Potomac Water Filtration Plant Improvements
The Potomac Water Filtration Plant Improvements project enhanced the plant's ability to treat and supply water for more than 1.6 million customers, while also reducing the owner's reliance on costly chemicals. Clark Civil and its joint venture partner ensured the plant could maintain its ongoing operations, even during an emergency situation.
The Potomac Water Filtration Plant Improvements project enhanced water quality, increased process reliability, and expanded plant capacity. In addition to demolishing existing structures, the joint venture team constructed four Rapid Mix Facilities, two Intermediate Pumping Stations, two Ultraviolet Disinfection Facilities, one Backwash Pump Station, and two Lime Feed Facilities. Two new Chlorination Facilities raplaced four existing Flocculators.
As the Potomac Water Filtration Plant is the main supply of water for the suburban Washington region, all construction was meticulously scheduled to ensure that the plant was in operation at all times. Construction was coordinated through phased shut-downs, and the project team was able to keep the plant operating at more than 50 percent capacity for their duration. On the tie-in to East Plant facility, the project team had 21 days to complete the difficult operation. Specialized crews were brought in to excavate and support the excavation, demolishing the existing 84-inch precast concrete pipe line. Careful planning and teamwork resulted in a successful shutdown that took one week less than planned.
Clark's dedication to the success of the project shone through when the plant faced an emergency situation during construction. A distribution line outside of the plant failed, which resulted in an unplanned outage. During this outage, the system demand was higher than the plant was able to distribute. Work on new chlorine diffusers had been planned for weeks later, but now needed to be completed within 48 hours to allow the plant to go to full production. The project team quickly mobilized and re-routed chlorine diffusers and successfully mitigated any disturbances in service.
The Potomac Water Filtration Plant Improvements project used a Construction Manager (CM)-at-Risk contract, which allowed construction of the project begin to before the design was complete. This process required extensive collaboration among all parties involved. Through the use of focus group meetings between the joint venture team, the Washington Suburban Sanitation Commission (WSSC), and architect/engineer PBS&J, all involved in the project's construction were able to build a “one team” mentality that resulted in the project's great success.
In addition to coordination drawings, the project team used BIM to further identify design discrepancies in the concrete layout. The cast-in-place concrete subcontractor used this technology extensively to lay out and coordinate the pour sequence.