Oro Valley told not to put reclaimed water in pond | News

Oro Valley’s intended use of reclaimed water to fill a 2.5-acre, former irrigation pond within the Vistoso Trails Nature Preserve would be “a violation” of the conservation easement overlaying the 202-acre parcel, according to a claim filed March 2 with the town.

In a 60-day notice, Archaeology Southwest urges town government to use “well water or municipal water to fill and maintain the proposed pond.

“Alternatively, we request the town not build the pond feature, but use the area to create a desert garden, as previously approved by the council in 2024,” writes Rui Wang, an attorney with Hofmeyr Law PLLC who is representing Archaeology Southwest.

A 60-day notice can be a precursor to litigation. It starts the period “within which Oro Valley must correct the threatened violation,” Wang writes.

The Oro Valley Town Council considered the 60-day notice in a closed session at the end of its March 4 meeting. After deliberation of just less than one hour, council told its attorney to act as directed in executive session. It has no public comment, according to a town spokesperson.

Archaeology Southwest is the “holder” or “grantee” of the conservation easement, which governs use of most land within the former Golf Club at Vistoso, on either side of Vistoso Highlands Drive. In its role, Archaeology Southwest is “obligated to enforce the terms of the easement and to uphold its conservation purposes,” Wang writes.

“Filling the preserve pond with reclaimed wastewater jeopardizes Oro Valley residents’ health and welfare, and degrades the easement purposes and values due to the documented presence of contaminants,” the claim says.

Archaeology Southwest argues per- and poly-fluoroalkyl substances, commonly called PFAS or “forever” chemicals, are suspended within reclaimed water. PFAS are deemed “hazardous substances” by the federal Environmental Protection Agency.

“Tucson Water has determined that levels of PFAS contained in the region’s reclaimed wastewater supply greatly exceed the maximum contaminant level of 4.0 parts per trillion (“ppt”) set by the EPA,” the claim continues. After wastewater is treated by Pima County, Oro Valley pays Tucson Water the cost to deliver its reclaimed water entitlement into the community.

“Because the pond will be a static reservoir, meaning water goes in but does not come out except through evaporation, PFAS levels in the pond water and sediments will only become more concentrated as contaminants remain behind while more reclaimed wastewater is added,” the claim said.

The conservation easement “explicitly” prohibits “the storage, dumping or other disposal of ‘hazardous or toxic materials’” within the preserve. It does allow Oro Valley to restore the former irrigation pond “in whole or part, or dedicated to another use” consistent with easement provisions.

Archaeology Southwest has the right to “preserve and protect” assets within the preserve, among them natural, scenic, open space, historical, biological, cultural, and recreational conservation values, Wang writes. Those are “of great importance” to Oro Valley residents, and are “worthy of protection under the conservation purposes.”

 The conservation easement agreement “allows our client to bring legal action to do so,” Wang writes. Archaeology Southwest could pursue legal injunction to stop use of reclaimed water, “temporarily or permanently.”

“In sum, the use of PFAS-contaminated reclaimed wastewater to fill the 2.5-acre pond at the preserve is a violation of the terms of the conservation easement granted to Archaeology Southwest by Oro Valley,” the claim concludes. “For all the above reasons, we request the town of Oro Valley reverse its decision to use reclaimed wastewater to fill the preserve pond or, alternatively, revert to its 2024 plans and use the space to create a desert garden per the Town’s 2024 Master Plan.”

Pond bids are advertised

Oro Valley has called for bids on the pond project, with proposals from contractors expected March 20. Town Manager Jeff Wilkins said about $1.5 million remains unspent from the originally budgeted $2 million for pond restoration and other work at the preserve.

“We did design it with alternatives,” Wilkins said of the pond project. Water circulation, parking, irrigation, landscaping, and other subsets are identified within the overall pond bid package, he said.

“We will make sure we take that to the council,” he added.

In September, Rebecca Field of the consulting firm Kimley Horn said the estimated cost “to do everything” in and near the pond site was $3.71 million, plus another $135,000 for annual operations, maintenance and the purchase of water.

At that time, town engineer Paul Keesler shared complexities related to the council’s decision to fill the pond.

Reclaimed water lines, used for years when the golf course was operational, are near the structure, and Oro Valley does intend to tap the reclaimed water resource.

However, Keesler said, if reclaimed water is not circulated, “you end up with a cesspool. That’s what you have to abate, and that’s what you have to design for.”

Two years of pond talk

For years, preserve neighbors have repeatedly complained about the condition of the abandoned pond and nearby grounds, and called for the town to refill it. The depression has been idle and empty since the golf course was closed more than seven years ago.

In April 2024, at the urging of Mayor Joe Winfield, the town council voted to proceed with a “desert garden” design for the pond area, without refilling.

After months of public pressure, in November 2024 the council changed its direction, voting to reconsider the “desert garden” decision and learn more about pond feasibility and cost.

Then, in April 2025, it voted 4-2 to support a phased approach to replenish the pond with reclaimed water. At that time, Winfield repeated his position, saying filling the pond “runs counter to policy, common sense, and our community’s values about water conservation.

“An artificial pond, originally created to serve a golf course, in my view does not align” with Oro Valley’s water conservation ethic, the mayor said.