McAlpine Creek Effluent Filter Upgrade and Expansion
Charlotte Water’s first Design-Build project and the first
municipal WWTP PDB project in North Carolina, communication
among the team was key in the project’s success. Early and frequent
communication with NC DEQ was also essential, developing an approach
that would allow construction to begin before design was complete.
This two-phased permitting approach included a preliminary
Authorization to Construct (ATC) prior to completing the design,
followed by a final ATC after design was completed. The project
increased the firm effluent filtration capacity from 40 to 80-mgd,
and included the addition of nine new filters, a new filter influent
pump, a new filter backwash pumping station to convert the existing
filters from a gravity to a pumped backwash system, and other
ancillary upgrades to facilitate automation of the filtration system.
Additional project components included piping secondary effluent flow
through an abandoned chlorine contact basin, demolishing/ filling the
chlorine contact structure, chemical feed improvements, slope
stabilization, and miscellaneous stormwater improvements. The
project also included multiple piping connections and new isolation
gates in existing structures that required detailed sequencing and
contingency planning to install. Crowder prequalified subcontractors,
administered bid packages, and managed construction activities.
Crowder self-performed critical components of the project to maintain
schedule, cost, quality, and safety.