At that facility, treated wastewater is disposed of by injecting it into deep wells that reach 3000 feet into the earth's boulder zone. Federal regulators, however, say the Water and Sewer Department has been pumping untreated or insufficiently treated sewage into the well. As a result of this pumping operation, the regulators contend, the sewage has leaked into the Floridan Aquifer, a brackish groundwater source 1500 feet above the boulder zone.
Federal officials also contend that untreated or partially treated sewage has been percolating from holding ponds around the facility into the Biscayne Aquifer, Dade's primary source of drinking water. (The ponds are designed to store treated wastewater in case a power failure temporarily shuts down the deep-injection wells.) This past month the EPA sent a letter to Metro-Dade warning that the agency may file a separate lawsuit in the matter.
Federal officials won't comment on the notice. Clemente admits there may have been a time when equipment malfunction during a period of heavy flow caused partially treated sewage to be released into the holding ponds. But he says he knows of no instance of untreated sewage being sent to the ponds. Any possible contamination to the Biscayne Aquifer, Clemente adds, would pose no threat to the public health because the holding ponds aren't near any drinking-water wells.
As for the claim that the Water and Sewer Department is sending raw or partially treated sewage into the deep-injection wells, Clemente says nine months ago his engineers detected ammonia in the Floridan Aquifer -- a possible indicator of treated effluent. While the sewer director says he's not certain where the ammonia came from or whether it was caused by sewage, engineers believe effluent deposited in the boulder zone may have leaked back up a nearby monitoring well, through a hole in the pipe, and into the Floridan Aquifer. Ever since the ammonia was discovered, Clemente says, Metro has been waiting for state approval to seal off the suspect well.
"I don't know if [the federal officials] have any information that we don't have," Clemente says. "We've been working on this with consultants for almost a year. Again, these are allegations, and regulatory agencies, when they come at you, come at you with a lot of things.
"I'm more concerned about the reaction of the feds and the state than the actual situation," Clemente continues. "I don't think the situation is that critical compared to the other situations we're dealing with.