Engineers and contractors are working to improve and clean equipment and test water in Hattiesburg's south wastewater lagoon to improve efficiency and save money.
"Like the motor in your car, if it's gunked up with junk, it's not going to run as well as if it's got clean motor oil in it," said Carter Carroll, Hattiesburg City Council president.
Clean equipment can pump more bubbles into the water. More air in the water keeps it cleaner and gets rid of the smell.
"They haven't been cleaned for many years, so we're maybe going to clean it every six months for the next year," said John Hinde, president of Air Diffusion Systems, which created the aeration system in Hattiesburg's lagoon. "Right now, there are 1,500 diffusers. Each one creates a billion bubbles, so if you do the math, 1,500 times a billion, you have 1.5 trillion bubbles out here that turn over 30 million gallons of water every two to three minutes."
Keeping that system running efficiently keeps the city from spending extra money in energy costs.
"We're saving approximately 20 percent on our energy bill because we've been able to cut back on some of the blowers here," Carroll said. "We spend about $1 million a year on electricity, so 20 percent is a substantial amount of savings. We hope to do much more in the future."
Hinde said, "by cleaning the system, you save the energy that pays for the cleaning."
He said systems typically need to be cleaned once a year, and portions replaced every 10 to 15 years.
"As a matter of practice, every 10 to 15 years, the diffusers should be replaced, so we're advising the council now that it's five years old, that we're going to have them try to produce the funding for the next five to 10 years," Hinde said.
Carroll said the council realizes good maintenance is essential to keep the lagoon functioning well and the city from having to build a new treatment system.
"We need to keep constant maintenance out here and that is much less than having to build a mechanical plant," Carroll said. "So we're saving $150 million without building a plant. Just think, the interest alone could do the maintenance here and save our ratepayers a lot of money."
The city is also paying $20,400 to test multiple spots in the lagoon for eight weeks, so engineers can put the equipment in the water where it needs the most cleaning.