AWWA DSS71321

The Green Bay Water Utility (GBWU) decided to implement a capital improvement project to increase their pumping capacity at their raw water pump station. Eight hundred horsepower (hp) pumps are planned for installation, which will discharge into one of two water mains that will convey the raw water to the GBWU treatment facility. The system consists of the raw water pump station at lake level, which pumps to the water treatment plant at the high point of the community. The reasoning behind this was to be sure that the water consumed by the community is pumped only once, enroute to the treatment plant. Knowing this operational requirement, it became most important to ensure that the raw water supply pumping system and its operation was as energy-efficient as it could reasonably be. This paper expands upon the utility's approach to the operation, which will result in a reduction of over 1,000,000 kWh per year by assessing the utilization of the variable speed drives to work around the seasonally changing peak electric demand times and still meet water demand flow rates. Includes figures.