The U.S. Environmental Protection Agency’s standards for lead content in plumbing materials and fixtures underwent significant improvements in 1987, with the intention of reducing the potential for lead contamination of drinking water. Therefore, ADEQ, in consultation with Arizona Department of Health Services (ADHS), the Arizona School Facilities Board (SFB) and the Arizona Department of Education (ADE), focused the screening program on school buildings constructed prior to 1987, before the more protective construction standards went into effect. The screening program also included schools located in areas ADHS identified as at high risk for childhood lead poisoning, as well as schools educating children five years of age and younger. Because lead in drinking water may not be a problem limited to older buildings, the screening program also included a limited number of newer school buildings constructed per the current lead plumbing requirements to verify the standards are in fact protective and not impacting drinking water.

The number of public school district buildings targeted in the initial scope of the screening program approached 7,000.