Nitrate in tap water

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States Affected
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People Affected
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Toxicity Rating
Health Effects

Cancer: Ovarian, thyroid, kidney, bladder, and colorectal. Blue baby syndrome (methemoglobinemia), thyroid disease. Low birthweight, premature birth, and neural tube defects (NTDs). Harm to fetal growth and child development.

The legal limit is
Health Guideline
0.14 ppm
what is considered unhealthy
Legal Limit
10 ppm
What is nitrate?
Nitrate is a chemical found in fertilizers, food, sewage, and animal waste. It’s considered safe in food as it’s naturally found in some vegetables and added to processed meats to prevent bacteria growth. However, elevated ingestion of nitrate through drinking water is associated with cancer, blue baby syndrome, thyroid issues, and additional health risks.
How does nitrate get into tap water?
Nitrate typically finds its way into our water sources from agricultural runoff that contains manure and/or fertilizer used to treat farm fields, golf courses, and yards. Wastewater, sewage, and septic systems can lead to nitrate contamination as well.
Nitrate can’t be seen, smelled, or tested. Therefore, it often spills into water supplies undetected. If nitrate isn’t removed, it can survive in groundwater and surface water for years
Why is nitrate in tap water harmful? What does nitrate do to your body?
Nitrate has been linked to a litany of dangers from various types of cancer to reproductive issues. Here are some of the most common health concerns associated with elevated exposure to the chemical:
  • Cancer: Ovarian, thyroid, kidney, bladder, and colorectal.
  • Blue baby syndrome (methemoglobinemia).
  • Thyroid disease.
  • Low birthweight, premature birth, and neural tube defects (NTDs).
  • Harm to fetal growth and child development.

Several studies have examined the link between nitrate in drinking water and the aforementioned health risks, but many have led to inconclusive results. That’s why this 2018 study re-examined the evidence to rank the health concerns most likely associated with drinking nitrate. The study found the most common adverse health outcomes from drinking nitrate are colorectal cancer, thyroid disease, blue baby syndrome, and neural tube defects.
Can nitrate cause cancer?
A 2019 study by EWG scientists estimated that nitrate pollution in drinking water causes more than 12,000 cases of cancer a year in the U.S. Meanwhile, nitrate is classified as “probably carcinogenic to humans” by the International Agency for Research on Cancer (IARC).
How much nitrate is safe?
The U.S. EPA set a Maximum Contaminant Level (MCL) of 10 mg/L that includes a grave warning stating, “Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die.”
Epidemiological research suggests the EPA’s 10 mg/L MCL does not sufficiently protect public health. In fact, EWG recommends an MCL of 0.14 mg/L to protect against cancer risk and adverse birth outcomes. That’s about 70 times lower than the amount of nitrate the EPA allows in public water supplies today.
Is nitrate in bottled water?
Yes, nitrate can be found in bottled water. While the EPA regulates tap water, the FDA regulates bottled water because it is classified as food. The FDA allows 10 mg/L of nitrate in bottled water, matching the regulations set for tap water by the EPA. Remember, epidemiological research suggests this standard does not sufficiently protect public health.
What can I do about nitrate in my tap water?
Clearly Filtered’s breakthrough Affinity® Filtration Technology removes up to 99.9% of nitrate from tap water. Upgrade to our superior water filters so you never have to worry about nitrate lurking in your water again. Remember, typical carbon filters do not remove Nitrate.
How does Clearly Filtered do at Removing Nitrate in tap water?
Clearly Filtered with
Affinity Filtration Technology Product
Water Pitcher Filter
Under-the-Sink FIlter
Water Bottle Filter
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Nitrate in tap water Removal

1. EWG Tap Water Database: Nitrate. Accessed April 1, 2021.

2. EWG. Nitrate in U.S. Tap Water May Cause More Than 12,500 Cancers a Year. April 1, 2021.

3. PubMed. Drinking Water Nitrate and Human Health: An Updated Review. April 1, 2021.

4. ScienceDirect. Exposure-based assessment and economic valuation of adverse birth outcomes and cancer risk due to nitrate in United States drinking water. April 1, 2021.

5. Minnesota Department of Health. Nitrate in Drinking Water. April 1, 2021.

6. Newswise. University of Illinois Chicago: Nitrate in maternal drinking water may impair fetal growth. April 1, 2021.

7. EHP. Prenatal Exposure to Nitrate from Drinking Water and Markers of Fetal Growth Restriction: A Population-Based Study of Nearly One Million Danish-Born Children. April 1, 2021.

8. CDC. Nitrate and Drinking Water from Private Wells. Accessed April 1, 2021.