Pima County officials have come out with another reason why wastewater treatment should remain under a single, region-wide entity — cost.
In the ongoing dispute over ownership of a small wastewater treatment facility in northern Marana, the county has released an economic analysis that shows the costs of treatment at the Marana Wastewater Treatment Facility run more than five times those of other county facilities.
Jackson Jenkins, director of the Pima County Regional Wastewater Reclamation Department, presented the analysis to the Marana Chamber of Commerce on Tuesday, Feb. 15.
According to the analysis, the low capacity at the facility contributes to the difference in treatment costs.
The Marana facility costs about $4,100 to treat an acre-foot of wastewater, compared to $720 to treat the same volume of water at the Ina Road Wastewater Treatment Facility.
The Marana facility serves the Gladden Farms area, while the Ina Road facility serves the Continental Ranch and Dove Mountain areas of town.
County officials estimate the average cost per acre-foot for treatment throughout the system costs $664. An acre-foot equals about 325,000 gallons.
Costs are kept lower for ratepayers throughout the county’s service area because they are based on the average costs of treatment.
The county estimates that treatment costs to Marana residents would increase by 13 percent, while costs for conveyance and pumping waste to the facility would increase eightfold from $5 to $40 per year if the town took over the facility.
The analysis follows a thus-far successful effort on the part of Marana to get a law passed in the Arizona Legislature that would allow a city or town to take over county-operated sewer systems.
The proposed law, SB 1171, has met with approval from the full Arizona Senate and awaits movement in the House. The entire delegations from Legislative Districts 25 and 26 endorsed the proposal.
The districts include all of Oro Valley and Marana and much of Pima County.
Marana Chamber president Ed Stolmaker said the organization supports the town’s efforts to get a wastewater treatment facility.
“If we don’t ensure water resources for the future, the costs will be enormous,” Stolmaker said.
The town’s efforts have been aimed at gaining access to long-term water futures. State and federal laws mandate a gallon-for-gallon replacement of groundwater.
Currently, Marana water utility only uses to groundwater and does not receive an allocation of effluent or treated water. A large number of residents receive water from Tucson Water.
If it operated a treatment facility, the town could use effluent for recharge purposes and for turf and golf course irrigation. That would increase Marana’s ability to grow in the future by minimizing its groundwater consumption.
“I believe with SB 1171, it will put us in a position that will help us in the future,” Stolmaker said.
County officials oppose the legislation, saying it would unfairly transfer assets paid for by its ratepayers to Marana without fair compensation. The county also has argued that law could result in the fragmentation of the regional treatment system, creating rate disparities throughout the region.
Marana and Pima County have been at odds over wastewater treatment since 2007, when the town annexed the area that includes the small treatment facility in the northern part of the town.
The town council at the time broke an intergovernmental agreement with the county, established in 1979 to provide wastewater treatment services for Marana, and asserted the right to take ownership of the treatment facility.
The county quickly reclassified the area as a park to prevent Marana from taking the facility.
Following that, Marana filed a lawsuit against the county in an effort to gain the treatment facility.
While a final resolution to the case has not been reached, a judge last year ruled that the facility belongs to county. The judge also decided that Marana has a rightful claim to some of the infrastructure nearby including pipelines.