By Cassie McClure
Published in the Las Cruces Sun-News 1/31/21
Water wells typically have a long life and Well 40 is no exception; it has brought Las Cruces Utilities (LCU) customers water since 1988. However, a well’s casing life span has a finite end or, as in this case, a rebirth. New efficiency monitoring implemented by LCU, will allow this well to provide water for many decades to come.
“It’s been a good preventive and efficient detection success,” Adrienne L. Widmer, P.E., LCU interim assistant director, explained. “We obtained data that allowed us to make strategic decisions to ensure this well could be re-drilled and make use of a majority of the existing infrastructure.”
In 2016, LCU’s Supervisory Control and Data Acquisition (SCADA) system detected a pumping pattern in the old well that wasn’t necessarily unsuspected but provided a pro-active approach prior to well failure. It was concluded that Well 40 was reaching the end of its abilities to provide water. LCU engineers and consultants took it from there, drawing up plans to decommission the old well by securing it, filling it partially with cement, and establishing the new well site, about 20 feet from the current location.
Drilling a new well is a huge undertaking and an almost once in a lifetime event. An offer was extended to tour the well construction for the LCU Board of Commissioners. In December 2020, Commissioners William Little and Dr. Harry Hardee joined Widmer, LCU Director Delilah Walsh, LCU Engineer Associate Fernando Ortiz, and well-drilling contract lead Andrew Feltman, a senior hydrogeologist with John Shomaker & Associates at Well 40.
The machines were chugging loudly, sucking thick mud from a hole that would become the new well down into the Jornada Basin, when the group came out to the bustling site off Arroyo and Holman Roads.
It was a planned 80 days to drill approximately 1,160 feet and install the 18-inch stainless steel casing and screen. At the time of the tour, the crew had already drilled 625 feet, slowly pulling out mud, and every 60 feet checking for any deviation to the drilling. The crew showed how a spring-loaded metal rod is lowered into the new hole. The spring propels a small ball into a target – about the size of a quarter, to confirm the well is heading in the right direction.
Feltman was pleased by the “behavior” of the soil that allowed for smooth progress. Mud tests are taken every three hours to check the viscosity. With a mixture of water and air, the type of soil that the crew encounters, gives them a sense of what to expect as they drill. Samples of the soil layers they encounter are saved at every 10 feet for documentation.
The new well is expected to be an upgrade in capacity from 1,700 gallons per minute to 2,000 gallons, along with a casing that will likely last over 50 years. Currently, the new well is on track for the January 2021 construction completion date.
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.
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PHOTO 1: From left to right, LCU Director Delilah Walsh, LCU Board of Commissioners Dr. Harry Hardee and William Little at the Well 40 site.