In the 1970s, Lake Jackson in the Upper Ocmulgee River basin suffered high nitrogen levels and phosphorous, resulting in excessive lake algae.
As a result of changes induced by the federal Clean Water Act of 1972, the city of Covington and Newton County Water & Sewerage Authority constructed a land application system to irrigate treated wastewater.
David Croom, Covington’s Water Reclamation Division manager, was the first to oversee the new system in 1985.
“They gave me a key to the gate, a map and a dog, and said, ‘Good luck,’” Croom said, laughing. The stray dog came with the property. Croom will retire next year from a job that he loves and a system that he has shepherded through four expansions.
The land application system has more than doubled in size to 2,000 acres and is now permitted for 9.6 million gallons per day of wastewater treatment capacity. A lush forest, riparian and wetland areas, and grasslands cover 1,200 acres, soaking up the treated water and benefiting from the nutrients that would damage the lake.
A conventional sewage treatment plant uses chemicals to pre-treat wastewater before depositing it into a lake or stream. Newton County treats the wastewater, and then Covington sprays it onto 15 fields and lets Mother Nature do the rest.
Here is how the process works, according to the Georgia EPD’s “Guidelines for Slow-Rate Lane Treatment by Spray Irrigation”: Wastewater is sprayed onto the land, where it evaporates or enters the groundwater. Soil bacteria stabilize the remaining organic components. Soil and plants take up the ammonia, nitrogen and phosphorous, and a minimal amount of those nutrients reach the groundwater. “Properly designed and operated land treatment systems produce a percolate water of high quality and thus protect ground and surface water resources,” Croom said.
Soil quality is monitored by the Georgia Environmental Protection Division, along with the quality of discharge, storage pond effluent, groundwater and adjacent surface water.
While land application is common, systems this size are not, Croom said. The water is distributed through 100 miles of pipe, 9,000 sprinklers, two 400-HP pumps and two storage ponds. Staff is dedicated to maintaining the infrastructure as well as the greenspace and its inhabitants. Their priorities are soil and water protection, wildlife, aesthetics and timber production, which has earned the system a Forest Stewardship certification from the Georgia Forestry Commission.
The city has harvested over $1 million in timber over the decades. Though some may frown upon the harvesting of timber, Croom said the city replants every tree and continues the cycle. “We like to think of this site as being sustainable,” he said.
In addition to the timber revenue, municipalities with conventional treatment systems may be jealous of Covington’s good relationship with the neighbors. There are no odor complaints, Croom said.
“It takes about five minutes to convince them that we’re the best neighbors you can ever have,” Croom said. On a day-to-day basis, “you’d never know it was a wastewater treatment plant.”