Malfunctions close sewer plant

May 21, 2003 11:00 pm

By SUNNY LOCKWOOD

After three weeks of full operation, Angels Camp's new wastewater plant was shut down Tuesday because of equipment failure, but may be restarted tomorrow.

City Engineer Gary Ghio said malfunctions filled the new plant with raw sewage, causing operators to shut the facility down while crews clean up the mess.

In the meantime, city sewage is being treated by the temporary plant that was set up while the new plant was being built. The temporary facility hadn't been dismantled yet, "just in case something went wrong," Ghio said.

Interim Chief Plant Operator Carol Woolf said this morning that crews are still hosing down the intermediate basin, the filters and other areas where raw sewage flowed.

"It's my intention to get back in the normal mode as soon as possible," she said. "I'm hoping we can start up (the new plant) by tomorrow, but everything has to be clean first."

Ghio said the crews "Hose it all down to break it up, then it's all recycled through the plant again," he said. "There's no health hazard here. We didn't spill. We've just got to get it cleaned up and get back on line."

The mechanism that failed is called a motor operated valve, Ghio said, and controls the flow of raw sewage into the batch reactor — the first treatment stage.

A decanter arm in the batch reactor also failed. This part allows treated water to flow into the intermediate basin, but it froze in a position that allowed partially treated and raw sewage to flow into the basin.

From there, the sewage flowed into the new filters, and would have continued flowing into another treatment basin, but Woolf took corrective action.

"I got here quick enough Tuesday morning to make sure it didn't get beyond the filters," Woolf said. "I switched the flow to the temporary treatment facility.

"It has enough storage there for a week or two. But we'll have the filters up and running again by the end of the day Thursday."

City Administrator Tim Shearer said the shutdown won't cost the city anything extra thanks to the temporary plant.