OAR 340-094-0120
Closure Requirements

If a municipal solid waste landfill is subject to 40 CFR, Part 258 as provided in 40 CFR, §258.1, the owner or operator shall comply with closure and post-closure care requirements in 40 CFR, Part 258, Subpart F. All municipal solid waste permittees shall also comply with this rule for any landfill that closes after January 1, 1980.


When solid waste is no longer received at a municipal solid waste landfill, the person who holds or last held the permit issued under ORS 459.205 (Permit required) or, if the person who holds or last held the permit fails to comply with this section, the person owning or controlling the property on which the landfill is located, shall close and maintain the site according to the requirements of ORS Chapter 459 (Solid Waste Management), all applicable rules adopted by the Commission under ORS 459.045 (Rules) and all requirements imposed by the Department as a condition to renewing or issuing a disposal site permit.


Unless otherwise approved or required in writing by the Department, no person shall permanently close or abandon a municipal solid waste landfill, except in the following manner:


All areas containing solid waste not already closed in a manner approved by the Department shall be covered with at least three feet of compacted soil of a type approved by the Department graded to a minimum two percent and maximum 30 percent slope unless the Department authorizes a lesser depth or an alternative final cover design. In applying this standard, the Department will consider the potential for adverse impact from the disposal site on public health, safety or the environment, and the ability for the permittee to generate the funds necessary to comply with this standard before the disposal site closes. A permittee may request that the Department approve a lesser depth of cover material or an alternative final cover design based on the type of waste, climate, geological setting, degree of environmental impact;


Final cover material shall be applied to each portion of a municipal solid waste landfill within 60 days after said portion reaches approved maximum fill elevation, except in the event of inclement weather, in which case final cover shall be applied as soon as practicable;


The finished surface of the closed areas shall consist of soils of a type or types consistent with the planned future use and approved by the Department. Unless otherwise approved by the Department, a vegetative cover of native grasses shall be promptly established over the finished surface of the closed site;


All surface water must be diverted around the area of the disposal site used for waste disposal or in some other way prevented from contacting the waste material;


All systems required by the Department to control or contain discharges to the environment must be completed and operational.


Closure of municipal solid waste landfills shall be in accordance with the detailed Final Engineered Site Closure Plans approved in writing by the Department pursuant to OAR 340-094-0110 (Closure and Post-Closure Care: Closure Plans).


Closure approval:


When closure is completed, the permittee shall submit a written request to the Department for approval of the closure;


Within 30 days of receipt of a written request for closure approval, the Department shall inspect the facility to verify that closure has been effected in accordance with the approved closure plan and the provisions of OAR 340, divisions 93 and 94;


If the Department determines that closure has been properly completed, the Department shall approve the closure in writing. Closure shall not be considered complete until such approval has been made. The date of approval notice shall be the date of commencement of the post-closure period.

Source: Rule 340-094-0120 — Closure Requirements, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=340-094-0120.

Last Updated

Jun. 8, 2021

Rule 340-094-0120’s source at or​.us