T.O. PIPE LEAKS SEWAGE; PROBLEM LINE SPILLS 15,000 GALLONS OF WASTEWATER.
An additional 15,000 gallons of raw sewage leaked from Thousand Oaks' ill-fated Unit W sewer pipe Tuesday - the third spill from the line in six months.
City inspectors reported the leak late Tuesday after finding a pool of untreated wastewater in a dry basin adjacent to the pipe. Crews worked through the night pumping between 12,000 and 15,000 gallons of sewage into a truck and transporting it to the Hill Canyon Treatment Plant.
State regulators said there were no initial signs that the wastewater ever reached the Arroyo Conejo or contaminated any other watercourse, but water samples were taken to test bacteria levels.
``We also believe some of the sewage seeped into the groundwater, but we can't really estimate how much,'' said Veronica Cuevas-Alpuche, sanitation engineering associate with the Los Angeles division of the California Regional Water Quality Control Board.
Only two weeks ago, the water quality board slapped the city with a record $2.3 million fine for an 86-million-gallon sewage spill that occurred after the same section of the aging Unit W pipe ruptured during a storm.
The agency also is completing an investigation into a second leak from the same pipe reported last month, when about 14,400 gallons of sewage spewed from the pipe over an undetermined number of days.
Work crews managed to contain last month's leak by encasing the damaged pipeline with concrete. Mel Henson, public works superintendent for the city, said Tuesday's leak appeared to be coming from behind the concrete encasement.
Between 4 p.m. - when the leak was first discovered - and 2 a.m., workers scrambled to vacuum the waste collecting and transport it to the treatment facility while officials figured out how to stop the flow.
``We were trying to decide whether to start jackhammering to get under the concrete encasement. That seemed pretty risky, though. We were afraid of making the situation worse,'' Henson said.
Then, for unknown reasons, the leak stopped.
``For some reason it just quit leaking. We don't know why,'' he said.
City inspectors will remain on alert for the next several days to monitor the pipeline while work crews scramble to complete construction of a new line before the next rainy season.
Also, Henson said a plastic liner was laid in the basin in case another leak occurs and the waste begins pooling again. The liner is intended to minimize saturation into the ground and groundwater.
County environmental health manager Elizabeth Huff said there appears to have been no health risks associated because the wastewater never reached the Arroyo Conejo or any other waterway.
Dennis Dickerson, executive director for the California Regional Water Quality Control Board's Los Angeles office, said the agency will continue to investigate the leak but could make no other comment Wednesday.
Thousand Oaks City Attorney Mark Sellers was away on vacation, and the defense attorneys with Gibson, Dunn and Crutcher hired to represent the city in matters related to the sewage spill did not return phone calls Wednesday afternoon.
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|Publication:||Daily News (Los Angeles, CA)|
|Date:||Aug 20, 1998|
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