Bay Bacteria Sampling

On February 26^th, 2025, 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, no precipitation was recorded at TF Green. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers than during the previous sampling event.

Fecal coliform counts were lower in the Providence River, compared to the previous sampling on December 18^th (geometric mean of 7 MPN/100 mL compared to 91 MPN/100 mL on 12/18). The maximum count (430 MPN/100 mL) was measured at the Point St. Bridge sampling location.

Enterococci results had an overall geometric mean of 15 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 146 MPN/100 mL at the Point St. Bridge sampling location.

The next scheduled sampling date is March 12.

​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​m	Enterococci
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.​​​​​​​​​​

On December 18^th, 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 20^th (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 20^th (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​m	Enterococci
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.​​​​​​​​​​

On November 7th, 2024 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, no precipitation was recorded at TF Green. 

​Overall, bacteria counts in the Seekonk River were lower compared to previous sampling (October 9th, 2024); in the Providence River, bacteria counts were similar compared to the previous sampling event (October 23rd, 2024). 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 51 MPN/100 mL and 11 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at Bishop Point. 

Enterococci results had an overall geometric mean of 14 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 31 MPN/100 mL at Point St. Bridge.

The next scheduled sampling date is November 20th.

​​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​m	Enterococci
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.​​​​​​​​​​

​On October 9th, 2024 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, precipitation totaled 0.81 inches as recorded at TF Green. Overall, bacteria counts were higher in both the Seekonk River and the Providence River compared to the previous sampling event (September 25th, 2024). 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 69 MPN/100 mL and 37 MPN/100 mL, respectively). The maximum count (930 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 75 MPN/100 mL at Point St. Bridge.

The next scheduled sampling date is October 23rd.

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 Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric ​m​e​a​n​ ≤50​ MPN/1​​00​ m​L​ <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	Geometric 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.​​​​​​​​​​

On September 25th, 2024 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, precipitation totaled 0.78 inches as recorded at TF Green. Overall, bacteria counts were lower in the Seekonk River and higher in the Providence River than during the previous sampling event. 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 46 MPN/100 mL and 14 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at all sites except Point St Bridge, which was 63 MPN/100 mL.

The next scheduled sampling date is October 9th.

​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 Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric ​m​e​a​n​ ≤50​ MPN/1​​00​ m​L​ <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	Geometric 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.​​​​​​​​​​

On September 11th, 2024, 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, precipitation totaled 0.02 inches as recorded at TF Green. Overall, bacteria counts were higher in the Seekonk River and lower in the Providence River than during the previous sampling event. 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 54 MPN/100 mL and 8 MPN/100 mL, respectively). The maximum count (930 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at all sites except Point St Bridge, which was 63 MPN/100 mL.

The next scheduled sampling date is September 25th.

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 Coli​fo​rm	Enterococci
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	Geometric 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.​​​​​​​​​​

​On August 28th, 2024 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, precipitation totaled 0.38 inches as recorded at TF Green. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers than during the previous sampling event.

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 53 MPN/100 mL and 13 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at Bishop Point and Point St Bridge. 

Enterococci results had an overall geometric mean of 14 MPN/100 mL. Enterococci counts ranged from 110 MPN/100 mL at Point St. Bridge to <10 MPN/100 mL at all other sites.

The next scheduled sampling date is September 11th.

​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 Coli​fo​rm	Enterococci
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	Geometric 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.​​​​​​​​​​

​On August 14th, 2024 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, precipitation totaled 0.05 inches as recorded at TF Green. Overall, bacteria counts were lower in the Seekonk River and higher in the Providence River than during the previous sampling event. 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 95 MPN/100 mL and 38 MPN/100 mL, respectively). The maximum count (930 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 14 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at Phillipsdale Landing, South FP East, Gaspee Point, and Conimicut Point to 121 MPN/100 mL at Point St Bridge.

The next scheduled sampling date is August 28.

​​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 Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric ​m​e​a​n​ ≤50 MPN/1​​00​ mL​ <10% ​o​f​​ samples >400 MPN/100 ​mL	Geom​etric mean ≤35 colo​nies​/100 mL​ All sa​mples ≤104 colonies/100 ​​mL2
Shellfishing	Geometric 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.​​​​​​​​​​

On August 1st, 2024 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, precipitation totaled 0.11 inches as recorded at TF Green. Overall, bacteria counts were higher in both the Seekonk and Providence Rivers than during the previous sampling event. 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 249 MPN/100 mL and 33 MPN/100 mL, respectively). The maximum count (2300 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 14 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at Gaspee Point and Conimicut Point to 86 MPN/100 mL at Point St Bridge.

The next scheduled sampling date is August 14.

​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 Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric ​m​e​a​n​ ≤50 MPN/1​​00​ mL​ <10% ​o​f​​ sam​ples >400 MPN/100 ​mL	Geom​etric mean ≤35 colo​nies​/100 mL​ All sa​mples ≤104 colonies/100 ​​mL2
Shellfishing	Geometric 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.​​​​​​​​​​