Editors' Summary: In mid-1997, the Illinois Pollution Control Board promulgated two rules that will affect the way contaminated sites are cleaned up in the state: the Tiered Approach to Corrective Action Objectives (TACO) rule and the Illinois Site Remediation Program (voluntary cleanup program) rule. This Article describes the TACO and voluntary cleanup program rules and the changes they make. The Article first gives some background on how cleanups were formerly conducted in Illinois. Next, the Article discusses the TACO rule and its corresponding "tiers" of cleanup objectives, including its approach to remediating contaminated groundwater. The Article then discusses the voluntary cleanup program rule, and concludes with an assessment of the new rules' impact.