As used in RCW 70A.15.6200 through 70A.15.6220, the following terms have the following meanings.

(1) "Acid deposition" means wet or dry deposition from the atmosphere of chemical compounds with a pH of less than 5.6.

(2) "Critical level of acid deposition and lake, stream, and soil acidification" means the level at which irreparable damage may occur unless corrective action is taken.