Sustainable water management is in an era of rapid change. Worsening drought and increasing water demand across the U.S. have pressured utilities to develop new water supplies and deliver more with ageing infrastructure. Meanwhile, implementation costs continue to rise, straining tight budgets. This alone might seem daunting for utilities, yet there is still a further challenge.
A new generation of emerging contaminants—specifically per- and polyfluoroalkyl substances (PFAS)—pose significant risks to water supplies for thousands of communities. In response, some water utilities have had to augment their treatment systems to keep consumers safe and meet strict regulations on PFAS in drinking water. The dual challenges of water scarcity and quality threats pose a seemingly immense task for utilities. And while a perfect solution doesn’t exist, there is something close to it: potable reuse.
Potable reuse is a powerful drought mitigation and water resiliency solution. At the same time, potable reuse treatment technologies like Reverse Osmosis (RO) and Granular Activated Carbon (GAC) have proven effective for PFAS removal. We see an opportunity for potable reuse solutions to provide additional value, supporting resiliency while removing PFAS from the water cycle. For communities planning to invest in both PFAS and reuse systems, it makes sense to integrate both solutions to reduce long-term capital expenditures.
In practice, the integration of PFAS treatment into potable reuse is relatively straightforward. It involves the inclusion of an RO or GAC filtration step into the potable treatment train. Indeed, regenerable ion exchange resins and novel sorbents have added benefits and can be considered as alternatives to GAC.
We see an opportunity for potable reuse solutions to provide additional value, supporting resiliency while removing PFAS from the water cycle
While this approach is imminently viable, it poses an additional question: what happens with the spent media or RO concentrate? In past decades, disposing of those materials posed significant risks. Thermal regeneration of spent media, which is the dominant form of PFAS destruction, carries a host of negative environmental impacts, from air pollution to GHG emissions. Ocean discharge of PFAS-laden RO concentrate carries similar potential negative environmental impacts.
Yet, today’s technologies have changed the picture, providing more sustainable, safe and adaptable solutions. Super Critical Water Oxidation (SCWO), for instance, destroys PFAS under high pressures and temperatures, while Electrochemical Oxidation (EO) applies an electrical current to treat PFAS-laden streams. These solutions have already been commercialised globally, and PFAS and potable reuse have become increasingly integrated and implemented.
In communities with water-dependent industries, a water outage can result in millions of dollars in economic damage. A study by the Metropolitan Water District of Orange County, found that just a 15% reduction in water supply would reduce local economic output by $6.5 billion and lead to 19,000 lost jobs across Orange County. Integrating PFAS and reuse technologies can allay this risk, simultaneously expanding supply while ensuring compliance to limit service disruptions.
Integrated potable reuse and PFAS management can also mitigate the effects of outflows from conventional wastewater treatment facilities, in some cases protecting agricultural land that has increasingly experienced PFAS contamination. This not only carries economic upsides but also obvious social and economic benefits.
While an integrated reuse and PFAS treatment system may seem daunting to implement and manage, it is greater than the sum of its parts. Together, these two solutions can provide more safety, resilience, and value for consumers while helping preserve critical resources and mitigate contamination for decades to come.
