AN open hatch of the Dandan water tank on Thursday prompted the Commonwealth Utilities Corporation to issue a “boil water” notice, CUC water/wastewater Division Manager Kevin Watson said during a board meeting on Friday.
He said after discovering that the hatch on top of the Dandan tank had been opened, they contacted CUC’s compliance and safety department and the Department of Public Safety to investigate.
Watson said as part of best management practices, they isolated the tank to prevent any of its water from reaching customers.
“We also made provisions to route water from another service area as much as we could to limit the affected persons or…affected customers,” he added.
Laboratory personnel then took samples of water from the surface of the reservoir and conducted multiple chemical analyses, he said.
Because the results of bacteriological tests would be available after 18-24 hours, Watson said they left the tank isolated during that time.
He said the results of one of the tests indicated that everything was good.
Watson said they also investigated the reservoir and determined that there was no sign that anything had been introduced into the water.
“We let the analysis to play out,” he said. The next day, Friday, the results from the samples indicated it had no coliform bacteria, Watson added. “The samples taken the day before the discovery and all those results were without coliform bacteria as well. The water was safe. No coliform bacteria were in our distribution system.”
But they did detect the presence of coliform on the surface water samples, he said.
Still, the presence of coliform from the surface could have been caused by something blown in through the open hatch or even in the process of taking a sample itself, Watson said.
He said when they got the positive result for the presence of coliform, they followed up with a confirmation sample.
“And we are waiting for those results now,” he said.
They also contacted the Bureau of Environmental and Coastal Quality which, he added, agreed with the steps CUC was taking.
CUC also didn’t need to issue a boil water notice, “but we thought it was prudent to do a precautionary [notice], and precautionary means it’s basically up to the customers. Even if the risk is very slight, there is still a possibility,” Watson said.
As for the tank, he said it had been secured and the hatch was closed and padlocked.
After learning that the samples tested negative for coliform, CUC on June 23 issued an announcement that the precautionary boil water notice was no longer in effect.
Kevin Watson
