field note · water · the honest answer

Is water from your air conditioner safe to drink?

No, not as it comes out of the drain. It is close to distilled when it forms, which sounds promising, and then it runs across a coil and sits in a pan where the temperature is exactly what waterborne bacteria like best. Every US plumbing code that mentions it puts it in the non potable column, and that is the right place for it. What it is genuinely good for is the rest of this page.

What the EPA actually measured

The EPA sampled condensate from thirteen air handling units across four locations and reported the results in 2022 and 2023. The findings were consistent and they are the reason for the answer above.

Heterotrophic plate counts of a thousand to ten thousand colonies per millilitre. For comparison, the number usually cited as a ceiling for drinking water is five hundred.
Culturable Legionella, including Legionella pneumophila serogroup 1, the one associated with Legionnaires disease.
Non tuberculous mycobacteria, Mycobacterium avium and Mycobacterium intracellulare.
At one site, elevated lead and copper. Condensate is nearly free of minerals, which makes it corrosive, and corrosive water pulls metal out of old plumbing.

An earlier EPA study of HVAC condensate reuse found the same pattern and added a detail worth knowing: the biofilm in the drain pan was far more contaminated than the water running through it. The pan is the problem, not the sky.

The CDC does not discuss drinking condensate, but it does put the growth range for Legionella at 25 to 45 degrees Celsius and tells building operators to keep condensate pans and coils clean of biofilm and corrosion. A condensate pan in summer sits in the middle of that range.

EPA Science Inventory: water quality of air conditioning condensate, 20 September 2022, and the assessment presented at the WateReuse Symposium in March 2023. Earlier HVAC condensate reuse work presented in 2018. CDC Legionella control toolkit, read 16 September 2026.

What it would take to make it drinkable

There is no approved route in the United States for treating air conditioner condensate into drinking water. Building water reuse in the US is written around log reduction targets for each end use, and condensate appears in the non potable end uses. So this is not a case of a missing filter. It is a case of a missing regulatory path.

Physically, the train would have to be the full one: particle filtration, robust disinfection with a residual that survives in storage, a barrier for metals, and remineralisation to stop the water attacking the pipes it then sits in. Even the EPA's own study of a purpose built water from air machine, which had all of that inside it, still reported high heterotrophic counts in the treated water.

The short version: a countertop filter jug does not turn condensate into drinking water, and neither does boiling, because boiling does nothing about lead.

What it is legitimately good for

This is the part that gets buried under the drinking question. Condensate is a real water source, it is already being produced, and in most buildings it is thrown away.

Irrigation. The mineral free profile that is a problem for pipes is fine for most plants, and it is what the EPA lists first among the uses.
Toilet and urinal flushing, where local rules allow it.
Cooling tower makeup water, which is the largest use in commercial buildings.

How much water is there? The EPA's estimate is roughly 3 to 10 gallons a day per thousand square feet of conditioned space, in the right climate. For a house that is a watering can. For an office tower it is a supply worth plumbing.

What the rules say, by name

2021 International Plumbing Code, chapter 13 lists captured condensate as an alternate on site non potable water source, alongside graywater, rainwater and reclaimed water.
Uniform Plumbing Code, chapter 15 covers alternate water sources for non potable applications, and the 2024 edition adds a section on condensate drainage recovery. California adopts this as chapter 15 of its own plumbing code.
Texas, title 30 of the Administrative Code, sections 210.81 to 210.85, defines alternative on site water to include air conditioner condensate and allows irrigation, composting, and toilet and urinal flushing in homes. The quality limits published for residential use are E. coli below 14 MPN per 100 millilitres as a thirty day geometric mean and total suspended solids below 10 milligrams per litre.
Austin, Texas, city code chapter 15-13 goes further and requires it: commercial and multifamily buildings built after 5 September 2017 with a cooling tower of 200 tons or more must collect and reuse their condensate, and permit applications from 1 December 2023 for projects of 250,000 square feet or more must include an on site reuse system.

Code references read on 16 September 2026. The Texas limits are as published by the EPA in its summary of that state's reuse rules, updated 22 April 2026. Local adoption varies, so the rule that binds you is your city's, not this list.

If what you actually want is emergency water

The instinct behind this question is usually a good one: there is water going down a drain and it feels wasteful. But for drinking in an emergency, condensate is the hardest path and the least reliable, because it stops the moment the power does.

The boring answers beat it. Our blackout kit page counts the drinking water already sitting in your house, which for most homes with a tank water heater is more than people expect. Our rain barrel calculator gives the gallons a roof catches per inch of rain in your state. And if the water you have is questionable rather than absent, our treatment dose tool gives the federal dose for the container you actually have.

Sources, with the date of each

EPA Science Inventory, water quality of air conditioning condensate and implications for onsite use, 20 September 2022.
EPA Science Inventory, water quality assessment of AC condensate for onsite collection and use, WateReuse Symposium, March 2023.
EPA Science Inventory, using HVAC condensate as a reuse option for water conservation, 2018.
CDC, controlling Legionella in other devices and in cooling towers, read 16 September 2026.
2021 International Plumbing Code, chapter 13. Uniform Plumbing Code, chapter 15. California Plumbing Code 2022, chapter 15.
Texas Administrative Code, title 30, sections 210.81 to 210.85, as summarised by the EPA, page updated 22 April 2026.
Austin city code, chapter 15-13, regulation of onsite water reuse systems.

One honest gap: we could not find a single document from the EPA or the CDC that says in plain words "do not drink air conditioner condensate". The prohibition is structural rather than stated, which is to say condensate is classified as non potable and no potable route exists for it. Pages that quote such a sentence are quoting each other.