As part of the water treatment process, wastewater is fed into residual drying beds, a belt filter press, or a centrifuge, depending on location, in order to separate the water from the natural waste and chemical coagulants as a result of the treatment process. The solids remaining after this separation is the Wastewater Treatment Residuals ("Residuals"). Denver Water has Residuals drying beds located at the Foothills Water Treatment Plant ("Foothills"), Recycle Plant ("Recycle"), and at the Residuals Ponds at 41st Avenue (the "Ponds"). At these locations, the wastewater is pumped to the beds where it filters through layers of sand, rocks, and clay. Once filtered through, the Residuals are what remain on the surface and must be removed, hauled and disposed of at a nearby landfill. The Work at Recycle and Foothills is currently performed by Denver Water’s Transmission and Distribution crew, however; Denver Water wishes to contract the Work for the foreseeable future. The Marston Water Treatment Plant ("Marston") has a belt filter press where the Residuals are essentially pressed out of the water. The remaining water is fed through a drain and released into natural waterways while the Residuals are transported via conveyor belt and dumped into two (2) twenty (20)-yard roll-off containers for transportation and disposal. A third roll-off container is kept on-site for use when a roll-off is removed and being dumped. At the Moffat Water Treatment Plant ("Moffat"), the wastewater is fed into a centrifuge where the Residuals and water are separated. The Residuals are fed into twenty (20)-yard roll-off containers for transportation and disposal. A third twenty (20)-yard roll-off is kept on site for use when full roll-offs are removed for disposal. In addition to the centrifuge system, the drying beds located at the Ponds act as the permanent disposal location for flocculation and sediment disposal for the Moffat Water Treatment Plant during plant outages and maintenance and also acts as a back-up for Residuals disposal (similar to the drying beds located at Foothills and Recycle) in the event the centrifuge is down or requires maintenance. The Ponds have not been properly cleaned in approximately three (3) years. As such, the Contractor can expect to have to perform a more comprehensive initial removal of Residuals from the Ponds.
Due to the differences in Work, there could be an opportunity to split the Work into three (3) schedules, Schedule I: removal, hauling, and disposal of Residuals from Foothills Water Treatment Plant and the Recycling Plant to a nearby landfill, Schedule II: hauling and disposal of Residuals from Moffat to Ralston Reservoir and from Marston to a nearby landfill, and Schedule III: removal, hauling, and disposal of Residuals from the Ponds to Ralston Reservoir. Proposers may submit a Proposal in response to one (1), multiple, or all three (3) schedules. Denver Water reserves the right to award to multiple Proposers if deemed to be in the best interest of Denver Water.
