Contaminant · Water
Nitrate
What it is
Nitrate enters drinking water mainly from fertilizer runoff, animal manure, and septic systems. It is most common in agricultural areas and in private wells, where it can be present without any taste, smell, or color.
Why it matters
The EPA sets a maximum contaminant level of 10 mg/L (as nitrate-nitrogen) for drinking water. That regulatory threshold is the reference point. We score whether a filter is certified to reduce nitrate, not any health outcome. Standard carbon filters and most pitchers do not remove nitrate.
What removes it
Reverse osmosis (NSF/ANSI 58) or ion exchange certified for nitrate reduction. This is important: a typical carbon pitcher or faucet filter does NOT reduce nitrate, so certification for nitrate specifically is what matters.
Reference: EPA National Primary Drinking Water Regulations; nitrate MCL 10 mg/L.
Scored filters certified for Nitrate
- 7.3Waterdrop G3P800 Tankless RO
A tankless 800 GPD reverse-osmosis system IAPMO-certified to NSF/ANSI 42, 53, 58, 401 and 372 for a broad contaminant list including lead, PFAS, arsenic, nitrate and fluoride.
- 7.2AquaTru Classic Countertop RO
A no-plumbing countertop 4-stage RO purifier certified to NSF standards for lead, PFAS, fluoride and arsenic with an efficient drain ratio.
FAQ
- Does a Brita or carbon pitcher remove nitrate?
- No. Activated-carbon pitchers and faucet filters are not designed for nitrate. You need a system certified to NSF/ANSI 58 (reverse osmosis) or a certified nitrate-selective ion-exchange filter.
- Does boiling remove nitrate?
- No. Boiling concentrates nitrate rather than removing it. Use a certified reverse-osmosis system.