Since its incorporation, the City of Sedona has spent at least $340 million (inflation-adjusted) to build, refurbish, and operate a sewage reclamation facility, but the facility accounts for the total electricity consumed and electricity-related greenhouse gases. accounted for 83% of Those discharged from urban facilities.

origin

According to the City’s 1988 Wastewater Facility Plan, Sedona’s sewage treatment plant began in 1978 with the decision of the Northern Arizona State Council to adopt the 208 Water Quality Management Plan under the terms of the Clean Water Act. increase.

Amendments to this plan in 1984 and 1988 called for the creation of a central sewer system to serve the entire Sedona Plan Area.

On April 18, 1988, the Arizona Department of Environmental Quality issued a document stating that the Sedona Sanitary District, established prior to the incorporation of the City of Sedona, had made insufficient progress in implementing the 208 Plan. ADEQ threatened to withhold approval of the new sewage system if the district and later the city did not meet the deadlines set in the central sewer installation plan.

Faced with ADEQ’s ultimatum, Sedona voters subsequently approved the establishment of a central sewer system in a referendum on June 6, 1989.

The statutory authority for whether ADEQ may issue such an ultimatum is Arizona Revised Statutes 49-106, which states that rules adopted by the Department must be observed statewide and approved by appropriate local legislatures. or by an officer, and as provided in Section 18 of the Arizona Administrative Code. – 5-303 requires sewage facilities to comply with a water quality management plan established by a designated planning agency.

The construction of Sedona’s central sewage system did not preclude the use of a purification system within the city.

Currently, the city’s website states that “the city provides sewage services to about half of Sedona’s residents and businesses.” “The rest have their own sewers and purification systems.”

City of Sedona Ordinance Section 13.15 currently requires all properties within reach of the municipal sewer system to be connected to the sewer system and, except temporarily, to operate a septic tank system or private sewer system. No new permits are granted.

economic

The initial construction cost of the Sedona sewage treatment plant was estimated at $22.5 million in 1989. Adjusted for inflation according to the Consumer Price Index, in 2023 dollars he would be worth $54.54 million.

In 2000, the city began a sewage treatment plant renovation at an estimated cost of $8.8 million (equivalent to $15.356 million in 2023 dollars).

A review of the city’s budget from fiscal 2004 to the present shows that at least $212.9 million was spent on the operation and maintenance of the sewage system, including construction and capital improvement projects, during this period. increase. Adjusted for inflation, this would put him over $270 million in 2023 dollar terms.

Administrative expenses of $11.4 million were the smallest of the plant’s expenses. This 19-year operating budget put him just over $47 million, and each year’s operating budget allocation has nearly doubled over the past decade.

Construction and capital improvement projects related to the sewer system cost Sedona residents more than $67.3 million, and the facility’s debt service costs were at least $87 million during this period. Arriving at an estimate of the City’s spending on these components of the system is a result of changes to the City’s budget format in 2012 that force staff to list construction and capital improvements separately from the sewage budget without showing annual totals. , and the changes made in 2015. , if the debt service costs were also stated separately.

Over the past 34 years, the city’s sewage treatment plant spending has totaled at least $340 million, adjusted for inflation, or an average of $10 million annually.

A May 31, 1989 Sedona Red Rock News editorial considered objections to the power plant, and one of the residents’ objections was that gradual price increases would ensure that the cost of the system would ” It would cost $300 million to get rid of it,” he said. Has completed. ”

30-year estimated costs of alternative waste disposal methods [on the basis of 6,788 housing units and 2,789 hotel rooms] that is:

• Johkasou Systems: $84.9 million, including $54 million for the initial cost of 7,718 septic systems [assuming three hotel rooms to be equivalent to one residential unit] And $30.9 million to pump those tanks every three years
• Incineration toilet: $264.2 million (including initial cost and replacement cost of $130.9 million after 15 years), based on 2 per house and 1 per hotel room for a total of 16,365, electricity consumption is $133.3 million based on 2 kWh consumption per use, 6 uses per day, average electricity cost 6.2 cents per kWh
• Composting toilet: $66.8 million (includes $65.5 million initial cost and 15-year replacement cost, $1.3 million for evaporative fan electricity)

energy and emissions

The City of Sedona’s electricity consumption in calendar 2022 was approximately 3,961 MWh, down slightly from 3,976 MWh in 2020. Sewage treatment plants and associated systems were responsible for 3,302 MWh and 3,190 MWh of this usage, respectively, up from 2,224 MWh in the financial year. In 2022, it accounted for 83% of the city’s total electricity use.

Meanwhile, the amount of wastewater treated at the plant has been very stable, varying from 403.89 million gallons in 2015 to 402.6 million gallons in 2021.

According to a 2020 study by the University of San Francisco, the Arizona Public Service’s current generation mix produces greenhouse gas emissions of 440 grams of CO2 per kilowatt hour. On this basis, in 2022 he would have emitted 1,544 tonnes of greenhouse gases due to the electricity consumption of the sewage treatment plant. Studies of direct greenhouse gas emissions from sewage plants indicate that the Sedona sewage treatment plant is likely to add an additional 300 to 500 tonnes of CO2 equivalent from sewage treatment plant emissions. I’m here. itself.

Per capita emissions average 16 tons per year in the United States and 4 tons per year globally, according to the Nature Conservancy.

Estimated annual emissions from alternative methods of wastewater treatment are:

• Johkasou system: 1,953 tons, based on a typical system emitting 230 kg of CO2 equivalent per year, according to the Water Environment Research Foundation
• Amount of toilets incinerated: 34,682 tons based on electricity consumption
• Composting toilet: 347 tons based on electricity usage

Anaerobic digesters have lower installation and discharge costs than waste disposal methods such as sewers, septic tanks, composting, or incineration, but have lower minimum temperatures than Sedona’s average annual temperature of 63 degrees Celsius. Must be maintained at 68 degrees Fahrenheit. An anaerobic system will require a site-specific design to function well in Sedona’s climate, but development has the potential to achieve net zero emissions.

environmental concerns

NACOG and ADEQ officials argued at the time of system construction that this was a necessary step to maintain groundwater quality and the health of Oak Creek. At a community meeting on May 11, 1989, city spokesman John Roberts said Sedonans had been “overloading” the soil with sewage for years, too close to the surface for 45% of the Sedona area. Argued that there is a rock and that it cannot be allowed. Allows the leaching field to function properly.

Conversely, L. George Pratt wrote to NEWS on May 4, 1988, in which he pointed out: Properly installed and maintained systems are equal from an environmental point of view. The EPA has said the same thing. His current EPA guidance still indicates that properly installed and installed septic tanks pose no danger to water quality or human health.

The June 2002 update of NACOG’s 208 Plan recognized that “there are no new restrictions on existing purification systems.” [within the Oak Creek watershed] Justified at the moment. ”

“The city of Sedona has no reports of septic tank pollution or disease outbreaks,” said John Snickers, divisional manager of the Arizona Water Company. Yavapai County Development Services likewise has no record of groundwater contamination caused by the purification system within the city limits.

A partial list of known environmental pollution incidents caused by Sedona’s central sewage treatment plant includes:

• February 26, 2008: View Drive, unknown quantity
• August 2, 2017: View Drive, amount unknown
• June 28, 2020: Canyon Drive Roundabout, 1,000 Gallons
• July 7, 2020: Canyon Drive Roundabout, 2,000 Gallons
• August 4, 2020: Hillside Shopping Center, 15-20,000 Gallons
• October 28, 2020: Arroyo Pinon Drive, 500-700 Gallons
• July 23, 2021: El Camino Lift Station, 1,500 Gallons
• March 4, 2022: New Age Center, amount unknown
• March 28, 2023: Mystic Hills Lift Station, 22,000 Gallons

“The spill doesn’t happen when admins are at work,” Sedona resident James Heyer said after the March 28 leak. “If the workers were careful and the equipment was properly maintained, there would be no spills. Who was laid off?”

repair

Given the high environmental costs of the plant, city sustainability manager Bryce Beck said the sewage treatment plant closure and sewage treatment plant will be closed as part of the city’s climate change and sustainability plan update process. He declined to comment on whether the city is investigating alternative methods of disposal.

City public affairs director Lauren Brown said the city had no plans to investigate the plant closure, arguing that such a decision was “impossible.”