By Cassie McClure
Published in the Las Cruces Sun-News 1/16/21
After nearly 12 years at work, some wells that monitor the Griggs-Walnut Groundwater Plume Remediation Project at 163 N. Cottonwood St. will be rehabilitated or replaced. This may lead to some nearby neighborhoods hearing more activity in the area intermittently for approximately two to four weeks from the middle of January into February.
The water treatment facility, managed by Las Cruces Utilities (LCU), at the Griggs-Walnut Superfund Site clears the groundwater of the chemical perchloroethylene — commonly referred to as PCE — to make the water drinkable. The four monitoring wells are used for sampling, analyses, and current mapping locations of the PCE plume on an annual basis.
“Residents may hear whining, fluctuating hammering, or pounding depending on what phase of installation or rehabilitation the contractor is at during the replacement project,” Adrienne L. Widmer, P.E., interim assistant utilities director, said. “There is no concern about the PCE plume spreading or that there will be any service outages.”
PCE is a man-made chemical used for dry cleaning clothes and degreasing metal and was first detected in Las Cruces groundwater in 1993. The affected water wells were immediately taken offline. The facility processes more than 350,000 gallons of water per day, removing the PCE and making the water suitable for drinking.
The contaminated groundwater is pumped from two offline municipal wells — No. 18 and No. 27 — and passes through air strippers that expose the impacted water to oxygen, which dissipates the PCE, removing it from the water. Chlorine is then added to the treated water before it is transferred to the Upper Griggs Reservoir, off Triviz Drive, and distributed for consumption.
In June 2011, both the Las Cruces City Council and the Doña Ana Board of County Commissioners approved the Environmental Protection Agency’s Modified Administrative Order and provided an intent to comply to EPA. The action allowed for the construction of a water treatment facility.
The plume, known as the Griggs-Walnut Groundwater Plume Superfund Site, at one time, stretched from west of Solano Drive to east of Interstate 25, generally between East Griggs Avenue and East Hadley Avenue. The polluted water ranges from about 190 feet to 650 feet below ground level. Due to the water treatment facility efficiency, the plume continues to shrink in size.
Yellow Jacket Drilling Service, LLC, of Phoenix, Arizona, won the bid for the Flute Well Replacement project and the total time frame to complete this project is an estimated 75 working day at a cost of $1,378,406.22.
LCU can be reached at 575-528-3500 from 8 a.m. - 5 p.m. Monday through Friday. LCU provides services to approximately 100,000 Las Cruces residents and businesses.
PHOTO 1: Yellow Jacket Drilling Services, LLC installing a new monitoring well in the Doña Ana County Fleet Maintenance Facility parking lot.