The Illinois legislature approved, and Gov. Bruce Rauner (R) is expected to sign, legislation requiring tests for lead in drinking water in the state’s schools and day-care centers.

On the final day of the Illinois 99th General Assembly, the Illinois House and Senate Jan. 10 voted to approve SB 550, a bill that requires testing for lead at certain school buildings or facilities under the control of a school district or a public, private, charter or non-public day or residential educational institution built before Jan. 1, 2000.

If lead concentrations exceed 5 parts per billion, the facility must provide...