The federal Environmental Protection Agency has proposed delaying the implementation of a set of Florida-specific water quality standards for 90 days, allowing for the approval of a set of replacement rules drafted by the state.

Though the rules were mandated following a lawsuit brought by environmental firm Earthjustice on behalf of a coalition of environmental groups, the EPA has allowed the Florida Department of Environmental Protection to develop and implement its own set of rules.

Three residents of rural Southwest Miami-Dade and three leading environmental groups have sued the county to stop an expansion of rock mining on agricultural land outside the urban development boundary that the plaintiffs say was approved in violation of state law.

The suit, filed in December in Miami-Dade Circuit Court, is the latest sally in long-running conflicts among homeowners and environmentalists on one side and companies that use blasting to extract limestone rock used in construction from a vast network of open mines on the western end of the county.

The use of sulfate in agricultural areas near the Florida Everglades is creating an enormous mercury problem - with seemingly no end in sight.

The Florida Everglades are often thought of as the state's wildest and most untamed area, well-protected and far from the grind of urban civilization, a lush wetland with a folkloric reputation that separates it from the hustle and bustle of nearby Fort Lauderdale and Miami.

Some of the state's most ubiquitous creatures call the area home: manatees, alligators, wading birds. But lurking below the surface, amid the highly diverse flora and fauna, is a surprisingly large amount of a notoriously toxic substance: Methylmercury.