Drinking Water Quality: What is in Your Tap Water?
Numerous contaminants can find their way into your drinking water source whether it is a river, lake, stream, spring, reservoir or well. Industrial processes can release contaminants such as heavy metals like cadmium or mercury as well as other harmful chemicals. Pesticides and herbicides end up in the water due to agricultural and residential activities. Not all sources of contaminants are due to humans however. Microorganisms like viruses, bacteria and parasites, as well as many other contaminants like radium (a radionuclide), are naturally-occurring. All of these contaminants influence water quality.
The Safe Drinking Water Act was passed in 1974 to help protect and regulate public drinking water and limits the presence of contaminants in community water systems which are those systems that serve the same people year-round. The Environmental Protection Agency (EPA) sets and enforces water quality standards for approximately 90 contaminants in drinking water systems. For each contaminant, the EPA identifies the maximum contaminant level (MCL) allowed in drinking water as well as the maximum contaminant level goal (MCLG). Any level below the MCLG is not known to pose any risk to human health. The MCL and MCLG for each primary contaminant as well as the source and potential health effects from long-term exposure to the contaminant can be found at the EPA’s Drinking Water Contaminants page .
How can you learn what is in your tap water?
Drinking water quality can vary considerably by location due to differences in the water source as well as the treatment processes. Therefore it is very important to learn about the quality of your own drinking water as it may be quite different from that of a relative or friend who may live in the same city but uses a different water system. Your local water supplier is required to produce an annual Consumer Confidence Report by July 1st of the calendar year and you can contact the supplier directly or visit their website (if available) for this report. Also, the EPA posts some Consumer Confidence Reports online and provides the database, Drinking Water Watch. This searchable database consists of information provided by state agencies regarding drinking water quality for 17 states.
Everyone should learn about the quality of their drinking water. It is especially important for immune-compromised individuals to understand their drinking water quality. These individuals include pregnant women, elderly adults, transplant patients, those with HIV/AIDS, and individuals receiving chemotherapy. If you are in one of these categories, the EPA advises discussing your drinking water quality with your physician because you may be more susceptible to contaminants. For example, according to the EPA, Cryptosporidium (a microscopic parasite) can pass through the filtration and disinfection processes, though this is an extremely rare occurrence. Healthy individuals will not likely experience any symptoms but if you are immune-compromised, you may experience severe or even fatal symptoms. Any individual, healthy or immune-compromised, can take additional precautions by filtering their drinking water with a water purifier that is proven to remove chemical contaminants as well as bacteria, parasites, and cysts from the water.