Senoia’s proposed new sewer plant will be an “extended aeration” system, and nearby residents shouldn’t be able to see it, hear it – or smell it, according to engineer Chris Poje.
Poje, with G. Ben Turnipseed Engineers, gave a presentation on the sewer expansion plans at a public meeting held Monday prior to the Senoia City Council meeting.
The city currently has a land application system with a capacity of just under 500,000 gallons per day. The proposed new plant would be a stream-discharge system with 1 million gallon per day capacity.
The plant will be designed to be expandable to up to 4 MGD – though that won’t be needed until many years into the future, Poje said.
When Senoia’s sewer system first was created – the expansion of an industrial system – land application sewer was popular. Instead of being piped to a stream, treated wastewater is sprayed onto grass.
At the time, it was expensive to treat wastewater to a high enough standard to be discharged into some smaller streams, Poje said.
But the LAS systems became an issue in the ongoing tri-state water wars with Florida and Alabama, because water being sprayed on fields was water that wasn’t going back into streams and rivers. So the pendulum swung back to stream discharge.
Advances in sewer treatment and plant design have made it easier to treat wastewater to higher levels, according to Poje.
Regardless, one of the requirements of the permitting process with the Georgia Environmental Protection Division was to determine if the LAS system could be expanded. That wasn’t feasible, Poje said.
“So the EPD agreed with us that stream discharge into Keg Creek would be the best option for the city,” he said.
The U.S. Fish and Wildlife Service is requiring the city to do a survey of freshwater mussels 25 feet upstream and 125 downstream of the proposed discharge site.
The sewer plant will be located along Hwy. 85 on land that was donated to the city as part of a development project. The developers of Keg Creek Landing, on Seavy Street at Hwy. 85, donated the land in return for being able to develop the subdivision at a significantly higher density.
Poje had diagrams of two different configurations of the plant on the property, and said the first option is more suitable. His diagram showed the plant built with four aeration basins, each able to treat 1 million GPD. The plant will be built with one aeration basin, and more can be added when expansion is needed.
There will be no chlorine used for disinfection, Poje said. Instead, the plant will use UV light.
Poje and his team are working on finalizing the Environmental Information Document for the upgrades.
Poje’s presentation was during a public meeting that is required by the state and the federal Clean Water Act. A meeting was also held to get public input on the city’s plan to apply for a loan and grant from the USDA Rural Utilities Service Program to build the new plant. There were no public comments during the loan portion of the meeting.
Once the environmental document is complete, it will be sent for final approval. Once the environmental document is complete, the design process is approved and funding is in place, the plans will be prepared and specs will go out to bid for a general contractor, Poje said.
Time-wise, the best-case scenario would have the project out to bid in 12 months, Poje said. Construction will take approximately 18 months.