Water Filter Facts: What's In Your Tap?

Row of white sinks and faucets

77 percent of Americans use some kind of water filtering process according to an annual survey done by popular brand, Aquasana.

While these results favor what the company sells, interest in filtering out common contaminants in tap water has consistently gone up over the past few years. Covid-19 caused a slight upsurge, and the survey found that many people don't trust what's coming out of their faucets.

Many are choosing faucet-mounted filters as one of the safest, most environmentally-friendly, and economic choice. They offer on-demand water, are convenient, easy to setup yourself, and relatively affordable—but are they worth it?

We'll dive deep into the world of water filter facts to find out what's in your tap, and what you can do about it.

How Safe Is Your Tap Water?

Your municipality ensures large-scale filtration cleans your tap water according to government regulations. All municipal tap water is treated with chlorination to kill off microorganisms like bacteria, viruses, and parasites, and ran through various stages of filtration.

This doesn't mean there won't be small amounts of lead, leftover chlorine, and/or chloramine, various VOC's (volatile organic compounds), and PFAS, nitrates or other harmful compounds that can't be seen or tasted.

Trace amounts of these chemicals are leftover during the filtration process, and lead can come from the specific plumbing fixtures in your home.

Not all tap water is the same, either. Depending on where you live, your city or region may get its water from nearby lakes, rivers, streams, or local aquifers if using groundwater.

Check out the interactive map from the EPA (Environmental Protection Agency)'s website to see where your water comes from. There's a lot of information about drinking water if you want to dive deeper into the topic.

So while tap water will be different by region, most of it will contain some trace amounts of unwanted chemicals or contaminants. That's why many households choose to filter their water.

Types of Contaminants

Many harmful contaminants can't be tasted, seen, or smelled, although contaminated well water may give off an unpleasant odor and taste. The most common ones that are found in municipal tap water are lead, chlorine, VOC's (volatile organic compounds), PFAS, chemicals, and hard minerals.


According to the CDC (Center for Disease Control), there is no safe amount of lead in water, and the EPA lists the maximum safe level for lead at zero because of health implications even at low amounts.

And yet, the majority of homes contain plumbing with some kind of lead, which is how it can contaminate your water, even if city water tests say lead levels are low.

While basic fixtures like faucets, fittings, solder, and pipes may contain lead, the most common source is the service line that comes in from your municipal main water line.

If your home was built before 1988, there's a chance it may still be getting water from lead service lines as these were banned in new homes after this date, however it depends on your location.

For example, homes in Chicago continued to use lead service lines up until 1988, while other communities stopped during the war to use lead for weapons. Call your water service provider to get more information on your home's service lines, or inquire with your municipality.

There are ways to identify lead pipes and fittings in the house, but there is no way to see if the underground service line is lead unless you know it was replaced.

Collect the most information you can about your home's plumbing fixtures, and use a water test to determine the exact amount of lead coming out of your faucets.

A combination of reverse osmosis and activated carbon filtration is the only way to bring lead levels down to zero.


Drinking water must be chlorinated to kill microorganisms like bacteria, viruses, and parasites. Different communities use either chlorine or chloramine, and there is always a trace amount of these chemicals leftover in your water.

While the CDC and government regulations suggest that the amount is safe, some people may be more sensitive than others. The idea is that it's better to have this small amount in order to prevent waterborne disease or outbreaks from microorganisms.

Notwithstanding the taste, chlorine has been shown to have long-term health effects in some humans and animals, mainly in the form of asthma, allergies, bladder issues, congenital abnormalities, and respiratory problems.

Boiling or distilling water may remove chlorine, but not chloramine. One of the best ways to remove any leftover chlorination chemical is with a carbon filter.


VOC's or "volatile organic compounds" can be found in common household products like paint, cleaners, sprays, glues, gas, solvents, pesticides, air fresheners, and are even found in furniture and fabric.

You can usually detect them by smell: when you take the cap off a permanent marker, paint a room, or notice a "new couch" smell, that's the VOC's you're smelling.

All VOC's can cause serious health effects like cancer, skin and mouth irritations, nervous system damage, as well as kidney or liver damage.

Unfortunately, VOC's can enter the water system quite easily when products are disposed of improperly or produced in the first place.

These items leach into the groundwater and find their way into the city's water system through a number of different methods, mainly through water runoff and spillage.

City water is only tested for some VOC's, so it's still important to test your water, especially if you're using groundwater sources or get your water from a well. Since VOC's are organic compounds, aka "carbon-based", a carbon filter will remove them.


PFAS stands for "per- and polyfluorinated alkyl substances" and are commonly known as "forever chemicals" (which rolls off the tongue better...).

Like VOC's, PFAS are found in certain common household items like non-stick cookware, fire and stain-resistant fabric and carpets, and linings of fast food boxes and cartons.

Adverse health effects caused by PFAS include improper immune and thyroid functioning, kidney and liver disease, dis-regulated insulin and lipid levels, reproductive problems, and cancer.

According to a study by the U.S. Geological Survey, around 45 percent of tap water across the country includes one or more kinds of these chemicals.

The study found that the amount of type of PFAS were consistent among city water and wells, meaning all water sources are at risk, although water near urban centers have higher exposure.

Activated carbon filters and reverse osmosis systems have shown to be the most successful at removing PFAS from drinking water.

Chemicals and Minerals

Many of the minerals found in tap water are considered essential to your health. These include calcium, magnesium, potassium, sodium, and even trace amounts of iron, manganese, copper, selenium, and zinc.

The amount will depend on the water source your water comes from, and if it's high in these minerals, your water is considered "hard". Water softeners are recommended in areas with hard water.

Unfortunately, non-essential and harmful chemicals and minerals can also end up in your drinking water.

Agricultural practices allow herbicides, pesticides, and nitrates from fertilizer to enter groundwater systems. Mercury, perchlorate, and pharmaceuticals are found in tap water from manufacturing and household pollution.

Arsenic, asbestos, radium, and other heavy metals have also been found in some tap water, which is another reason it's important to check your water system's annual testing report, as many aren't held to compliance.

Reverse osmosis removes all contaminants and minerals, including the essential ones, so you need to supplement your drinking water with essential minerals. Bottled water has also had all essential minerals filtered out.

Most carbon filters will not remove the essential minerals that you need in your drinking water, but this information is not always easy to find.

How to Test Your Water

Water suppliers must provide a Consumer Confidence Report to their customers every year that describes what contaminants have been found in the drinking water.

It may be emailed to you or sent along with your bill, but not all suppliers give out this information so freely since most water doesn't meet federal guidelines.

Remember that city water is only tested on a given day, and conducting your own private test through an accredited lab is the only way to get an accurate reading of what's running through your taps.

If you have lead service lines or plumbing fixtures, this will go undetected by the water company's annual testing.

A lab test will be able to either confirm or dismiss the CCR's numbers and give you an exact idea of what it is that you should be removing from your drinking water to help you choose the best filter.

Keep in mind that certain contaminants like PFAS, percholate, cysts, and algal toxins (among others) are not federally regulated, and therefore not tested by your water supplier.

How to Choose the Best Filter

Test First

The first step before purchasing a water filter of any kind is to identify the contaminants in your drinking water. While the CCR can give you an idea of certain levels, the best way to remove the harmful elements is to test what's coming out directly from your taps.

Point-of-Use/ Point-of-Entry

"Point-of-entry" filters treat the home's entire water supply before it reaches specific faucets or taps. "Point-of-use" are also excellent at filtering contaminants, but they will only do so at the source.

Example of point-of-use are under sink, faucet-mounted filters, or pitcher filters. Faucet and under sink filters are better than pitcher filters as they generally remove more contaminants.

Faucet filters are considered excellent point-of-use filtration systems because they remove contaminants directly at the source.

It's a good idea to place one of these on all of your home's faucets and taps, as even water used for bathing, cooking, cleaning, and washing your clothes should have contaminants like PFAS and VOC's removed.

Look For NSF-Certified Filters

NSF/ANSI certification is the only regulation that's been developed for water treatment filters, as well as reverse osmosis and purification systems. There are no federal regulations in place for residential water filtration.

Look for NSF certified filters when buying point-of-entry filters, but remember that there are different types of certification, and not all NSF water filters will remove all contaminants.

The contaminants that the filter will remove or reduce will be listed somewhere on the box or in the product information.

NSF/ANSI 42 filters will remove "aesthetic impurities" like chlorine and taste/ odors, whereas NSF/ANSI 53 reduce contaminants with a health effect according to the EPA guidelines.

Best Faucet-Mounted Filters

For most faucet water filters, an activated carbon filter will do the job. These filters remove odors and unpleasant tastes, including chlorine/ chloramine, as well as other contaminants.

Look for the Standard 53 label on the filter. These are certified to remove not only unpleasant odors, but also heavy metals, pesticides, VOC's, and PFAS.

They can be expensive to maintain, since the filters must be replaced regularly, so make sure to find out what replacement filters cost and how often they need changing.

Faucet filters are convenient ways to get on-demand filtered water, but they can also be bulky. Many of them aren't compatible with pull-down faucets, so make sure the fit is right before purchasing.

Under sink mounted filters are another option if you want on-demand filtered water that's better at filtering out contaminants than a pitcher filter, but won't change the aesthetics of your kitchen faucet.


How can I check if my tap water is safe to drink?

Call your municipality if you didn't receive your CCR drinking water quality report which is ready by July every year. They'll be able to send one directly to you, or tell you where you can find it online. They may also be able to walk you through the results, as it can often be a lot of information to go through.

Will I get a CCR drinking water report if I live outside of the city?

If you get your water from a well or other non-municipal system like a campground you will not receive a CCR water report. If living in a campground or other non-community system, ask the site manager for a report. If you have a well, you'll need to do your own private test.

How can I tell if there's lead in my tap water?

A state-certified lab test is the best way to confirm in there's lead in your water. Call your local water supplier to find out any information they might have regarding your home's service lines. You can try to identify lead plumbing fixtures yourself, or contact a reputable plumber to check.

How do I find a certified lab that will test my water?

Before you book a water test, call the Safe Drinking Water Hotline at 1-800-426-4791 to find a state-certified lab in your area. The non-profit Healthy Babies Bright Futures gives out tests specifically for lead in water and allows you to pay what you can.

How do I know if a filter is NSF certified against lead?

NSF/ANSI 53 or 58 certifications specifically reduce lead in drinking water. Note the term "reduce" and not "remove". You can call NSF's customer service line at 1-800-673-8010 for specific questions and concerns, but make sure to read a product's full description before purchasing.

Why does my water taste bad?

Chlorine and chloramine are the main culprits for bad tasting water, but essential minerals can also leave a certain flavor that not everyone likes. If the water is discolored, has a weird smell, and tastes bad, then you may have problems with microorganisms and bacteria, or too much iron in your water.

Can I just use a pitcher water filter?

Make sure water pitcher filters are rated for removing VOC's and other contaminants like lead before buying one. Common brands like Brita or ones installed in your fridge mainly improve the taste of your water, or reduce chlorine. Countertop water filters made for off-grid living are better at removing the majority of harmful contaminants.

Does boiling tap water purify it?

Boiling your water does not remove lead, but it can help remove chlorine. High temperatures will kill off bacteria and parasites, which aren't usually a problem in municipal water, but can be in wells or other systems. Run your tap for five minutes with cold water in between use if you have a lead service line, otherwise, 1-2 minutes is sufficient.

Are faucet water filters worth it?

Water filters are worth the investment in your health, especially if you have high lead content. They're also good at removing contaminants like VOC's and PFAS that aren't federally regulated. Any type of water filter will help to purify your drinking water, but the best ones will have the proper NSF rating to eliminate the specific contaminants found in your water test.