|
Water Treatment Water Supply System Improvements, Moline, Illinois (continued) Major plant additions were made in 1950 and 1960. Numerous upgradings and modernizations since that time improved plant operations and treatment economies. For instance, based on studies conducted by the city with Greeley and Hansen's assistance, the facility began using polymer and alternative coagulants to reduce lime requirements, thus reducing chemical and sludge disposal costs. Converting the existing sand filters to dual-media filters in 1986 resulted in doubling the original filtration capacity to 4 gallons per minute per square foot. In 1996, Greeley and Hansen completed a study that used current and possible future water treatment regulations as a basis to evaluate existing plant rehabilitation and new plant alternatives and determine long-range plans for the city's water treatment facilities. Near-term planning pointed out areas for upgrading and modernizing of the existing plant to meet pertinent treatment requirements. After weighing the options and costs, Greeley and Hansen determined that the city could continue to make improvements to the existing plant and meet treatment regulations more cost effectively than if they opted to construct an entirely new facilty. |