Title
Authorizing the City Manager to award a construction contract for the Colorado River Raw Water Intake Screens to Underwater Construction Corporation in the amount of $254,756.
Summary
The City’s Colorado River Intake currently diverts all of the raw water from the Colorado River to fill Lake Pflugerville. This intake system is the primary source of the City’s drinking water and will be absolutely critical to effectively maintain for years to come. The Colorado River Basin, along with many other water bodies around the Central Texas region, currently has zebra mussels that have found their way into and around our Colorado River Intake. This invasive species will attach to any infrastructure that it can and thrive for years if left alone. Staff have found evidence that the invasive species will attach to the intake screens over time and will have to be manually scraped off as the air burst system does not effectively remove them from the screens. Without this intervention, the screens would have a diminished flow throughput which could create significant problems during peak summer demands.
On November 24, 2020, City Council approved the treatment system that is currently in place that protects the suction and discharge pipelines from the mussels from attaching and being transported alive into Lake Pflugerville. This treatment system does not protect the suction screens where the water is currently being pulled through as we were limited to the location of the injection of the treatment chemical. This contract will replace the current stainless steel screens with a copper-nickel screen that has proven in various water utilities to prevent the accumulation of zebra mussels on the screens. These types of screens have been installed or are being installed in surrounding cities where their source water is considered “infested” with zebra mussels. The City has had successful projects with Underwater Construction Corporation in the past at the Colorad...
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