ANTONOVICH ASKS GRAND JURY TO PROBE MTA CONTRACTING.

Byline: David Bloom Daily News Staff Writer

Los Angeles County Supervisor Michael D. Antonovich called Thursday for a grand jury investigation of subway walls in the first segment of the Metro Red Line.

The Army Corps of Engineers says the walls of the $1.45 billion tunnel segment are at risk of being eaten away by chemical-laced ground water, the Daily News disclosed last week.

In a letter to Los Angeles County grand jury foreman Robert Hoffman, Antonovich said ``incompetence, graft or intentional low-balling'' and the use of poor construction methods could mean millions of dollars more will have to be spent on the subway.

According to the Corps report, materials scientists said ``poor construction practices'' used in building the Red Line segment between Union Station and MacArthur Park could expose concrete in tunnel walls to sulfates, acidic water and chlorides that would shorten the concrete's service life by up to 85 percent.

The decay problems were made worse by a leaky polyethylene liner and the use of overly watery concrete in building the tunnel walls, the report said.

But Stanley Phernambucq, the MTA's top construction officer, said the true exposure levels to the chemicals are far lower than those projections, thus reducing the decay problems.