Frozen pressure switch, faulty alarm causes water tank overflow off Buena Vista Road

Homeowners dealing with damaged water lines that burst after freezing may find some consolation in hearing the Columbus Water Works also is not immune from that curse of frigid weather.

Early this morning the water froze in a pressure switch on a tank atop a hill between Higgs Drive and Upland Way, south of Buena Vista Road in the Belvedere area, and an alarm to warn workers the tank had filled didn't activate.

The result: The 3-million-gallon tank continued to fill until the water reached an overflow pipe, ran out of the tank and down the hill onto nearby streets, including busy Buena Vista Road.

The overflow continued from about 1:30 to 2:30 a.m. Witnesses summoned the fire department, which alerted the water works to shut down the tank. But by that time water had washed onto Buena Vista Road in freezing temperatures, creating an icy traffic hazard.

Jim Patterson of the water works explained the system this way: Because the water authority's lines work on a gravity feed, in some areas the water must be pumped into an elevated tank before it can flow downhill.

This tank has at its base a tube that fills when the tank is full, exerting enough pressure to press a switch that closes the tank valves, so no more water goes in. Although that tube had a heating element on it, it froze, blocking the pressure switch, and an alarm that should have warned workers back at the water treatment plant never went off, Patterson said. So the tank filled until it overflowed.

The water works is not the only entity that had a problem with the freezing weather. Property owners all over town have discovered that as overnight temperatures dropped into the teens and daytime weather remained unusually cold, pipes froze and burst. Some breaks in unoccupied buildings were not discovered for hours or days, so the water kept flowing out as the water meters kept running up.

How does the water works handle that?

Property owners who prove they've had such damage can get what's called a "one-third leak adjustment." Patterson said. According to water works policy, the customer first must repair the damage and provide proof, such as a plumber's receipt, and then wait until the water authority sends an inspector to ensure the repairs were effective. If not, no credit will be given until the work is judged to be sufficient. Once that requirement is satisfied, the water works will examine the two highest bills issued during the time the leak occurred and use a formula to determine what credit the customer gets. The customer still must keep paying bills until this process is completed.

This story was originally published January 12, 2010 at 2:45 PM with the headline "Frozen pressure switch, faulty alarm causes water tank overflow off Buena Vista Road."