The record rains of the past few days flooded out sewage treatment plants in Fulton, Cobb and Gwinnett counties, dumping millions of gallons of untreated sewage into local waterways.
So, water already polluted by oil and gasoline, trash, pesticides and other ground contaminants will also be carrying debris and bacteria from human waste.
The greatest damage occurred at Atlanta’s R.M. Clayton plant — the largest in the southeastern U.S. — which was swamped by at least four feet of water Tuesday when the Chattahoochee River surged more than 12 feet beyond flood level.
City officials said they’d seek federal help to repair potentially “tens of millions of dollars” in damages. They could not even estimate when the plant, which can treat as much as 240 million gallons of sewage a day, would be fixed.
“It’s sad,” said George Barnes, with Atlanta’s Department of Watershed Management. “And, it’s going to take a heck of an effort to get it back in service. We can’t even get out there to do anything.”
The city, Barnes said, can’t even begin pumping out water from the plant until the flood recedes. Because of its low elevation, any water pumped out would just pour back in, he said.
“I’ve been around since 1968 and I’ve never seen anything like this,” Barnes said.
The flood that took out Atlanta’s Clayton plant also swamped Cobb County’s R.L. Sutton water treatment plant, which sits across the river in south Cobb. Officials there said the plant was “partially treating” sewage before dumping into the Chattahoochee.
Meanwhile, Gwinnett officials lost service at the Yellow River Water Reclamation Facility near Lilburn, which was underwater. They said Tuesday it would be two days before repairs could begin. The facility takes in wastewater flows from Lawrenceville, Norcross and some areas in between.
In Atlanta, the rains were so severe that the water swamped the entire tunnel system the city has built over the past several years to limit sewage overflows. The work was part of the $4.1 billion overhaul of Atlanta’s antiquated water/sewer system.
“I’d hate to think how bad things would be if it weren’t for the tunnels,” said Janet Ward, watershed spokeswoman.
Barnes said the $131 million Nancy Creek sewage tunnel was overwhelmed by inflow of rainwater into old, leaky sewer pipes. So, the 8-mile tunnel has been overflowing a combination of raw sewage and rainwater, Barnes said.
The tunnel, he noted, also runs to the Clayton plant, which is off line from the flood.
The rains also flooded the city’s $190 million deep storage tunnel for combined sewage. The 8.5 mile-long east tunnel has been the most controversial part of the city’s pipe overhaul. It holds 177 million gallons of combined sewage, which are normally treated at a separate plant on the R.M. Clayton site.
Barnes said that plant has not flooded and continued to operate Tuesday. However, he said the full tunnel has allowed combined sewage to spill from combined sewage overflow facilities around the city.
All the flooding did not impact Atlanta’s drinking water intake, just up river from the Clayton sewage treatment plant, officials said.
That doesn’t mean the flooded plants aren’t a health hazard. The damaged plants around metro Atlanta continue to dump untreated, or not-fully-treated sewage into floodwaters that then end up rising into homes and businesses.
“This is a tragedy,” said Atlanta Councilwoman Carla Smith, who heads the council’s utilities committee. “We’ve gotten way to much water all at the same time.”
Staff writers Pat Fox and Eric Stirgus contributed to this report.