Overall, the Enterococci geometric mean for the Seekonk and Providence Rivers was 12 MPN/100 mL, a slight decrease from the previous sampling date. Enterococci concentrations ranged from below detection at four stations to 31 MPN/100 mL at the Point Street Bridge station. 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.
Week of May 6 – May 12, 2018
Water Column Clarity
Water clarity was measured at eight locations in the Providence and Seekonk Rivers on May 9, 2018. A total of 0.15 inches of rain occurred during the five days prior to sampling. Overall, average clarity decreased from the previous week by 1.1 m, to 1.7 m. The largest decrease (2.6 m) was observed at Conimicut Point. Secchi depth ranged from 0.8 m at Pomham Rocks to 2.8 m at Point St. Bridge. There was no evidence of a north to south water clarity gradient.
Week of April 29 – May 5, 2018
Water Column Clarity
Water clarity was measured at eight locations in the Providence and Seekonk Rivers on May 2, 2018. A total of 0.72 inches of rain occurred during the five days prior to sampling. Overall, average clarity increased from 2.3 m the previous week to 2.8 m. Secchi depth ranged from 1.8 m at Phillipsdale Landing to 4.0 m at Conimicut Point, showing a slight north to south water clarity gradient.
