New Mexico
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New Mexico water profile

Nitrate in New Mexico community water systems

New Mexico's nitrate splits two ways: the dairy country of the eastern plains around Clovis and Portales, and the Santa Fe basin, where high readings hide in shallow wells. See where the pattern concentrates and what each reporting system measured in the three years from August 9, 2023 to August 9, 2026.

Browse all 558 New Mexico systems →

Search by the utility or system name shown on a water bill. Example: City of Clovis. Private wells are not in this inventory.

100%
of the state’s 558 active community water systems have a current result here
558
systems with a current nitrate result
1,926,903
people served by those reporting systems
3.9%
of reporting systems at or above 5 mg/L
How to read these numbers Each system is placed into a band by its most recent reported result within a rolling three-year window. The bands describe how strongly human activity, read from nitrate, has marked a water source; they are not a safety verdict. Figures describe system reporting, not nitrate measured at an individual tap.

How New Mexico's systems fall across the five bands

Most systems report below 3 mg/L

Natural background
0.00–0.99 mg/L as N
361 systems · 539,737 served
Human impact likely
1.00–2.99 mg/L as N
129 systems · 971,893 served
Human impact clear
3.00–4.99 mg/L as N
46 systems · 252,541 served
Health-study range
5.00–9.99 mg/L as N
20 systems · 161,581 served
Above the federal limit
10.00 mg/L and above
2 systems · 1,151 served

Each system appears in one band only, placed by its most recent reported result in the current three-year window. Counts sit beside people served so a small number of larger systems cannot hide behind a row of tiny ones. Of the 22 systems reporting 5 mg/L or more, 5 stayed at or above 5 across the whole three-year range; the other 17 reached it only on a high sample and otherwise ran lower.

Most recent reading Jun 2026; the typical system was last tested around Feb 2026. 515 systems sampled their own water; 43 systems carry a supplier’s result.

The named systems

Every reading here belongs to a utility with a name

Highest recent readings
SystemMost recent resultBandBased onPeople served
Sunlit Hills Water System11.20 mg/LFeb 2026a high point — runs lowerAbove the federal limit35 samples1,018
Virden Water System10.50 mg/LApr 2025Above the federal limit5 samples133
Espanola Water System9.07 mg/LFeb 2026a high point — runs lowerHealth-study range13 samples12,012
Cuatro Villas Mdwca9.07 mg/LFeb 2026a high point — runs lowerHealth-study rangeinherited from supplier420
Homestead Water Company8.43 mg/LDec 2025Health-study range5 samples222
Desert Ranch Mdwca7.60 mg/LJun 2026Health-study range5 samples89
Valley Estates Water & Sewer Association6.92 mg/LMay 2026Health-study range6 samples194
Trailer Ranch Senior Mobile Home Commun.6.76 mg/LSep 2025Health-study range3 samples200
Largest systems
SystemMost recent resultBandBased onPeople served
Albuquerque Water System2.80 mg/LFeb 2026Human impact likely6 samples560,326
Rio Rancho Water & Ww Services3.20 mg/LApr 2026a high point — runs lowerHuman impact clear23 samples107,350
Las Cruces Municipal Water System1.08 mg/LMay 2026Human impact likely70 samples98,175
Santa Fe Water System (City Of)6.16 mg/LOct 2025a high point — runs lowerHealth-study range23 samples90,810
Roswell Municipal Water System1.80 mg/LJan 2026Human impact likely31 samples54,025

Each result shows its date and what it rests on, so a lone sample is never taken for a settled measurement. A single high sample is not a complete account of what a household drinks.

Where higher nitrate concentrates

Dairy country east, a shallow-well story at Santa Fe

Human impact is clear on drinking water served in 20 of New Mexico’s 33 counties. Each is shaded by how many of its systems reported 3.00 mg/L as N or above. Shading counts systems, not severity — a county with many small utilities can outrank one holding a single larger system that reads higher. The table beside the map splits the two bands so that difference stays visible.

NM counties shaded by number of community water systems reporting nitrate at or above 3.00 mg/L as NCounties are shaded by how many community water systems reported nitrate at or above 3.00 mg/L as N in the three years from August 9, 2023 to August 9, 2026. The same counts appear in the table below this map.Luna County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveTorrance County — 2 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveGrant County — 2 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveUnion County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveOtero County — 4 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveHidalgo County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveCibola County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveEddy County — 5 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveRio Arriba County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveLincoln County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveSocorro County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveTaos County — 2 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveSanta Fe County — 4 systems at 3.00–4.99 mg/L as N; 9 systems at 5.00 mg/L as N or aboveSandoval County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveQuay County — 2 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveDoña Ana County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveLea County — 5 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveCurry County — 3 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveBernalillo County — 6 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveRoosevelt County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or above
none1–23–56–1112–2526+Number of drinking water systems reporting ≥3.00 mg/L NO₃–N per county as of August 9, 2026

Santa Fe leads this layer with 9 reporting systems, followed by Curry, Lea, Rio Arriba. Dairy country east, a shallow-well story at Santa Fe. Coverage note: the map places 99% of New Mexico’s reporting systems. The other 3 sampled their own water but have no county in the records, so the map understates New Mexico and reads as a floor.

Counties with the most systems at or above 3 mg/L as N
County3–4.99≥5Total ≥3
Santa Fe4913
Bernalillo617
Lea527
Curry336
Eddy505

Counts use each system's most recent reported result in the current three-year window. A system appears in only one of the two bands. Coverage note: the map places 99% of New Mexico’s reporting systems. The other 3 sampled their own water but have no county in the records, so the map understates New Mexico and reads as a floor.

Find a specific New Mexico system

What the statewide pattern says

Lagoons on the plains, shallow wells in the basin

New Mexico's higher nitrate comes from two documented settings: the state-monitored dairy belt on the eastern plains, and shallow basin-fill wells in the Espanola Basin around Santa Fe.

New Mexico is one of the few states that requires dairies to monitor their own groundwater, which produced a rare statistical picture: across 94 permitted dairies and 1,031 samples, median nitrate was 4.4 mg/L and 36 percent of dairies reported results above the 10 mg/L federal limit. The worst cases sat downgradient of waste lagoons and stock pens (medians to 18 mg/L), and high readings were rare where the water table lay deeper than 100 feet (USGS/EPA animal-feeding-operations proceedings). The dairy belt clusters over river alluvium and the Ogallala on the state's east side — Curry, Lea and Roosevelt country, which is where this page's map concentrates.

Around Santa Fe, the Bureau of Geology's basin-wide geochemical study found nitrate from under 0.1 to 15 mg/L with a 1.5 mg/L median — and a sharp structural pattern: every reading above 6 mg/L came from wells shallower than 500 feet. A significant nitrate-chloride correlation (r = 0.62) points to septic influence, with documented MCL exceedances near the landfill and in one fractured-bedrock well (New Mexico Bureau of Geology and Mineral Resources, southern Espanola Basin geochemical study).

Between those two settings the state runs low: deep Ogallala and confined basin-fill water is largely protected by depth, which is exactly the variable the dairy statistics identify as protective.

The supported source reading is dairy waste — lagoons, pens and land-application — on the eastern plains; septic and localized sources in shallow Santa Fe basin wells — not a certified source at any individual system (Nolan and Hitt, 2006).

The general science — how nitrate moves, why some ground is vulnerable, and why the legacy lingers — is laid out with its sources on Where nitrate comes from.

Questions this page answers

What the New Mexico pattern does—and does not—say

Where does nitrate concentrate in New Mexico community water systems?

Santa Fe leads this layer with 9 reporting systems, followed by Curry, Lea, Rio Arriba. Dairy country east, a shallow-well story at Santa Fe.

Why do New Mexico's dairies show up in a nitrate map?

Because the state requires permitted dairies to monitor groundwater, and the compiled results are striking: 36 percent of dairies reported nitrate above the federal limit, with the highest values downgradient of waste lagoons and stock pens. The dairy belt sits over the same alluvial and Ogallala water rural residents drink.

What protects a New Mexico well from nitrate?

Depth. In the dairy monitoring data, high nitrate was rare where the water table was deeper than 100 feet, and in the Santa Fe basin every reading above 6 mg/L came from a well shallower than 500 feet. Deep Ogallala and confined basin-fill water is largely shielded; shallow wells are the exposed population.

Does a high public-system result mean a nearby private well is high?

No. It is a local sentinel, not a well-specific result. It shows that nitrogen and a transport pathway have reached groundwater in the area; a certified-lab test is still the only way to know a specific private well.

Sources and provenance

What this page rests on

  1. NitrateSmart inventory: 558 New Mexico community water systems with a current nitrate result in the three years from August 9, 2023 to August 9, 2026. Figures count people served by reporting systems, not measured tap exposure.
  2. Nolan BT, Hitt KJ (2006). Vulnerability of Shallow Groundwater and Drinking-Water Wells to Nitrate in the United States. Environmental Science & Technology 40(24):7834–7840.
  3. Dubrovsky NM, and others (2010). Nutrients in the Nation's Streams and Groundwater, 1992–2004. USGS Circular 1350.
  4. USGS/EPA animal feeding operations proceedings. Statistical analysis of nitrate monitoring at 94 New Mexico dairies — median 4.4 mg/L; 36% of dairies above the MCL; lagoons and stock pens the severe cases; depth protective below 100 ft.
  5. New Mexico Bureau of Geology and Mineral Resources. Geochemistry of groundwater in the southern Espanola Basin, Santa Fe County — nitrate <0.1 to 15 mg/L, median 1.5; all values >6 mg/L in wells shallower than 500 ft; nitrate-chloride correlation r = 0.62 indicating septic influence.
  6. New Mexico Environment Department groundwater discharge-permit record (dairy lagoon leakage cases, Bernalillo area) — cited as agency record.