Management of Treated Wood
This guidance document is prepared by MnDOT personnel and is intended only for use on MnDOT projects, including partnership projects, and MnDOT Maintenance Operations.
MnDOT has prepared this guidance document to provide its internal procedures and requirements for work performed on MnDOT rights of way, including MnDOT-owned facilities.
Any optional procedures will be indicated in the document. Any deviation from procedures contained in this document must be discussed with Regulated Materials Unit personnel prior to implementation.
This document should not be construed as a full description of all regulations pertaining to the subject matter. Contact the Regulated Materials Unit in the MnDOT Office of Environmental Stewardship for additional information or legal requirements.
Treated wood is regulated by the Minnesota Pollution Control Agency. Chemicals used to preserve wood may be toxic and could impact the environment through normal use or disposal if not properly managed. MnDOT is responsible for proper disposal of treated wood products that have been taken out of service or are a waste.
Examples of Treated Wood
Sources of treated wood include but are not limited to the following: creosote, pentachlorophenol, CCA (chromated copper arsenate or green treat), ACQ (alkaline copper quat), CA (copper azole), borate, copper naphthanate and disodium octaborate tetrahydrate.
Disposal and Recycling Requirements Landfill
Treated wood can be disposed of in MnDOT approved landfills. Approved landfills include MPCA permitted mixed municipal solid waste landfills and MPCA permitted industrial waste landfills. Do not dispose in MPCA permitted demolition landfills. Some of these landfills have a more stringent acceptance policy and may not accept some types of treated wood. MnDOT approved list of waste contractors.
Any treated wood may be reused for beneficial purposes provided that it is in a condition where it is reusable in its original form or in a secondary application such as fence posts or landscaping timbers. Treated wood cannot be chipped and used as mulch or as wood chips.
MnDOT can transfer ownership to another entity outside of MnDOT for beneficial reuse. This must be documented with a treated wood transfer of ownership form.
Records must be maintained that indicate the type of treated wood, quantity, date and disposal location. Types of record documentation include manifests, invoices, or scale tickets. If the treated wood is beneficially reused by another entity outside of MnDOT, a completed and signed Transfer of Ownership Form is an acceptable management record.
There are no transportation restrictions for treated wood materials.