There are approximately 50,000 different water systems in the U.S. serving safe water to nearly 290 million people, and for the most part, they do a wonderful job. When problems occur, it’s typically for one of two reasons. Either. . .

1) The pipes and infrastructure delivering the water are old and degraded and in need of maintenance. Problems can occur in the water main pipes themselves or in those that run from the water main to your house. As Jack Barber states, “Distribution pipes can be coated with dangerous layers of mineral, biological and chemical deposits that re-contaminate the water as it travels from the treatment plant to your tap. And some pipes are very old, including lead leaching cast iron pipes from the late 1800’s, as well as thousands of miles of asbestos water pipes laid in the 1950’s.” (Barber, 2014, p. 6) This can release toxins like lead into your pipes, and acidic water (often created from the chlorine used to purify it) can cause iron to leach into pipes, which can bind to chlorine and make it ineffective, leaving your water prone to bacteria like Legionella.

2) The water source itself that drinking water is drawn from is polluted. Not everything can be removed from the water by treating it, and sometimes the treatment process itself adds potentially toxic byproducts. “Public health agencies concentrate on disinfecting water to protect us from infectious diseases,” notes Dr. Andrew Weil. “They largely ignore the problem of toxic contaminants, one of which is the very chlorine commonly used for disinfection.” (Weil, 1995, p. 161)

Sometimes incompetence plays a role (such as in the case of Flint, Michigan) because water utilities either skip steps or don’t adequately treat the water based on the unique source they are drawing from. This can leave the water toxic or acidic, further eroding infrastructure and resulting in more contaminants being leached into the water supply.

Why the quality of your tap water might depend on where you live

The quality of your tap water often depends on the type of system that is serving you. More of the problems typically come from smaller utilities that are haphazardly run. “Tiny utilities – those serving a few thousand people or less – don’t have to treat water to prevent lead contamination until after lead is found,” write Laura Ungar and Mark Nichols. “Even when they skip safety tests or fail to treat water after they find lead, federal and state regulators often do not force them to comply with the law.” They cite one example in which “Notices and orders were the EPA’s weapons against Coal Mountain’s testing violations for 5 years, after which nothing changed, and West Virginia asked that no further federal action be taken.” (Ungar & Nichols, 2016)

“You might have to get more training to run a hot dog stand than a small water system,” says Paul Schwartz of the Campaign for Lead Free Water. A water system in Black Canyon, Colorado, that serves 335 people was run by a farmer who spends most of his days in the fields. In West Texas, the Klondike Independent School District’s water safety was handled by superintendent Steve McLaren, whose day job is running a school system serving 260 students. In New Jersey, lead levels of 124 ppb were found at a Lawrenceville school whose water supply system is run by school maintenance staff. (ibid) It’s no accident that most of the health-based violations occur in systems serving less than 10,000 people. (Heyworth, 2011)

Smaller water systems in rural communities are also prone to things like agricultural runoff and septic tank leakage. So it’s a one-two punch: not only are those running the system less qualified, but they can have more problems to contend with.

Private wells can also be a problem depending on where you live, especially since you’re the person in charge of water treatment in this case. The source of the water also matters. As a general rule, well water is safer than surface water, unless you live in an area where fracking is occurring. “If your provider draws from a surface water source, like a lake or a river, you might have cause for more concern than if it draws from, say, an underground aquifer,” says Sonya Lunder of the Environmental Working Group. (ibid)

Not only is surface water from rivers and lakes more likely to be contaminated to begin with, but this often forces utilities to treat it with more chemicals, leading to excessive disinfectant byproducts in your water.

Learning more about the quality of your own tap water

To find out more about the quality of tap water in any particular area, visit the Environmental Working Group’s tap water database at