One month after the Kent County Water Authority E coli scare, there is still no definitive answer about what caused the bad test result, which prompted a four-day boil-water advisory for Coventry, West Warwick, East Greenwich and other communities served by KCWA.
“We couldn’t find that particular bacteria again,” said KCWA General Manager Tim Brown in an interview Monday. “We tested it after the tank was isolated and never found it again.”
Brown said the likely cause of the E coli test result was stagnation in a water storage tank off Wakefield Street in West Warwick, the site of the sample that tested positive for E coli on Sept. 20. That tank remains off line.
The chlorine “residual” level in the Wakefield Street tank was very low at the time of the bad test, said Brown, .02 percent. The minimum for the system is .2 percent. Chlorine is used as a disinfectant.
Brown said the Wakefield Street tank was “locked up,” causing the water stagnation. A lock up happens when a valve gets locked in the closed position. In this case, a new pumping protocol kept positive pressure on the value, forcing its closure. Brown said the other tanks were all tested for a similar problem but none of the others had an issue. He said the problem with the Wakefield Street tank was its close proximity to the booster station.
Another contributing factor could be an overall decrease in water use, which has dropped in recent years with the disappearance of some industrial and commercial users.
“It is affecting how we are operating the system and that could have caused some of the lock up in the tank,” said Brown.
According to Brown, there is no plan to increase rates because of the E coli incident. The system has had a significant infrastructure improvement plan in place since 1999. At $5.4 million a year, it accounts for about 25 percent of the water authority’s overall budget.
Rates may be going up, however, because Providence has put in a request to raise its rates to the state Public Utilities Commission, which will probably make a ruling by the end of the year, Brown said. KCWA buys water from Providence.“If the rates go up,” said Brown, “... it’s because of Providence Water and wholesale prices going up.”