415 ILCS 40/1
For the purposes of this Act:
"Public water supply" means all mains, pipes and structures through which water is obtained and distributed to the public, including wells and well structures, intakes and cribs, pumping stations, treatment plants, reservoirs, storage tanks and appurtenances, collectively or severally, actually used or intended for use for the purpose of furnishing water for drinking or general domestic use in incorporated municipalities; or unincorporated communities where 10 or more separate lots or properties are being served or intended to be served; State-owned parks and memorials; and State-owned educational, charitable, or penal institutions.
"Department" means the Department of Public Health.
"Director" means the Director of the Department of Public Health.
"Owners or Official Custodians" means any individual, public or private corporation, political subdivision, government agency, municipality, public or private institution, industry, co-partnership, association, firm, trust, estate or any other entity whatsoever.
415 ILCS 40/1