Tap Water and Bottled Water
How it works
Let’s talk about tap water. Many of us in the USA drink it at home or in restaurants without giving it much thought (if we’re fortunate!). But what exactly is tap water? And is it safe for us to drink? Let’s take a deep dive into where our tap water comes from, what’s in it, and what the best option is for us to drink.
Where does tap water originate from and how are we using it?
How it works
Tap water in the USA comes primarily from three sources— lakes, rivers, and groundwater, though now some waster is coming from newer sources like seawater in San Diego County. While the mass majority of the world’s water exists in the oceans, very few sources are using ocean or seawater to convert to drinking water because of the lack of technology and challenges to desalinate it.
The origin of your water depends on where you are turning on the tap. With over 100,000 lakes and 250,000 rivers across the county, plus hundreds of reservoirs, there’s a lot of variance in the source of water for Americans. Some cities, like Boston and San Francisco, get 100% of their drinking water from reservoirs, while other cities and towns rely on rivers and lakes, or a combination. For example, Washington DC collects 100% of their drinking water from the Potomac River, New Orleans collects from the Mississippi River, while Chicago relies on Lake Michigan for all of its drinking water.
According to the Environmental Protection Agency (EPA), nearly half the water we use is from our toilet (24%) and shower (20%), with another sizable usage coming from our clothing washer (17%), and then, of course, our faucet (19%).
What’s the process from the source to my sink?
Once collected, tap water goes through a treatment process to sanitize the water before it ends up in your glass or shower. There are four steps in this process: coagulation and flocculation, sedimentation, filtration, and finally disinfection.
The first step, coagulation, and flocculation is a process in which chemicals are added into the water to attract the dirt and other undesirable particles that are going to be filtered out. When they bind together, this is called “floc.” The sedimentation process occurs next when is when the floc settles at the bottom of the tank. The filtration process is up next— water is filtered to remove any dissolve particles of dust, parasites, microorganisms, bacteria, and chemicals.
Finally, the water is disinfected to ensure any remaining microbial contaminants are eliminated. To do so, chemicals such as chlorine, chlorinates, or chlorine dioxides are added to the water. Disinfecting the water is a necessary step in preventing outbreaks of “waterborne infections and parasitic diseases,” according to the World Health Organization (WHO). This is also the stage where some cities add fluoride to prevent tooth decay in water-drinkers— don’t worry, we’ll dive into that further.
After the treatment process, my water is totally clean and safe… right?!
Now that we know the process of water treatment, let’s look at the effects of the process, and what slips through the cracks. Ultimately this process is regulated by the EPA, who sets limits on 90+ contaminants in our water supply through the federal Safe Drinking Water Act (SDWA), though that only applies to public water systems servicing more than 10,000 people. Communities smaller than that are not regulated under the SDWA— those are monitored every five years for up to 30 contaminants through the Unregulated Contaminant Monitoring Rule by the EPA.
According to Neilsen Research Corporation, some of the most common contaminants that remain in our tap water include aluminum, arsenic, copper, iron, lead, pesticides and herbicides, uranium, and more. Each of these has their own list of potential dangers or side effects. For example, consumption of too much copper can lead to diarrhea, nausea, visiting and even liver damage and kidney disease. Lead, on the other hand, generally comes from the pipes that the water travels through, and can have life-altering effects on children (slowed growth, anemia, lower IQ, and more), pregnant woman (premature birth and reduced growth of the fetus), and adults (reproductive problems, decreased kidney function, and cardiovascular effects). Several cities are plagued with lead-infested water, including the infamous case of Flint, Michigan. Some major cities have had challenges with lead in their water supply, including Pittsburg, Pennsylvania, and Milwaukee, Wisconsin. Some of the most contaminated water is in low-income rural areas, according to the New York Times, including areas of Oklahoma and Texas.
Every water supply has its own set of contaminants, and you can check out your local supply using the EWC’s Tap Water Database by using your zip code. My local drinking water, which is considered some of the best in the nation, still showed up with seven contaminants above the health guidelines set by the EPA, all of which were associated with cancer. You can also refer to the EPA’s comprehensive list of regulations for known contaminants and their acceptable levels.
Pharmaceuticals have also been found in the water system by way of sewage— either when people excrete them, or when people flush their extra drugs down the toilet. While the pharmaceuticals have only been found in trace amounts, and research has not yet shown it to have an impact on the humans consuming it, the WHO warns that we do not yet know the long-term effects of intake of trace amounts of pharmaceuticals. The chlorination treatment process that most tap water undergoes removes about 50% of the pharmaceuticals found in the system, according to WHO, but it depends on the type of drug, according to a study by Harvard.
It’s not just the contaminants that prove to be an issue in our tap water— it’s also byproducts of the treatment process itself. Introducing chlorine into our water system produces halogenated disinfection byproducts (DPS), which has shown linkages to bladder cancer, for example, as well as reproductive and developmental effects since we end up consuming it ourselves.
What’s the deal with fluoride? Isn’t it good for my teeth?
Fluoride has been added to the majority of the USA public water system since the 1960s, and not without controversy. Added to our water to aid in the prevention of cavities (also called caries), there has been much discussion and debate about the health risks associated to ingesting the gas (yep— fluoride is a gas!). As of 2014, about 74% of people on community water systems (public water) received fluoridation, varying by state (Hawaii has the lowest rate at 11.7% while Washington DC has 100% fluoridation rates), according to the Center for Disease Control (CDC). Ironically, the overall rate of cavities across the globe is decreasing for both populations that are and are not treating their water with fluoride, Harvard reports. We can probably thank good toothpaste and trusty electronic toothbrushes, as well as more information on dental hygiene in general, for that.
Unfortunately, fluoride doesn’t stay exclusively on your teeth, research shows a number of various concerns about the ingestion of it. A 2014 research study found that fluoride poses “significant costs in relation to cognitive impairment, hypothyroidism, dental and skeletal fluorosis, enzyme and electrolyte derangement, and uterine cancer.” It also has not been shown that ingesting fluoride via your tap water is the best way to prevent cavities— many kinds of toothpaste or mouthwashes that contain the ingredient are equally if not more effective.
So is there anything good in my tap water?
Despite the fact that you can buy “mineral water” in bottled form, there are many minerals that occur naturally in your tap water. Calcium, magnesium, and sodium were all found in levels that are high enough to support our health in our tap water. Those minerals are sometimes stripped from hard whatever, however, according to a research study out of Washington University in St. Louis.
What are the alternatives to tap water?
Despite common conception, bottled water is doesn’t prove to be a much safer or cleaner alternative to tap water. In addition to the challenges of the energy usage and materials used to create and bottle water, as well as the abundance of plastic it adds to our waste stream, bottled water hasn’t been shown to be significantly safer for consumption or lower in contaminants. And while tap water is regulated by the EPA, bottled water is regulated by the FDA which has a separate set of rules and is focused more heavily on labeling than perhaps the contaminants in the bottle (they do have some regulations, but not as hefty as the EPA). A 2014 study showed that BPA and PET from the plastic may leach into the water if it’s left in warm conditions. All that added on to the fact that bottled water may, in some cases, just be tap water leads to the conclusion that bottled water is a thing to avoid.
Okay, so bottled water is out. How about the live or raw water trend? Sometimes opting for the most natural isn’t the best case scenario— and here is one of them. Yes, 100% pure water will avoid fluorination, traces of pharmaceuticals, or traveling through lead pipes, but it also has a host of potentially dangerous consequences. Parasites, pesticides, and harmful bacteria lie in much of our water supply, not to mention the fact that it is outrageously expensive. If we look to the developing world that is often tormented with waterborne disease and illness with deadly consequences, we can see a sampling of what drinking unprocessed water may do to us.
The seemingly best option is to filter your tap water— that way you get affordable, easy to access, zero-waste water, filtered to remove whatever contaminants or fluoride that may be causing you harm. That way you get clean, fresh water, whenever you need it, with positive benefits to you and the environment.