A pure water source is essential. If you have well water, it should be tested for common contaminants, including arsenic, nitrates, pesticides, lead, solvents, pathogens and pharmaceuticals. Municipal water supplies are required to meet a federal standard for drinking water, but they may still contain unknown chemicals (contaminants not identified through current testing), lead from pipes or unwanted added chemicals, such as chlorine or fluoride. Fortunately, your water can be filtered in your home or apartment. Under-sink units that use a reverse osmosis process or structured matrix filter are two good choices. And if you own your home, a whole-house filter will remove chlorine from all water sources.
Drinking bottled water is not a perfect solution. Indeed, many bottled water companies are taking water directly from municipal water supplies and not using any additional filtration or purifying processes. And the federal government imposes few regulations on bottled water. Even the plastic bottle may contain harmful chemicals that can leach into the water. If you have concerns about the quality of the water you are drinking, you can buy filtered water or purified water in glass bottles. Better yet, fill glass or stainless steel bottles with your own filtered water.