Tara Franey – Narrabay

April 29, 2026

Nutrient samples were collected from seven river stations and seven bay stations on April 29^th. All bay stations were sampled at the surface and bottom. 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), and dissolved inorganic nitrogen (DIN) were observed Pawtuxet River @ Broad St (TN = 1,040 ppb, DIN = 942.2 ppb). The highest total dissolved nitrogen (TDN) was observed at Blackstone River @ Slater Mill (1,750 ppb). However, a significantly higher TDN compared to the TN observed at this site may indicate an issue with the sampling or analysis. The lowest TN, TDN, and DIN were observed at Moshassuck River @ Footbridge at Mill St (TN = 524 ppb, TDN = 573 ppb, DIN = 408.1).

Among the bay stations sampled, the highest surface TN, TDN, and DIN were observed at Pawtuxet Cove (TN = 971 ppb, TDN = 1,260 ppb, DIN = 739.1). The lowest surface TN was observed at Pomham Rocks (359 ppb). The lowest TDN was observed at Conimicut Point, Pomham Rocks, and Bullock Reach Buoy (<100.0 ppb). The lowest surface DIN was observed at Conimicut Point (13 ppb, reflecting minimum detection limits for DIN).

The next scheduled sampling date is May 12^th, 2026.

April 15, 2026

Nutrient samples were collected from thirteen river stations and eight bay stations on April 15^th. All bay stations were sampled at the surface, and Edgewood Shoal was sampled at the surface and bottom. In the five days prior to sampling, 0.03” 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 Ten Mile River @ Central Ave (TN = 1,680 ppb, TDN = 1,680 ppb, DIN = 1,388.7 ppb). The lowest TN and TDN were observed at Moshassuck River @ Higginson Ave (TN = 426 ppb, TDN = 416 ppb). The lowest DIN was observed at Coles River @ Milford Rd (149 ppb).

Among the bay stations sampled, the highest surface TN and TDN were observed at Phillipsdale Landing (TN = 1,024 ppb, TDN = 975.5 ppb, average of duplicates). The highest DIN was observed at Pawtuxet Cove (729.8 ppb). The lowest surface TN and TDN were observed at Conimicut Point (TN = 474 ppb, TDN = 168 ppb). The lowest surface DIN was observed at Conimicut Point and Bullock Reach Buoy (13 ppb, reflecting minimum detection limits for DIN).

The next scheduled sampling date is April 29^th, 2026.

April 1, 2026

Nutrient samples were collected from fourteen river stations on April 1^st. In the five days prior to sampling, 0.08” 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 = 1,790 ppb, TDN = 2,240 ppb, DIN = 1,608 ppb). The lowest TN, TDN, and DIN were observed at Coles River @ Milford Rd (TN = 602 ppb, TDN = 574 ppb, DIN = 215.3 ppb).

The next scheduled sampling date is April 15^th, 2026.

May 20, 2026

On May 20^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, trace amounts of precipitation were recorded at TF Green.

Fecal coliform counts were lower in the Seekonk River, compared to the previous sampling on May 7^th (geometric mean of 91 MPN/100 mL compared to 103 MPN/100 mL on 5/7). Fecal coliform counts were similar in the Providence River, compared to the previous sampling on May 7^th (geometric mean of 26 MPN/100 mL on both sampling days).

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 74 MPN/100 mL at Point Street Bridge.

The next scheduled sampling date is June 3^rd.

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.

May 7, 2026

On May 7^th, 2026, sixteen 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, 0.28” of precipitation was recorded at TF Green.

Fecal coliform counts were lower in the Seekonk River, compared to the previous sampling on April 23^rd (geometric mean of 103 MPN/100 mL compared to 223 MPN/100 mL on 4/23). Fecal coliform counts were lower in the Providence River, compared to the previous sampling on April 23^rd (geometric mean of 26 MPN/100 mL compared to 16 MPN/100 mL on 4/23).

Enterococci results had an overall geometric mean of 21 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 988 MPN/100 mL at Point Street Bridge.

The next scheduled sampling date is May 20^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.

April 23, 2026

On April 23^rd, 2026, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; four of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, 0.21” 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 previous sampling on April 8^th (geometric mean of 223 MPN/100 mL compared to 80 MPN/100 mL on 4/8). Fecal coliform counts were also higher in the Providence River, compared to the previous sampling on April 8^th (geometric mean of 16 MPN/100 mL compared to 10 MPN/100 mL on 4/8).

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 20 MPN/100 mL at Phillipsdale Landing.

The next scheduled sampling date is May 6^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.

April 8, 2026

On April 8^th, 2026, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; four of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, 0.26” of precipitation was recorded at TF Green. Overall, bacteria counts were slightly lower than during the previous sampling event.

Fecal coliform counts were similar in the Seekonk River, compared to the previous sampling on March 25^th (geometric mean of 80 MPN/100 mL compared to 88 MPN/100 mL on 3/25). Fecal coliform counts were lower in the Providence River, compared to the previous sampling on March 25^th (geometric mean of 10 MPN/100 mL compared to 25 MPN/100 mL on 3/25).

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 41 MPN/100 mL at Point St. Bridge.

The next scheduled sampling date is April 23^rd.

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

Surface chlorophyll data were collected on October 15, 2025, while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuary. The average chlorophyll concentrations were categorized as good in all areas. The average chlorophyll concentrations were also categorized as good over all areas surveyed. Overall, chlorophyll ranged from 0.64 µg/L to 3.60 µg/L with an average of 1.57 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

October 1, 2025

Surface chlorophyll data were collected on October 1, 2025, while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuary. The average chlorophyll concentrations were categorized as fair in the Seekonk River, and as good in all other areas. The average chlorophyll concentrations were categorized as good over all areas surveyed. Overall, chlorophyll ranged from 2.07 µg/L to 10.16 µg/L with an average of 4.94 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

September 17, 2025

Surface chlorophyll data were collected on September 17, 2025, while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuary. The average chlorophyll concentrations were categorized as good in the Northern Providence River Channel and the Seekonk River, and as fair in all other areas. The average chlorophyll concentrations were categorized as fair over all areas surveyed. Overall, chlorophyll ranged from 0.98 µg/L to 20.49 µg/L with an average of 6.73 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.