Bay Bacteria Sampling

On June 4th, 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, 0.39 inches of precipitation was recorded at TF Green. Overall bacteria counts remained approximately the same as the previous sampling event.

Fecal coliform counts were higher in the Seekonk River, compared to the Providence River (geometric mean of 93 MPN/100 mL for the Seekonk River compared to 30 MPN/100mL for the Providence River) for sampling conducted on June 4th. The maximum count (430 MPN/100 mL) was measured at the Point Street Bridge sampling location.

Fecal coliform counts were lower in the Providence River, compared to the previous sampling on May 21st (geometric mean of 30 MPN/100 mL compared to 45 MPN/100 mL on 5/21). Fecal coliform counts were higher in the Seekonk River, compared to the previous sampling on May 21st (geometric mean of 93 MPN/100 mL compared to 37 MPN/100 mL on 5/21). 

Enterococci results had an overall geometric mean of 18 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 183 MPN/100 mL at Point St Bridge.

The next scheduled sampling date is June 18th.

​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 May 21st, 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, 0.04 inches of precipitation was recorded at TF Green. Overall bacteria counts were lower than during the previous sampling event.

Fecal coliform counts were lower in the Seekonk River, compared to the Providence River (geometric mean of 37 MPN/100 mL for the Seekonk River compared to 45 MPN/100mL for the Providence River) for sampling conducted on May 21st. The maximum count (2,300 MPN/100 mL) was measured at the Point Street Bridge sampling location.

Fecal coliform counts were lower in the Providence River, compared to the previous sampling on May 7th (geometric mean of 45 MPN/100 mL compared to 369 MPN/100 mL on 5/7). Fecal coliform counts were lower in the Seekonk River, compared to the previous sampling on May 7th (geometric mean of 37 MPN/100 mL compared to 1121 MPN/100 mL on 5/7). 

Enterococci results had an overall geometric mean of 16 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 74 MPN/100 mL at Point St Bridge.

The next scheduled sampling date is June 4^th.

​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 May 7th, 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, 2.10 inches 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 Providence River (geometric mean of 1121 MPN/100 mL for the Seekonk River compared to 369 MPN/100mL for the Providence River) for sampling conducted on May 7th. The maximum count (9,300 MPN/100 mL) was measured at the Collier Point Park sampling location.

Fecal coliform counts were higher in the Providence River, compared to the previous sampling on April 23rd (geometric mean of 369 MPN/100 mL compared to 12 MPN/100 mL on 4/23). Fecal coliform counts were higher in the Seekonk River, compared to the previous sampling on April 23rd (geometric mean of 1121 MPN/100 mL compared to 72 MPN/100 mL on 4/23). 

Enterococci results had an overall geometric mean of 128 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at Conimicut Point to 2046 MPN/100 mL at Point St Bridge.

The next scheduled sampling date is May 21^st.

​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 April 23rd, 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, 0.05 inches of precipitation was recorded at TF Green. Overall bacteria counts were lower than during the previous sampling event.

Fecal coliform counts were higher in the Seekonk River, compared to the Providence River (geometric mean of 72 MPN/100 mL for the Seekonk River compared to 12 MPN/100mL for the Providence River) for sampling conducted on April 23rd. The maximum count (430 MPN/100 mL) was measured at the Point Street Bridge sampling location.

Fecal coliform counts were lower in the Providence River, compared to the previous sampling on March 26th (geometric mean of 12 MPN/100 mL compared to 38 MPN/100 mL on 3/26). Fecal coliform counts were higher in the Seekonk River, compared to the previous sampling on March 26th (geometric mean of 72 MPN/100 mL compared to 67 MPN/100 mL on 3/26).  

Enterococci results had an overall geometric mean of 12 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 20 MPN/100 mL at Point St Bridge.

The next scheduled sampling date is May 7th.

​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 March 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, 1.06 inches of precipitation was 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 Providence River, compared to the previous sampling on March 12^th  (geometric mean of 38 MPN/100 mL compared to 10 MPN/100 mL on 3/12). 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 Conimicut Point (geometric mean of two samples) to 20 MPN/100 mL at most other sites.

The next scheduled sampling date is April 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 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 March 12^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 higher in both the Seekonk and Providence Rivers than during the previous sampling event.

Fecal coliform counts were higher in the Providence River, compared to the previous sampling on February 26^th (geometric mean of 10 MPN/100 mL compared to 7 MPN/100 mL on 2/26). The maximum count (230 MPN/100 mL) was measured at the Point St. Bridge sampling location.

Enterococci results had an overall geometric mean of 12 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 411 MPN/100 mL at Point St. Bridge.

The next scheduled sampling date is March 26.

​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 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 April 24th, 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 0.28 inches as recorded at TF Green. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on March 27th, likely because of the drier weather leading up to sampling. 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 59 MPN/100 mL and 7 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 14 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at South FP East, Gaspee Point, and Conimicut Point to 41 MPN/100 mL at Phillipsdale Landing.

The next scheduled sampling date is May 8.

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.​​​​​​​​​​