Chlorate in New Mexico Drinking Water
Ranked by max chlorate detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR
Chlorate in New Mexico: what the data shows
New Mexico has 14 cities with chlorate data from the EPA's UCMR 3 program (2013–2015). Chlorate exceeded the 210 µg/L EPA lifetime health advisory in 7 of those cities. The state average max detected level is 787.4 µg/L. Chlorate is a disinfection byproduct that forms when chlorine dioxide or hypochlorite solutions are used to disinfect drinking water. It is most common in systems that use chlorine dioxide for taste-and-odor control or that store hypochlorite for extended periods. There is no federal MCL — the EPA lifetime health advisory is 210 µg/L. Chlorate can interfere with thyroid function by blocking iodide uptake, an effect of particular concern for pregnant women, infants, and people with thyroid conditions. Reverse osmosis and ion exchange (anion-specific) are effective at removing chlorate; standard activated carbon filters provide only modest reduction.
Cities exceeding 210 µg/L EPA lifetime HA (no MCL)
Chlorate data across New Mexico
Each dot is a city with UCMR 3 chlorate testing data. Cities where chlorate exceeds the 210 µg/L EPA lifetime health advisory are highlighted. Size reflects population served.
Top 10 cities by chlorate level in New Mexico
Highest Chlorate levels (µg/L)
All New Mexico cities ranked by chlorate level
| # | City | Level | Level | Over HA? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Las Cruces | 4512.0 µg/L | Over HA | 222 | F | |
| 2 | Ruidoso | 3000.0 µg/L | Over HA | 63 | F | |
| 3 | Alamogordo | 1150.0 µg/L | Over HA | 41 | F | |
| 4 | Ranchos De Taos | 930.3 µg/L | Over HA | 98 | F | |
| 5 | Santa Fe | 380.0 µg/L | Over HA | 200 | F | |
| 6 | Farmington | 240.0 µg/L | Over HA | 55 | F | |
| 7 | Clovis | 230.0 µg/L | Over HA | 66 | F | |
| 8 | Albuquerque | 169.0 µg/L | No | 232 | F | |
| 9 | Rio Rancho | 140.0 µg/L | No | 4 | B+ | |
| 10 | Los Lunas | 81.0 µg/L | No | 77 | F | |
| 11 | Las Vegas | 76.0 µg/L | No | 93 | F | |
| 12 | Carlsbad | 51.0 µg/L | No | 38 | F | |
| 13 | Gallup | 36.0 µg/L | No | 70 | F | |
| 14 | Los Alamos | 27.7 µg/L | No | 1 | A |
Frequently asked questions about chlorate in New Mexico
Is chlorate in New Mexico tap water dangerous?
Chlorate has no federal MCL. The EPA lifetime health advisory is 210 µg/L. 7 cities in New Mexico exceed this level. Chlorate can interfere with thyroid iodide uptake, which is a particular concern for infants, pregnant women, and people with hypothyroidism.
Where does chlorate in New Mexico water come from?
Chlorate is a byproduct of chlorine-based disinfectants — particularly chlorine dioxide and hypochlorite (bleach) solutions. Levels tend to be higher in systems that use chlorine dioxide for taste-and-odor treatment or store sodium hypochlorite at high concentrations or for long periods. Levels vary seasonally with disinfectant use.
How can I reduce chlorate exposure?
Reverse osmosis is the most effective home treatment for chlorate, typically removing 80–95%. Anion exchange systems also work but require regeneration. Standard activated carbon filters provide only limited chlorate reduction. Boiling does NOT remove chlorate.