In last week’s blog, we discussed the importance of drinking clean water, including an analysis of the contaminants of concern in general drinking water. This week, we will discuss details of water filtration, what is actually being removed by various processed, and why plastic water bottles are not the answer.
First, let’s discuss terminology. A water filter is the umbrella term universally used to describe most devices that clean our drinking water. Water filters use some type of filter medium, such as the activated carbon filters used in Brita pitchers, to physically strain out debris and bacteria. Most filters are also able to provide a cleaner taste, and to reduce the levels of pesticides and industrial chemicals in the water. Water purifiers, on the other hand, strain out bacteria, industrial chemicals, and pesticides in addition to removing many viruses from the water as well. To be classified as a water purifier, a water treatment device must remove 99.9999% or more of pathogenic bacteria, and must reduce viruses by 99.99%.
There are hundreds of brands of water filters available for home use, and various types of filtration technologies are used within them. Some brands use multiple filtration technologies within one unit, and some use just one filtration type. You should be able to go on the manufacturer’s website and look up specific information about which contaminants are filtered using their specific device. You can use your Annual Water Quality Report (CCR, or Consumer Confidence Report) to determine which contaminants are of the most concern to you, and then research whether your water filter or purifier is removing the contaminants of greatest concern to you.
Filters vary widely in quality, so it is important to do your research when selecting one. Some carbon filters are able to filter lead, mercury, asbestos, and VOCs, while some simply remove chlorine and improve the water’s taste. Caution should also be used when selecting purifiers; some water purifiers use harmful chemicals such as chlorine or iodine to remove viruses.
The most common types of filter mediums include activated carbon (both carbon block and granulated), ceramic, ion exchange, ozone, ultraviolet (UV) light, and reverse osmosis. You can read more about these types at http://www.ewg.org/research/
Many people mistakenly believe that drinking bottled water is the best option available to them. However, bottled water is largely unregulated and can contain water from various sources. In many cases, bottled water purchased in a store is simply tap water that was placed into a plastic bottle, and does not even include any filtration. While the EPA is responsible for monitoring the quality of tap water, bottled water is overseen by the FDA, who generally just assures that the advertising on the label (“water”) matches the contents of the bottle. The National Resources Defense Council (NRDC) estimates that 25% or more of bottled water is nothing more than tap water, and found that 22% of their tested water brands contained contaminant levels above state health limits.
Another concern for bottled water is leaching of chemicals from the plastic bottles into the water. When plastic is heated, it’s more likely to release compounds. During the time it takes for water bottles to travel from their place of manufacture to your home, they can often be found sitting in extremely hot warehouses, or on the back of trucks baking in the sun, increase the chances of contamination from heated plastic.
Some bottled water is simply put through a simple Brita style water filtration processed, whereas other bottled water is purified or distilled (which is not always preferable; distilled water is often referred to as ‘dead’ water since it is completely lacking in mineral content). Not only is bottled water an extremely poor choice for our environment, but it is also estimated to cost 2,000 times more than tap water.
In Part 3 of our water series, we will discuss the pros and cons of various water filtration options, plus our recommendations for water filters.