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  • The most common symptom of drinking water high in sulfates is diarrhea.
    • People are more likely to get diarrhea after drinking water that has over 500 mg/L of sulfate, especially if a person is not accustomed to it.
    • Drinking water with sulfate at levels exceeding 600 mg/L can cause strong laxative effects.
  • Dehydration can be a serious consequence of diarrhea.
  • The people who can easily experience the laxative effect and become dehydrated include babies and people who do not frequently drink that water such as tourists, hunters, students, and visitors. Some people can get used to higher sulfate concentrations in as little as one week, however, it is difficult to predict sulfate tolerance.
  • If using well water to mix infant formula it is important to know your sulfate level as an excessive amount may cause diarrhea and dehydration.
  • If a person gets sick he/she should drink water from a different source and consult with a medical provider if the diarrhea persists. The person should also take precautions for dehydration and follow medical recommendations for rehydrating.
  • Sulfate usually occurs naturally in the groundwater in New Mexico because the water dissolves it out of rocks, such as gypsum. Natural levels can be increased by contamination from mines, mills, landfills, sewage and other manmade sources.
  • Public water systems should not have sulfate above 250 milligrams per liter (mg/L) to avoid undesirable taste and odor as recommended by New Mexico Environment Department and the United States Environmental Protection Agency (EPA).
  • To avoid loose stool and diarrhea in persons not used to high levels of sulfate, the EPA advises public water systems and private wells not have sulfate above 500 mg/L.
  • To find the quality of your drinking water contact your community water system provider. If you are on a private well, have your drinking water tested regularly.
  • Hydrogen Sulfide and Sulfur bacteria can be present in low oxygen water (such as deep wells). These bacteria use sulfur as a source of energy and produce hydrogen sulfide gas which has a "rotten egg" smell. There is no established EPA safe drinking water level for hydrogen sulfide. The concentrations in private drinking water supplies are usually below any levels that would cause health concerns. The odor can be detected at concentrations as low as 0.03 parts per million (ppm). Learn more about bacteria in well water.
Sulfate can be removed by treating the water with reverse osmosis or distillation. These treatment methods require careful maintenance. Carbon or other mechanical filters, standard water softeners or boiling do NOT remove sulfate. To find a treatment system certified to remove sulfate consult with the Water Quality Association or at 630-505-0160 or NSF international (formerly the National Sanitation Foundation) or at 1-800-NSF-MARK (1-800-673-6275).

Treatment for sulfur bacteria (which can produce hydrogen sulfide) may include shock chlorination. Learn more about the Center for Disease Prevention and Control (CDC) well disinfection guidelines.

Learn more about private well water and treatment.

Showering and bathing

There is not a significant health risk from bathing or showering in water with high levels of sulfate. Avoid getting the water in your mouth. If you use treatments in your hair, consult with your hair stylist.

Sulfate and animals

Animals are sensitive to high levels of sulfate so you might consider providing bottled water to your pets and livestock until you have consulted with a veterinarian.

Sulfate and plants

It is okay to water your household plants with the tap water. If you are concerned about your garden or agricultural crop you should contact your local Extension Office for guidance.
If you get your water from a public drinking water system, contact:
If you get your water from a private well, you should have your well water tested:
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Content updated: Thu, 4 Jun 2020 16:26:02 MDT