The Star Valley Water and Sewer Commission did in four months what the town tried to do over the last four years —establish a comprehensive plan for a town wide sewer system.
While the plan details a steep $46.8 million price tag to construct a sewage collection and treatment system, it could be constructed in phases, spreading the cost out over many years and with most residents hooked up to aging septic systems, the benefits of a sewer system are far-reaching. Not only would the system eliminate worry of contaminated drinking water, it would allow the town to grow, adding much-needed commercial businesses to the Highway 260 corridor.
Currently, most groundwater wells in Star Valley are shallow and tap into an aquifer influenced by storm water runoff and infiltration, according to the preliminary sanitary sewer master plan designed by Tetra Tech.
“This raises the concern of the possible effect of septic system effluent leaching into the groundwater wells,” said Tetra Tech engineer Garrett Goldman.
“The Town of Star Valley needs to be cognizant of this possibility and the overall effect it will have on the town if existing groundwater wells start showing signs of contamination.”
Only 84 residents of Houston Creek Landing and Pine Ridge are hooked to a centralized sewage system, the Houston Creek Landing Treatment Facility. The rest of the town is on septic systems that “would not meet current standards for septic septic systems both from a configuration standpoint as well as location relative to existing domestic water wells.”
Presently, it is unknown if any wells are contaminated because they are privately owned and residents do not have to test their water. However, as the town grows and septic systems get older, the possibility of contamination rises, the plan states.
“By considering and acting on the development of a sanitary sewage collection and treatment system at this time, the town of Star Valley is taking a proactive approach to the potential problem,” Goldman said. “This proactive approach allows the town to be in control of the desired outcome which will ultimately save the town money.”
The plan details constructing a treatment facility and trunk line that can handle an estimated 2.6 million gallons per day of wastewater.
The trunk line would be located in an area to maximize gravity flow and extend into the most number of adjacent neighborhoods. The most probable area for the line would be along Houston Creek, extending from the south end of town to the intersection of Moonlight Drive and Highway 260. The line would then split at the highway, heading east and west to connect homes and businesses along the corridor.
Connecting the neighborhoods along Houston Creek is priority No. 1, the plan states, because of the number of homes “served by septic systems and is thought to be the most immediate source of future contamination to groundwater wells and Houston Creek.”
In proposed phases two and three, the trunk line would be extended to residential areas north of Highway 260, along Houston Creek and Goat Camp Wash. Finally, in phase four, the sewer line would run east along the highway, connecting the Gila County Maintenance Yard, Dealer’s Choice and Diamond Point Shadows.
While the plan lays out one option for the location of the trunk line, it offers several options for the location of a treatment facility.
Four potential wastewater sites were identified along the Houston Creek drainage corridor.
“Each site has inherited issues associated with it, both positive and negative.”
The first site is north of the Houston Creek and Stewart Creek convergence on the undeveloped eastern bank of Houston Creek.
This site is downwind of all development and most of Star Valley could drain to the site by gravity flow. The downfalls include: there is no road leading to the area, and it is part of the Tonto National Forest.
The second proposed site is just north of the first and can be on the west or east side of Houston Creek. The site is within the Tonto National Forest and near homes, so there is the possibility of odors affecting homeowners.
The third site is also near several homes, in a private meadow off Sprague Ranch Road, currently being used as a horse boarding and training facility.
Besides being near homes, the site is upstream from several homes, so waste would have to be pumped up from these areas.
The final location is near the Lion Springs and Houston Creek confluence, on the east side of Houston Creek. This site is also near homes and some distance upstream from the southern boundary of town, the plan states. Placing a treatment facility here would also eliminate the possibility of using the site as a park.
Tetra Tech sees site one as the preferred location with its distance from homes.
The total cost to construct the trunk line and treatment facility is $24.8 million, not including the cost to extend lines into neighborhoods or to homes.
Add in another $22 million to provide sanitary sewer service and the grand total for the overall design and construction is $46.8 million.
If the town waits 10 years, the cost of the system jumps to $62.87 million, assuming a 3 percent per year inflation rate.
While it would be impossible for the town to pay for the system itself, there are several options including the most traditional — a municipal bond. The town could also pursue government grants and loans, congressional earmarks and public/private partnerships.
Councilor George Binney questioned what effect constructing the system in stages would have on the cost per resident. Would one neighborhood bear the cost burden of the trunk line and treatment facility?
Water and Sewer Commission chair and town Councilor Vern Leis said the commission’s next task is analyzing Tetra Tech’s study and determining what steps to take next.
“We have to answer a lot of questions before we know what the hook-up costs will be,” Leis said.
In addition, the commission plans to analyze what organization would design, construct and operate the sanitary district. Tetra Tech recommends the town either develop its own sanitary department and assume all responsibility or be annexed by the Northern Gila County Sanitary District. The first allows the town to remain in control, but also requires it obtain all funding. The second option gives someone else the responsibility of maintaining the system and finding funding, however, the majority of landowners would have to agree to the annexation.
The commission plans to analyze the preliminary sewer plan and update the council with any conclusions or specific recommendations in six months.
Leis added that this study offers a complete picture of what Star Valley needs today. What the council or town decide to do with it is up to them.
Commission member Bill Davis said it is the commission’s job to study all the choices and present the council with the best option.
“Our job is to remove all doubts,” Davis said, “so when we come to the council and lay out all the options, they do not have to think about the what-ifs.”