NEW (Nutrient, Energy, Water) Sustainability Principles Drive Technology Selection in Advanced Water Reclamation Application

The Crooked Creek Water Reclamation Facility (WRF) is the oldest of three Gwinnett County, Georgia water reclamation facilities. The original facility was constructed in 1972. Major capacity upgrades were completed in 1985 and in 1990. There has also been an almost continuous program of process upgrades since that time through the present. Current permitted maximum monthly average day flow (MMADF) capacity is 60,000 m3/d (16 mgd). The WRF is currently rehabilitating and upgrading the activated sludge process and influent wastewater is being diverted to another facility to limit flow to approximately 30,000 to 37,500 m3/d (8 to 10 mgd) to facilitate construction activities.In 2012, a facility plan was prepared to identify longer-term upgrades to the liquid, solids, and odorous air treatment systems. A major project goal was that these upgrades enhance facility sustainability and meet more stringent effluent limits to allow possible future discharge to Lake Lanier, the drinking water supply for the Atlanta metropolitan area.A comprehensive planning framework was developed to facilitate appropriate balancing of technical and cost factors applicable to the Crooked Creek WRF in a long-term capital improvements plan. This included assessments of competing process and technology selections for the liquid, solids and odorous air streams.Following development of the project goals and vision by the project stakeholders, a long list of alternate process and treatment technologies were brainstormed and analyzed. The outcome of the screening level analysis was a short-list of the most promising solutions. The short-listed technologies and process options were then investigated in more depth using whole-plant process modeling to quantify the relative energy and carbon benefits of the alternate plant configurations aimed at producing low levels of nutrients in its effluent.The evaluation demonstrated that sustainability principles can be incorporated into selection of a technology/approach that appropriately balances the competing aspects of nutrient removal, energy efficiency, and water reclamation needs while considering financial and operational constraints.