Environmentalists and Hinkley residents have filed a lawsuit to stop an open-air sewage sludge composting plant from being built near that town, made famous by the move "Erin Brockovich."

The lawsuit filed yesterday against San Bernardino County alleges that supervisors approved the plant without fully analyzing its potential impact on air quality and public health.

The suit also contends that the project doesn't adequately protect the threatened desert tortoise and the Mojave ground squirrel.

The groups behind the suit say they're not trying to stop the plant. They say they just want to force the county to enclose it and filter its odors.

But officials with Nursery Products, the company building the plant, says that option is too expensive and that the county did a thorough job in evaluating the open-air project when it cleared its construction.