Nutrients Sampling

​Nutrient samples were collected from seven river stations and seven bay stations on September 4th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there was trace precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN) and total dissolved nitrogen (TDN) were observed at Blackstone River @ Stateline (TN = 1,340 ppb, TDN = 1,560 ppb). The highest dissolved inorganic nitrogen (DIN) concentration was observed at Moshassuck River @ Footbridge at Mill St. (1,158 ppb). The lowest TN and TDN were observed at Blackstone River @ Slater Mill (TN = 951 ppb, TDN = 958 ppb), while the lowest DIN was observed at Pawtuxet River @ Broad St. (665 ppb).

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 = 963 ppb, TDN = 610  ppb, DIN = 368 ppb). The lowest surface TN and TDN were at Conimicut Point (TN = 456 ppb, TDN = 167 ppb, average of duplicates), while the lowest surface DIN concentrations were observed at Conimicut Point, Edgewood Yacht Club and Pomham Rocks (13 ppb, reflecting minimum detection limits).

The next scheduled sampling date is September 18, 2024.

Nutrient samples were collected from 14 river stations and 8 bay stations on July 26th. 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 0.47 inches of rainfall recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN) and total dissolved nitrogen (TDN) concentrations were observed at Ten Mile River @ Central Ave. (TN = 1,470 ppb, TDN = 1,550 ppb); the highest dissolved inorganic nitrogen (DIN) concentration was observed at Pawtuxet River @ Broad St. (1,120 ppb).  The lowest TN and TDN were observed at Moshassuck River @ Footbridge at Mill St. (TN = 654 ppb, TDN = 688 ppb, average of duplicates), while the lowest DIN was at Coles River @ Milford Rd. (147 ppb).

Among the bay stations sampled, the highest surface TN was observed at Pomham Rocks (989 ppb), the highest surface TDN was observed at Phillipsdale Landing (940 ppb), and the highest surface DIN was observed at Pawtuxet Cove (679 ppb). The lowest surface TN was observed at India Point Park (TN = 731 ppb), while the lowest surface TDN and DIN were at Bullock Reach Buoy (TDN = 230 ppb, DIN = 24.0 ppb). Chlorophyll a concentrations at the surface bay stations were moderately elevated this week; concentrations averaged 14.5 μg/L overall with a maximum of 26.4 μg/L at Bullock Reach Buoy.

The next scheduled sampling date is August 8, 2023.

Nutrient samples were collected from 14 river stations and 8 bay stations on July 26th. 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 0.47 inches of rainfall recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN) and total dissolved nitrogen (TDN) concentrations were observed at Ten Mile River @ Central Ave. (TN = 1,470 ppb, TDN = 1,550 ppb); the highest dissolved inorganic nitrogen (DIN) concentration was observed at Pawtuxet River @ Broad St. (1,120 ppb).  The lowest TN and TDN were observed at Moshassuck River @ Footbridge at Mill St. (TN = 654 ppb, TDN = 688 ppb, average of duplicates), while the lowest DIN was at Coles River @ Milford Rd. (147 ppb).

Among the bay stations sampled, the highest surface TN was observed at Pomham Rocks (989 ppb), the highest surface TDN was observed at Phillipsdale Landing (940 ppb), and the highest surface DIN was observed at Pawtuxet Cove (679 ppb). The lowest surface TN was observed at India Point Park (TN = 731 ppb), while the lowest surface TDN and DIN were at Bullock Reach Buoy (TDN = 230 ppb, DIN = 24.0 ppb). Chlorophyll a concentrations at the surface bay stations were moderately elevated this week; concentrations averaged 14.5 μg/L overall with a maximum of 26.4 μg/L at Bullock Reach Buoy.

The next scheduled sampling date is August 8, 2023.

Nutrient samples were collected from seven river stations and seven bay stations on July 12th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 1.91 inches of rainfall recorded at T.F. Green, all from a rain event on July 10th. 

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 = 1,140 ppb, TDN = 1,080 ppb, DIN = 796 ppb). The lowest TN and TDN were observed at Woonasquatucket River @ Manton Ave. Bridge (TN = 664 ppb, TDN = 633 ppb, average of duplicates), while the lowest DIN was at Blackstone River @ Stateline (357 ppb).

Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Pawtuxet Cove (TN = 1,100 ppb, TDN = 882 ppb, DIN = 640 ppb, average of duplicates). The lowest surface TN and DIN were observed at Conimicut Point (TN = 577 ppb, DIN < 13.0 ppb), while the lowest surface TDN was at Bullock Reach Buoy (181 ppb). Chlorophyll a concentrations at the surface bay stations were relatively low at most sites and moderately elevated at Edgewood Yacht Club and Pawtuxet Cove; concentrations averaged 5.46 μg/L overall with a maximum of 15.7 μg/L in one of the duplicate samples at Edgewood Yacht Club.

The next scheduled sampling date is July 26, 2023.​

Nutrient samples were collected from 14 river stations and nine bay stations on June 28th. 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 and the morning of, there were 1.51 inches of rainfall recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN) concentration was observed at Warren Reservoir/Kickemuit River (1,590 ppb), while the highest total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River @ Central Ave. (TDN = 1,310 ppb, DIN = 970 ppb). The lowest TN and TDN was observed at Moshassuck River @ Higginson Ave. (TN = 505 ppb, TDN = 479 ppb, average of duplicates), while the lowest DIN was at Coles River @ Milford Rd. (109 ppb).

Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Phillipsdale Landing (TN = 1,120 ppb, TDN = 772 ppb, DIN = 522 ppb). The lowest surface TN was observed at Conimicut Point (600 ppb), the lowest surface TDN was at Edgewood Yacht Club (206 ppb), and the lowest surface DIN was at Pomham Rocks (14.8 ppb). Chlorophyll a concentrations at the surface bay stations were relatively low at most sites but elevated at Edgewood Yacht Club, Pomham Rocks, and India Point Park; concentrations averaged 12.34 μg/L overall with a maximum of 22.3 μg/L at Edgewood Yacht Club.

The next scheduled sampling date is July 12, 2023.​

Nutrient samples were collected from seven river stations and seven bay stations on June 14th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.59 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 = 1,560 ppb, TDN = 1,360 ppb, DIN = 1,150 ppb). The lowest TN and TDN was observed at Woonasquatucket River @ Manton Ave. Bridge (TN = 796 ppb, TDN = 772 ppb), while the lowest DIN was at Blackstone River @ Bikepath Bridge (314 ppb).

Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Pawtuxet Cove (TN = 1,220 ppb, TDN = 984 ppb, DIN = 767 ppb). The lowest surface TN and TDN concentrations were observed at Conimicut Point (TN = 586 ppb, TDN = 153 ppb), while three locations – Conimicut Point, Edgewood Yacht Club, and Phillipsdale Landing – had surface DIN concentrations below the detection limit of 13.0 ppb. Chlorophyll a concentrations at the surface bay stations were relatively low, averaging 5.59 μg/L across all sites with a maximum of 11.9 μg/L at Phillipsdale Landing.

The next scheduled sampling date is June 28, 2023.​

Nutrient samples were collected from 14 river stations and eight bay stations on May 31st. 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 was no rainfall recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN) concentration was observed at Warren Reservoir/Kickemuit River (1,770 ppb), while the highest total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River @ Central Ave. (TDN = 1,650 ppb, DIN = 1,360 ppb). The lowest TN was observed at Moshassuck River @ Footbridge at Mill St. (790 ppb), the lowest TDN was at Palmer River @ Rt. 6 (715 ppb), and the lowest DIN was at Coles River @ Milford Rd. (122 ppb).

Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Phillipsdale Landing (TN = 1,250 ppb, TDN = 903 ppb, DIN = 570 ppb). The lowest surface TN and TDN concentrations were observed at Conimicut Point (TN = 444 ppb, TDN = 167 ppb), while several locations – Conimicut Point, Edgewood Yacht Club, Bullock Reach Buoy, and Edgewood Shoal – had surface DIN concentrations below the detection limit of 13.0 ppb. Chlorophyll a concentrations at the surface bay stations were relatively low at most sites but elevated at Edgewood Yacht Club, Pomham Rocks, and India Point Park; concentrations averaged 12.1 μg/L overall with a maximum of 26.6 μg/L at Pomham Rocks.

The next scheduled sampling date is June 14, 2023.​

Nutrient samples were collected from seven river stations on May 17th and seven bay stations on May 18th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.01 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 Ten Mile River @ Central Ave. (TN = 1,360 ppb, TDN = 1,310 ppb, DIN = 1,080 ppb). The lowest TN, TDN, and DIN concentrations were observed at Woonasquatucket River @ Manton Ave. Bridge (TN and TDN = 743 ppb, DIN = 538 ppb, average of duplicates).

Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Pawtuxet Cove (TN = 1,110 ppb, TDN = 1,010 ppb, DIN = 778 ppb). The lowest surface TN and DIN concentrations were observed at Conimicut Point (TN = 439 ppb, DIN = 13.0 ppb), while the lowest surface TDN concentration was observed at Bullock Reach Buoy (149 ppb, average of duplicates). Chlorophyll a concentrations at the surface bay stations were relatively low, averaging 9.61 μg/L across all sites with a maximum of 14.0 μg/L (average of duplicates) at Bullock Reach Buoy.

The next scheduled sampling date is May 31, 2023.

Nutrient samples were collected from 14 river stations and eight bay stations on May 3rd. 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 3.64 inches of rainfall recorded at T.F. Green due to some heavy rain events on April 29th and 30th. 

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 @ Central Ave. (TN and TDN = 1,020 ppb, DIN = 686 ppb). The lowest TN and TDN concentrations were observed at Blackstone River @ Stateline (TN = 565 ppb, TDN = 512 ppb), while the lowest DIN was observed at Palmer River @ Rt. 6 (69.9 ppb).

Among the bay stations sampled, the highest surface TN concentration was observed at Edgewood Shoal (895 ppb), while the highest surface TDN and DIN were observed at Phillipsdale Landing (TDN = 798 ppb, DIN = 507 ppb). The lowest surface TN was observed at Pawtuxet Cove (753 ppb), the lowest surface TDN was observed at Pomham Rocks (662 ppb), and the lowest surface DIN was observed at India Point Park (437 ppb, average of duplicates). Chlorophyll a concentrations at the surface bay stations were relatively low, averaging 2.33 μg/L across all sites with a maximum of 4.10 μg/L at Edgewood Shoal.

The next scheduled sampling date is May 17, 2023.​

Nutrient samples were collected from eight local river stations, and seven bay stations on April 19, 2023. All bay stations were sampled at surface and bottom. In the five days prior to sampling, there was 0.17 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) were observed at Blackstone River at Stateline. The TN, TDN, DIN were 1,210 ppb, 1,220 ppb, and 951.4 ppb, respectively. The lowest TN, TDN and DIN were observed at the duplicate samples collected at Pawtuxet River at Broad Street. The TN, TDN and DIN averaged 535 ppb, 246.5 ppb, and 66.7 ppb, respectively. 

Among the bay stations sampled, the highest TN, TDN, and DIN were observed at Ten Mile River at Central Ave. The TN, TDN, DIN were 2,300 ppb, 2,000 ppb, and 1,727 ppb, respectively. Among the bay stations sampled, the highest TN (1,290 ppb), TDN (1,060 ppb), DIN (818.9 ppb) were observed at Phillipsdale Landing. The lowest surface TN (378 ppb) and TDN (129 ppb) were observed at Conimicut Point. The lowest surface DIN (13 ppb) was observed at Bulluck Reach Buoy. Chlorophyll a concentrations at the bay stations increased from the previous sampling event, averaging 10.2 ug/L across all sites. The maximum result (15.17 ug/L) occurred at Bullock Reach Buoy.

Data from additional sampling dates (typically every two weeks) are pending analysis and writeup.​