City water operations staff updated the subcommittee on an ongoing PFAS consultant contract and a planned technical study aimed primarily at the Airport Well Field.

Nathan Graham, Water Operations Superintendent, summarized the 2022 well testing that detected PFAS in several wells and said Airport Well 5 had the highest levels and was removed from distribution. He noted the EPA’s 2023 regulation established a maximum contaminant level (MCL) of "4 parts per trillion": "They set a maximum contaminant level or an MCL. They set it at 4 parts per trillion." Graham said current sampling shows some wells below the MCL while Airport Well 5 tested at about four times the MCL on average.

Graham described the consultant scope: a hydrogeological evaluation, particle‑tracking modeling to identify likely PFAS sources and migration paths, siting analysis for new wells in the Airport area, and a cost‑analysis comparing treatment versus drilling new supply wells. The study will produce a series of technical memoranda and a consolidated PFAS roadmap report with recommendations for immediate, intermediate and long‑term actions; staff expect pilot testing of candidate technologies to be part of the work.

On treatment options, Graham said the study will evaluate granular activated carbon (GAC), ion exchange and proprietary media such as Fluorosorb. He summarized tradeoffs: GAC is widely used and generally understood but requires backwash and has higher capital cost and residual handling needs; ion exchange offers higher selectivity and a smaller footprint but can be sensitive to water chemistry and produces a concentrated waste stream when resins are regenerated.

Committee members emphasized extended pilot testing and raised disposal concerns for spent media and brine. Graham said some disposal or reactivation pathways exist regionally and that ADEQ has identified Prescott as a disadvantaged community that may qualify for funding; he estimated scoping costs in the "couple $100,000 range" and said ADEQ may contract with consultant Dibble to fund added scope that would let staff evaluate Chino system wells as well.

Graham said the consultant contract includes staff and public workshops (virtual and in‑person), two meetings set for council or the public to present recommendations, and a final roadmap about 48 weeks after notice to proceed. Staff will return with more detailed cost and schedule information during contract negotiations.