SAN DIEGO--Multi-Million Gallon Sewage Spill (Update)greenspun.com : LUSENET : TB2K spinoff uncensored : One Thread
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Sewer line that broke had failed repeatedly Multimillion-gallon spill was second since 1991
By Terry Rodgers UNION-TRIBUNE STAFF WRITER March 14, 2000
A San Diego sewer line responsible for a 36 million-gallon raw sewage spill last month has a history of major failures and was identified as a high priority for replacement nine years ago.
Although work to replace the problem sewer was started nearly two years ago, the project hit a snag and was never completed.
The same sewer main -- a stretch of pipeline that runs along Alvarado Creek near San Diego State University -- was the source of a massive sewage spill in March 1991 that is remarkably similar to the one last month.
After the earlier pipe failure, which caused an estimated 5.1 million gallons of untreated sewage to flow for five days into the San Diego River and ultimately the Pacific Ocean, a city engineer recommended replacing and moving the 1,000-foot-long section of pipe to a location less susceptible to storm erosion.
In his May 1991 memorandum, Water Utilities Department engineer Jafer Kazem noted that the vulnerable section of the line -- located on the north side of Interstate 8 near Adobe Creek Falls -- had also split apart in 1980 after it was undermined by storm runoff.
"We are attaching high priority to this project and request that it be included in the list of the (annual capital improvement) projects," Kazem's memo stated.
It said the work was necessary "in order to prevent further breaks in the future."
The city of San Diego was fined $50,000 for the 1991 sewage spill by the state Regional Water Quality Control Board. The city was deemed negligent because city repair crews failed to respond to the spill until two days after it was reported by a hiker who smelled the contaminated water.
The state agency is investigating the city's actions in the recent spill, which Metropolitan Wastewater officials say is the largest release of untreated sewage in city history. It was undiscovered for seven days.
Metro Wastewater official Charles Yackly said he could not fully explain why the city still has not relocated the Alvarado sewer main, a 21-inch-diameter pipe that is relatively new at 33 years old, but which is located in a hard-to-reach, highly erodible canyon.
"I don't know all the reasons for the delays," said Yackly, who oversees the city's sewage collection system. "I do know that the scope of the project changed a couple of times."
Work to relocate the sewer line to safer terrain -- the south side of the freeway -- finally began in June 1998 under a $3.5 million contract. While boring under the freeway, the contractor encountered rock more dense than a soil report had predicted. The contractor's problems were not connected to an 8-foot-deep sinkhole that Caltrans had to fill with concrete in March 1997.
In June 1999, after 75 percent of the sewer replacement project was completed, the city suspended the contract, and work was stopped.
The city is rebidding the project, which, unless it is accelerated, would be finished in one year.
Nine months after work stopped, a manhole on the same stretch of sewer was cracked open by a tree that fell during a rainstorm. Untreated sewage spilled into the river and went undetected.
After the spill was discovered Feb. 28, county health officials closed approximately two miles of beaches in Ocean Beach, Mission Beach and Mission Bay. The beach closure lasted four days. A small number of fish and crayfish in the San Diego River were found dead after the spill, and at least two surfers reported becoming sick.
"The city has apparently not learned anything from past experiences," said Donna Frye, who monitors ocean pollution for the Center for Marine Conservation.
Frye and other local environmentalists have urged the Regional Water Quality Control Board to fine the city $36 million -- one dollar for each gallon of untreated sewage that was spilled.
"The city has to be held responsible for not taking care of problems when they know they exist," Frye said. "They could have averted this from happening."
Responding yesterday to Frye's comments, Metro Wastewater director Dave Schlesinger said: "Hindsight is always 20/20. It's unfair to characterize the city's entire record by one spill that occurred in Alvarado Canyon."
Under the law, the regional board can levy a fine of more than $360 million for the sewage spill. But officials with the agency say it is highly unlikely that the maximum penalty will be imposed.
Money from such fines, which are ultimately borne by sewer ratepayers, typically goes into a statewide pollution cleanup and abatement account.
Schlesinger told the regional board last week that, as a result of the massive spill, the city now intends to spend as much as $250,000 to install state-of-the-art equipment which would provide for early detection of sewer breaks.
The early detection system can be put into place as quickly as within the next six months, he said.
The plan would involve retrofitting 98 in-pipe flow meters with a remote sensing device that would trigger an alarm at the city's computerized sewer system monitoring center in Kearny Mesa.
A high-technology warning system using fiber optic cable continuously monitors the city's newly completed high-pressure sewage sludge line, which runs for 17.5 miles between Point Loma and Mira Mesa. No major city in the United States has a system for detecting breaks along gravity-flow sewage lines, Schlesinger said.
San Diego had major problems with its sewage system during the 1980s and early 1990s. They culminated in 1991 with a $500,000 fine imposed by a federal judge, who also forced the city to implement a $2.5 million low-flow toilet installation program.
The city's sewage-spill record has been improving steadily since 1995, when 429 spills were reported. Last year, the city recorded 314 sewage spills, a 10 percent increase from the previous year. While the number of spills over the two-year period increased, the volume of untreated sewage that reached recreational waters over the two-year period decreased from 3,096 gallons to 285 gallons.
-- (Dee360Degree@aol.com), March 14, 2000