How to Remove Nitrates From Tap Water (What Actually Works)
Magnus JernShort answer: Nitrates are dissolved salts, so a basic carbon filter and boiling won't help (boiling even concentrates them) — but a quality carbon block like TAPP/EcoPro reduces about 70-80% of nitrates (independently lab-tested), usually enough to get below the legal limit. For very high levels (typically private wells), use reverse osmosis or ion exchange. Most of your nitrate actually comes from food, not tap water. Here's where nitrates come from, the safe limits, and how to remove them.
Where do nitrates come from?
Nitrate forms when nitrogen combines with oxygen, so it ends up naturally in surface and groundwater. It's used mainly in inorganic fertilizers — hence the assumption that agricultural run-off is the source of all nitrate — but it also forms from underground plant decay (which is why many vegetables are naturally high in nitrate, the main source for humans). The other major sources are animal-waste run-off, over-use of fertilizers, and human sewage from septic systems. Rising fertilizer use, waste disposal and land-use change have progressively increased groundwater nitrate over the last 20 years — in Germany this has raised real concern.
Where does nitrate come from in drinking water?
In public tap water the risk is low: treatment plants monitor and treat source water, so levels are generally safe. Private wells are the bigger challenge — fertilizers, septic systems, animal feedlots and industrial/food waste, often worsened by poor well construction or location.
Does my tap water contain nitrates?
Ask your supplier for a water-quality report (or, in Spain, check our water quality database); or use test strips for a quick approximation. Limits:
- WHO / EU: 50 mg/L (ppm), as nitrate (NO₃) — set with water authorities worldwide, based on risk to infants and pregnant women. WHO nitrate report (2011).
- US EPA: 10 mg/L (ppm), as nitrate-nitrogen — set in 1962 after a blue-baby-syndrome scare; reviewed but never changed (EWG argues it should be lower).
They look different but use different units and are roughly equivalent. Per official reporting, all large US utilities reported nitrate below 10 ppm in 2022, so exceeding the limit in public supply is unlikely.
How dangerous are nitrates?
Most nitrate exposure comes from vegetables, fruit and cured meat — tap water is relatively low. At higher concentrations it can pose a risk, primarily to infants and pregnant women (the 50 mg/L guideline is based on methaemoglobinaemia — "blue baby syndrome" — in bottle-fed infants). Babies and pregnant women should not be exposed above 50 ppm, and preferably not above 10 ppm.
What removes nitrates — and what doesn't
|
Method |
Removes nitrates? |
|---|---|
|
Carbon block (e.g. EcoPro/TAPP) |
✅ ~70-80% — enough to get below the limit in most cases (lab-tested; verify %) |
|
Reverse osmosis |
✅ Yes — for high levels / wells |
|
Ion exchange (nitrate-selective) |
✅ Yes |
|
Distillation |
✅ Yes |
|
Basic granular carbon / standard jug |
❌ Little to none |
|
Boiling |
❌ No — concentrates nitrates |
The best water filter for nitrates
Depending on your level, a carbon-block faucet filter such as TAPP/EcoPro reduces about 70-80% of nitrates (see independent lab tests) — an easy-to-install alternative to bulkier, pricier reverse osmosis or ion exchange, and enough to get well below the legal limit for typical tap water. For wells with high nitrate, reverse osmosis or ion exchange is generally required. (See how EcoPro works and removes nitrates.)
FAQ
Does a carbon filter remove nitrates? A quality carbon block (EcoPro/TAPP) reduces ~70-80% — usually enough for typical tap water. Basic granular carbon and standard jugs don't. For very high levels use RO or ion exchange.
How do I remove nitrates from water "naturally"? There's no simple natural fix — boiling makes it worse. Use a carbon block, reverse osmosis, ion exchange or distillation.
Does reverse osmosis remove nitrates? Yes — very effective, especially for wells with high levels.
What's the safe limit for nitrates? WHO/EU 50 mg/L (as nitrate); US EPA 10 mg/L (as nitrate-nitrogen). The main risk is for infants under 6 months and pregnant women.
Does boiling remove nitrates? No — it concentrates them.
How do I know if my tap water has nitrates? Check your utility's report or test — especially important for private wells and farming areas.
Sources
- WHO — Nitrate and nitrite in drinking-water (guideline): https://www.who.int/publications/i/item/9789241549950
- US EPA — National Primary Drinking Water Regulations: https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
- CDC — Nitrate in drinking water: https://www.cdc.gov/nceh/drinkingwater/nitrate.html
- EFSA — Nitrate scientific opinion: https://www.efsa.europa.eu/en/efsajournal/pub/1817
