City of Altamonte Springs Potable Reuse Demonstration Pilot Project (pureALTA)

As its population grows, Florida’s existing groundwater supplies are not projected to meet future demand, driving state leaders to look for alternative water supplies. Potable reuse is one possible option. Traditional treatment trains consisting of membrane filtration followed ultraviolet (UV) light disinfection, or a combination of UV and advanced oxidation (AOP) can include high construction costs, high operating costs, and the generation of a waste brine stream that must be disposed of. While coastal communities can discharge this brine to the ocean, inland communities like the City of Altamonte Springs, Florida cannot, making certain advanced treatment methods impractical.

With these challenges in mind, Carollo partnered with the City to identify and develop an optimal treatment train that could use alternative technologies that would eliminate the need for brine disposal while meeting stringent drinking water requirements. The resulting processes would be piloted in a potable reuse demonstration, called pureALTA.

Carollo began with an extensive review of successful potable reuse projects and their water quality results in Florida and throughout the United States. By comparing these studies with Florida Department of Environmental Protection (FDEP) standards for indirect potable reuse and drinking water quality, the team was able to hone their water quality objectives, begin vetting treatment processes, and develop the pureALTA testing protocols as well as operational standards and finished water quality targets.

Once the water quality, testing, and monitoring procedures were in place, Carollo led the design of the pureALTA facility, a 20gpm permanent advanced water treatment demonstration system that receives treated wastewater effluent from the Altamonte Springs Regional Water Reclamation Facility. As designed, the pureALTA Pilot Demonstration provides multiple treatment barriers for pathogen and pollutant removal, resulting in purified water that meets all regulatory and advisory health levels for drinking water and potable reuse. Remarkably, the facility does so without generating a brine stream and with treatment cost estimates that averaged 35-52 percent lower than membrane-based advanced treatment processes.

Extensive testing over a 12-month period included collection and analysis of nearly 5500 water quality samples and hundreds of hours of online monitoring for approximately 165 chemical and biological parameter. During that time, the pureALTA project consistently met all pathogen and chemical water quality standards currently being applied to potable reuse projects in the United States.

pureALTA is one of a limited number of pilot-scale studies that are helping define guidelines for future potable reuse applications in Central Florida and the United States.  team is actively working with FDEP will use the project’s results to guide development of future IPR and DPR projects in Florida, and facilitate the within the state’s drinking water statutes and regulations.