Roswell, NM Hard Water Guide: Softeners, Wells & RO

Updated October 25, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Roswell source	Groundwater from the San Andres water basin; 20 producing wells, 41 million gallons a day capacity	City of Roswell CCR (2024)
Roswell hardness	Not published in the city's water quality report; test your tap	City of Roswell CCR (2024)
Other results	Nitrate 1.47 to 4.09 ppm (limit 10); uranium 2 µg/L (limit 30); natural fluoride 0.73 to 0.87 ppm	City of Roswell CCR (2024)
Hardness scale	Hard: 7 to 10.5 gpg; very hard: above 10.5 gpg; 1 gpg = about 17 ppm	NDSU Extension
Softener sodium	About 8 mg/L added per grain of hardness removed	NDSU Extension
Iron and manganese	Standard softeners handle up to about 10 ppm; more may need a separate filter	NDSU Extension
Private wells	Owner is solely responsible; test yearly for bacteria, nitrate and arsenic, uranium every 5 years	NM Environment Department
Plumbing license	CID MM-1 covers installing and servicing plumbing fixtures and piping	14.6.6 NMAC
Handyman exemption	Small jobs up to $7,200 a year, but not plumbing, electrical or gas work	14.6.2.8 NMAC

Where does Roswell's water come from?

Groundwater. The City of Roswell's 2024 Consumer Confidence Report says the city's water is drawn from the San Andres water basin, with twenty wells currently producing, a capacity of 41 million gallons a day and 24 million gallons of reservoir storage. The aquifer has shaped the city from the start: in 1890 Nathan Jaffa drilled a back-yard well on Richardson Avenue that revealed a major aquifer and sparked Roswell's first real growth. Roswell had 48,422 residents at the 2020 census, and Chaves County had 65,157.

Why is the water hard?

Because of the rock it moves through. At Bottomless Lakes State Park, southeast of the city, water in the San Andres artesian aquifer rises along faults and dissolves the gypsum-rich Seven Rivers Formation, opening the sinkholes that became the lakes. Bitter Lake National Wildlife Refuge, northeast of town, has many sinkholes formed the same way. Gypsum is calcium sulfate, and dissolved calcium is one of the two minerals, with magnesium, that make water hard. The city's 2017 report adds that decreasing water levels in aquifers can increase the concentration of minerals.

The city's reports we reviewed don't print a hardness number. To know yours, test at the tap. NDSU Extension's scale reads results like this: 3.5 to 7 grains per gallon is moderately hard, 7 to 10.5 is hard, and above 10.5 is very hard. One grain per gallon is about 17 parts per million.

Do softeners add sodium?

Yes. NDSU Extension says roughly 8 mg/L of sodium is added for every grain of hardness removed, and people on sodium-restricted diets should take that into account with their doctor. It recommends leaving one kitchen tap unsoftened for drinking and cooking and doesn't recommend softened water for lawns, gardens or houseplants. Potassium chloride can replace salt, though it costs more and the softener uses about 10 percent more per regeneration.

What else is in the water?

The 2024 Roswell report lists nitrate from 1.47 to 4.09 ppm against a limit of 10, uranium at 1 to 2 micrograms per liter against a limit of 30, and fluoride at 0.73 to 0.87 ppm, which the city says is natural because it doesn't add fluoride. No contaminant exceeded its limit. The one violation in the report was a late public notice about asbestos monitoring in September 2024, corrected the next day. A softener doesn't treat nitrate or uranium. If you want to lower them at the tap, ask about point-of-use systems certified for those contaminants.

I'm on a private well. What now?

Test it. The New Mexico Environment Department says private well owners are solely responsible for the safety and quality of their water and that its Drinking Water Bureau doesn't regulate private wells, so its advice is a recommendation. It suggests testing every spring for coliform bacteria, nitrate and arsenic, uranium every five years, testing when you buy a home with a well, and adding iron, manganese and total dissolved solids as needed. NMED's Ground Water Quality Bureau holds free water fairs that screen for arsenic, fluoride, iron, nitrate, pH, sulfate and conductivity, but it says those are screenings only and don't replace a certified lab.

Who can install a softener in New Mexico?

The Construction Industries Division of the Regulation and Licensing Department licenses contractors. Its MM-1 plumbing classification covers installing, altering, repairing and servicing plumbing fixtures and piping, and a softener tied into your water line is plumbing work. New Mexico's handyman exemption, which lets someone do small jobs worth up to $7,200 a year without a contractor license, specifically excludes plumbing, electrical wiring and gas fitting. Ask the company which CID license it or its plumber holds, look it up, and ask whether your job needs a permit and who issues it for your address.

Questions to ask before you hire

What CID license do you or your plumber hold, and what's the number?
What hardness, iron and manganese did you measure, and how did you size the unit?
How will the unit be protected from freezing and summer heat?
Will outdoor taps and irrigation stay on hard water?
What maintenance does the system need, and what does the warranty cover?

Common questions

How hard is Roswell's water?

The City of Roswell's water quality report doesn't publish a hardness number. The water comes from the San Andres basin, which dissolves gypsum, so test your tap.

What license does a softener installer need in New Mexico?

Softener installs are plumbing work, which the Construction Industries Division licenses under classifications such as MM-1. The handyman exemption doesn't cover plumbing.

Is well testing required in New Mexico?

No. NMED says private well owners are solely responsible for their water and recommends yearly tests for bacteria, nitrate and arsenic.

Roswell, New Mexico hard water guide (2026)