Posted on: Wednesday, July 17, 2002

Wahiawa sewage safeguards improved

By Scott Ishikawa
Advertiser Central O'ahu Writer

WAHIAWA — The city has made mechanical and procedural improvements to its Wahiawa Wastewater Treatment Plant following a weekend spill into Lake Wilson of 878,000 gallons of treated wastewater that wasn't disinfected.

Community leaders questioned why it took city wastewater officials at least 12 hours before the spill was detected. The spill has forced state health officials to prevent public use of Lake Wilson — it's also known as Wahiawa Reservoir — for fishing or boating for at least a week.

City Environmental Services deputy director Frank Doyle said procedural changes have been made to the plant's detection system to prevent another lengthy delay such as the one that occurred during the weekend spill.

"First thing we did was make sure the ultraviolet system was properly hooked up to the plant detection system, as well as our citywide detection system in the event of another malfunction," Doyle said. New operational changes also were instituted for additional regular maintenance and routine checks at the plant.

"We're done everything to make sure something like this is caught earlier," he said.

Doyle said the spilled wastewater went through all the treatments at the city's Wahiawa Wastewater Treatment Plant except for an ultraviolet light filtering system that normally disinfects the wastewater after it has received tertiary treatment, the highest level for removal of pollutants. Following the ultraviolet light treatment, the effluent is then released into the reservoir.

But the ultraviolet light system malfunctioned starting Saturday night, and shut down intermittently until the problem was discovered during a routine check and fixed at 11 a.m. Sunday, according to the city.

The city Wastewater Treatment and Disposal Division notified state Department of Health officials and posted warning signs.

Wahiawa Neighborhood Board chairman Donovan Dela Cruz said the board will discuss the issue at its next monthly meeting Aug. 19.

Since the Wahiawa treatment plant had undergone $14 million in upgrade improvements, some in the community wondered why an alarm system did not go off during the spill.

"You would think with all the improvements, they would have had some sort of safety net," Dela Cruz said.