Historical News

October 3, 2024

Water Column Profiles

​Water column profiles were conducted at seven locations in the Providence and Seekonk River estuaries on October 3, 2024 using a Seabird Electronics profiler. In the five days leading up to the survey, no precipitation was recorded at T.F. Green.  Water column stratification varied between the sites this week, from well-mixed to weakly stratified.

Dissolved oxygen (DO) conditions were not observed to be below the hypoxia threshold (2.9 mg/L) at any site profiled this week. The highest fluorescence readings for the week were measured around 1 meter below the surface at Edgewood Yacht Club.

September 25, 2024

Water Column Profiles

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on September 25, 2024 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.78 inches of precipitation were recorded at T.F. Green. Water column stratification at the sites varied from well-mixed to weakly stratified.​

Dissolved oxygen (DO) conditions were below the hypoxia threshold (2.9 mg/L) in the lower portion of the water column at Edgewood Yacht Club and Pomham Rocks. The highest fluorescence readings for the week were measured around 1 meter below the surface at Pawtuxet Cove.

September 11, 2024

Water Column Profiles

​Water column profiles were conducted at seven locations in the Providence and Seekonk River estuaries on September 11, 2024 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.02 inches of precipitation were recorded at T.F. Green. Water column stratification at the sites varied from well-mixed at Edgewood Yacht Club and Point Street Bridge, to moderately stratified at Phillipsdale Landing. 

Dissolved oxygen (DO) conditions were below the hypoxia threshold (2.9 mg/L) in the lower portion of the water column at Edgewood Yacht Club, and in the middle and lower portions of the water column at Phillipsdale Landing. The highest fluorescence readings for the week were measured around 1 meter below the surface at Phillipsdale Landing.​

September 4, 2024

Water Column Profiles

​Water column profiles were conducted at seven locations in the Providence and Seekonk River estuaries on September 4, 2024 using a Seabird Electronics profiler. In the five days leading up to the survey, no precipitation was recorded at T.F. Green. Water column stratification at the sites varied from well-mixed at Pomham Rocks, to weakly stratified at all other profiled sites.

Dissolved oxygen (DO) conditions were below the hypoxia threshold (2.9 mg/L) in the lower portion of the water column at Phillipsdale Landing, Edgewood Yacht Club, and India Point Park. The highest fluorescence readings for the week were measured around 1 meter below the surface at Pomham Rocks. ​

December 18, 2024

Bacteria Sampling

On December 18th, 2024, fifteen stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; four of these stations were also sampled for enterococci bacteria. Further sampling was planned for the day in the Seekonk River, but was omitted due to weather issues. In the five days prior to sampling, 0.46" of precipitation was recorded at TF Green.

Fecal coliform counts were higher in the Providence River, compared to the previous sampling on November 20th (geometric mean of 91 MPN/100 mL compared to 9 MPN/100 mL on 11/20). The maximum count (430 MPN/100 mL) was measured at the Save the Bay sampling location.

Only one fecal coliform sample was analyzed from the Seekonk River, with a fecal coliform count of 43 MPN/100mL at Crook Point. This is higher than the geometric mean from samples taken on November 20th (14 MPN/100 mL), but may not be representative of the Seekonk River as a whole.

Enterococci results had an overall geometric mean of 66 MPN/100 mL. Enterococci counts ranged from 37 MPN/100 mL at Conimicut Point (geometric mean of two samples) to 121 MPN/100 mL at Point St. Bridge. 

The next scheduled sampling date is January 2.

​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 
 ​​
​Fec​al Co​li​fo​r​mEnterococci
Primary Con​​​t​a​c​t1​​​​​

Geom​e​tric ​m​e​a​n​ ≤50​ MPN/1​​00​ mL​
<10% ​o​f​​ samples >4​00 MPN/100 ​mL

Geom​etric mean ≤35 colo​nies​/100 mL​​
All sa​mples ≤104 colonies/100 ​​mL2

Shellfishing

Geometr​ic mean ≤14 MPN/100​ mL
<10% of samples >49 MPN/100 mL3​

NO ENTEROCOCCI CR​ITERIA​
1Fecal coliform primary contact criteria app​lied 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.​​​​​​​​​​


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