“Follow the Flush” with a Free Tour!

Narragansett Bay Commission Offers Free Clean Water Tours: Follow the Flush!

In celebration of Rhode Island Clean Water Week, the Narragansett Bay Commission (NBC) will offer free public tours of its award-winning Field’s Point Wastewater Treatment Facility in Providence on Saturday, April 12 from 10:00 AM to 1:00 PM.

The tours will include a look at the region’s most sophisticated water quality lab, “touch-a-truck” and “touch-a-boat” with the NBC’s maintenance and research vehicles, a clean water scavenger hunt, and other fun activities.

“This facility is simultaneously one of the oldest and most advanced clean water facilities in the nation,” said NBC Chairman Vincent Mesolella. “We’re so excited to give the public the opportunity to ‘follow the flush’ and view the process that has made Narragansett Bay cleaner than it has been in 150 years.”

In addition, the NBC will issue certificates of completion to all students who take the tour that may be redeemed for extra credit at school (but students are advised check with their teacher first).

“I am confident that anyone who experiences this tour will be amazed and appreciative by the clean water efforts in our community,” Mesolella added.

Members of the public can book a tour on the half hours between 10:00 AM and 1:00 PM by emailing nbcpr@narrabay.com. Spaces are limited. The tour will take approximately 90 minutes.

The NBC joins four other clean water agencies in Rhode Island offering free public tours during Rhode Island Clean Water Week. Information on other tours is available at ricwa.org

September 9 – 15, 2024

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was good to fair this week. Weather was dry, with no precipitation recorded at T.F. Green. The Blackstone River flow remained below the 20-year daily daily median. Surface salinity averaged 21.6 ppt and ranged from 16.5 ppt to 26.4 ppt. At the bottom, salinity averaged 26.7 ppt and ranged from 21.4 ppt to 29.4 ppt. Temperatures continued to decrease this week, averaging 22.2°C at the surface and ranging 19.1°C – 24.9°C. At the bottom, temperatures averaged 21.5°C and ranged 20.7°C – 23.4°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) during the week. Surface DO average 10.43 mg/L and ranged from 4.13 mg/L to 18.24 mg/L. Bottom DO concentrations averaged 4.5 mg/L and ranged from 2.5 mg/L to 10.8 mg/L. The longest periods of hypoxic conditions spanned an hour and a half, occurring at the bottom depth on the morning and then again in the afternoon of September 11th. During these periods, bottom DO averaged around 2.62 mg/L and 2.79 mg/L, respectively. Chlorophyll readings increased from last week, averaging 51.20 µg/L at the surface and 32.3 µg/L at the bottom. Maximum chlorophyll at the surface reached 95.4 µg/L on the evening of September 13th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Sondes were swapped this week on the morning of September 10th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.4 ppt, 29.2 ppt, and 30.8 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.0 – 29.1 ppt, mid salinity ranged 27.7 – 30.4 ppt, and bottom salinity ranged 30.0 – 31.5 ppt. Surface temperature averaged 21.3°C and ranged from 20.2°C to 23.4°C. Mid temperatures averaged 20.9°C and ranged from 20.1°C to 22.6°C. Bottom temperatures averaged 20.2°C and ranged from 19.3°C to 21.1°C. DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week.   Surface DO averaged 8.3 mg/L and ranged 6.1 – 11.3 mg/L. In the mid waters, DO averaged 6.6 mg/L and ranged 4.7 – 9.7 mg/L. At the bottom, DO averaged 4.5 mg/L and ranged 3.4 – 6.6 mg/L.  Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the week. Readings averaged 12.0 µg/L at the surface, 12.7 µg/L at mid-depth, and 6.9 µg/L at the bottom.  The maximum surface chlorophyll was 30.7 µg/L on the afternoon of September 9th.

September 2 – 8, 2024

Phillipsdale Landing

Sondes were swapped this week on the morning of September 5th.  Overall, water quality at Phillipsdale Landing was good to fair this week. Weather conditions were dry, with only a trace amount of precipitation recorded at T.F. Green. The Blackstone River flow remained below the 20-year daily median. Surface salinity averaged 21.7 ppt and ranged from 14.8 ppt to 25.6 ppt. At the bottom, salinity averaged 25.7 ppt and ranged from 20.4 ppt to 28.4 ppt. Temperatures continued to decrease this week, averaging 22.7°C at the surface and ranging 20.6°C – 24.6°C. At the bottom, temperatures averaged 22.4°C and ranged 21.6°C – 24.3°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) briefly during the week. Surface DO average 8.2 mg/L and ranged from 3.73 mg/L to 15.08 mg/L. Bottom DO concentrations averaged 4.9 mg/L and ranged from 2.4 mg/L to 10.5 mg/L. The longest period of hypoxic conditions (1 hour, 30 minutes) occurred at the bottom depth on the morning of September 4th. During this period, bottom DO averaged around 2.53 mg/L. Chlorophyll readings decreased from last week, averaging 34.9 µg/L at the surface and 21.7 µg/L at the bottom. Maximum chlorophyll at the surface reached 79.24 µg/L on the morning of September 2nd. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Overall, water quality was good to fair at Bullock Reach this week. Salinity averaged 27.6 ppt, 28.9 ppt, and 30.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 25.9 – 28.6 ppt, mid salinity ranged 26.8 – 30.2 ppt, and bottom salinity ranged 28.4 – 31.2 ppt. Surface temperature averaged 21.9°C and ranged from 20.6°C to 23.5°C. Mid temperatures averaged 21.7°C and ranged from 20.6°C to 23.3°C. Bottom temperatures averaged 20.9°C and ranged from 19.7°C to 22.7°C.

DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 7.5 mg/L and ranged 5.6 – 10.5 mg/L. In the mid waters, DO averaged 6.3 mg/L and ranged 4.3 – 8.8 mg/L. At the bottom, DO averaged 4.5 mg/L and ranged 2.9 – 8.0 mg/L.  Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the week. Readings averaged 15.4 µg/L at the surface, 12.0 µg/L at mid-depth, and 2.9 µg/L at the bottom.  The maximum surface chlorophyll was 40.7 µg/L on the afternoon of September 3rd.

August 26 – September 1, 2024

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was good to fair this week. Weather was rainy, with 1.38 inches of precipitation recorded at T.F. Green. The Blackstone River flow fluctuated through the week in response to rain, but remained below the 20-year daily median for most of the week. Surface salinity averaged 20.2 ppt and ranged from 12.9 ppt to 24.4 ppt. At the bottom, salinity averaged 24.5 ppt and ranged from 18.9 ppt to 28.2 ppt. Temperatures continued to increase this week, averaging 24.0°C at the surface and ranging 21.0°C – 26.6°C. At the bottom, temperatures averaged 23.4°C and ranged 22.2°C – 25.0°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) at the surface throughout the week, while DO at the bottom waters dropped below the hypoxic threshold throughout the week. Surface DO average 7.70 mg/L and ranged from 2.96 mg/L to 16.08 mg/L. Bottom DO concentrations averaged 3.7 mg/L and ranged from 1.4 mg/L to 8.0 mg/L. The longest period of hypoxic conditions (9 hours) occurred at the bottom depth during the evening of August 29th. During this period, bottom DO averaged around 2.00 mg/L. Chlorophyll readings increased from last week, averaging 49.5 µg/L at the surface and 18.8 µg/L at the bottom. Maximum chlorophyll at the surface reached 108.3 µg/L on the afternoon of August 29th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Sondes were swapped this week on the morning of August 27th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 26.6 ppt, 28.3 ppt, and 30.1 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 24.8 – 28.1 ppt, mid salinity ranged 26.3 – 30.0 ppt, and bottom salinity ranged 28.3 – 31.2 ppt. Surface temperature averaged 23.4°C and ranged from 21.7°C to 24.5°C. Mid temperatures averaged 22.8°C and ranged from 21.5°C to 24.2°C. Bottom temperatures averaged 21.5°C and ranged from 20.1°C to 23.0°C.

DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) at the surface and mid depths throughout the week.  Bottom DO sporadically dropped below the hypoxia threshold this week. Surface DO averaged 7.8 mg/L and ranged 5.5 – 9.5 mg/L. In the mid waters, DO averaged 5.7 mg/L and ranged 3.2 – 8.6 mg/L. At the bottom, DO averaged 3.9 mg/L and ranged 2.7 – 6.1 mg/L.  The longest period of hypoxic conditions (1 hour and 30 minutes) occurred at the bottom depth during August 31st.  During this period, bottom DO averaged around 2.83 mg/L. Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the week. Readings averaged 16.2 µg/L at the surface, 11.6 µg/L at mid-depth, and 3.3 µg/L at the bottom.  The maximum surface chlorophyll was 30.4 µg/L on the morning of September 1st.

Bullock Reach Buoy

On a bright and warm June morning, the EM team embarked on the inaugural deployment of the RIPDES required monitoring Bullocks Reach buoy, marking the commencement of this season’s environmental data collection efforts. Prior to deployment, EM staff conducted thorough on shore testing of the buoy system to ensure optimal performance. Navigating to the predetermined coordinates, EM initiated the deployment process. The buoy also features a weather station to monitor atmospheric conditions including wind speed, air temperature, and humidity.

May 21, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on May 21, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, less than 0.1 inches of precipitation were recorded at T.F. Green.  Water column stratification varied between the sites this week from weakly stratified at Phillipsdale Landing and Pawtuxet Cove to well-mixed at all other sites.

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 recorded this week was measured around 2.5 meters below the surface at Pomham Rocks.

May 14, 2025

Water column profiles were conducted at seven locations in the Providence and Seekonk River estuaries on May 14, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 1.73 inches of precipitation were recorded at T.F. Green.  Strong stratification of the water column stratification was observed at all sites.

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 recorded this week was measured around 2 meters below the surface at Conimicut Point.

May 7, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on May 7, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 2.1 inches of precipitation were recorded at T.F. Green.  Water column stratification varied between the sites this week from weakly stratified at Point Street Bridge to strongly stratified at all other sites.

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 recorded this week was measured around 1.5 meters below the surface at Edgewood Yacht Club.

April 17, 2025

Phytoplankton samples were collected on April 17, 2025 at Bullock Reach and analyzed in the laboratory shortly after collection.

It was sunny, clear and breezy on this day. The water temperature was 6.11 degrees Celsius, and Sonde data was not recorded.

The qualitative tow net sample had a moderate filtration time and the filtrate was golden brown with some particulates.

The analysis of the quantitative whole water sample revealed a total of 590,000 cells/L. The microflagellates were found at 337,000 cells/L. The most predominant phytoplankton genera were Dinoflagellate spp. at 93,000 cells/L, Thalassiosira spp. at 44,000 cells/L, and Chaetoceros spp. at 43,000 cells/L.

200x phase contrast micrograph of Pleurosigma spp.

Pleurosigma is a genus of marine pelagic diatoms which are shaped like an elongated diamond. They are present throughout the world and breed particularly well in bays, inlets and ports. These diatoms are motile, and they employ a pulsating of the body to induce gliding movement as well as occasional circular rotations around one end of the organism to change course.

August 19 – 25, 2024

Phillipsdale Landing

Sondes were swapped this week on the morning of August 20th.  Overall, the water quality at Phillipsdale Landing was good to fair this week. Weather conditions included sporadic rain events, with 0.49 inches of precipitation recorded at T.F. Green. The Blackstone River flow declined over the week, dropping below the 20-year daily median at midweek. Surface salinity averaged 20.1 ppt and ranged from 12.4 ppt to 25.2 ppt. At the bottom, salinity averaged 23.6 ppt and ranged from 17.4 ppt to 26.7 ppt. Temperatures continued to increase this week, averaging 23.3°C at the surface and ranging 21.7°C – 24.9°C. At the bottom, temperatures averaged 23.1°C and ranged 22.1°C – 24.8°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO average 6.6 mg/L and ranged from 2.7 mg/L to 13.7 mg/L. Bottom DO concentrations averaged 4.2 mg/L and ranged from 1.7 mg/L to 10.3 mg/L. The longest period of hypoxic conditions (6 hours, 30 minutes) occurred at the bottom depth between the night of August 20th to the morning of August 21st. During this period, bottom DO averaged around 2.52 mg/L. Chlorophyll readings decreased from last week, averaging 20.76 µg/L at the surface and 15.9 µg/L at the bottom. Maximum chlorophyll at the surface reached 126.5 µg/L on August 21st around midday. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Overall, the water quality was good to fair at Bullock Reach this week. Salinity averaged 26.9 ppt, 28.2 ppt, and 29.2 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 24.9 – 28.3 ppt, mid salinity ranged 25.8 – 29.6 ppt, and bottom salinity ranged 28.0 – 30.4 ppt. Surface temperature averaged 22.9°C and ranged from 21.3°C to 24.2°C. Mid temperatures averaged 22.5°C and ranged from 21.5°C to 23.9°C. Bottom temperatures averaged 21.9°C and ranged from 20.6°C to 23.3°C.

DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week at the surface and middle depths. Bottom DO dropped below the hypoxia threshold infrequently throughout the week. Surface DO averaged 7.1 mg/L and ranged 4.5 – 11.3 mg/L. In the mid waters, DO averaged 5.5 mg/L and ranged 3.6 – 8.4 mg/L. At the bottom, DO averaged 4.3 mg/L and ranged 2.3 – 7.3 mg/L.  The longest period of hypoxic conditions (1 hour, 15 minutes) occurred at the bottom depth on the morning of August 19th.  During this period, bottom DO averaged around 2.58 mg/L. Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the week. Readings averaged 17.4 µg/L at the surface, 13.0 µg/L at mid-depth, and 9.0 µg/L at the bottom.  The maximum surface chlorophyll was 42.1 µg/L on the afternoon of August 23rd.

August 12 – 18, 2024

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was fair to poor this week. Weather conditions included sporadic rain events, with 1.18 inches of precipitation recorded at T.F. Green. The Blackstone River flow fluctuated through the week in response to rain. Surface salinity averaged 16.3 ppt and ranged from 7.0 ppt to 23.5 ppt. At the bottom, salinity averaged 25.0 ppt and ranged from 14.9 ppt to 28.5 ppt. Temperatures continued to increase this week, averaging 24.4°C at the surface and ranging 22.5°C – 26.7°C. At the bottom, temperatures averaged 23.4°C and ranged 22.2°C – 24.8°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) over the week. Surface DO average 8.3 mg/L and ranged from 2.0 mg/L to 21.8 mg/L. Bottom DO concentrations averaged 1.7 mg/L and ranged from 0.5 mg/L to 6.2 mg/L. The longest period of hypoxic conditions (1 day, 12 hours and 15 minutes) occurred at the bottom depth between the night of August 13th to the morning of August 15th. During this period, bottom DO averaged around 0.86 mg/L. Chlorophyll readings increased from last week, averaging 51.1 µg/L at the surface and 25.6 µg/L at the bottom. Maximum chlorophyll at the surface reached 219.8 µg/L on the afternoon of August 12th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Sondes were swapped this week on the morning of August 15th. Overall, the water quality was good to fair at Bullock Reach this week. Salinity averaged 26.3 ppt, 28.7 ppt, and 30.8 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 22.8 – 25.3 ppt, mid salinity ranged 21.8 – 24.8 ppt, and bottom salinity ranged 20.3 – 23.1 ppt. Surface temperature averaged 24.1°C and ranged from 22.8°C to 25.3°C. Mid temperatures averaged 23.1°C and ranged from 21.8°C to 24.8°C. Bottom temperatures averaged 21.4°C and ranged from 20.3°C to 23.1°C.

DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) at the surface. Middle and Bottom DO dropped below the hypoxia threshold sporadically throughout the week. Surface DO averaged 8.7 mg/L and ranged 5.6 – 13.7 mg/L. In the mid waters, DO averaged 4.6 mg/L and ranged 2.1 – 9.0 mg/L. At the bottom, DO averaged 3.0 mg/L and ranged 1.8 – 5.1 mg/L.  The longest period of hypoxic conditions (1 day, 10 hours, and 45 minutes) occurred at the bottom depth during the night of August 16th until the morning of August 18th.  During this period, bottom DO averaged around 2.29 mg/L. Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the week. Readings averaged 20.1 µg/L at the surface, 13.4 µg/L at mid-depth, and 4.1 µg/L at the bottom.  The maximum surface chlorophyll was 54.5 µg/L on the afternoon of August 13th.

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