Does Your Water Contain an Unsafe Level of Nitrite?

Today, I’ll continue my review of some of the more common drinking water contaminants with a look at Nitrite. I’ll touch on how Nitrite can affect water quality and share information on things you can do to minimize your family’s exposure to the contaminant.

Nitrite is a naturally occurring chemical compound found in soil and water. It typically gets into our drinking water supply in the following ways: 1) through the erosion of natural deposits, 2) from runoff from fertilizer use, and 3) from leaking septic tanks. Consuming water containing Nitrite at levels equal to or greater than 1 mg/L can cause adverse health effects.

Fortunately, Nitrite is one of the drinking water contaminants regulated by the EPA. This means public water companies are required to monitor their water supply for Nitrite and work to ensure the water they provide their customers does not exceed the legal limit for the contaminant. However, even with this standard in place, it’s still possible for your tap water to contain excessive amounts of Nitrate.

How Nitrite Can Affect Water Quality and Your Health

Both natural processes (e.g., erosion of naturally occurring deposits in the Earth’s crust) and human activities (e.g., use of fertilizes) can contaminate our water supply with Nitrite.

What is Nitrite, exactly? Nitrite is a chemical compound formed when plant and animal materials decompose. It is commonly used for fertilizer and food preservation.

How can drinking water that contains Nitrite affect your health? Children below six months of age who consume water that contains elevated levels of Nitrite could become seriously ill and, if left untreated, they may die. If your child has been exposed to excessive Nitrite, he or she may be short of breath, or his or her skin may turn blue in color.

At what level can Nitrite cause health problems? Nitrite is known to cause adverse health effects when its concentration in drinking water is at or above 1 mg/L. 

In an effort to protect our health, the EPA established legally enforceable standards to limit the amount of Nitrite in our drinking water. Public water companies are required to ensure the concentration of Nitrite in the water they provide their customers is kept at or below 1 mg/L.

Given available treatment technology, water utility companies should be able to provide drinking water that meets this quality standard. However, at least one public water system violated the regulatory limit for Nitrite in 2019.

Does Your Drinking Water Contain a Harmful Amount of Nitrite?

Public water companies are required to provide customers with an annual water quality report, also known as a Consumer Confidence Report (CCR). Inside this report, you’ll find important information about your drinking water, including where it comes from, and whether it tested positive for any regulated contaminants like Nitrite.

Most Populated Areas with Violations for Nitrite from 2015 to 2019

Water System
Lexington, IL
Chrisman, IL
Garden City, SD
Garden City

If you’re curious to know how much Nitrite was found in your city’s drinking water, grab a copy of the latest CCR and look for the section of the report that covers “Inorganic Chemicals.” Here, you’ll find test results for Nitrite as well as other contaminants like Antimony, Arsenic, Barium, and Cadmium.

How to Interpret Your Water Quality Report

When looking at your water quality report, you can expect to see test results for Nitrite reported in Milligrams per Liter (mg/L) or Parts per Million (ppm). So, when you read your report, just keep in mind that 1 mg/L is equivalent to 1 ppm.

Below is an example of what you might see on your annual water quality report if Nitrite is detected in your town’s drinking water:

Example Water Quality Report

MCLG (1)MCL (2)Average
Your Water

Definitions from the EPA:
1. Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
2. Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.

In this example, water samples contained an average of 3 ppm of Nitrite, exceeding both the public health goal level (MCLG) and the legal limit (MCL) for the contaminant.

Will You Be Notified If Your Water Contains an Unsafe Level of Nitrite?

In addition to providing you with an annual quality report, your water company is required by the EPA to notify you if they identify a problem with your drinking water.

If your water company delivers water that could negatively impact your health, they have to notify you of the situation within the timeframe set by the EPA. Depending on the severity of the issue, the company is given 24 hours to 30 days to provide this notice.

If your city’s water exceeds the Maximum Contaminant Level (MCL) for Nitrite, you can expect your water company to be given no longer than 24 hours to notify you of the violation. Typically, you will receive this notice via media outlets such as television or radio, or through another approved method of communication.

What Can You Do to Remove Nitrite from Your Tap Water?

Fortunately, if you want to limit your family’s exposure to Nitrite, there are several affordable yet effective options for removing the contaminant from your tap water.

But how can you tell which products work and which ones don’t? Well, if you want peace of mind, I recommend choosing a water treatment product that is certified by NSF International (NSF) to be effective at removing Nitrite from water.

What does the NSF certification represent? When a product is NSF certified to remove Nitrite, you can rest assured that:

  • the manufacturer’s contaminant reduction claims have been verified;
  • the system was tested to confirm it adds nothing harmful to the water;
  • the system has been found to be structurally sound;
  • the product’s advertising, literature, and labeling have all been verified as accurate;
  • and there is testing in place to determine whether the quality of the product is consistent over time.

Do all NSF certified water filters work against Nitrite? Water treatment devices can earn certification for meeting one or more NSF standards or protocols. But only certain NSF certified products, like Reverse Osmosis devices that meet NSF standard NSF/ANSI 58 for Nitrite, are certified to reduce the amount of the Nitrite in your water.

One such product, OptimH2O Reverse Osmosis + Claryum by Aquasana, is NSF certified to remove up to 82.4% of the Nitrite found in your tap water. This device requires installation underneath your sink, so the manufacturer recommends enlisting the help of a professional to make sure it gets done right.

3 steps for selecting the right water treatment system for your family:

  1. Review your area’s annual water quality report to find out what’s in your drinking water.
  2. Determine which contaminants you’d like to reduce from your water.
  3. Select a water treatment product that is NSF certified to work effectively against those contaminants you’d like to reduce from your tap water.

Just remember, no matter which water treatment product you choose, you need to make sure to perform the routine maintenance suggested by the manufacturer. This will help keep the device in proper working order and limit your family’s exposure to Nitrite.



I’ve moved several times over the years, so I know just how stressful it can be to relocate. I want to help put your mind at ease. That’s why I research and write about all the things I think you should consider when moving to a new town.

Recent Content