Oregon Revised Statutes Public Health and Safety § 466.160

(1) The hazardous waste treatment, storage or disposal site permit shall require a fee based either on the volume of material accepted at the site or a percentage of the fee collected, or both. The fees shall be calculated in amounts estimated to produce over the site use period a sum sufficient to:

(2) The amount so paid shall be held in a separate account and when the amount paid in by the permittee together with the earnings thereon equals the amount of the financial assurance required under ORS 466.150 (6), the permittee shall be allowed to withdraw the financial assurance.

(3) If the site is closed before the fees reach an amount equal to the financial assurance, appropriate adjustment shall be made and the reduced portion of the financial assurance may be withdrawn.