Casa Grande studies options to allocate reclaimed water as local supplies tighten

Casa Grande city officials heard a study-session briefing on reclaimed wastewater, commonly called effluent, that laid out ways the city could allocate a scarce and increasingly valuable local resource.

Catherine Sorensen, director of research at the Kyle Center for Water Policy at the Morrison Institute and a former Phoenix and Mesa water director, told the council that Arizona treats effluent differently from surface water and groundwater and that the Arizona Department of Environmental Quality regulates its quality. "Effluent, of course, is water that's collected in a sanitary sewer and treated for subsequent use," Sorensen said, adding that uses depend on treatment level and that some communities already pursue advanced treatment for direct potable reuse.

Why it matters: Sorensen said recent Department of Water Resources modeling for the Pinal Active Management Area shows groundwater is essentially "spoken for," increasing the importance of how a city manages reclaimed water. Choices about selling, recharging, dedicating or reserving effluent will affect housing, jobs and environmental amenities and could limit options for future councils.

Options and trade-offs: Sorensen described four broad approaches. First-come, first-served is administratively simple and can generate immediate revenue, but it can lock the city into low-value uses. A set-aside model reserves portions of supply for policy priorities (Sorensen used 30% for housing and 40% for industry as an illustrative example), while a highest-economic-benefit strategy prioritizes projects demonstrating job creation or other measurable community benefits; Sorensen cited Chandler27s focus on higher-value uses as a regional example. Recharging reclaimed water at a groundwater facility creates long-term storage credits that are fungible and often cheaper than constructing new transmission pipelines.

Contracts and safeguards: Sorensen urged careful contract design, noting past cases (she pointed to early Palo Verde reclaimed-water sales) where contracts lacked price escalators or reopening clauses and therefore limited flexibility as circumstances changed. She recommended clauses such as price escalation, limited reopener language, take-or-pay provisions to recover fixed costs, curtailment language to prioritize potable needs in extreme shortages, and efficiency or reuse requirements for industrial customers so the city can recapture saved water.

Council questions and local details: Council members asked whether effluent pricing follows a statewide market. Sorensen said pricing is highly local and depends on infrastructure costs, delivery method and volumes; large-volume users often pay less per unit. She explained that long-term storage credits differ from pipeline deliveries and that some customers need direct deliveries rather than relying on pumped credits.

Local constraints and next steps: City staff noted Casa Grande27s area of hydrologic impact and the potential need to pipe effluent to other recharge locations to maximize credits. Speaker 4 said Arizona Water Company will present the Alternative Designation of Assured Water Supply (ADOS) program at the next study session so the council can see modeling of allocation scenarios and better estimate what is already allocated versus what could be made available.

Where this stands: The session was informational; no policy decision or vote was taken. The council can ask staff to model effects of different allocation methods, examine price ranges across comparable cities, and evaluate contract templates that include flexibility and public-interest protections.