Well Water in Estancia Basin, New Mexico
Torrance County · Population ~16,000 (Torrance County) · Aquifer: Estancia Basin (closed basin)
Hardness: Variable — often extremely high due to TDS
The Estancia Basin is a closed drainage — no surface water flows in or out. The communities of Moriarty, Estancia, and Mountainair depend solely on groundwater recharged by precipitation. Water levels are dropping, the water is often brackish, and the basin has been identified as a "hotspot for drying" with a high proportion of wells that have likely dried out.
A Closed Basin Running Out
The Estancia Basin is geologically unique in central New Mexico: it's a closed drainage basin. No rivers flow in. No rivers flow out. The only water entering the aquifer comes from rain and snowmelt. And the basin is pumping out water far faster than nature replaces it.
Water levels are declining more than 2 feet per year in the center of the basin. The Estancia has been identified as a "hotspot for drying" with a "high proportion of wells that have likely dried out."
This isn't a problem that's coming — it's a problem that's here.
Brackish Water
Even where wells haven't gone dry, the water quality is challenging. The Estancia Basin produces notably brackish water:
- Mean total dissolved solids: ~1,300 mg/L (EPA secondary standard is 500 mg/L)
- Some wells exceed 12,000 mg/L TDS — approaching the salinity of some brackish surface waters
- Mineral content increases from west to east across the basin
High TDS water tastes salty or bitter, causes rapid scale buildup, and can affect crop irrigation. At the highest concentrations, it's essentially unusable without treatment.
The Concentration Problem
As the water table drops, the remaining water becomes more concentrated with dissolved minerals. A well that produced 1,000 mg/L TDS water five years ago may produce 1,500 mg/L today. The minerals don't go anywhere — there's just less water to dilute them.
This means water quality in the Estancia Basin is on a one-way trajectory: it will get worse over time, not better.
What Estancia Basin Residents Face
If you're on a well in the Estancia Basin, you're likely dealing with some combination of high TDS, extreme hardness, sulfate (bitter taste, laxative effects), and the ongoing risk of your well going dry.
Treatment for high-TDS water typically requires reverse osmosis — either point-of-use at the kitchen sink or whole-house for severe cases. Point-of-use RO runs $239-$600 plus installation. Whole-house RO for extremely brackish water can run $4,500-$20,000+ and requires significant maintenance.
Test your water annually and track TDS levels over time. If they're rising, your aquifer is depleting.
Every well is different. Two wells on the same street can produce completely different water. The data on this page reflects documented conditions in the Estancia Basin area, but the only way to know what's in your water is to test it.
Sources
- USGS — Estancia Basin Groundwater Resources
- NM Bureau of Geology — Estancia Basin Hydrogeology
- NM Office of the State Engineer — Basin Water Level Monitoring
- NMED — TDS and Brackish Water Characterization