Until the Blenheim water tower is back in action, there’s a chance the recent boil water advisory in South Kent could recur.
Tim Sunderland, general manager of the Public Utilities Commission (PUC) said a pump failure at the south water treatment plant led to a drop in pressure that triggered the advisory.
Sunderland said 12,000 customers were impacted by the advisory, which told residents to boil their water before using it. The advisory was in place for more than 48 hours, but that’s largely due to the fact two water samples, taken a minimum of 24 hours apart, have to show no contamination before the advisory can be lifted.
The maintenance being done on the Blenheim water tower had an impact on the issue, Sunderland said, as it is out of service at the moment.
“Normally the tower provides storage of water and additional pressure to the system,” he said. “With that out of service, the reaction of pressure in the system is quite quick.”
But the tower won’t be back online for another month, as sandblasting work and repainting is taking place on the tower, inside and out.
Sunderland said the PUC plans for when towers are taken out of service, and in the Blenheim tower’s case, preplanning began a year ago. Staff look at all redundancies, but mechanical failures are a possibility.
“It will be about 30 days before the tower comes back online. We don’t expect it to happen again, but there’s always a chance.”
Sunderland said the pump shut down and by the time the operator could get to the treatment plant to get it running again, the pressure had dropped to below 20 psi.
“As soon as the pressure goes below 20 psi, we are mandated to report,” Sunderland explained.
Sunderland said when pressure in the system drops to 20 psi or lower, there’s the possibility external water could make it into the internal distribution network, and that triggers the advisory.
Blenheim residents reported having brown water on Saturday, and Sunderland said that was to be expected.
“The brown water is a sign of the reduction of pressure. The water flow is agitated or sometimes reversed. If you have cast iron pipes, and Blenheim has, the biofilm that normally grows inside those pipes gets agitated and you can get brown water,” he said.
The method used to notify residents had some people critical of how they learned of the advisory.
But Sunderland defended how the boil water advisory information was delivered.
“Before social media, it was hand delivery of notices. We still do that for smaller water breaks,” he said. “For the size and the scope last week (Aug. 4), to his the masses as quickly as possible, the public health unit directed us to go mass media. I think we did that quite adequately.
“The hand delivery of notices would have taken 24 hours or more and an army of bodies.”
