Is Tap Water Safe to Drink in the US? (According to Data)

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On the surface, tap water looks and tastes clean enough. We know that public water systems treat our drinking water and make it safe to drink – but how safe is safe?

In this guide, we’ll be looking at the safety of tap water according to organizations like the Environmental Protection Agency (EPA). We’ll also share the common contaminants found in tap water, and how to treat your tap water to remove these contaminants.

๐Ÿšฐ Is Tap Water in the USA Safe to Drink?

Yes, tap water in the USA is safe to drink – technically.

What this means is that public water systems must follow regulations implemented by the Environmental Protection Agency to ensure that their water is treated before use – but many suppliers, especially in rural regions, exceed legal limits for certain contaminants.

An NRDC report found that violations by public water systems put more than 77 million Americans at risk, and that many citizens live in regions that don’t comply with the EPA’s regulations. Tens of water suppliers were found to either fail to test their water properly or fail to report their test results to a local authority.

tds map
Source: United States Geological Survey

โ” How Safe is Public Drinking Water?

The water that leaves our taps has been tested and treated by public water systems. This should technically mean that our water is safe for consumption.

However, local pollution, financial constraints, and water suppliers’ failure to follow the EPA’s guidelines have a detrimental effect on the quality of the water that is supplied to our homes.

Natural water sources contain the likes of chemicals, metals, and microbes – and these contaminants aren’t removed as thoroughly as most of the public would prefer.

Specific Tap Water Safety Guides

๐Ÿ†š EPA vs EWG On Water Safety

When it comes to drinking water safety, public water suppliers must legally follow regulations set out by the Environmental Protection Agency (EPA for short), based on information from the Safe Drinking Water Act (SDWA).

The EPA has Maximum Contaminant Levels, or MCLs, for all contaminants deemed to be a health risk in drinking water. Public water suppliers must treat their water to remove these contaminants to below their individual MCLs.

The problem with these MCLs is that some organizations think that they’re too lenient. The Environmental Working Group (EWG for short) has produced its own Standards for drinking water contamination, and they’re much more stringent than the EPA’s.

For instance, the EPA’s legal limit for mercury is 2 PPB (parts per billion), while the EWG’s legal limit for this contaminant is 1.2 PPB. The EPA’s legal limit for arsenic is 10 PPB, while the EWG’s legal limit for this contaminant is 0.004 PPB. There are many impurities that the EPA has no federal legal limit for, but the EWG believes should have a limit, such as aluminum, chlorate, PFOA, and manganese.

Plus, there are some contaminants that aren’t even regulated by the EPA, such as some metals, industrial chemicals, and cyanotoxins.

What does this mean? According to the EWG, even if we’re drinking water with contaminants below the legal limits, our water might still be unsafe for drinking.

You can view the full EWG Drinking Water Standards chart here.

municipal treated tap water

๐Ÿ’ง Where does Public Drinking Water Come From?

Public drinking water comes from a number of surface water (on-ground) and groundwater (below-the-ground) sources, including lakes, rivers, reservoirs, wells and aquifers.

Surface water is the most common drinking water supply because it’s the easiest to attain. However, surface water is exposed to surface runoff and atmospheric pollution, so it’s often more contaminated, and requires more thorough treatment.

The amount of clean water is greater underground, so some large water suppliers exclusively use groundwater for their public drinking water. Groundwater tends to be cleaner than surface water because it’s filtered by the earth’s rocks and soils as it seeps underground.

๐Ÿ†š Public Water Vs Private Well Water

Public water and private well water supplies might come from similar locations, but the end result is very different.

Most private wells are supplied by groundwater from an underground aquifer. This water is transported to a person’s home without being treated. There are no legal enforcements in place for treating well water, and the homeowner is responsible for making their water safe for consumption. This has its benefits, giving the consumer more control, but it’s also more expensive and nowhere near as convenient as drinking pre-treated public water.

Public water is supplied by either groundwater or surface water. This water must be treated by the supplier before it’s delivered to the community. Treatment often involves chlorination, but doesn’t guarantee the removal of all drinking water contaminants. So, while public drinking water tends to be safer to drink than well water, it’s still laced with contaminants – and it contains an additional chemical: chlorine.

Public water vs well water supply

๐Ÿ†š Tap Water Vs Bottled Water

Tap water and bottled water are regulated by different organizations. Bottled water is considered a food product, so the FDA regulates bottled water while tap water is regulated by the EPA.

Many bottled water sources are filtered more thoroughly than tap water. Bottled water manufacturers have the freedom to treat their water however they prefer, without the financial constraints of a large public water supplier.

Does this mean that bottled water is always safer to drink than tap water? Not necessarily. Some bottled water is essentially just water from the tap, with a very similar drinking water quality. Bottled water may still contain traces of contaminants that pose a serious health risk.

However, consumers can pick and choose between bottled water products to find the safest drinking water, while this isn’t an option for tap water – we get what we’re given.

Tap water vs bottled water

๐Ÿงช How is Public Water Treated?

There are several steps involved in the public water treatment process:

  1. Coagulation: Suspended particles are removed, and chemicals like alum are added into the water to attract dirt.
  2. Sedimentation: Particles produced during coagulation are removed, leaving sediment-free water.
  3. Filtration: Several layers of sand, gravel, and charcoal are used to remove smaller particles from water.
  4. Disinfection: Chemicals like chlorine or chloramine are added to kill germs like viruses, bacteria, and other microorganisms.
  5. Storage: Treated water is held in a reservoir before being transported to homes around the community.

๐Ÿงซ Why Does Drinking Water Still Contain Contaminants?

You might be wondering why public water still contains contaminants if it’s treated by water systems before traveling to our homes.

The problem is that the public water treatment process isn’t thorough enough to remove all contaminants. This wouldn’t be viable for a large-scale application – it’d be expensive and time-consuming.

Plus, public water suppliers only have to remove contaminants as instructed by the EPA. Some contaminants that aren’t regulated by the EPA can still linger in water.

So, while water treatment removes some contaminants, the water quality of the end product still won’t be exceptional.

Person holding a glass of dirty water

โ˜ข๏ธ Which Contaminants Are Common in Tap Water?

We’ve listed the contaminants you’re most likely to find in public water supplies below.

Chlorine or Chloramine

Chlorine or chloramine are guaranteed to be added to your water during the disinfection stage of treatment.

These chemicals are only found in trace amounts in your water, and there’s no evidence to suggest that drinking chlorinated water is dangerous to human health. However, disinfection chemicals affect the taste of contaminated water – and some people would simply rather not drink bleach in their water.


The EPA’s MCL for lead is 0 – meaning that no amount of lead is ever considered safe in public water.

Lead gets into water through local contamination, or – most commonly – lead pipes and fixtures in your home or community water system. Lead is known to build up to dangerous levels in the body over time, potentially resulting in lead poisoning. Headaches, vomiting, mood disorders, abdominal pain, joint and muscle pain, and difficulties with concentration and memory are all signs of lead poisoning.

Lead poisoning through ingestion


Arsenic is a tasteless, odorless element that has an MCL of 10 PPB in public water supplies. Arsenic is highly carcinogenic, and long-term exposure to this element leads to skin lesions and various cancers.

As a natural component of the earth, arsenic is prevalent in the water, land, and air. For this reason, arsenic is a common groundwater and surface water contaminant.

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Fluoride is added to many public water supplies as a result of community fluoridation programs. This natural mineral has a range of dental health benefits, and it’s added to water to prevent tooth decay.

However, fluoride is a controversial mineral due to its known negative effects on bone health. Overconsumption of fluoride can lead to skeletal fluorides, a bone disorder that causes painful bones and joints, and the increased risk of bone breaks. Too much fluoride may also cause dental fluorosis, or discoloration of the teeth.

Hexavalent Chromium

Hexavalent chromium, or chromium-6, is found naturally in soils, rocks, and volcanic dust. This chemical has an MCL of 0.1 PPM, and is known to have short- and long-term effects, including kidney and liver damage, skin and nasal irritation, sinus and nasal cancers, and eye irritation and damage.

Hexavalent chromium gets into water in two ways: through natural runoff and industrial pollution.

Hexavalent Chromium contamination from industrial waste

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Pharmaceuticals are found in trace amounts in water sources used for public drinking. These contaminants end up in water through human and animal waste.

We don’t know much about the health risks of consuming pharmaceuticals in water, and there are no confirmed human risks from exposure to minute concentrations of drugs. However, most people would rather not drink pharmaceuticals in their water supply.

๐Ÿ“ How to Make Tap Water Safe to Drink

By now you should know that while public water is technically safe for consumption, it still contains traces of potentially dangerous contaminants.

Drinking contaminated water has a whole host of potential human health implications. The only way to ensure your water quality is good enough for safe drinking is to treat the water at your home.

The best way to make tap water safe is to use a water filter. Some of the best water filters for treating public water are:

Water Filter Pitchers

Water filter pitchers are plastic pitchers with a filter attachment. Water is added to the top chamber, and must flow through the filter to pass into the bottom chamber.

Some water filter pitchers offer exceptional contaminant removal, reducing lead, heavy metals, chlorine, chloramines, VOCs, nitrate, fluoride, arsenic, bacteria, and other contaminants.

Water filter pitchers use gravity filtration, so they can take up to 20 minutes to filter an entire jug of water.

clearly filtered high performance water filtration pitcher

Under-Sink Filters

Under-sink water filters are installed underneath your kitchen sink.

These systems consist of several different types of filters, each tasked with removing different contaminants, like heavy metals, chlorine taste and odor, arsenic, fluoride, VOCs, and nitrates.

Under-sink filters provide filtered water on demand. When you turn on your faucet, water flows through the filters before leaving the tap.

Reverse Osmosis Filters

Reverse osmosis filters are the most through water treatment solutions on the market.

These water filters send water through several filter stages and a semipermeable membrane, which prevents all contaminants larger than water particles from passing through.

If you’re looking to achieve pure water, reverse osmosis is your answer. This water filtration method removes everything, from metals to chemicals, microorganisms to minerals and salts.

Tank-Based RO System

Whole Home Filters

Whole home filters are the best choice if you want to drink, shower in, cook with, and wash your clothes and dishes in clean, contaminant-free water.

A whole home water filter is installed at your main water line, upstream of your water heater. This means that your hot and cold water supply will be filtered.

Whole home water filters can remove contaminants like chlorine, heavy metals, fluoride, VOCs, arsenic, and pharmaceuticals.

๐Ÿง  Is Tap Water Safe to Drink? FAQs

How do I know if tap water is safe to drink?

If you get your tap water from a public water system, you know that it’s been treated and is “safe” to drink. You could also check your annual Water Quality Report (otherwise known as a Consumer Confidence Report) or test your water if you want to see which contaminants it contains.

water testing with tap score

Is tap water as safe as bottled water?

This depends on the quality of the tap water and the bottled water. Generally, bottled water is safer than tap water because it has been filtered to improve its quality. Read the label carefully to learn what your bottled water contains and how it has been treated.

Is it safe to drink water from the bathroom sink?

Yes, drinking water from your bathroom sink is generally safe. However, we wouldn’t recommend regularly drinking from your bathroom sink water, because this water is more likely to contain heavy metals and bacteria than your kitchen sink water. Why? Because the pipes supplying your bathroom sink may have a buildup of these contaminants. In short, your bathroom sink isn’t designed to drink from, but you’ll probably be fine.

Is it OK to drink tap water everyday?

Yes, it’s okay to drink tap water every day. Of course, you need to trust your local water supplier that your water is adequately treated (there have been several notable instances where this isn’t been the case). There are certain contaminants that can accumulate in the body to unsafe levels, such as lead. Drinking clean, filtered tap water is safer than drinking water straight from your tap.

Is drinking tap water healthier?

Drinking tap water isn’t healthier than drinking any other type of water. Tap water tends to contain healthy minerals and salts, but you could probably find these in a filtered water supply or bottled water, too. Plus, tap water contains trace contaminants, some of which aren’t healthy at all.

Does the US purify tap water?

The US treats all public tap water supplies, but it doesn’t purify them. Purifying water involves eliminating every single contaminant, leaving only pure water. In the US, tap water is treated – meaning that some of the contaminants are filtered out, but many remain in trace amounts.

Where in the US is tap water unsafe?

Tap water is technically safe in all parts of the US that have treated public drinking water supplies. Of course, there are still instances where the public is let down – such as the Flint, Michigan drinking water crisis. And there are still trace contaminants found in “safe” drinking water supplies. Some people would argue that no supply of water in America is truly safe.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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