Balancing the Three Pillars of Sustainable Design for the Sugar Creek WWTP Expansion Project

Charlotte-Mecklenburg Utilities (Utilities) in Charlotte, NC, is in the process of expanding its 20 million gallons per day (mgd) Sugar Creek Wastewater Treatment Plant (WWTP). The Sugar Creek WWTP, originally constructed in its existing configuration in 1929, was one of the first activated sludge plants in the United States. At that time, this rural location was several miles from the bustling center of town. Today, the plant is located in the heart of the urbanized south Charlotte community with a thriving business and shopping district and many large residential neighborhoods. As the area has grown, the plant has had to increase its rated capacity to 20 mgd through a series of expansion and upgrade projects. The existing Sugar Creek WWTP includes the following major liquid stream process components — influent flow equalization, primary clarification, an activated sludge process (aeration basins, blowers, and secondary clarifiers), effluent filtration, UV disinfection, and post aeration. Primary and waste activated sludge (WAS) biosolids from this facility are pumped to Utilities' McAlpine Creek WWMF for stabilization and disposal. Given the close proximity of the community to the facility, Utilities completed an extensive odor control project with participation from the surrounding community in 1999. For nearly 80 years, the Sugar Creek WWTP has served the City of Charlotte and has helped balance the region's significant economic growth with protection of water quality. In May 2007, a Wastewater Treatment Plant Expansion Study recommended various expansion and upgrade projects for Utilities, including a two-phase expansion of the Sugar Creek WWTP from 20 mgd to 34 mgd (the Project). Phase I of this expansion effort is to be completed by 2012, with Phase II scheduled for completion by 2016. Charlotte-Mecklenburg Utilities has set forth as a major goal of this Project the incorporation of sustainable design principles. The Project Team has developed many sustainable design opportunities that have been categorized under the three pillars of sustainable design — economic, social, and environmental.