August 7, 2024
Surface Mapping
Surface chlorophyll data were collected on August 7, 2024 while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuaries. The average chlorophyll concentrations were categorized as fair in all areas surveyed. Overall, chlorophyll ranged 1.72 to 24.79 µg/L with an average of 7.32 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
August 1, 2024
Surface Mapping
Surface chlorophyll data were collected on August 1, 2024 while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuaries. The average chlorophyll concentrations were categorized as fair in all areas surveyed. Overall, chlorophyll ranged -0.45 to 63.34 µg/L with an average of 11.02 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
August 28, 2024
Bacteria Sampling
On August 28th, 2024 twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; five of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, precipitation totaled 0.38 inches as recorded at TF Green. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers than during the previous sampling event.
Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 53 MPN/100 mL and 13 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at Bishop Point and Point St Bridge.
Enterococci results had an overall geometric mean of 14 MPN/100 mL. Enterococci counts ranged from 110 MPN/100 mL at Point St. Bridge to <10 MPN/100 mL at all other sites.
The next scheduled sampling date is September 11th.
The table below lists the Rhode Island bacteria standards for primary contact and shellfishing established by the Rhode Island Department of Environmental Management (RIDEM). RIDEM defines primary contact as any recreational activities in which there is prolonged and intimate contact with water, involving considerable risk of ingesting water (e.g., swimming, diving, water skiing and surfing). Please note that the RIDEM bacteria standards are provided here for informational purposes only and are not intended to indicate official state compliance with primary contact or shellfishing standards.
Summary of Rhode Island Bacteria Standards for Saltwater Primary Contact and Shellfishing
| Fecal Coliform | Enterococci |
| Primary Contact1 | Geometric mean ≤50 MPN/100 mL
<10% of samples >400 MPN/100 mL
| Geometric mean ≤35 colonies/100 mL
All samples ≤104 colonies/100 mL2 |
| Shellfishing | Geometric mean ≤14 MPN/100 mL
<10% of samples >49 MPN/100 mL3 | NO ENTEROCOCCI CRITERIA
|
1Fecal coliform primary contact criteria applied only when adequate enterococci data are not available;
2Single sample maximum criterion for determining beach swimming advisories at designated beaches as evaluated by the Rhode Island Department of Health;
3For a three-tube decimal dilution
February 21, 2024
Nutrients Sampling
Nutrient samples were collected from seven river stations on February 21st. In the five days prior to sampling, there were 0.05 inches of precipitation recorded at T.F. Green.
Among the stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Pawtuxet River @ Broad St (TN = 1,280 ppb, TDN = 1,250 ppb, DIN = 1,100 ppb, average of duplicates). The lowest TN, TDN, and DIN were observed at Moshassuck River @ Higginson Ave. (TN = 722 ppb, TDN = 676 ppb, DIN = 561 ppb, average of duplicates).
The next scheduled sampling date is March 6, 2024.
February 7, 2024
Nutrients Sampling
Nutrient samples were collected from 14 river stations on February 7th. There was no precipitation recorded at T.F. Green in the five days prior to sampling
Among the stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River @ Central Ave (TN = 1,800 ppb, TDN = 1,840 ppb, DIN = 1,780 ppb). The lowest TN, TDN, and DIN were observed at Coles River @ Milford Rd (TN = 635 ppb, TDN = 582 ppb, DIN = 363 ppb).
The next scheduled sampling date is February 21, 2024.
