By Brian Mittge, Friday, May 30, 2003, bmittge@chronline.com, The Chronicle
Crews working for the city of Centralia Thursday discovered and fixed a long-forgotten, corroded valve that may have been leaking raw sewage into the Chehalis River for decades.
City officials reported the leak to the Washington Department of Ecology, which complimented the city on quickly and honestly fixing the problem.
Centralia Utilities Manager Dick Southworth said the leak was in a forgotten bypass that was originally designed to allow the city's raw sewage to be dumped into the river in case of problems at the wastewater treatment plant.
That was a common precaution in decades past, but as that idea fell out of favor, renovation work blocked off that bypass with steel sometime in the past, possibly around 1978, Southworth said.
The bypass, about 30 feet underground, was forgotten, and eventually rusted out, he said. No one knows when.
"Nobody knew about it until we went down and investigated this thing this morning," Southworth said Thursday afternoon.
Workers Thursday estimated it had been leaking between one and five gallons of raw sewage per minute underground, eventually flowing into the river, he said.
Hmmm - 5 gallons per minute is 'only' 300 gallons per hour and is 'only' 7200 gallons per day. |
They plugged the gate in concrete to make sure the bypass is plugged forever, Southworth said.
The Chehalis River, although bloated with floodwaters in the winter, drops to low levels that can be toxic to fish during the summers, according to studies by the Department of Ecology.
The leak "could explain some of the contamination in the river," said Southworth.
Both Centralia and Chehalis dump their treated wastewater into the river, and both are building new wastewater treatment plants, in part because of the impaired water quality.
It was work on Centralia's new plant that led to the discovery of the leaky valve, said Southworth.
The city's current plant is on Mellen Street, wedged between the Chehalis River and Interstate 5, which was built after the plant was in place.
The new plant is a few miles northwest of the city. Workers preparing to build a big pump station to move the raw sewage from the old plant to the new one discovered an old manhole cover Thursday morning near the Mellen Street plant, Southworth said.
After removing asphalt and dirt, they took off the manhole cover and knew they had a problem when the deep, dark shaft had a bad smell, he said.
"We're overjoyed we found it. If we hadn't have found (the leak), it would have kept going on." said Southworth. "You spend all this money and you're hoping to improve your treatment at the new plant, and maybe the river isn't improving."
Sandy Howard, a Department of Ecology spokesperson, said aging sewer systems around the state have unexpected problems pop up all the time. She said the DOE doesn't plan to fine the city for the decades of leaking sewage.
"There's no blame to be placed. We think it's very positive that they found it, reported it, and fixed it. It's one more pollution source that's getting taken care of, and that's a good thing for the area down there," she said.
Brian Mittge covers politics, the environment and Lewis County government for The Chronicle. He may be reached by e-mail at bmittge@chronline.com, or by telephoning 807-8237.
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