Railroad Ties: An Essential Biomass Fuel

Millions of railroad ties are replaced every year in the United States – enough to fill an entire football field, seventy stories high, according to industry estimates. One-third of these used ties are ground up for landscaping mulch, with the remainder sold as biofuel for creating electricity and heat. Biomass Power Association members are some of the largest consumers of this fuel.

The benefits of railroad tie fuel (RTF) are compelling. The used ties allow biomass boilers to operate more efficiently by complementing higher moisture fuels like forestry residues. The results of using RTF in biomass power production include:

  • Enhancing healthy forests,
  • Promoting recycling for urban wood,
  • Allowing states to meet renewable energy goals, and
  • Reducing methane emissions that would otherwise occur if the ties were left to decompose or be landfilled.

As a result of a 2006 case—Natural Resources Defense Council v. the US Environmental Protection Agency—EPA was forced to develop regulations to define what is a “fuel” and what is a “waste.” Earlier this year, the Agency issued a draft rule clearly designed to encourage the continued use of railroad tie fuel. The Agency noted the fuel value of railroad ties as a “nonhazardous biomass alternative to fossil fuel.” Nevertheless, the Draft Rule creates a convoluted test—called the “legitimacy criteria”—that has the net effect of disqualifying potentially 80% of all railroad tie fuel used by the biomass industry.

EPA’s proposal limits the use of RTF to boilers that are also equipped to burn fuel oil because fuel oil has so-called “contaminants” at levels that are similar to those found in railroad ties. As a result, only boilers that currently, or at one time, have installed a fuel oil delivery system can use railroad ties. This disregards the key facts that (1) the emissions are the same whether a boiler co-fires railroad ties with natural gas or fuel oil or burns the ties alone, and (2) the Agency has, for years, encouraged the energy sector to replace fuel oil with cleaner burning natural gas. The net effect of the proposed rule would be to restrict railroad ties to only boilers currently (or formerly) equipped with fuel oil delivery mechanisms.

For boilers that do not fit into this category—and there are many—the industry will be forced to stop burning railroad ties or spend millions of dollars to install oil delivery systems that will never be used and whose only purpose is to meet a regulatory criterion. Regardless of whether the boiler uses natural gas or fuel oil, the environmental performance is identical. So for identical boilers using railroad ties—the one co-firing with natural gas will be considered using a “waste” while the other co-firing with fuel oil will be considered a “fuel.”

In fact, if EPA’s Draft Rule is adopted in its current form, the environment is ultimately the loser. If railroad ties cannot be used for energy, their fate is a landfill. The discarded material would take up millions of cubic feet of landfill space and decompose over time, creating 1.65 million tons of greenhouse gases annually.


EPA needs to adopt a final rule that takes into account the environmental and clean energy benefits of railroad tie fuel, while relying upon federally enforceable state air permits to assure that use is protective of the public health.