(2) For the purposes of this section, "avoidable pollution" or "avoidable contamination" means pollution or contamination arising from:
(a) The acts or omissions of the lessee or its officers, employees or agents; or
(b) Events that could have been prevented by the lessee or its officers, employees or agents through the exercise of a high degree of care. [1961 c.619 §18; 1967 c.421 §171]