Treated Wood Waiver Form Templates
The State Aid Bridge Office, under advisement from the MnDOT Office of Environmental Stewardship and significant assistance, input and vetting from the timber industry, has developed a treated wood waiver letter for local agencies to use as a template on projects that contain treated wood, and where they wish to waive the use restrictions set forth in MnDOT’s approved preservatives for the treatment of timber products Table 1 and Product definition and MnDOT use restriction of approved wood treatments Table 2.
The Treated Wood Template Waiver forms will allow timber bridge owners to use a wider variety of preservative treatments that have been adopted by both the AASHTO and EPA for their project application. It gives the local owner the ability to consider factors such as environmental risk, cost, and durability in their final selection of wood preservatives, all with the understanding they can discuss the potential environmental liability associated with their selection of wood preservative with the MnDOT Office of Environmental Stewardship at any time.
Below are three distinct treated wood waiver form templates based on structure type for local agencies to choose from: Timber Vehicular Bridges, Pre-fabricated Pedestrian/Bicycle Bridges or Timber Boardwalks. Each template will have a list of recommended wood preservatives specific to the structure type. We are confident the template waiver forms will stimulate better coordination between the owner, owner’s consultant, treated wood supplier and State Aid Bridge during plan preparation activities.
Note that these waiver form templates may only be utilized on locally owned treated wood structures that are not located within MnDOT Right of Way. Conformance with MnDOT Approved/Qualified Products is required for any use of treated wood within MnDOT Right of Way.
- Waiver form template for pre-fabricated pedestrian/bicycle bridges (Word)
- Waiver form template for timber boardwalks (Word)
- Waiver form template for timber vehicular bridges (Word)
The following is a list of informational websites regarding wood and wood treatments.
- American Wood Protection Association
- Western Wood Preservers Institute
- Preservation Treatment Summary - Forest Products Laboratory (PDF)
The following is a summary table of common preservatives used in treatment of wood products. This table was developed in cooperation with local area treated wood suppliers and is provided for informational purposes only. This information should not be used exclusively when determining the appropriate preservative(s) for a specific project. The above-mentioned websites as well as your local area treated wood suppliers can provide additional helpful information. Also, refer to the MnDOT Approved/Qualified Products Treated Wood webpage for a list of approved preservative treatments and associated use restrictions to be followed on projects within MnDOT Right of Way. Contact the MnDOT Office of Environmental Stewardship at 651-366-3617 to discuss any potential environmental liability associated with your selection of wood preservatives.