Landia mixers are part of Gardner standards

At Gardner, southwest of Kansas city, US, site superintendent Scott Millholland keeps the Kill Creek water resource plant clean, fully serviced and at optimum efficiency as protecting the environment, waterways and his team are paramount.

At Gardner, rebuilds on the Landia mixers were not required until 14 years of service

Millholland completed 25 years of service, when the Kill Creek facility was built in 2002 by Kruger as a bio-denitro-phased oxidation ditch technology plant.

Two mixers made by Landia were there since the plant first opened, keeping everything in suspension in the ‘racetrack’ nitrification and denitrification setup

“We pull them up every spring and fall to pull off any rags and make sure there is nothing on the magnetic plug rings — and after checking them over, put them back into service. They are an integral part of what we do here,” Millholland said.

Millholland added that the Landia mixers have a strong, solid design and are easy to maintain

According to him, their rotors are on for an hour and a half, while the mixers run for 45mins. At 13amps, they are super-low on energy usage, when compared to blowers. “We have replaced 130amp blowers with new units that are 50amps, so it has been a quick payback,” Millholland added.

Keeping 21-year-old mixers in good condition is a reason Gardner has been recognised as an outstanding wastewater treatment facility. Each of the 23 lift stations in and around Gardner are also checked every day to ensure that all of the wastewater is getting through properly. Serving a population that has leapt from 6,900 people in 1998 to a figure approaching 25,000 today, Kill Creek has won the Kansas Water Environment Association (KWEA) wastewater treatment plant (WWTP) of the year seven times, and in 2020, Millholland received the William D. Hatfield award for wastewater operator of the year. The title honours operators have contributed to preserving and enhancing the water environment through their leadership, example, enthusiasm and hard work. Millholland oversees the facility, leading and mentoring his team, and also works as an operator and engineer.

The plant was originally designed to serve a population of 25,000 with a processing capacity of 2.5 million of gallons (MGD). Currently running at about 2.3MGD, with room to expand because it is modularised to 7.5MGD without disrupting operations. Gardner is also said to be one of the fastest growing cities in the US. In addition to significant population growth, Kill Creek water resource plant also have to meet the task of reducing phosphorous and nitrogen outputs to meet stricter discharge permits.

Scott Millholland, recipient of the William D. Hatfield award for wastewater operator of the year

“We have made some operational process adjustments to tackle this,” said Millholland, “From lagoons, fixed film plant with trickling filter, rotating biological contactor, chlorine, package plant and then full treatment plant, Gardner do everything on an on-call basis, from checking the water and wastewater plants, [to] water breaks, [and] turning meters on and off. For new challenges such as reducing phosphorous and nitrogen, all of our equipment, including the mixers from Landia, will play their part.”