Tertiary Filtration Upgrade to Disk Filters

West Chicago, IL

From 1985 to 2016, the City of West Chicago utilized sand filtration for tertiary treatment at the West Chicago Regional Wastewater Treatment Plant (WWTP). The plant had two sets of five (5) sand filter units that were installed in 1985, each measuring approximately 30 ft. long by 12 ft. wide, located in the tertiary treatment building. Each tank included an aluminum weir, air diffusers, filter media, an under drain system, and 30 HP backwash pumps. Each of the ten existing units was housed in a carbon steel tank. The City spent considerable time and money rehabilitating tanks by sand-blasting, re-coating, and adding new sand. However, due to ongoing corrosion issues it was determined that the filters needed to be replaced.

Clark Dietz investigated alternatives for tertiary filter equipment. Requirements considered when investigating replacement equipment included materials, maintenance requirements, initial capital and O&M costs, capacity to reduce odors, ability to fit within the existing space, and expandability. The results of the evaluation was a recommendation to replace the existing sand filters with a disk filtration system. The City selected the disk filtration system based on a Request for Proposals prepared by Clark Dietz and sent to disk filtration system equipment vendors. Proposals were received from five manufacturers and evaluated by Clark Dietz.

Clark Dietz then designed filtration system upgrades around the selected filter equipment, Kruger’s Hydrotech Discfilter, and provided construction phase services for the installation. The new filters meet IEPA Standards in less than half of the space of the existing filters, giving the plant the option to use the extra space for additional filters in the future. The new filters use less backwash water and are covered to minimize the potential for filter flies.


2019 ACEC Illinois Engineering Excellence Merit Award