WaterVerge
Manganese Contamination

Manganese in New Mexico Drinking Water

Ranked by max manganese detected (µg/L) · UCMR 4 data (2018–2020) · Data from EPA SDWIS & UCMR

29
Cities Tested
8
Over SMCL
28%
% Over SMCL
67.5 µg/L
State Avg
▲ 10% vs national
vs National
157
Health Violations

Manganese in New Mexico: what the data shows

New Mexico has 29 cities with manganese data from the EPA's UCMR 4 program (2018–2020). Manganese exceeded the 50 µg/L EPA secondary MCL in 8 of those cities. The state average max detected level is 67.5 µg/L. Manganese occurs naturally in groundwater and surface water. Elevated levels are common in areas with iron-rich geology and in systems that draw from reservoirs with low dissolved oxygen. The secondary MCL of 50 µg/L is based on aesthetic concerns (taste, staining), but health-based guidelines suggest neurological effects at higher concentrations. Emerging research links chronic manganese exposure in drinking water to neurodevelopmental effects in children, including reduced IQ and behavioral issues. Oxidation filtration and water softeners are effective at removing manganese from household water.

Cities exceeding 50 µg/L EPA Secondary MCL

New Mexico
28%
8 of 29 cities
▲ 10% above national rate (worse)
National avg
18%
729 of 4068 cities

Manganese data across New Mexico

Each dot is a city with UCMR 4 manganese testing data. Cities where manganese exceeds the 50 µg/L EPA secondary MCL are highlighted. Size reflects population served.

All New Mexico cities ranked by manganese level

# City Level Level Over SMCL? Violations Grade
1 Las Cruces 600.0 µg/L
Over SMCL 222
F
2 Clovis 410.0 µg/L
Over SMCL 66
F
3 Dona Ana 321.0 µg/L
Over SMCL 21
F
4 Deming 165.0 µg/L
Over SMCL 50
F
5 Santa Fe 70.0 µg/L
Over SMCL 200
F
6 Sunland Park 68.4 µg/L
Over SMCL 116
F
7 Albuquerque 65.0 µg/L
Over SMCL 232
F
8 Artesia 59.9 µg/L
Over SMCL 75
F
9 Farmington 36.0 µg/L
No 55
F
10 Ruidoso 34.0 µg/L
No 63
F
11 Ramah, Pinehill 32.0 µg/L
No 6
F
12 Gallup 30.9 µg/L
No 70
F
13 Santo Domingo 30.0 µg/L
No 24
A-
14 Roswell 15.0 µg/L
No 14
D
15 Alamogordo 4.3 µg/L
No 41
F
16 Chaparral 2.9 µg/L
No 18
C-
17 Rio Rancho 2.2 µg/L
No 4
B+
18 Espanola 2.1 µg/L
No 186
F
19 Jemez Springs 1.9 µg/L
No 69
F
20 Hobbs 1.8 µg/L
No 24
F
21 Las Vegas 1.1 µg/L
No 93
F
22 Portales 1.0 µg/L
No 11
B-
23 Los Alamos 1.0 µg/L
No 1
A
24 Silver City 0.8 µg/L
No 40
F
25 Lovington 0.5 µg/L
No 178
D
26 Carlsbad 0.5 µg/L
No 38
F
27 Taos 0.5 µg/L
No 58
F
28 Los Lunas 0.5 µg/L
No 77
F
29 Holloman Air Force Base 0.4 µg/L
No 2
C+

Frequently asked questions about manganese in New Mexico

Is manganese in New Mexico tap water harmful?

The EPA secondary MCL for manganese is 50 µg/L, set primarily for aesthetic reasons (taste, color, staining). 8 cities in New Mexico exceed the secondary MCL. However, emerging research links chronic manganese exposure above 50–100 µg/L to neurodevelopmental effects in children, including reduced IQ.

How can I remove manganese from my drinking water?

Oxidation filtration (such as greensand or birm filters) is the most common and effective method for removing manganese from well water. Water softeners using ion exchange also work well. Standard carbon filters provide limited manganese removal. If your water has a metallic taste or brown/black discoloration, manganese may be the cause.

What causes high manganese in New Mexico water?

Manganese occurs naturally in groundwater and surface water, particularly in areas with iron-rich geology. Low dissolved oxygen conditions (common in deep wells and reservoir bottom waters) increase manganese solubility. Industrial sources include mining, steel production, and battery manufacturing. Seasonal changes in reservoir water chemistry can cause manganese spikes.