US lawIllinoisRegulationsTitle 35 — ENVIRONMENTAL PROTECTIONCHAPTER I: POLLUTION CONTROL BOARDPart 301 — INTRODUCTION301.42035 Ill. Adm. Code 301.420Underground WatersYear: 2026Length: 21 wordsOfficial source Section 301 Section 301.420 Underground Waters "Underground Waters" means any waters of the State located beneath the surface of the earth.Previous35 Ill. Adm. Code 301.415Next35 Ill. Adm. Code 301.421