Daria DiBiasio – Narrabay

March 25, 2026

On March 25^th, 2026 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, 1.83 inches of precipitation was recorded at TF Green. This was the first sampling event of 2026.

Fecal coliform counts were higher in the Seekonk River, compared to the Providence River (geometric mean of 88 MPN/100 mL for the Seekonk River compared to 25 MPN/100mL for the Providence River) for sampling conducted on March 25th. The maximum count (150 MPN/100 mL) was measured at the Off BP Outfall sampling location.

Enterococci results had an overall geometric mean of 21 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at Conimicut Point and Point Street Bridge to 52 MPN/100 mL at Phillipsdale Landing.

The next scheduled sampling date is April 8^th.

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.

Table adapted from Rhode Island Water Quality Regulations (250-RICR-150-05-1); see regulations for complete details.

December 24, 2025

Nutrient samples were collected from seven river stations on December 24^th. In the five days prior to sampling, 0.77” of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Pawtuxet River @ Broad St. TN = 1,670 ppb, TDN = 1,700 ppb, DIN = 1,567.1 ppb). The lowest TN, TDN, and DIN were observed at Moshassuck River @ Higginson Ave. (TN = 563 ppb, TDN = 572 ppb, DIN = 424.3 ppb).

The next scheduled sampling date is January 7^th, 2026.

December 10, 2025

Nutrient samples were collected from thirteen river stations on December 10^th. In the five days prior to sampling, 0.07” of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Ten Mile River @ Central Ave. (TN = 3,100 ppb, TDN = 3,130 ppb, DIN = 2,793.0 ppb). The lowest TN and TDN were observed at Moshassuck River @ Higginson Ave (TN = 480 ppb, TDN = 554 ppb). The lowest DIN was observed at Coles River @ Milford Rd. (245.7 ppb).

The next scheduled sampling date is December 24^th, 2025.

November 26, 2025

Nutrient samples were collected from seven river stations and one bay station on November 26^th. The bay station was sampled at the surface and bottom. In the five days prior to sampling, 0.59” of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN) and dissolved inorganic nitrogen (DIN) were observed at Pawtuxet River @Broad St (TN = 1,740 ppb, DIN = 1,562.0 ppb). The highest total dissolved nitrogen (TDN) was observed at Woonasquatucket River @Valley St (TDN = 1820 ppb). The lowest TN and TDN were observed at Moshassuck River @Footbridge at Mill St (TN = 536 ppb, TDN = 723 ppb). The lowest DIN was observed at Woonasquatucket River @ Manton Ave. Bridge (DIN = 389.4 ppb).

At the bay station sampled, Phillipsdale Landing, the surface concentrations were as follows: total nitrogen (TN) = 1,420 ppb, total dissolved nitrogen (TDN) = 1,380 ppb and dissolved inorganic nitrogen (DIN) = 1018.5 ppb.

The next scheduled sampling date is December 10^th, 2025.

November 13, 2025

Nutrient samples were collected from six bay stations on November 13^th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, 0.69” of precipitation were recorded at T.F. Green.

Among the bay stations sampled, the highest surface total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Pawtuxet Cove (TN = 1,160 ppb, TDN = 1200 ppb, DIN = 940.8 ppb). The lowest surface TN, TDN, and DIN were observed at Bullock Reach (TN = 540 ppb, TDN = 464 ppb, DIN = 258.0 ppb).

The next scheduled sampling date is November 26^th, 2025.

November 12, 2025

Nutrient samples were collected from seven river stations on November 12^th. In the five days prior to sampling, 0.69” of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Pawtuxet River @ Broad St. (TN = 1,520 ppb, TDN = 2,430 ppb, DIN = 1,340.6 ppb). The lowest TN and DIN were observed at Moshassuck River @ Footbridge at Mill St. (TN = 533 ppb, DIN = 342.2 ppb). The lowest TDN was observed at Woonasquatucket River @ Manton Ave. Bridge (669 ppb).

The next scheduled sampling date is November 13^th, 2025.

December 3, 2025

On December 3rd, 2025, thirteen stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; two of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, 0.97 inches of precipitation was recorded at TF Green. Overall, bacteria counts were higher than during the previous sampling event.

Fecal coliform counts were higher in the Seekonk River, compared to the Providence River (geometric mean of 471 MPN/100 mL for the Seekonk River compared to 56 MPN/100mL for the Providence River) for sampling conducted on December 3rd. The maximum count (1,500 MPN/100 mL) was measured at the Crook Point sampling location.

Fecal coliform counts were higher in the Providence River, compared to the previous sampling on November 19th (geometric mean of 56 MPN/100 mL compared to 22 MPN/100 mL on 11/19). Fecal coliform counts were higher in the Seekonk River, compared to the previous sampling on November 19th (geometric mean of 471 MPN/100 mL compared to 31 MPN/100 mL on 11/19).

Enterococci results had an overall geometric mean of 208 MPN/100 mL. Enterococci counts ranged from 122 MPN/100 mL at Phillipsdale Landing to 504 MPN/100 mL at Point Street Bridge.

The next scheduled sampling date is December 17^th.

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

Table adapted from Rhode Island Water Quality Regulations (250-RICR-150-05-1); see regulations for complete details.

October 15, 2025

Phytoplankton samples were collected on October 15, 2025 at Bullock’s Reach and analyzed in the laboratory shortly after collection.

It was sunny and windy on this day. The water temperature was 16.13 °C and the salinity was 26.53 psu.

The qualitative tow net sample had a short to moderate filtration time. The filtrate was light tan and contained some dark precipitates.

The analysis of the quantitative whole water sample revealed a total of 69,000 cells/L. The microflagellates were found at 30,000 cells/L. The most predominant phytoplankton genera were Chaetoceros spp. at 31,000 cells/L, Prorocentrum spp. at 3,000 cells/L, and pennate diatoms at 3,000 cells/L.

400x phase contrast image of *Dinophysis acuminata*

Dinophysis acuminata is a marine phytoplankton species of dinoflagellates that is found in the coastal waters of Rhode Island and north Atlantic waters. This is one of several phototrophic species that are classed as toxic, as they produce okadaic acid which can cause diarrhetic shellfish poisoning (DSP).

October 29, 2025

Nutrient samples were collected from thirteen river stations on October 29^th. In the five days prior to sampling, trace amounts of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Ten Mile River @ Central Ave. (TN = 2,710 ppb, TDN = 2,720 ppb, DIN = 2,640.0 ppb). The lowest TN was observed at Moshassuck River @ Footbridge at Mill St. (590 ppb). The lowest TDN was observed at Palmer River @ Rt. 6 (691 ppb). The lowest DIN was observed at Coles River @ Milford Rd. (101.4 ppb).

The next scheduled sampling date is November 13^th, 2025.

October 15, 2025

Nutrient samples were collected from seven river stations and seven bay stations on October 15^th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, 2.41” of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Blackstone River @ Bikepath Bridge (TN = 1,390 ppb, TDN = 1,390 ppb, DIN = 971.9 ppb). The lowest TN, TDN, and DIN were observed at Moshassuck River @ Footbridge at Mill St. (TN = 577 ppb, TDN = 542 ppb, DIN = 310.8 ppb).

Among the bay stations sampled, the highest surface total nitrogen (TN) and dissolved inorganic nitrogen (DIN) were observed at Phillipsdale Landing (TN = 1,320 ppb, DIN = 833.0 ppb). The highest surface total dissolved nitrogen (TDN) was observed at Pawtuxet Cove (1770 ppb). The lowest surface TN, TDN, and DIN were observed at Bullock Reach (TN = 642 ppb, TDN = 522 ppb, DIN = 245 ppb).

The next scheduled sampling date is October 29^th, 2025.