While the fate of the Marana Wastewater Treatment Facility has yet to be legally determined, Pima County and the Town of Marana continue to disagree on issues outside of the courtroom. 

One of the ongoing points of dissention between the two jurisdictions pertains to how facility ownership will affect the wallets of Marana citizens.

In the Sept. 12 edition, Marana staff outlined how a county-owned facility could prove vastly more expensive for Marana residents, as the Town would potentially have to purchase its water credits from the Central Arizona Groundwater Replenishment District (CAGRD), while also being unable to take advantage of the plant’s discharge for groundwater replenishment.  

The Town’s demonstration of those numbers can be found along with the original story on explorernews.com.

Now, Pima County Administrator Chuck Huckelberry is refuting the accuracy of those numbers, and presenting some of his own to argue that a county-owned facility is a better option for Marana residents.

According to Huckelberry, the purchase of water credits from the CAGRD would not be nearly as detrimental to Marana citizens as Town staff claims, and in some cases, is already being utilized.

“The CAGRD is presently used by some Marana residents who have had to join the CAGRD to obtain an assured water supply for their subdivision,” said Huckelberry. 

Huckelberry attached one Marana resident’s property tax statement, which lists the yearly contribution to the CAGRD at $80.58, or $6.71 per month.

“I have said in the past and continue to say that the CAGRD is a viable solution to Marana’s perceived water problem,” said Huckelberry.

Huckelberry also supplied water bills from various parts of Pima County to include Green Valley, Vail, Southwest Tucson, and the Tucson Mountains, whose residents each pay the CAGRD assessment for water service.

Their average annual water costs are about $51, or about $4 per month, according to Huckelberry’s documentation.

Huckelberry also refuted Marana’s estimated expenses in purchasing water from the CAGRD. The Town’s research showed the most recently published cost per acre-foot from CAGRD to be $671.

“The CAGRD rate is not $671 per acre-foot,” said Huckelberry. “The rate last year was $427 per acre-foot.”

If using Marana’s number of $671 per acre-foot, the expense to provide water for the state mandated 100-year supply for its 33,290 entitled lots would be $744.67 million. When dividing that number by the 33,290 lots, the result is $22,369 per new household.

Town Manager Gilbert Davidson said if the Town does not control its wastewater, this amount would have to spread as an impact fee to new homeowners, which Huckelberry calls “ridiculous.”

“This amount is typically not paid as an impact fee; it is paid on an annual property tax bill every six months or paid through a water company assessment on a monthly basis,” said Huckelberry. “Using Marana’s $744 million number, divided by 33,000 residences, divided by 100 years, divided by 12 months, the cost equals $18.80 per month. This amount looks quite different than an impact fee of (more than) $22,000 per house and much closer to the actual groundwater replenishment direct bill for an actual Marana resident of $6.71 per month.” 

According to Huckelberry, the biggest omission in Marana’s argument is the cost to convert sewage to water. 

“First, you must determine the amount of water to be used to support the stated Marana growth by 33,000 houses,” said Huckelberry. “Using Marana’s number of $744 million, divided by $671 per acre-foot yields 1,108,000 acre-feet over the 100-year period. Next, determine the amount of wastewater from 33,000 houses by multiplying 33,000 residences by the current average volume of wastewater generated per home of 215 gallons per day (assuming 2.7 people per residence and 80 gallons per person per day), and converting it into acre-feet. This yields approximately 794,000 acre-feet over the 100-year period.”

Huckelberry said Marana’s appropriation of the wastewater facility requires the Town to set aside effluent for the Southern Arizona Water Rights Settlement Act.

“This is approximately one-third of their effluent, leaving the Town of Marana with approximately 529,000 acre-feet of effluent for water supply purposes,” said Huckelberry.

“Next, you need to determine the cost to treat the 794,000 acre-feet of sewage to create 529,000 acre-feet of effluent for Marana’s recharge and beneficial use.”

Huckelberry said first, the Town has to pay the County $15 million for the existing facility, but in order to accept the sewage generated from more than 33,000 new homes, Marana would be required to expand the facility to a capacity of seven to nine million gallons per day.

“This would likely cost $150 million in capital improvements,” said Huckelberry.

Additionally, Huckelberry said Marana will have to pay annual operating costs and maintenance expenses on the facility for a 100-year span. According to the 2009-2010 Pima County Wastewater Facility operating costs provided by Huckelberry, Marana’s operating expenses were higher than any other wastewater facility at $4,142 per acre-foot.

“None of our other facilities approach this per acre-foot cost for operating and maintenance,” said Huckelberry. “Smaller facilities have much higher costs. Using the typical annual operating and maintenance cost of $1,081 per acre-foot for the Green Valley facility, and $1,398 per acre-foot for the Avra Valley facility, or an average of $1,239 per acre-foot, times the total acre-feet of sewage being treated of 794,000 acre-feet, yields a total cost of $984,163,000.”

Huckelberry said Marana will have to recharge the water in order to receive credit for it, meaning the Town will need to construct recharge basins and pay average operating and maintenance expenses per acre-foot over the same period. Referencing the City of Tucson’s capital and operating expenses associated with the Sweetwater Recharge Facility, Huckelberry said this would add another $40 million to the cost, bringing Marana’s total to $1.189 billion in total expenses.

“In this analysis, Marana pays $1.189 billion to turn 529,000 acre-feet of effluent into water for the Town, and is then required to purchase the balance of the required 580,000 acre-feet from the CAGRD at $671 per acre-foot: an additional cost of $389 million to $1.189 million equals $1.578 million, which is over a billion dollars more than what Marana thinks they will save under the present scheme. Are the Marana taxpayers better off in this scenario? No. Everyone should remember that arithmetic is important when considering fundamental government policy.”

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