Historical News
Week of September 17 - September 23, 2023
Nutrients Sampling
Nutrient samples were collected from 14 river stations and 8 bay stations on September 20th, 2023. Edgewood Shoal was sampled at the surface and bottom; all other bay stations were sampled at the surface only. In the five days prior to sampling, there were 1.55 inches of rainfall recorded at T.F. Green with the majority accumulated during a heavy rain event on September 18th.
Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River at Roger Williams Ave. (TN = 1,305 ppb, TDN = 1,195 ppb, DIN = 771.5 ppb; all averaged with duplicates). The lowest TN and TDN were observed at Woonasquatucket River @ Valley St. (TN = 665 ppb, TDN = 635 ppb), while the lowest DIN was at Coles River @ Milford Rd. (DIN = 139.2 ppb).
Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Pawtuxet Cove (TN = 1,120 ppb, TDN = 1,070 ppb, DIN = 638.3 ppb). The lowest surface TN was observed at Conimicut Point (TN = 799 ppb), while the lowest surface TDN and DIN were observed at Bullock Reach (TDN = 607 ppb, DIN = 300 ppb). Chlorophyll a concentrations at the surface bay stations averaged 2.8 μg/L overall with a maximum of 4.2 μg/L at Bullock Reach Buoy.
Week of September 3 - 9, 2023
Nutrients Sampling
Nutrient samples were collected from seven river stations and seven bay stations on September 6th, 2023. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there was no rainfall recorded at T.F. Green.
Among the river 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 = 1,560 ppb, TDN = 1,510 ppb, DIN = 1,271.3 ppb). The lowest TN, TDN, and DIN were observed at Moshassuck River @ Higginson Ave. (TN = 539 ppb, TDN = 640 ppb, DIN = 483 ppb).
Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Pawtuxet Cove (TN = 994 ppb, TDN = 799 ppb, DIN = 633.4). The lowest surface TN was observed at the Bullock Reach Buoy (TN = 438 ppb), the lowest surface TDN was observed at Pomham Rocks (TDN = 155 ppb), and lowest surface DIN was at Edgewood Yacht Club (DIN = 20 ppb). Chlorophyll a concentrations at the surface bay stations averaged 4.5 μg/L overall with a maximum of 7.9 μg/L at Conimicut Point.
Week of August 20 - 26, 2023
Nutrients Sampling
Nutrient samples were collected from fourteen river stations and eight bay stations on August 23rd, 2023. Edgewood Shoal was sampled at the surface and bottom; all other bay stations were sampled at the surface only. In the five days prior to sampling, there were 2.16 inches of rainfall recorded at T.F. Green due to a heavy rain event on August 18th.
Among the river stations sampled, the highest total nitrogen (TN) concentration was observed at Pawtuxet River @ Broad Street (TN = 1,815 ppb, average of duplicates), while the highest total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN) concentrations were at Ten Mile River @ Central Ave. (TDN = 1,480 ppb, DIN = 1,013.9 ppb). The lowest TN and TDN were observed at Ten Mile River @ Roger Williams Ave. (TN = 510 ppb, TDN = 666 ppb), while the lowest DIN was at Coles River @ Milford Rd. (97.4 ppb, average of duplicates).
Among the bay stations sampled, the highest surface TN, TDN, and DIN were observed at Pawtuxet Cove (TN = 1,020 ppb, TDN = 892 ppb, DIN = 662.3 ppb). The lowest surface TN and DIN were observed at the Bullock Reach Buoy (TN = 540 ppb, DIN = 119.5 ppb), while the lowest surface TDN was at Conimicut Point (276 ppb). Chlorophyll a concentrations at the surface bay stations averaged 3.95 μg/L overall with a maximum of 7.02 μg/L at Conimicut Point.
Week of August 6 - 12, 2023
Nutrients Sampling
Nutrient samples were collected from seven river stations and seven bay stations on August 9th, 2023. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.48 inches of rainfall recorded at T.F. Green.
Among the river 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 = 1,390 ppb, TDN = 1,520 ppb, and DIN = 1244.2 ppb). The lowest TN and TDN were observed at Moshassuck River @ Footbridge at Mill Street (TN = 741.5 ppb, TDN= 680.5 ppb, average of duplicates), while the lowest DIN was at Blackstone River @ Bikepath Bridge (DIN = 484.7 ppb).
Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Phillipsdale Landing (TN = 1,050 ppb, TDN = 919 ppb, DIN = 561 ppb). The lowest surface TN, TDN, and DIN concentrations were observed at Conimicut Point (TN = 738 ppb, TDN = 360 ppb, DIN = 143.2 ppb). Chlorophyll a concentrations at the surface bay stations averaged 4.16 μg/L overall with a maximum at the Bullock Reach Buoy (6.94 μg/L, average of duplicates).
June 17, 2024
Bacteria Sampling
On June 17th, seventeen 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 0.06 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 135 MPN/100 mL and 52 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at Collier Point Park.
Enterococci results had an overall geometric mean of 18 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at Gaspee Point and Conimicut Point to 98 MPN/100 mL at Point St Bridge.
The next scheduled sampling date is July 3.
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 | Geometric mean ≤35 colonies/100 mL |
| Shellfishing | Geometric mean ≤14 MPN/100 mL | NO ENTEROCOCCI CRITERIA |
Table adapted from Rhode Island Water Quality Regulations (250-RICR-150-05-1); see regulations for complete details.
