Outdoor Wood Boilers 

There are a number of Ramsey residents in the rural areas of the city that use exterior solid fuel-fired heating devices (also known as outdoor wood boilers or hydropic heaters) as a primary heating source and indoor wood-burning fireplaces as a secondary heating source during the winter months to help ease the burden of the cost of other fuel sources. This is a common practice among rural communities throughout the state of Minnesota. The past few years, it has become more of a health concern for a few Ramsey residents living in proximity to properties using outdoor boilers. The concerns stem from the woody smell entering their homes and even the constant heavy smell of burning wood outdoors. At times, it smells like the residents may be burning illegal materials such as green-treated wood and/or trash. 
 

Due to the complaints the City received this past winter, the City Council reviewed the current regulations in City Code at their February 25, 2025, work session meeting (minutes are attached).  One of the outcomes of the City Council discussion was to have the Environmental Policy Board (EPB) consider the current City Code regulations for outdoor wood boilers and to determine if any amendments may be warranted to potentially improve air quality where these units are in use.  However, it is important to understand that any code amendments related to outdoor wood boilers would only be applicable to new units being installed.  Any code amendments would not impact existing outdoor wood boilers that were installed in accordance with the regulations at the time of installation, as these would be considered lawful non-conforming units.

Ramsey City Code Section 106-334 (attached for your review) outlines the current regulations. City Code requires these outdoor boilers to be setback 75 feet from any property line, restricts them to only the side or rear yard of a property, and identifies materials not to be used or burned.  Additionally, the City's Nuisance Chapter in City Code states that dense smoke, noxious fumes, gas and soot, or cinders in unreasonable quantities are considered to be a nuisance.  Finally, installation of an outdoor wood boiler does require a mechanical permit through the Building Division.  There have been no permits issued for new systems in the past several years. 

Above and beyond the City's regulations, approximately ten years ago, the Environmental Protection Agency (EPA) developed New Source Performance Standards (NSPS) pertaining to outdoor wood boilers (attached).  Beginning in May 2020, all outdoor wood boilers sold or installed in Minnesota must comply with the 2020 emission standards.  These standards result in more efficient devices with significantly reduced emissions compared to older units. 

Ramsey has long sought to maintain a balance between rural character and urban growth, which is identified as one of the primary objectives in the 2040 Comprehensive Plan.  There does not seem to be any desire to ban outdoor wood boilers, and there was no specific direction to amend City Code to further restrict these devices.  However, if the EPB feels that more stringent standards may benefit those in proximity to an outdoor wood boiler, some potential considerations for code amendments could include:

• Restricting them to only the Rural Residential and MUSA Reserve zoning districts.
• Increasing the setback distance.
• Requiring a minimum stack height (typically, this would include a minimum stack height above ground and a requirement that it be 2-5 feet taller than the peak of surrounding homes within a specified distance of the boiler).  However, for optimal operation, the units should not be altered (at least not beyond the manufacturer's recommendations).
• Rather than specifying what cannot be burned, modify the language to specify what can be used as fuel in these outdoor boilers (such as seasoned cord wood, wood pellets made from clean wood, corn, other materials as authorized by the Minnesota Pollution Control Agency).

This case is being handled as part of Staff's regular duties.

Staff does not have a recommendation.  This case is intended to solicit feedback from the EPB on whether any additional standards should be considered by the City Council for outdoor wood boilers.

Based on discussion.