Pick up a bottle of water and read the front panel. Depending on what it says, you are holding a product defined by a federal standard of identity, a product that may have started in a municipal treatment plant, or both at once.
Here is the fact that organizes everything else. The water in that bottle and the water in your kitchen tap answer to two different federal agencies under two different laws. FDA puts it in one sentence on its own page: “EPA regulates public drinking water (tap water), while FDA regulates bottled drinking water.”
That is not a scandal. It is a jurisdictional line that has been in place since the Safe Drinking Water Act passed in 1974. But it produces real differences in what gets tested, how often, and who ever finds out the result.
Two agencies, two laws, one glass of water
FDA regulates bottled water as a packaged food under the Federal Food, Drug, and Cosmetic Act. That is the whole basis for the difference. A bottle of water is legally a food product, in the same category as a jar of pasta sauce.
The two systems are stitched together by one statute. Under 21 U.S.C. 349, when EPA issues a national primary drinking water regulation, FDA has until 180 days before that rule takes effect either to set a bottled water standard of quality for the contaminant or to publish a finding that one is not necessary. Where EPA set a maximum contaminant level, FDA’s limit must be no less stringent. Where EPA required a treatment technique, bottled water requirements must be no less protective of public health. If FDA misses the deadline, EPA’s rule becomes the bottled water standard automatically.
So the numbers broadly track each other. What differs is the machinery around them.
A bottler operates under current good manufacturing practice rules written specifically for bottled water, at 21 CFR part 129. Water has to come from an approved source. Product water gets tested for total coliform at least once a week, and for chemical, physical and radiological parameters at least annually. Source water chemistry is checked yearly, radiological content every four years, and records stay at the plant for at least two years. FDA inspects bottling plants under its general food safety program, with states inspecting some under contract.
Now compare that with the tap. A community water system has to publish its results to every customer each year in a Consumer Confidence Report, covered in detail in another article here. Nothing comparable exists for bottled water: the bottler’s results go into a file at the plant, available to a regulator rather than to you.
The trade-off runs in both directions. Tap water is monitored more often and reported publicly, then travels through your service line and your building’s plumbing, which no report covers. Bottled water skips that last stretch of pipe entirely, and its results are never published to the person drinking it.
One cross-reference is written into the regulation itself: your utility’s annual report has to tell you that FDA sets bottled water limits providing the same public health protection as EPA’s. If you draw from a private well rather than a utility, none of this applies to your tap, and a separate article covers that split.
What the legal names on the label mean
FDA’s standard of identity sits at 21 CFR 165.110. It defines bottled water as water intended for human consumption and “sealed in bottles or other containers with no added ingredients except that it may optionally contain safe and suitable antimicrobial agents.” Fluoride may be added within set limits.
The regulation then defines a short list of specific names. It helps to sort them by what they describe, because the regulation does not.
Names that describe where the water came from
Spring water has the most specific definition and the most misunderstood one. The water must come from an underground formation that flows naturally to the surface, collected either at the spring or through a bore hole tapping the same formation. A bore hole requires a demonstrated hydraulic connection to the spring, the same stratum, and a matching composition, and water must still flow naturally through the spring’s own opening. The label has to identify the spring’s location.
Notice what the definition does not say. It says nothing about treatment. Spring water is routinely filtered, ozonated or otherwise disinfected, which the regulation permits, and the quality standards still apply. “Spring” tells you about geology, not about what happened afterward.
Artesian water comes from a well tapping a confined aquifer where the water level stands above the top of the aquifer. A pump may be used to bring it up. The term describes pressure underground and carries no quality meaning at all.
Mineral water is the one term on a label that comes with a number attached. It must contain at least 250 parts per million of total dissolved solids, come from a geologically and physically protected underground source, hold a constant level and proportion of minerals where it emerges, and have no minerals added. Below 500 ppm of dissolved solids the label has to say “low mineral content.” Above 1,500 ppm it has to say “high mineral content.”
That threshold is worth sitting with. EPA’s secondary standard for total dissolved solids in tap water is 500 mg/L, set for taste rather than health. A mineral water labeled high mineral content carries at least three times that. It is not unsafe, just water a municipal system would log as a taste complaint.
Names that describe what was done to the water
Purified water is produced by distillation, deionization, reverse osmosis or another suitable process, and it has to meet the definition of purified water in the United States Pharmacopeia. This is the term readers most often misread. It describes a process and the resulting purity. It says nothing whatsoever about where the water started.
Distilled water is a permitted alternative name for purified water when distillation was the process used. The same logic gives you deionized water and reverse osmosis water: purified water with the method named.
Sparkling bottled water contains, after treatment and any replacement of carbon dioxide, the same amount it had at the source. Seltzer, soda water, tonic water and club soda are a different matter: FDA regulates those as soft drinks.
The municipal-source disclosure most people never see
Here is the mechanism behind the “bottled tap water” story you have probably heard.
When bottled water comes from a community water system, 21 CFR 165.110 requires the label to state “from a community water system” or, as appropriate, “from a municipal source.” The placement rules are specific. It goes on the principal display panel, immediately before or after the product name with no text in between, in type at least half the size of the statement of identity and no smaller than one sixteenth of an inch.
Then comes the exemption that does most of the work. The disclosure does not apply if the water has been treated to meet the purified water or sterile water definition and is labeled accordingly. A bottler that draws municipal water, runs it through reverse osmosis and sells it as purified drinking water is not required to print the municipal-source statement anywhere.
Both things are true at once: the disclosure requirement is real, and the most common route for city water into a bottle is the route that does not trigger it. So if you see “from a municipal source,” believe it. If you do not see it, you have learned nothing, especially on a bottle labeled purified.
The two corrections worth carrying away: purified describes a process, not a source. Spring water does not mean untreated.
Cost per gallon, worked out on paper
Do this arithmetic once and you will not need an opinion about it.
Start with tap. EPA’s WaterSense program reports that the average family spends more than $1,000 a year on water costs, and that each American uses an average of 82 gallons a day at home, based on 2015 USGS data. For a household of four, that is 328 gallons a day, or 119,720 gallons a year. Divide $1,000 by 119,720 and you get about $0.008 per gallon, under a penny.
That calculation is generous to bottled water twice over. The $1,000 figure often includes sewer service, and a household drinks a tiny fraction of those gallons; most go to toilets, laundry and irrigation.
Better still, run it on your own bill. Many utilities bill in CCF, meaning hundred cubic feet, and one CCF is about 748 gallons. Divide your total by the gallons it covers and you have your real rate.
Now bottled. A 24 pack of 16.9 ounce bottles holds 405.6 fluid ounces. A US gallon is 128 fluid ounces, so the pack is 3.17 gallons. Divide the shelf price by 3.17. A $5 pack is about $1.58 a gallon. A $7 pack is about $2.21. Single serve is a different market: a 20 ounce bottle is 6.4 to the gallon, so a $2 bottle from a cooler works out to $12.80 a gallon.
Set those against a penny. The case price runs roughly 190 times tap; the cooler bottle runs over 1,500 times. Those multipliers are large, and they are the same ones that apply to coffee, which nobody argues about. The point is not to make a case but to let you decide with a number rather than a feeling, and to show that bulk packs and a refillable bottle move the math far more than the brand does.
When bottled water is the right call, and how to store it
A few situations make bottled water clearly the right choice, and they are worth naming precisely.
A boil water advisory. EPA’s guidance on emergency disinfection says local authorities may recommend using only bottled, boiled or disinfected water when service is interrupted. Boiling works too: a rolling boil for one minute, or three minutes above 5,000 feet, after letting cloudy water settle and filtering it through a clean cloth. If you cannot boil, EPA describes disinfecting with regular unscented household bleach, 8 drops of 6 percent or 6 drops of 8.25 percent per gallon, doubled for cloudy or very cold water, left to stand 30 minutes.
A well problem. A private well owner with a positive test result needs a safe source while the problem is diagnosed and fixed. Testing and treatment are covered in other articles here.
Emergencies and outages. Ready.gov advises storing at least one gallon of water per person per day for several days, for drinking and sanitation. Commercially bottled water should be kept in its sealed original container in a cool, dark place. Water you bottle yourself should be replaced every six months.
No safe tap access. Travel, construction, an outage, a system under a long-term advisory.
One boundary matters: bottled water is not automatically the answer to a specific contaminant. A label does not report PFAS results, for example, and a separate article covers that. Buying bottled to solve a named contaminant problem, without knowing what is in the bottle, solves nothing in particular.
On storage, heat is the variable that matters. PET bottles carry trace antimony left over from manufacturing, and temperature drives how much migrates into the water. A 2017 study of 66 bottled waters in Environmental Monitoring and Assessment found antimony at 0.168 to 2.263 micrograms per liter at 24 degrees Celsius, rising to 0.240 to 6.110 after storage at 50 degrees, with temperature the principal factor. A 2020 study in Acta Biomedica found no significant change after three months at room temperature but rising concentrations at 50 degrees. EPA’s enforceable limit for antimony in tap water is 0.006 mg/L, or 6 parts per billion.
Both studies are small and both were done in hot climates, so treat them as a measured effect rather than a health finding. The practical version needs no alarm: a case of water that has spent August in a car trunk is not the same product as the same case in a closet.
On when to involve a professional. During an advisory, follow the notice your utility issues and call your local health department if the instructions are unclear. If someone at home is pregnant, immunocompromised, or an infant drinking formula, ask a clinician what to use rather than deciding alone. And vomiting or diarrhea that persists after a water event, especially in a young child or an older adult, is a reason to call a clinician rather than wait.
Microplastics: real measurements, unsettled meaning
This subject deserves care, because the measurements and their meaning sit in completely different evidence tiers.
The measurements are real. A 2019 analysis in Environmental Science & Technology pooled 402 data points from 26 studies and estimated that Americans ingest roughly 39,000 to 52,000 microplastic particles a year from food, rising to 74,000 to 121,000 once inhalation is counted. People meeting their water intake entirely from bottled sources may take in an additional 90,000 particles a year, against about 4,000 for people drinking only tap water. The authors call these figures subject to large variation and likely underestimates.
The methods behind such numbers vary a great deal. A 2019 critical review in Water Research assessed 50 studies of microplastics in drinking water and its freshwater sources and found only four scored positively on every quality criterion the authors proposed. Reported concentrations spanned ten orders of magnitude. Two different numbers in that field do not necessarily disagree; often they are measuring different things in different ways.
The health significance is not established. This sits in the insufficient evidence tier, which is different from both harmless and harmful. A 2026 review in Advances in Food and Nutrition Research surveys what is known about occurrence in the food chain and states plainly that significant knowledge gaps remain on long-term exposure and dose-response relationships. Laboratory and animal work raises hypotheses about inflammation and oxidative stress, but no human dose-response relationship has been established at the levels people encounter.
The honest sentence is that we do not yet know. Practically, that makes microplastics a poor basis for switching in either direction: the measured difference runs toward tap water being lower, and the health meaning of either number is unknown.
Environmental wording and the FTC Green Guides
Environmental claims on packaging have their own rulebook, and it sits in its own bucket. The FTC Green Guides at 16 CFR part 260 are guidance, not regulation. They state the Commission’s current views and do not bind the FTC or the public. The FTC can still act against a deceptive claim, but it has to prove the practice is unfair or deceptive under the FTC Act rather than simply point at the Guides.
Several of its rules are concrete enough to use in an aisle. An unqualified general claim such as “eco-friendly” conveys far-reaching benefits, so the FTC says marketers generally should not make one. A degradable claim is deceptive if the item will not completely break down within one year after customary disposal, and the FTC notes that landfills, incinerators and recycling facilities do not provide the conditions for that. A recyclable claim needs qualification unless a substantial majority of consumers can recycle the item, with substantial majority defined as at least 60 percent. Recycled content claims should be quantified by weight when only part of the product qualifies.
Sort the words on a bottle into categories and the label gets easier to read. The standards of identity are regulation. The Green Guides are government guidance. A mark from a private standards body such as NSF International, which certifies bottled water and water filters, is a private certification rather than a government approval, and federal law does not require a bottler to carry one. And “natural,” “pure,” “premium” and “pristine” on a water label are undefined, which means they are decoration.
What to check before you buy
A short routine, in the order the label gives you the information.
- Read the statement of identity, not the photograph. The mountain is artwork; the words naming the product are regulated.
- Look for “from a community water system” or “from a municipal source.” If it is there, believe it. If it is absent, you have learned nothing, particularly on purified water.
- Decide which kind of claim you are buying. Spring and artesian describe a source; purified and distilled describe a process. Neither is a safety ranking.
- Use the mineral statements. Low mineral content means below 500 ppm of dissolved solids. High mineral content means above 1,500 ppm.
- Treat a private certification mark as what it is, a private certification.
- Price it per gallon before comparing brands. Divide a 24 pack price by 3.17.
- For emergency storage, keep sealed original containers cool and dark, and rotate anything you bottled yourself every six months.
- Ignore any environmental adjective that is not quantified.
The most useful change is in what you expect a label to do. A bottled water label is a legal statement about where water came from and what was done to it. It is not a quality score, and no phrase on the front panel reports what is in that bottle today. For numbers rather than names, two documents give them: your utility’s annual report for tap water, and a laboratory result for your own tap.
Sources
- U.S. Food and Drug Administration. “FDA Regulates the Safety of Bottled Water Beverages Including Flavored Water and Nutrient-Added Water.” fda.gov
- U.S. Food and Drug Administration. “Bottled Water Everywhere: Keeping it Safe (Consumer Update).” fda.gov
- U.S. Food and Drug Administration. “Bottled Water/Carbonated Soft Drinks Guidance Documents & Regulatory Information.” fda.gov
- Electronic Code of Federal Regulations. “21 CFR 165.110: Bottled water.” ecfr.gov
- Electronic Code of Federal Regulations. “21 CFR Part 129: Processing and Bottling of Bottled Drinking Water.” ecfr.gov
- Office of the Law Revision Counsel, U.S. House of Representatives. “21 U.S.C. 349: Bottled drinking water standards; publication in Federal Register.”
- U.S. Environmental Protection Agency. “Overview of the Safe Drinking Water Act.” epa.gov
- U.S. Environmental Protection Agency. “Emergency Disinfection of Drinking Water.” epa.gov
- U.S. Environmental Protection Agency. “WaterSense: Statistics and Facts.” epa.gov
- U.S. Environmental Protection Agency. “National Primary Drinking Water Regulations.” epa.gov
- U.S. Environmental Protection Agency. “Secondary Drinking Water Standards: Guidance for Nuisance Chemicals.” epa.gov
- Electronic Code of Federal Regulations. “40 CFR 141.153: Content of the reports.” ecfr.gov
- U.S. Department of Homeland Security (Ready.gov). “Water.” ready.gov
- Federal Trade Commission. “Green Guides.” ftc.gov
- Electronic Code of Federal Regulations. “16 CFR Part 260: Guides for the Use of Environmental Marketing Claims.” ecfr.gov
- NSF International. “Bottled Water.” nsf.org
- PubMed. “Cox KD, et al. “Human Consumption of Microplastics.” Environmental Science & Technology, 2019. PubMed. DOI: 10.1021/acs.est.9b01517.” doi.org
- PubMed. “Koelmans AA, et al. “Microplastics in freshwaters and drinking water: Critical review and assessment of data quality.” Water Research, 2019. PubMed. DOI: 10.1016/j.watres.2019.02.054.” doi.org
- PubMed. “Bogdanović T, Pleadin J. “Microplastics as unexplored emerging contaminant: A challenge for food safety.” Advances in Food and Nutrition Research, 2026. PubMed. DOI: 10.1016/bs.afnr.2026.02.003.” doi.org
- PubMed. “Al-Otoum F, et al. “Impact of temperature and storage time on the migration of antimony from polyethylene terephthalate (PET) containers into bottled water in Qatar.” Environmental Monitoring and Assessment, 2017. PubMed. DOI: 10.1007/s10661-017-6342-3.” doi.org
- PubMed. “Allafi AR. “The effect of temperature and storage time on the migration of antimony from polyethylene terephthalate (PET) into commercial bottled water in Kuwait.” Acta Biomedica, 2020. PubMed. DOI: 10.23750/abm.v91i4.8463.” doi.org