Nitrite in Drinking Water: Health Risks, Sources, and How to Remove It
Nitrite is an inorganic contaminant with an EPA Maximum Contaminant Level (MCL) of 1 mg/L. Because of its potential to cause acute health issues in vulnerable populations, monitoring this contaminant is critical for water safety.
Health Effects
Consuming water with elevated nitrite levels can lead to health complications in infants. Specifically, this contaminant is known to cause blue baby syndrome in infants. Because of this serious effect, protecting infants from exposure is crucial.
How Nitrite Gets Into Tap Water
Nitrite gets into drinking water from several human and agricultural sources. It commonly enters water supplies through fertilizer runoff, septic tanks, and discharges from sewage treatment. These activities can release the contaminant into water resources that supply tap water.
How to Remove Nitrite From Your Water
Nitrite can be effectively removed from drinking water using specific filtration and treatment systems. The primary treatment methods for this contaminant are ion exchange and reverse osmosis. Installing these systems can help ensure your water remains within safe limits.
Should You Test Your Water?
To check for nitrite in your drinking water, you can review your local consumer confidence report or search the WaterQ database. If you use a private well near potential sources of contamination, having your water tested by a certified laboratory is recommended. You can also look up your local water system on WaterQ or check the Nitrite data page for reported levels in your area.
Frequently Asked Questions
Is Nitrite dangerous in drinking water?
Yes, nitrite can be dangerous in drinking water, particularly for infants. It is known to cause blue baby syndrome in infants. Because of this acute health concern, the EPA has established a strict Maximum Contaminant Level of 1 mg/L.
How does Nitrite get into tap water?
Nitrite enters tap water supplies primarily through fertilizer runoff, septic tanks, and sewage treatment. These sources can release the contaminant into groundwater or surface water systems.
How can I remove Nitrite from my water?
You can remove nitrite from your drinking water by using treatment systems such as ion exchange or reverse osmosis. These methods are effective at lowering the levels of this inorganic contaminant.
Source: EPA National Primary Drinking Water Regulations and WaterQ National Database. For more contaminants, visit our contaminant library.
What actually removes nitrate
Nitrate is the contaminant where boiling actively hurts: it concentrates the nitrate as water evaporates, so the standard "boil it to be safe" instinct makes the problem worse. Carbon does not remove it and neither does a softener. Reverse osmosis at the tap, or whole-house anion exchange on a farm well, are the real options. If there is an infant in the house and your area has agricultural runoff, treat this as urgent.
Works
- Reverse osmosis (NSF 58)The broadest removal available at home: arsenic, nitrate, fluoride, PFAS, TDS.
- Anion exchangeWhole-house option for nitrate and uranium on well water.
Will not fix this
- Basic activated carbon (NSF 42)
- Carbon certified for lead (NSF 53)
- Ion-exchange water softener
- UV disinfection (NSF 55)
- Boiling Makes it worse — evaporation concentrates what's left behind.
Test before you buy.Nitrate can't be seen, tasted or smelled, and the right hardware depends on the concentration you actually have. A certified lab test costs a fraction of the wrong filtration system. Start with your local water quality report, and get a mail-in lab test if you're on a private well.
Options that carry the right certification
Ordered cheapest-adequate first. Prices are indicative bands and move often.
| Product | Certification | Upfront | Per year | |
|---|---|---|---|---|
| APEC ROES-50 EssenceUnder-sink | Built with WQA-certified components to NSF/ANSI 58.Catch:Needs an under-sink drain connection and a spare hole for the dedicated faucet. Strips minerals — some people dislike the flat taste. | $180–240 | $50–80 | Check price |
| AquaTru Countertop Reverse OsmosisCountertop | NSF/ANSI 42, 53, 58, 401 and P473 certified.Catch:Takes counter space and you refill a tank by hand. Wastes some water as brine, like all RO. | $400–500 | $80–130 | Check price |
| iSpring RCC7AK 6-Stage ROUnder-sink | WQA Gold Seal certified to NSF/ANSI 58.Catch:The alkaline remineralization stage adds minerals back, which slightly raises TDS readings — expected, not a fault. | $200–280 | $60–90 | Check price |
Certification listings change. Before buying, confirm the current listing for the exact model in the NSF certified products database — a manufacturer's marketing page is not a certification. WaterQ earns a commission on purchases made through these links at no extra cost to you; see our affiliate disclosure. This is general information, not medical or engineering advice.
For a full breakdown of certifications, running costs and the models worth considering, see our buying guide for nitrate.