Prescott Valley town officials on Tuesday detailed several water projects intended to preserve local groundwater and address emerging contaminants while increasing system redundancy. Utilities Director Neil Wadsworth described a pilot recharge study using “Parzana” infiltration elements, a planned PFAS treatment system for affected wells in the Quailwood area, and a planned 16-inch pipeline to connect the upper and lower portions of the town’s distribution system.

The Parzana pilot will test two closely matched basins — one control basin and one basin fitted with long infiltration elements — to measure whether the devices increase vertical infiltration through the area’s clay soils. “We’re going to build an identical basin, and we’re going to put this … into the bottom of the basin,” Wadsworth said. The town plans monthly fills for about a year to compare infiltration rates and evaporation loss.

Wadsworth said the Parzana pilot is budgeted at about $670,000 and structured as roughly a 60% loan and 40% grant, and that the town has a partner in Salt River Project. If the devices perform as expected, they would allow the town to recharge more stormwater into the aquifer rather than losing it to runoff and evaporation.

On contaminants, Wadsworth said PFAS compounds have been detected in a subset of the town’s wells and that the town has taken wells out of service where concentrations exceed the Environmental Protection Agency’s maximum contaminant level (MCL). “We have 3 wells down there that are turned off that we have not turned back on again,” he said, referring to Quailwood-area wells. He described a PFAS treatment project for Quailwood Well No. 3 that the town sought funding for from the state Water Infrastructure Finance Authority. “We asked them for $4,200,000 … We have forgivable principle of 90%,” Wadsworth said, referring to principal forgiveness built into the financing.

Wadsworth also described a planned 16-inch water main along the old Black Canyon Highway alignment to connect the upper system (Pronghorn Ranch/Stone Ridge/Grandville) to the lower system (Prescott Country Club/Quailwood/Highway 169). He said the pipeline will increase redundancy so the town can maintain supply when wells are taken out of service for repairs or contamination.

Wadsworth reported the town operates 26 wells in total and that PFAS has been detected in some but not all wells in the same area; he said the causes are not established. “We don’t know why it showed up in the wells,” he said, adding that PFAS is present widely in consumer products and in wastewater effluent. He noted the town’s wastewater plant does not currently remove PFAS and that the town discharges treated effluent to the Agua Fria.

Officials said the Parzana pilot will use potable water to ensure controlled, repeatable tests, and that the test basins will each fit on a single-family-style lot and sit about 600 feet apart so the tests will not influence each other. The PFAS treatment project and pipeline both depend on external financing and construction planning. Town staff also said they are preparing a conservation plan with public outreach expected during the scoping and study period.

The presentations closed with staff offering to take detailed follow-up questions from residents; Wadsworth said he would be available after the meeting for technical questions.