McAlpine Creek Effluent Filter Upgrade and Expansion

Pineville, NC

As 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.