Public Water Supply District #7 in Cass County, Mo., has combined an ultrafiltration membrane system with a ballasted flocculating/clarification system to deliver higher-purity water than ever before. The two treatment systems were designed by Koch Membrane Systems and Kruger of Denmark, respectively.

"Current and upcoming EPA regulations focused us directly towards new treatment techniques," Leonard Whiting, Cass County superintendent, said. "Many plants will not meet the regulations using current treatments. With this in mind, our efforts were geared toward pre-treatment alternatives and membrane technology."

Based on comments from the Missouri Department of Natural Resources (MDNR), the water district narrowed its consideration to membrane systems, and eventually to the Koch membrane system.

"Concerns from regulatory agencies and operators alike regarding the ability to maintain and operate such new technology were very present in the beginning," Whiting said. "The reality, however, is that the Koch system is very operator friendly and the 'hands-on' instruction is professional and detailed."

Criteria for MDNR approval included microbiological testing of the permeate, an extensive review of the facility and integrity testing. In addition, Koch's cartridge and adapter are housed inside clear components, enabling the operator to simply walk around the rack and check the integrity of the fibers. At the Cass site, 32 cartridges that contain more than 11,000 fibers are capable of producing approximately 1,000,000 gallons of water per day.

"We are secure in the knowledge that we have not only increased the quantity of water, but the quality of water to our customers, now and for years to come," Whiting said.