All Contaminants
NO₃

Nitrate

in Drinking Water

MODERATE RISK

Nitrate is a naturally occurring compound that becomes a health concern at elevated levels. It commonly enters water supplies from agricultural fertilizers, animal waste, and septic systems.

EPA Regulations

EPA Legal Limit

10 ppm (MCL)

This is the maximum contaminant level (MCL) that water systems must meet by law.

Health Guideline

10 ppm

The level below which no adverse health effects are expected.

Health Effects

Exposure to nitrate in drinking water can cause various health problems:

  • Blue baby syndrome (methemoglobinemia) in infants under 6 months
  • Oxygen deprivation in the blood
  • Potential links to certain cancers with long-term exposure
  • Thyroid problems
  • Increased heart rate
  • Nausea and headaches at very high levels

Common Sources

Nitrate can enter drinking water from various sources:

  • Agricultural fertilizers and runoff
  • Animal feedlots and manure
  • Septic tank leachate
  • Municipal wastewater treatment plants
  • Decaying plant material
  • Natural geological deposits

Minnesota Cities with Highest Nitrate Levels

RankCityNitrate LevelOverall Grade
#1Inver Grove Heights13.90 ppmF
#2Thief River Falls13.60 ppmF
#3Fergus Falls13.00 ppmF
#4Aitkin12.94 ppmF
#5CASS LAKE11.82 ppmF
#6Ely11.80 ppmF
#7Mankato11.60 ppmF
#8Rochester11.50 ppmF
#9Columbia Heights10.47 ppmF
#10CASS LAKE10.40 ppmF

How to Remove Nitrate

These filtration methods are effective at removing nitrate from drinking water:

  • Reverse osmosis (RO) systems - most effective
  • Ion exchange systems
  • Distillation
  • Note: Standard carbon filters do NOT remove nitrates

Frequently Asked Questions

What is Nitrate and why is it in drinking water?

Nitrate is a naturally occurring compound that becomes a health concern at elevated levels. It commonly enters water supplies from agricultural fertilizers, animal waste, and septic systems.

What are the health effects of Nitrate in drinking water?

Exposure to nitrate in drinking water can cause: Blue baby syndrome (methemoglobinemia) in infants under 6 months, Oxygen deprivation in the blood, Potential links to certain cancers with long-term exposure.

What is the EPA limit for Nitrate?

The EPA limit for nitrate is 10 ppm (MCL). The health guideline is 10 ppm.

How can I remove Nitrate from my drinking water?

The most effective methods to remove nitrate include: Reverse osmosis (RO) systems - most effective; Ion exchange systems.

Learn More from the EPA

For official information about nitrate in drinking water, visit the EPA website.

Visit EPA.gov

Check Your Water for Nitrate

Enter your address to see nitrate levels in your local water system.

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