Gwinnett looking for better routes for sewage

A stream of raw sewage hasn’t burst like a geyser over any of Gwinnett County’s roads — at least not yet.

It's remarkable, in a way. The sewage that enters the system at the Norris Lake pump station, near Snellville, has to travel 35 miles to get to Gwinnett's F. Wayne Hill Water Resources Center, near the Mall of Georgia. It takes 44 hours to get there. The slope isn't in its favor; that sewage is pumped all the way.

And pumping raw sewage takes a lot of horse power. Which means a lot of pressure. And the possibility of geysers.

"They actually do take out parts of roads," said Tyler Richards, the assistant director of Gwinnett's Department of Water Resources. "Water's not a problem, but sewage is a health hazard."

The county is looking for ways to decrease the chance of potentially dangerous spills caused by an inefficient sewer system. To that end, the county recently approved a proposal from a slate of consultants to look at ways to optimize their sewer system and plan for future growth. The work is expected to begin in January.

All told, Gwinnett has nearly 280 miles of force mains in the county — 10 percent of its total sewer lines. About 220 pump stations, many built by developers without much county oversight, help move the waste along.

Three-quarters of the county's sewer system was built and donated by developers, Richards said. They added lines and pump stations to connect the houses they were building to the sewer mains the county had in the area. The quick, organic growth meant the county didn't control its system. Over the past several years, it has been working to assess the pieces it has.

Now that the development boom has eased, the county is taking inventory of its system, which Richards and others think they can improve.

“The benefit of the recession to us is the ability to take a breath,” said Rebecca Shelton, the deputy director of field operations for the department. “Things are starting to grow again. It’s time.”

Because the Hill plant, the county's main wastewater treatment plant, is at one of the higher points in the county, some pumping is inevitable. But too many miles are risky. Those lines require corrosive chemicals to reduce the smell of sewage near air release valves, and the high pressure can lead to epic breaks. They are more likely to have issues than gravity lines, which simply let waste flow downhill.

Some of Gwinnett’s sewer mains are too large for their volume; they anticipated growth that did not come. To have the capacity but not the waste to fill them means more pressure to push the sewage through. In addition to the risk, it’s also more expensive.

And the county has some pump stations that are too close to the Chattahoochee River for comfort. A spill could pollute the waterway.

“Force mains and pump stations are an issue,” Shelton said. “Right now, we’re good, but what about the future?”

So consultants are looking at the possibility of rerouting sewage, reducing the distance waste travels, and shutting down some pump stations.

The department asked for $1.5 million in Gwinnett’s 2016 budget to create the plan, which they say will help save money going forward. The planning process will take a year or more, Richards said, though some changes might be made immediately as the study is done.

As Gwinnett continues to grow up, the county is trying to expand the number of people using sewer instead of septic. Whether an area is on one or the other dictates the amount and density of any new construction.

“This is such a complex system, there are many opportunities to improve it and optimize it,” Richards said. “We need to utilize what we have more efficiently.”