The practice of direct potable reuse (DPR), that of treating wastewater and providing it straight to consumers as drinking water with no environmental buffer, has always stoked a two-sided debate.
On the one hand, many consumers gag at the idea of drinking what had once been waste, before it has the chance to settle back into the larger, natural water supply. On the other, most water treatment professionals know that DPR provides water that is just as clean as any other source, more quickly and efficiently than when it is used to recharge an aquifer.
Despite the debate, source water scarcity issues and a better understanding of the practice from the public has seen it steadily rise in popularity. Pushing toward one of its largest milestones to date, DPR is on the path to legalization in one of the country’s most water-pressed states.
“Arizona has a growing population and is susceptible to drought,” said a spokesperson from the Arizona Department of Environmental Quality (ADEQ), which is revising the state’s reclaimed water rules in an effort to introduce legalized DPR. “Today’s state-of-the-art advanced water treatment technologies can remove contaminants to reliably purify water for drinking from virtually any source water to any desired standard of protection. With this assurance and based on the input from our stakeholders, we believe DPR will be supported.”
Since 1972, Arizona has had reclaimed water regulations which explicitly prohibited the use of reclaimed water for human consumption as of 1985. ADEQ chalks this restriction up to the era’s lack of technology to make such a practice safe and rule-makers’ failure to envision it.
Because prohibition of DPR is in the reclaimed water regulations and not in a statute, legislation isn’t necessary to allow for the practice, but rather a rulemaking process involving ADEQ, the Governor’s Regulatory Review Council, and the Secretary of State’s Office. ADEQ is currently revisiting many aspects of the rules and plans to propose revisions in multiple installments. The first will include interim criteria for DPR through the issuance of an “Individual Reclaimed Water Permit,” creating an advanced water treatment facility between an existing wastewater treatment plant and potable water treatment plant.
“ADEQ is in the process of revising these rules, last updated in 2001, which over time have been outpaced by the state’s water supply needs and advancements in treatment technologies,” the spokesperson said. “ADEQ is planning to release an informal rule proposal for comment in late spring 2017… Pending a variety of factors, it’s possible the first installment could make it through the Governor’s Regulatory Review Council in late fall.”
In the second installment of rulemaking, ADEQ will develop a detailed criteria for the wastewater purification necessary for legalized DPR, in conjunction with a panel of state and national experts. They will nail down specific treatment, monitoring, O&M, technical, financial, and management requirements. According to the ADEQ spokesperson, this panel will rely on technical guidance from the Steering Committee on Arizona Potable Reuse (SCAPR), a group that has been studying how DPR can be implemented in the state for years.
Between the work of SCAPR and its plans for specific and highly-protective DPR criteria, ADEQ is confident a path for the practice is clear. The spokesperson also cited ongoing public concern about increasing water scarcity and DPR’s ability to effectively augment current drinking water supplies with a protective, local, abundant, and drought-proof source of water as reasons why Arizona will be seeing widespread DPR in the near future.
“Our communities understand the importance of this source of supply,” the spokesperson said. “The comprehensive criteria ADEQ will be developing for DPR will include extensive measures for treatment, monitoring, and operation, as well as multiple layers of public health protection. These measures will ensure that a superior drinking water product will be provided for Arizona communities that may need it.”
ADEQ expects the state’s smaller communities, which have very little water resilience, to be among the first to incorporate DPR when and if it is accepted for widespread use. While it develops the forthcoming criteria, any specific plans for DPR application are on hold. However, if the first installment of revisions goes through, DPR could be conducted in a pinch.
“If an emergency need arises for DPR, ADEQ could issue an Individual Reclaimed Water Permit for an advanced water treatment facility that is fully protective of human health and the environment using any interim criteria adopted in the first rule installment,” the spokesperson said.
Any permits issued, criteria developed, and of course, fully-integrated DPR will all mark significant steps in getting the practice popularized around the world. ADEQ hopes others will learn from its efforts, as it has learned from others.
“While Arizona is not the first to pursue DPR in the United States or internationally, we hope our contributions and experience will be considered by other parties interested in and evaluating the possibility of DPR,” said the spokesperson. “We are looking to others to learn from their approaches and best practices as technologies continue to evolve and water supply demands change.”
Image credit:"Arizona," *Tim Grey © 2015, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/