Wondering if your tap water is safe to drink? It’s an important question, no matter where you live, but it’s one that is not always easy to answer.
Water collects contaminants in stages and it’s filtered in stages as well. So, logically, the first step to clean water is a clean source — the reservoir, lake, or river your city’s water comes from. This is generally known as your “Primary Water Source Type.” After this water is collected it goes to a water facility where the water is filtered so that it’s in a state that’s safe for human consumption. This water facility has a name, but it’s most commonly known, in the United States at least, by its “PWSID.”
Most of the water quality data that you can get online, including this MyTapWater.org will be based on the water that is tested after treatment of your PWSID.
After the PWSID though, water is distributed in large mains, which make their way to smaller mains, and ultimately to your home and its faucets. Along the way, especially in the piping of older homes, the water can pick up contaminants that were not present when the water left the treatment facility. At this point there is no testing aside from that done yourself (assuming you are not at a place like a school where the water might be tested with some regularity). Both testing and filtering at endpoints happens at the discretion of the owner so the EPA and other organizations are largely outside of the process by this point.
It’s worth noting now that the same applies to well water. Private drinking wells are essentially tiny little water facilities that the EPA does not regulate. Water sampling often isn’t required for these, but we’d recommend you do so periodically. The EPA will provide information for well owners and each state has helpful information as well, but it’s up to you to test and filter that water until it’s at a quality you are happy with.
Back to the faucet: At, right before, or right after the faucet you can filter your own water. There are any number of home filtering solutions ranging from about $20 to thousands of dollars, depending on the complexity, level of filtration, and volume of water you want to filter. There are many, many options here and many ways to make sure your water is quite pure and quite safe. But these really address the question of “Can my tap water be safe?” while this article is about if the water is safe.
Ultimately you can check for tap water safety by looking for violations in your water facilities testing. If you trust the regulations to determine what you should and should not be drinking then you can look for facility violations and know if your area has excessive amounts of any contaminant. You can then determine the best water filter for your needs and even test the filtered water if you want to take things to that level.
Safe vs. Pure
One distinction that often gets left out in all this is the difference between safety and purity. Purity — the lack of contaminants in water — is not the goal. After all, this is why we don’t drink distilled water! Water can have helpful minerals in it as well as non-H2O molecules that add to the flavor of the water. Water can also have contaminants in it that are totally safe to consume, but might a) not affect the water at all b) change the taste or c) change the smell in a way that you don’t enjoy. Water might also have additives that you may or may not want, fluoride being the most well-known.
Much of this decision-making comes down to personal preference, but the point is that water can be impure but also safe enough to drink. The EPA calls these “Secondary Drinking Water Standards” and marks them as a “nuisance” as opposed to an outright danger. These are non-mandatory water quality standards that the EPA set for 15 different contaminants. Water facilities do not have to follow these guidelines and finding the amounts left in by your facility may be difficult or even impossible. Ultimately, these level are one of the main reasons people buy water filters for their home, as they are uncomfortable with the smell, taste, or even the color of their water, even if it is deemed safe.