For purposes of this article, and for purposes of Section 16722 of the Government Code as applied to this article, the following definitions apply:

1. (a) “Board” means the department.
2. (b) “Committee” means the Hazardous Substance Cleanup Committee created pursuant to Section 78295.
3. (c) “Director” means the director.
4. (d) “Fund” means the state account.
5. (e) “Orphan site” means a site with a release or threatened release of a hazardous substance with no reasonably identifiable responsible parties.
6. (f) “Orphan share” means those costs of removal or remedial action at sites with a release or threatened release of hazardous substances, which costs are in excess of amounts included in a cleanup agreement.
7. (g) “Responsible party” means a person who is, or may be, responsible or liable for carrying out, or paying for the costs of, a removal or remedial action.