Corrales residents Tuesday evening panned a preliminary engineering report designed to lead to a plan that addresses the village’s future wastewater needs.
They said a possible village-wide wastewater system could be expensive and unnecessary and in contrast with the rural character of Corrales.
Stantec Consulting Services was hired to put the report together; the firm’s presentation to the Village Council proposed sewer system improvements intended to provide residents and business owners “a reliable and environmentally safe way to dispose of their wastewater.”
The costs of two possible systems would exceed $100 million, according to a presentation from Stantec senior project manager Raymond de la Vega.
Properties in Corrales rely on water wells and septic tanks, though in 2009, the village began work on its first public wastewater utility, consisting of a septic tank effluent pumping (STEP) system along Corrales Road.
That system allows the liquid portion of the wastewater generated at each property to be pumped from the on-site effluent tank into a conduit that moves it to a connection point in the Albuquerque Bernalillo County Water Utility Authority’s collection system, thus reducing the frequency at which each septic tank needs to be emptied.
Stantec says the existing sewer system has continually experienced component failures due to the construction
methods or materials originally used during its construction. The primary reoccurring issue is PVC pipe valve failure.
The failures require that the system be shut down while village staff makes the repairs, the firm says, creating a disruption within the village and leading to the realization that the system needs to be upgraded with the ability to divert the flow of wastewater around an obstruction so service can remain operational as the issues are resolved.
In other locations, there are no connections between septic tanks and the sewer system, leading to the waste leaks into the ground and eventually system backups for property owners septic lines are not properly being flushed out.
In explaining the need for action, de la Vega showed a map from the New Mexico Environment Department showing the locations of septic systems around the village. He said contamination levels have been increasing at Corrales Elementary School, the Corrales MultiPurpose Recreational Center and the Corrales Municipal Complex, with 15 excessive E. coli and coliform bacteria readings at those locations between 2011 and 2019.
The first alternative would extend the village’s wastewater collection system to unserved areas of Corrales while the existing STEP system remains in place and fully operational. It would also include the installation of a grinder sewer line along Old Church Road.
The rehabilitation of the existing septic tanks would eliminate the use of the disposal fields and reduce the amount of waste being introduced into the area. Estimated cost is $106.7 million.
The other choice involves replacing the existing STEP system mainline with an 18-inch gravity sewer along Corrales Road. That would permit customers to use the system to dispose of biosolids, eliminating the need for disposal fields and potentially septic tanks.
The estimated cost of that option is just below $103.1 million.
Several residents balked at those price tags, which could come with additional connection fees totaling thousands of dollars for property owners.
Grey Howell said Corrales would be better off upgrading the existing septic systems. He said expanding the sewer system village-wide could cut down on the village’s rural nature by encouraging higher-density development.
“Also, the money required from each household to hook up, and the monthly fees and on and on and on — that can go beyond the reach of a whole lot of us, myself included,” Howell said.
Mary Ann Bucha said many of the groundwater wells in the village are about 150 feet.
“Septic systems typically deal with the upper 10 feet,” she said.” We have a lot of sand here; by the time the water from the septic system reaches that well, it’s pretty clean.”
Bucha said a water committee she served on a few years back found no evidence of ongoing contamination in the system.
Patrick McClernon went further in condemning the proposals, saying a new sewer system isn’t just basic infrastructure, but could lead to the loss of low-density zoning and Corrales’ rural identity.
“Once a public sewer becomes available, the minimum lot size requirement that protects our open space … can legally be challenged,” McClernon said. “That’s because septic systems are what force these larger lot sizes. If the septic is no longer needed, landowners can subdivide, and developers will be eager to help them do it.”
Other speakers encouraged village leaders to seek other solutions, expressed concern about the future of disused drain fields and said no contamination was found in residential areas, meaning homeowners are effectively treating the water they use.
Councilors seemed cool to placing a substantial cost burden on property owners.
Once the final engineering report is completed, the project will move into the decision phase, when the village will decide which of the options to take or whether to discard both and optimize operations within the existing system.
The latter would mean taking no actions involving construction or additions to the system. The work would create slight increases in efficiency by continuing valve replacements, and performing proactive maintenance as needed, according to Stantec.
The firm says there are no direct capital costs with the “no action alternative,” but that as the infrastructure ages,o ngoing operation and maintenance costs will likely continue to increase.