"Enclose" means, for purpose of 35 Ill. Adm. Code 215.481(c), 215.482(b), 218.481(c), 218.482(b), 219.481(c) and 219.482(b), to cover any volatile organic liquid surface that is exposed to the atmosphere.
Ill. Admin. Code tit. 35, § 211.1990
Added at 17 Ill. Reg. 16504, effective September 27, 1993