Expediting of Permit May Have Cut MTA Subway Costs

The Metropolitan Transportation Authority has been saved from the threat of paying hundreds of thousands of dollars in added subway construction costs, the potential bill if subway tunneling had been forced to halt at the Los Angeles River for lack of the required county permit to dig under it.

The Los Angeles County Department of Public Works said Tuesday it had expedited the permit, but with many conditions to guard against damage to the vital flood-control channel.

A public works official said the permit was issued Monday, about six weeks sooner than would have been usual, and without requiring the MTA to immediately answer a key question on tunneling risks.

The MTA initially sought the permit from the county agency, which operates the flood-control system, in July 1994. But for the next 1 1/2 years, the transportation agency failed to answer a list of questions from public works engineers on how tunneling might harm the concrete-lined channel.

The agency began responding to the county’s questions only late last month, when the MTA began submitting full engineering reports to back up its formal permit application.

The MTA is building twin subway tunnels that will one day carry trains between North Hollywood and downtown, passing under the Santa Monica Mountains and through Hollywood. The southbound tunnel-digging crews are now only about 900 feet from the river at about Acama Street and Lankershim Boulevard and will begin passing under in it in about two weeks, at the current rate of progress.

If tunneling had been halted while the permit process took its normal course of two months, the contractor, the Obayashi Corp., would have been entitled to bill the MTA at least $50,000 a day in personnel and equipment costs associated with the delay.

“We don’t like to see someone having to spend an exorbitant amount of money on delay costs because we don’t like it when it happens to us,” said Robert L. Grindle, chief of the public works department’s inspections division.

“Some of what we asked for, we decided we didn’t need right away to issue the permit.”

Added Grindle: “Normally we would have issued the permit six to eight weeks from now. But due to the political nature of the MTA, our department figured it would be best to see what we could do to help them out.”

The permit lists 14 conditions that spell out a system for measuring possible sinking in the riverbed over three years, a request for immediate repair of potential damage and a demand that the MTA take out a $5-million insurance policy on its work--five times the usual amount in such cases.

Grindle said his department believes if the cement-lined channel sinks more than 1.5 inches as a result of soil settlement above the tunnel excavation, the flow of fast-moving water after a storm would surge through any cracks and do serious harm.

“We could get turbulence that could cause the cement floor of the channel to be undermined, and then you could potentially have flooding” in the streets alongside the channel, he said.

Grindle said the MTA has promised that settlement will not exceed 1.5 inches and would “more likely” be less than three-quarters of an inch.

Public works officials’ concerns were heightened in early April when the MTA acknowledged that the Hollywood Freeway had sunk 3.79 inches above a tunnel excavation in Studio City. Transit agency officials said they expected to spend $375,000 to shore up the tunnel and repave the freeway. The MTA, without admitting liability, has also agreed to pay for repairs to more than a dozen businesses along the tunnel route in North Hollywood.

A key condition of the permit: The county and the U.S. Army Corps of Engineers, which built the flood-control channel and retains some responsibility for its upkeep, will have final say on whether the channel has been damaged by tunneling.