County planners have chosen a new firm to conduct an environmental review of a proposed quarry east of Santa Margarita, effectively killing the hopes of a different firm to whom they sent the contract two months ago only to withdraw it under political pressure.

The project in question is the so-called Oster quarry, a proposed 60-acre hard rock and aggregate operation on a 260-acre parcel four miles east of Santa Margarita. The operation would be located at 6660 Calf Canyon Highway, which is also Highway 58, just east of the Salinas River bridge.

Planners on Tuesday will ask the Board of Supervisors to give the $406,000 contract to URS Corp. Should supervisors agree, it will take Benchmark Resources out of the picture.

Benchmark had been sent the contract, but just as it was about to go to the Board of Supervisors for final approval, Planning Director Jason Giffen and Environmental Coordinator Ellen Carroll pulled it back.

They said there was a “community perception problem” with the choice of Benchmark, a word choice that is echoed in a staff report that planners will present to the Board of Supervisors on Tuesday.

In the report, planners said community members perceived that “Benchmark was tied too closely to the mining industry and ... would not be able to prepare an objective and unbiased environmental impact report.”

Opponents of the quarry organized a sophisticated campaign and bombarded the county with scores of emails and other communications questioning not only Benchmark’s objectivity but also that of county planners.

After pulling back from Benchmark, the county sent out a new “request for proposals” — an invitation to firms that conduct EIRs to bid for the job. They allowed Benchmark to participate.

Dave Brown, Benchmark’s president, told The Tribune on Wednesday that the decision to go with URS was “surprising and unfortunate.”

Brown learned about the county’s decision from a reporter. County planners had not contacted him, he said.

Nonetheless, Brown said, he will not fight the decision.

“You don’t want to be on a job where they don’t want you,” he said.

He said the firm would make itself available in case it is needed.

Ken Johnston of Las Pilitas Resources LLC, which will develop the site, had complained earlier about being blindsided by the last-minute decision to drop Benchmark. But now he says he just wants to move forward.

His development lost two months, he said.