The engineer’s rendering of Hillsboro’s wastewater lagoon. The entire project covers 40 acres, with 35 acres of surface water divided into three cells.
What Hillsboro had to deal with was notification several years ago that its existing wastewater plant on the south edge of town was out of compliance with Kansas Department of Health and Environment regulations.
After weighing its options, the city council opted to build a lagoon system rather than upgrade its mechanical plant.
“The chief advantage of (the lagoon option) is that it’s not going to require as much electricity to operate,” Paine said.
“The way wastewater gets treated is that you pour air into it, and you use a mechanical process to actually do the blowing,” he said of the current system. “What makes that work is that there are micro-organisms we call ‘bugs’ that need the high oxygen level in order to feed on the nutrients that are in that basin.
“The constant blowing of air through there is a considerable expense for the cost of electricity to create the airflow.”
Meanwhile, a lagoon system incorporates a natural, much older technology by using the sun to create oxidation in a large, relatively shallow pool.
The project encompasses 40 acres of ground south and east of the current industrial park. The lagoon itself, with 35 acres of water surface, is divided into one large cell and two smaller cells with depths from 5 to 13 feet.
“The thing that makes them attractive is that you can use a large tract of land to have the water stored on site and go through the treatment process,” Paine said. “We’re able to use the natural waste process in a way that allows us to not be dependent on the electrical side.”
With the new system, waste will continue to be piped to the site of the old plant for flow measurement. Water treatment will be moved from the old site to the lagoons.
A pair of pipes has been installed from the existing plant to the lagoon. One pipe will send wastewater from the old plant site to the lagoon. The other pipe will bring return effluent from the lagoons to the discharge point, which is near the existing plant.
As the water completes its treatment process, it is pumped back to the site of the old plant and discharged into a nearby creek.
“It’s basically clean,” Paine said of the water. “It’s been through its disinfection. We’re not discharging bad stuff.”
The project contractor is APAC-Kansas of El Dorado. Its bid was $2,342,266. Interim funding comes from the KDHE Revolving Loan Program. Once construction is finished, The Rural Development Agency will finance the total project.
The contract with APAC calls for the project to be completed by January 2009.
“My guess is that it will be up and operating well before then,” Paine said. “But once the system begins to run, there’s a lot of de-bugging that we’ll have to go through because it will be an entirely new technology to us in terms of our operating the plant.”
The project took several years to get to the point of construction. RDA approved funding and presented a symbolic check to the city for $5.3 million in the summer of 2005.
However, the project became bogged down in bureaucratic reviews to the point that Paine enlisted the help of Rep. Jerry Moran’s office to get it moving.
“Remarkably things happened,” Paine said of Moran’s involvement.
The project encountered resistance during the planning stage, particularly from rural residents who live near the proposed project site. The primary concern was the potential for unpleasant odors emanating from the large lagoon.
Paine said lagoons that use anaerobic process do produce “rip-snorting smells that rip your head off.” But this system incorporates an aerobic approach that may release little more than a slight, musty smell from time to time.
“The design of both the existing plant and the new plant was really to deal with (smell) in a positive way.”
Paine said the city will organize a public ribbon-cutting event for the project once it is completed.
“It’s a way, as a local government, that we can say, ‘Here’s what we’re doing with the money you’re contributing. We want you to know about it, we’re proud of it, we want to take care of it,’” he said.
“Not everybody is going to be all that wowed about going out to a treatment plant (for a ribbon cutting), but it’s something we need to do.”