The solid byproduct of Peachtree City’s wastewater treatment process
is no longer destined for the landfill.
The bio-solid will instead be hauled to a plant in Plains, Ga., where
it will be composted into fertilizer, according to Larry Turner, general
manager of the Peachtree City Water and Sewer Authority.
In addition to being more environmentally friendly, the move will also
save a projected $27,000 a year, Turner said. That’s because the
price for landfill disposal has increased, while the cost of composting
the material has decreased in recent years.
The bio-solid is actually rich in nutrients, noted WASA operations division
manager Susan Johnson.
“Basically, the product that’s leaving our plant every day
and was going to the landfill is a nutrient-rich substance that can be
used as a soil amendment,” Johnson said.
Once the bio-solid is composted, it is rated Class A, meaning it can
be used on any type of plants including those grown for food, Turner
noted.
The bio-solid consists of organisms that die after treating the wastewater,
Johnson said. Also called “sludge,” the bio-solid is dewatered
through a conveyor belt that squeezes water out.
After that process, the bio-solid is collected in a 20-yard trailer
so it can be hauled off. Johnson said the city fills roughly seven of
these trailers a week.
Some sewer systems use incinerators to dispose of sludge, but air quality
guidelines make that problematic, Turner noted.
Ironically, the company WASA has contracted with for the composting
operations is headquartered in Peachtree City: Erthproducts. By contracting
out the service, WASA avoids the need to build and maintain additional
facilities, Johnson said.
She also noted that the sludge undergoes extensive testing once a year
for 129 different pollutants specified by the U.S. Environmental Protection
Agency.
