In the United States, we are very fortunate to have high standards for water purification and municipal water departments that source clean water for many residents of cities and towns. Government agencies on the state level, such as the New Hampshire Department of Environmental Services – or the federal level, such as the Environmental Protection Agency – enforce regulation and mandatory testing of public water supplies. If your home or business is connected to a town water supply, your water is tested daily. You can be confident that what comes out of the tap will be filtered and bacteria-free.
But that doesn’t mean town water is pure and problem-free. In fact, many people who receive town water in their homes will buy bottled water for drinking! Why is that?
There are several ways to remove bacteria from water. First, organic material must be filtered out. The larger particles like leaves, twigs and trash are mechanically sifted. After that, the finer particles are removed by coagulating them using a chemical treatment like aluminum sulfate. The process of sterilizing the water from harmful bacteria most often used by municipal water supplies is by adding chlorine or chloramine. These chemical additives provide a residual sterilization benefit – that is, it continues to work until it leaves the faucet in your house. Non-chemical solutions, such as ozone or UV light, are also available for municipal water treatment, but they are not often used because they do not continue killing bacteria after leaving the treatment plant.
Chlorine and chloramine present health risks. While chlorine does a fine job of killing bacteria, it can react with any organic material present in the water to form trihalomethanes (THM) – a known carcinogen regulated by the EPA. Chloramine is a chemical made by adding ammonia to chlorine. Chloramines are less prone to forming THM’s, but the ammonia can elevate nitrates in the water. As you can see, the process of sterilizing surface water so that it is suitable for consumption is a chemical balancing act. Even when it passes EPA regulation out of the treatment plant, there’s no guarantee that town water doesn’t pick up contaminants in the pipes in route to your house.
Can you drink municipal water? The answer is “Yes!” But like any contaminant, it is best treated at the point of entry. At the very least, a water treatment system for municipal water in the home requires down-flow carbon filtration to remove possible nitrates and THM, and chlorine filters to deal with the chlorine and chloramine.
Other water quality issues that show up in a water test may also be mitigated with these types of filters, or additional components can be added to correct them – such as a water softener for hard water or bacteria treatment. UV light filtration is very effective at removing bacteria at the point of entry in the home.
You don’t have to continue buying bottled water to drink. Imagine drinking the water right out of your faucet!