Most things found in well water are a considered conversation. Nitrate is the exception, and the reason is specific rather than general alarm.
The number
The EPA maximum contaminant level is 10 mg/L, measured as nitrogen.
What makes it unusual is the basis. Most drinking water standards are set around long-term exposure and lifetime risk. Nitrate's was set around an acute risk to infants — which is why it is one of the very few results that justifies acting before you have finished understanding.
Why infants specifically
In babies under roughly six months, nitrate can interfere with the blood's ability to carry oxygen, producing a condition usually called methemoglobinemia or "blue baby syndrome."
The practical consequence: if there is an infant in the house, or someone pregnant, or you are mixing formula with well water, nitrate is not a wait-and-see result. Use another water source until you have a number.
Boiling makes it worse
This one is worth repeating because the instinct is so strong and so wrong.
Boiling concentrates nitrate. Water leaves as steam; nitrate stays. The result is more nitrate per glass than you started with.
Boiling is the correct response to a bacteriological advisory and exactly the wrong response to a nitrate one. If a well has both problems, that conflict needs resolving deliberately rather than by instinct.
Where it comes from
Nitrate is largely a surface-derived contaminant: fertiliser, animal waste, septic systems, and decaying organic matter, carried down into groundwater.
Which makes it a useful indicator as well as a contaminant. Nitrate in a well means surface influence is reaching your water, and if nitrate is getting in, other things can too. That is why a nitrate finding often warrants a bacteriological test alongside it.
It also connects to depth and construction. A shallow well in a highly permeable formation, with a septic system nearby or agriculture upslope, is the classic setup.
What removes it
Reverse osmosis is the usual residential answer, and under-sink is the right placement — nitrate matters for what you drink and cook with, not what you shower in.
Ion exchange designed specifically for nitrate also works. A standard softener does not; it is configured for hardness.
Distillation works and is impractical at household scale.
Carbon does nothing. A carbon filter is the most commonly owned treatment device and it has no effect on nitrate whatsoever, which is a dangerous gap in assumptions if someone believes their filter is handling it.
Testing for it
Nitrate is not part of our in-home screen. It belongs with a laboratory or your county health department, and if there is an infant in the house it is worth asking for specifically rather than assuming a general panel covers it.
Once you have a number, sizing treatment is straightforward and we are happy to help with that part.
General information, not medical advice. If you have concerns about infant exposure, speak to a doctor and use an alternative water source in the meantime.