New water plant with river view
by Mike Kroll
On Monday night the Galesburg city council voted unanimously to approve the $17.5 million bid of Canton's Leander Construction to build a new water treatment plant adjacent to the city's current Oquawka pumping facility. Galesburg currently operates multiple wells on the banks of the Mississippi River and a pumping station that sends the water some 30 miles east to the existing treatment facility on West Main Street. Once this new facility is completed in the spring of 2010 all water treatment will be completed in Oquawka and the sand filters and chemical treatment facilities in Galesburg will be decommissioned.
“We will still maintain the West Main Street facility,” explained public works director Larry Cox, “where we store water in two large ground tanks, conduct water laboratory analysis and headquarter the water division. The older one of those tanks holds five million gallons of water and will need to be refurbished soon while the second newer tank holds four million gallons of water. The sand filters at West Main Street that will be eliminated are already past their useful life and we determined that it would be better for the pipeline to conduct all water treatment in Oquawka.”
In recent years the Galesburg City Council has been discussing serious problems with the aging water system and especially the pipeline to Oquawka which has suffered numerous leaks. That single pipeline is critical to providing water for the city and engineers have determined that it is in serious jeopardy along a specific section where leaks have been most common. It was determined that two factors contributed to the excessive wear on the pipeline, excess pressure and chemical corrosion. The chemical corrosion is due to the high amounts of chlorine that are currently mixed with the water at Oquawka prior to pumping east to Galesburg. By treating the water at Oquawka the necessary amount of chlorine will be greatly reduced lessening both corrosion potential and improving water quality or taste.
“The city recently purchased nearly 14 acres of farmland adjacent to our current Oquawka property but at a higher elevation adjacent to the highway,” noted Cox. Engineering drawings show that while the existing pumping station was threatened during the severe flood in 1993 the new facility will be located above the 500 year flood plain. The new facility was engineered by CTE Engineers of Chicago and Cox says it is a near twin of a treatment plant the firm did in Michigan about five years ago. CTE specializes in transportation and environmental infrastructure and was instrumental in evaluating the four bids that ware received for this project. Although the Leander bid is some $600,000 higher than CTE's original estimated price that also includes rehabilitation of the two gravel-packed wells that was scheduled but not originally included in the scope of this project.
Earlier projects addressing water division needs have already included refurbishing the Ranney collector that is the principal source of water at Oquawka. “Our rehab of the Ranney has been very successful and greatly improved its capacity,” said Cox. The new plant will have a standard operating capacity of 12 million gallons per day and its design affords the opportunity to expand that capacity should the need occur according to Cox.
The water treatment technology remains essentially the same as currently employed. The raw water is chemically treated with chlorine to kill bacteria, phosphates are added to address the continuing problem of many older Galesburg homes with lead water services and the water is fluoridated. Additionally the chemically treated water is mechanically filtered and aerated before it will be stored temporarily in one of two one million gallon finished water storage tanks on-site.
The entire new plant will be automated and the cost of the new automation includes replacement of the older automation currently in place at the pumping station. Because of this automation Cox says that the two current Oquawka staff will only need to be supplemented by the addition of a person splitting his or her time between Oquawka and the Galesburg plant. The computer-controlled nature of the new plant means that it can be both monitored and operated from Galesburg most of the time.
Cox emphasized that while this is the biggest water project yet tackled by the city it is only an early stage in what will likely amount to a 30+ year long project. Once this new plant is in operation the existing sand filters at West Main along with the chemical storage tanks will be eliminated and the older five million gallon ground storage tank will need to be refurbished. Soon thereafter two of the city's aerial water tanks will need to be replaced on the south side of town and at some point the huge project to repair and supplement the aging pipeline itself needs to be started.
Current plans for the pipeline are not to replace it but to construct a parallel section of pipeline adjacent to the most problematic area that will permit bypassing that section of old pipeline. Once this is in place the old pipeline section will be repaired. The hope is to proceed in this manner until there is an entirely redundant pipeline in place between Galesburg and the Oquawka treatment plant. This redundancy will make pipeline maintenance easier and greatly reduce the risk of catastrophic breech of the single pipeline. It is also important to remember that the pipeline is still just one link in the water distribution system. There is also the system of water mains, valves and towers necessary to deliver water to each home and business.
Cox was careful to note that while this seems like a huge endeavor it is really just part of the necessity of ongoing maintenance of any critical infrastructure. The Galesburg water system is aging and some parts of it are over 100 years old now and nothing lasts forever. “The scale and importance of this water system means that this project will never be totally complete. As we finish project after project the demands of time and maintenance will necessitate that eventually each component part will again require our attention again and again.”