OXFORD -- The Villages has been put on notice to fix a growing problem of sinkholes in the retirement community, which potentially could taint its drinking-water supply with storm water.

The Southwest Florida Water Management District has ordered The Villages to find a permanent solution for sinkholes that repeatedly emptied a large retention pond in northeast Sumter County. The pond is supposed to hold water year-round, and several residents paid premium prices for waterfront homes.

A deadline was set for Thursday, but now The Villages has requested more time -- until April 11 -- to submit a remedy, according to water-district officials.

"There is potential for problems if that retention pond is designed to capture pollutants," said water-districtspokesman Michael Molligan.

Molligan said The Villages is in a part of the state prone to major sinkhole problems. The area has relatively thin layers of soft soil on the surface, allowing water to flush quickly through to underlying limestone and groundwater supplies.

Rainwater draining through the soil can erode the limestone, which eventually gives way to the heavy soil above and creates sinkholes. Large retention ponds can worsen the problem, with even more water and weight on the surface.

Retention ponds collect stormwater runoff from streets and lawns, which can add oil, pesticides and other pollution. Developers often are required to line ponds with heavy clay or plastic liners to prevent the pollution from flushing into the underground aquifer.

"Sinkholes in retention ponds tend to facilitate the discharge of untreated storm runoff into the drinking-water aquifer and could pose a threat to public health and safety," water-management officials warned in a March 5 letter to Pete Wahl, administrator of the developer-controlled Village Center Community Development District government.

Wahl said the community's engineers are "looking for options" for a permanent fix. He would not discuss any of those options.

Water officials are concerned about a large retention pond The Villages calls Lago Bonito -- Spanish for "pretty lake."

Six homeowners there paid premium prices for waterfront homes. When a hole swallowed all the water last year, they picketed the developer to fix the problem.

Then another hole opened up last month -- infuriating the residents again.

"There have been, in fact, several occurrences of sinkholes over the years, and the plugging of these holes with compacted clay and/or concrete grout does not appear to be working," water managersreported. "Therefore, we believe a more permanent alternative needs to be found."

The Villages commonly uses concrete and clay for years to fill in holes that have opened up around the community. The water district suggests The Villages install synthetic liners underneath Lago Bonito as a more permanent fix.

Molligan said The Villages has discussed the sinkhole problem with water officials several times in the past. The community now installs plastic liners under its newer retention ponds to prevent sinkholes.