May 14, 2024
Water Column Clarity
Water clarity was measured at seven locations in the Providence River and Seekonk River estuary on May 14th, 2024. Rainfall totaling 0.1 inches was recorded at TF Green in the five days prior to the survey. Secchi depth averaged 2.4 meters, compared to 1.3 meters on the previous survey (December 13th). The lowest clarity this week (1.4 meters) was measured at Phillipsdale Landing, while the greatest clarity (3.4 meters) was measured at Bullock's Reach. There was a general north-to-south gradient of increasing water clarity among the sites this week.
July 17, 2024
Bacteria Sampling
On July 17, 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 1.10 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 188 MPN/100 mL and 24 MPN/100 mL, respectively). The maximum count (930 MPN/100 mL) was measured at Bishop Point.
Enterococci results had an overall geometric mean of 15 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at South FP East, Gaspee Point, and Conimicut Point to 85 MPN/100 mL at Point St Bridge.
The next scheduled sampling date is July 31.
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
July 3, 2024
Bacteria Sampling
On July 3, 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 1.53 inches as recorded at TF Green. Overall, bacteria counts were higher 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 367 MPN/100 mL and 44 MPN/100 mL, respectively). The maximum counts (930 MPN/100 mL) were measured at Bishop Point and Point St Bridge.
Enterococci results had an overall geometric mean of 20 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at South FP East and Conimicut Point to 145 MPN/100 mL at Point St Bridge.
The next scheduled sampling date is July 17.
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
July 24, 2024
Surface Mapping
Surface chlorophyll data were collected on July 24, 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 2.16 to 38.37 µg/L with an average of 11.21 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
July 17, 2024
Surface Mapping
Surface chlorophyll data were collected on July 17, 2024 while the R/V Monitor was underway collecting bacteria samples in the Providence and Seekonk River estuaries. The average chlorophyll concentrations were categorized as poor in the Seekonk River and as fair in all other areas. Overall, chlorophyll ranged 2.29 to 57.17 µg/L with an average of 18.45 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
