A Miami federal judge on Friday ordered a halt to rock mining on hundreds of acres in Northwest Miami-Dade County, saying quarries close to the county’s primary public water supply raised ’’grave concerns’’ of chemical and bacterial contamination.

The ruling, by senior US District Judge William Hoeveler, could have broad ripple effects on mining and construction in South Florida. The judge didn’t shut down Miami-Dade’s entire billion-dollar limestone rock industry but he demanded that three companies stop work by 5p.m. Tuesday in a dramatically expanded protective zone he imposed around the Northwest wellfield, source of drinking water for more
than 1 million people.

Hoeveler criticized county and federal environmental regulators for lax oversight, singling out the Army Corps of Engineers. The Corps, he wrote, had repeatedly exhibited ’’a disregard of its duty’’ for, among other things, largely ignoring the discovery of benzene, a petroleum component and solvent, in a once-pristine part of the Biscayne Aquifer in 2005.

’’In three decades of federal judicial service, this court has never seen a federal agency respond so indifferently to clear evidence of significant environmental risks related to the agency’s proposed action,’’ he wrote.

The decision pleased environmental groups that sued the Corps and the U.S. Fish and Wildlife Service in 2002 for permitting mining to expand to 5,400 acres of wetlands. That is only one part of the chain of massive 80-foot-deep rockpits the industry wants to dig in 77½ square miles near the Everglades.

A mining company representative predicted a devastating impact from the partial shutdown in the industry’s richest rock zone -- not just on mining companies but on Florida’s construction-driven economy. The area the industry calls the ’’Lake Belt’’ is home to four of the state’s five largest limestone mines and supplies half the state’s cement and fill.

’’Judge Hoeveler’s decision threatens planned and future road and highway projects, threatens to further dramatically increase the cost of every construction job in the state and threatens tens of thousands of jobs,’’ said Kerri Barsh, an attorney for White Rock Quarries, which was ordered to halt work on some tracts, along with Tarmac and Florida Rock.

Hoeveler’s order is intended to stand at least until federal agencies complete a new review of environmental impacts that the judge ordered in an initial ruling last March. That study is expected to be completed later this year.