Originally published in Island Ad-Vantages, January 31, 2019
Stonington Water Company cited for 2018 violation
by Rich Hewitt
The Stonington Water Company has been cited for exceeding federal levels for specific radioactive materials in the water last year.
The utility received notice from the state’s Drinking Water Program that it had violated the maximum contamination levels for “Gross Alpha” in April and August of 2018. Although the problem has been corrected and levels are back below federal limits, the running annual average for 2018 was 17.2 picoCuries, above the 15 picoCurie level set by the EPA.
According to Annaleis Hafford, the engineer from Olver Associates who manages the water company, the utility operates a radon removal system and also runs two uranium anion exchange systems, one for the summer wells and one for the main 110 well. That system uses a chemical process to replace uranium and other radioactive materials, which occur naturally in the granite and soil in town, with sodium. The state regularly monitors radioactive levels in the filtered water. The Gross Alpha represents all of the non-uranium radioactive elements in the water.
There were a number of factors that contributed to the problem, Hafford said, but the main failing was that the utility did not regenerate or replace the material used to filter those radioactive particles in the spring as it usually does, so the April reading was high. Hafford said both the 110 well and the summer wells were used extensively to meet summer demand, which resulted in another high reading in August.
The water company regenerated the filters in the fall, Hafford said, and the levels have been normal since then.
Water users were notified of the violation and Hafford noted that EPA’s calculated risk associated with drinking water above the MCL is one person in 10,000 who drinks two liters of water per day for 70 years. Although the risk is small, Hafford did not try to minimize the seriousness of the problem.
Although the problem has been corrected and the levels are back to normal, the report from the Drinking Water Program is based on a running average, so some of those high readings from 2018 will be included in the next report, Hafford said, and customers will have to be notified again. She said the DWP knows the problem has been corrected and she is working with the state to see if that requirement can be waived.
The water company is working to refill the standpipe after water levels dropped as low as 33 feet from a full level of 48 feet. The system lost the main production well on January 10 after a power outage. The pump on that well ran only half a cycle on that day and electricians determined that it was a problem with the motor.
Hafford said she suspects there is a problem with the power source to the well that affected the motor driving the pump. That suspicion is fueled by the fact that this is the second time they’ve had problems following a power outage. The pump that failed was just two years old, and should have lasted for at least 10 years, according to Town Manager Kathleen Billings.
Hafford said she will try to meet with Emera in an effort to track down the problem. She also is checking with the insurance carrier to see if the problem will be covered.
Meanwhile, the utility is working to refill the standpipe to its 48-foot level. Hafford said they used the summer wells when the main well was out of service and are using those wells intermittently to increase the water levels.
The utility was able to account for 62.8 percent of the metered water through its system, leaving 37.2 percent unaccounted for. That is the best reading since 2009 when the unmetered water figures were at 62.9 percent.
“That’s still lousy,” Hafford said, noting that the percentages should be up around 75 percent at least. “But it is getting better.”