Award of Merit: Water Structures Category
Columbine Water Treatment Plant Repair
Submitted by Sika Corporation
City of Thornton
Burns & McDonnell Engineers
Lyndhurst, New Jersey
In 2004-2005, an aggressive project was begun to improve the water quality and increase the water filtration capacity of the existing Columbine Water Treatment Plant in Thornton, CO, to 50 million gallons per day. The renovations required that the existing concrete filter and concrete clarifier basins be reconfigured and sealed to prevent water leakage and to accommodate a new membrane filtration system. This would provide an increased capacity over the conventional media filters and dramatically improve the water quality. Even with the new system, the membrane would still be vulnerable to damage if any foreign particles entered the filter basins. Foreign materials could cause severe damage to the membranes and disrupt the water flow to the city; therefore, a “quick build” system was required that would protect the concrete from a low pH environment and would not be compromised by outside conditions.
Some unique challenges on this project involved draining the filter basins, demolishing the gullet walls and support system for the old filters and under drain assemblies, and repairing concrete in the basins. The basins needed to be dried well enough to apply a protective coating to the walls and floors inside of it as well as the walls, floors, and ceilings of the reject tanks and clean-in-place (CIP) tanks.
The work was performed during the winter, after the roof had been taken off to facilitate the removal of the old equipment. The extremely tight construction schedule had demolition beginning in mid-October 2004 and a deadline for producing treated water by mid-March 2005. Any construction delays would severely jeopardize the city’s water supply. In the end, the project was successfully completed on time.