In Illinois, all school buildings constructed prior to January 1, 1987, must have every drinking water source tested for lead prior to December 31, 2017. (225 ILCS 320/29). A school building is defined as any building (or portion of a building) that may be occupied by more than 10 children or students, pre-kindergarten through grade 5, under the control of a school district or a public, private, charter, or nonpublic day or residential educational institution. The law requires testing for lead at each source of potable water, meaning where there is non-bottled water that may be ingested by children or used for food preparation, such as taps, faucets, drinking fountains, wash basins in a classroom occupied by children or students under grade 1, or similar points of use. School buildings constructed after January 1, 2000 are excluded from the potable water testing requirement, as well as bathroom sinks and wash basins used by janitorial staff.

If any of the samples taken in the school buildings exceeds 5 parts per billion, the School District or Chief School Administrator, or their designee, must “promptly provide an individual notification of the sampling results, via written or electronic communication, to the parents or legal guardians of all enrolled students and include the following information: the corresponding sampling location within the school building and the United States Environmental Protection Agency's website for information about lead in drinking water.” (225 ILCS 320/35.5(c)(3)). If any of the samples taken at the school are at or below 5 parts per billion, notification may be made by posting on the school’s website or, if desired, by individual notifications as would be done if the samples exceed 5 parts per billion.

If sampling is not timely completed, the Illinois Department of Public Health may refer the matter for enforcement. For school buildings constructed between January 2, 1987 and January 1, 2000, the deadline for sampling is December 31, 2018.