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.