http://water.epa.gov

http://water.epa.gov/drink/contaminants/index.cfm [Accessed: 19.12.2011]

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.