WHITTIER — City officials have been ordered by the state Waste Management Board to take immediate steps to determine if pockets of methane gas discovered at a city-operated dump pose any threat to nearby hillside homes.
The methane, highly explosive under certain conditions, was detected in varying amounts at the Savage Canyon landfill during a routine state inspection on Dec. 29. State officials want to make sure that the gas does not migrate underground into surrounding residential areas.
State and city officials say that homeowners along Summit and Crest drives are not in danger. The two winding roads are the closest streets to the well-hidden dump east of Uptown Whittier in the Puente Hills.
"We are concerned, but we do not believe there is an immediate danger," said Herb Iwahiro, chief deputy executive officer for the Waste Management Board in Sacramento. "The fact that the houses are on ridges above the landfill makes it difficult for the gas to move in that direction."
Yet the presence of methane, a colorless and odorless gas which is a byproduct of decomposing trash, prompted state officials last month to include Savage Canyon on a list with seven other California landfills in violation of minimum state landfill standards.
In some soil samples, taken from a depth of two to four feet below the surface, the levels of methane exceeded 50,000 parts per million. Some of those readings were taken within 100 feet of homes in the southwest corner of the landfill, said Christopher Peck, a spokesman for the state board.
At those levels, methane generally is considered explosive if exposed to any source of ignition--a match, a cigarette or a spark from a shovel blade striking a rock. Experts say even turning on an electric light could result in a fire or explosion if there is a sufficient buildup of methane in a small enclosed area.
Methane gas is common at many landfills, but this is the first time it has been detected at Savage Canyon, said Lou Sandoval, Whittier's director of public services. Opened in the mid-1930s, the dump handles all of the city's nontoxic garbage.
"All landfills generate methane," Sandoval said. "So this is not unique. . . . We always knew there was methane (at Savage Canyon). But this is the first time we have detected it."
Not the Only Problem
Methane is not the only problem at Savage Canyon. State inspectors also found drainage deficiencies and erosion at the dump. It has also been 12 years since an independent engineering firm has reviewed operations at the landfill, Peck said. Under state law, such a review must be conducted every five years.
The state board has given the city until mid-June to submit a plan and take action to correct problems at the 124-acre landfill. If the city fails to do so, the dump will be considered in non-compliance, the first step toward closing the facility.
Closing the dump would be a blow to Whittier because city officials consider it one of the city's major assests. Close to downtown Whittier, the landfill has been a moneymaker for the city and, more importantly, it has by far the longest life expectancy of any dump in Los Angeles County. While every other major landfill in the county is expected to be full by 1993 (under existing permits), Whittier's dump may be in business until 2036 if the facility's current problems can be remedied, officials said.
Spending $500,000 Planned
Confident they can satisfy state concerns, City Manager Tom Mauk said the city will spend about $500,000 during the next three months on the landfill.
The City Council two weeks ago hired a Los Angeles-based engineering firm, Mandeville & Associates, at a cost of $34,500 to examine operations at the landfill.
And city officials said grading and erosion problems at the dump, considered relatively minor by the state according to Peck, already have been corrected. Unless a landfill is properly graded, Peck said rain runoff can cause serious erosion, exposing trash and waste. That could pose a health hazard because high winds or water run-off could carry the uncovered trash into residential areas.
It will take longer to fully address the methane issue, Sandoval said. The city last week sent a plan for monitoring the methane at the site to the South Coast Air Quality Management District. The regional agency, along with the state, must approve the city's efforts to contain and ultimately remove the gas from the landfill.
The plan calls for the installation of a series of ground probes at various depths and places to determine how much methane exists. Sandoval said it will probably take six weeks for the plan to receive approval.
Meanwhile, Sandoval said the city will conduct periodic surface sweeps with hand-held detectors to check for methane. The city will also inspect several buildings at the landfill, including a heavy equipment storage shed and a cable television relay station.
New Structure Planned