While bottled water marketing conveys images of purity, inadequate regulations offer no assurance. Sales of bottled water in this country have exploded in recent years, largely as a result of a public perception of purity driven by advertisements and packaging labels featuring pristine glaciers and crystal-clear mountain springs. But bottled water sold in the United States is not necessarily cleaner or safer than most tap water, according to a four-year scientific study recently made public by NRDC.

National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards protect public health by limiting the levels of contaminants in drinking water. Visit the list of regulated contaminants with links for more details.