Bay Bacteria Sampling

On October 11, 2023, 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 0.36 inches as recorded at TF Green. 

Overall, bacteria levels were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on September 27^th. Fecal coliform levels were higher in the Seekonk River sites than in the Providence River sites (geometric means of 55 MPN/100 mL and 29 MPN/100 mL, respectively). The maximum concentration (430 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 17 MPN/100 mL and ranged from <10 MPN/100 mL at Gaspee Point, Conimicut Point, and Pawtuxet Cove to 187 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric ​me​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 September 27^th, 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 2.77 inches as recorded at TF Green. 

Overall, bacteria levels were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on September 14th, likely because the first event had less time in between the rainfall and sampling. Fecal coliform levels were higher in the Seekonk River sites than in the Providence River sites (geometric means of 475 MPN/100 mL and 237 MPN/100 mL, respectively). The maximum concentration (930 MPN/100 mL) was measured at both Phillipsdale Landing and Point St Bridge. 

Enterococci results had an overall geometric mean of 102 MPN/100 mL and ranged from 31 MPN/100 mL Conimicut Point to 1,354 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric ​me​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 September 14^th, twenty stations were sampled for fecal coliform bacteria in the Providence River and Seekonk River; five of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, precipitation totaled 1.23 inches as recorded at TF Green. 

Overall, bacteria counts were elevated this week. Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 6,012 MPN/100 mL and 965 MPN/100 mL, respectively). The maximum count (24,000 MPN/100 mL) was measured at Crook Point. 

Enterococci results had an overall geometric mean of 528 MPN/100 mL. Enterococci counts ranged from 85 MPN/100mL at Conimicut Point to 2,987 MPN/100 mL at Phillipsdale Landing.
​

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 C​​RITERIA

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 31^st, six stations were sampled for fecal coliform bacteria in the Providence River; one of these stations was also sampled for enterococci bacteria. There was a smaller set of stations sampled than normal due to weather conditions. Precipitation in the five days prior to sampling totaled 0.14 inches as recorded at TF Green. 

Overall, bacteria counts were higher in the Providence River this week than during the previous sampling event on August 16. The fecal coliform geomean for the Providence River was 110 MPN/100 mL this week. The maximum count (430 MPN/100 mL) was measured at the Save ​​the Bay site in the Providence River. 

Enterococci was only sampled at one site this week. Gaspee Point measured a non-detect enterococci count. 

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

​	​Fe​cal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 16, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers.  Five of these stations were also sampled for enterococci bacteria. Precipitation in the five days prior to sampling totaled 0.61 inches as recorded at TF Green.

The geometric mean of fecal coliform results for all sites was 149 MPN/100 mL compared to 41 MPN/100 mL on August 2. Overall, bacteria counts were higher in both the Seekonk and Providence Rivers this week than during the previous sampling event on August 2. Fecal coliform counts were geomeans of 435 MPN/ 100 mL in the Seekonk River and 90 MPN/ 100 mL in the Providence River. The maximum count (9300 MPN/100 mL) was measured at Bullock Reach Buoy in the Providence River.

Enterococci results had an overall geometric mean of 35 MPN/100 mL. Enterococci counts ranged from non-detect at a Gaspee Point and Conimicut Point to 238 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 2, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers.  Five of these stations were also sampled for enterococci bacteria. Precipitation in the five days prior to sampling totaled 0.66 inches as recorded at TF Green.

The geometric mean of fecal coliform results for all sites was 41 MPN/100 mL compared to 463 MPN/100 mL on July 19. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on July 19. Fecal coliform counts were geomeans of 97 MPN/ 100 mL in the Seekonk River and 28 MPN/ 100 mL in the Providence River. The maximum count (930 MPN/100 mL) was measured at Point St. Bridge in the Providence River.

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from non-detect at Gaspee Point, Conimicut Point, and a Phillipsdale Landing duplicate to 52 MPN/100 mL at Point St. Bridge. 

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 July 19, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers.  Five of these stations were also sampled for enterococci bacteria. Precipitation in the five days prior to sampling totaled 3.96 inches as recorded at TF Green, most of which occurred on July 16.

The geometric mean of fecal coliform results for all sites was 463 MPN/100 mL compared to 3472 MPN/100 mL on July 5. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on July 5. Fecal coliform counts were geomeans of 289 MPN/ 100 mL in the Seekonk River and 578 MPN/ 100 mL in the Providence River. The maximum count (9300 MPN/100 mL) was measured at Point St. Bridge in the Providence River.

Enterococci results had an overall geometric mean of 26 MPN/100 mL. Enterococci counts ranged from non-detect at a Phillipsdale Landing duplicate to 158 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 July 5, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers.  Five of these stations were also sampled for enterococci bacteria. Precipitation in the five days prior to sampling totaled 1.25 inches as recorded at TF Green, most of which occurred on July 4.

The geometric mean of fecal coliform results for all sites was 3472 MPN/100 mL compared to 31 MPN/100 mL on June 21. Overall, bacteria counts were higher in both the Seekonk and Providence Rivers this week than during the previous sampling event on June 21. Fecal coliform counts were geomeans of 3160 MPN/ 100 mL in the Seekonk River and 3629 MPN/ 100 mL in the Providence River. The maximum count (46,000 MPN/100 mL) was measured at Off FP Outfall in the Providence River.

Enterococci results had an overall geometric mean of 1250 MPN/100 mL. Enterococci counts ranged from 246 MPN/100mL at a Conimicut Point duplicate to 5475 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 June 21, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers.  Five of these stations were also sampled for enterococci bacteria. Precipitation in the five days prior to sampling totaled 1.30 inches as recorded at TF Green.

The geometric mean of fecal coliform results for all sites was 31 MPN/100 mL compared to 17 MPN/100 mL on June 7. Overall, bacteria counts were higher in the Seekonk River this week than during the previous sampling event on June 7. Fecal coliform counts were geomeans of 256 MPN/ 100 mL in the Seekonk River and 12 MPN/ 100 mL in the Providence River. The maximum count (4300 MPN/100 mL) was measured at Bishop Point in the Seekonk River.

Enterococci results had an overall geometric mean of 12 MPN/100 mL. Enterococci counts ranged from non-detect at Conimicut Point, Phillipsdale Landing, South FP East, and Gaspee Point to 41 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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 June 7, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers.  Five of these stations were also sampled for enterococci bacteria. Precipitation in the five days prior to sampling totaled 0.14 inches as recorded at TF Green.​

The geometric mean of fecal coliform results for all sites was 17 MPN/100 mL compared to 73 MPN/100 mL on May 24. Overall, bacteria counts were lower in the Seekonk River and Providence River this week than during the previous sampling event on May 24. Fecal coliform counts were geomeans of 41 MPN/ 100 mL in the Seekonk River and 12 MPN/ 100 mL in the Providence River. The maximum count (210 MPN/100 mL) was measured at Point St. Bridge in the Providence River.

Enterococci results had an overall geometric mean of 15 MPN/100 mL. Enterococci counts ranged from non-detect at South FP East and Gaspee Point to 52 MPN/100 mL at Point St. Bridge.

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

​	​Fecal Coli​fo​rm	Enterococci
Primary Con​​​t​a​c​t1​​​​​	Geom​e​tric me​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.​​​​​​​​​​​