shop   |   eNews   |   find a trail Better Business Bureau Accredited Charity
Share this page:
Former railroad corridor in Washington, DC.
Many railroad corridors exist near areas with potential environmental contamination.


Contaminant – Any physical, chemical, biological or radiological substance such as an element, compound, mixture, solution, etc., that can be found in any media (air, water, soil) and may be harmful to human health or have adverse effects on the environment.

Phase I – This phase of corridor assessment includes research on the history of the property and a visual inspection of the space.

Phase II – This phase of corridor assessment includes testing and sample-based (water testing, soil samples, etc.) research to find the overall severity of the problem and inform Phase III. This phase of assessment may cost $20,000 or more to conduct.

Phase III – This phase of corridor assessment considers the results of Phase II and determines the best way to proceed with trail construction.

Trails glossary and acronyms.


RTC Resources

Understanding Environmental Contaminants: Lessons Learned and Guidance to Keep Your Rail-Trail Project on Track

Ask Our Listserv:
Learn about trail development from the experts! Join our listserv to be connected to more than 900 trail managers, advocates and builders across the country.

Visit RTC's Trails and Greenways Publication Library

For more information, please contact the appropriate regional or national office.


Additional Resources

Considering Contamination in a Rail-Trail Conversion: The National Transportation Alternatives Clearinghouse (formerly the National Transportation Enhancements Clearinghouse) newsletter from 2004 with tips and case studies concerning trail contaminants.

Best Management Practices for Controlling Exposure to Soil during the Development of Rail-Trails: Massachusetts Department of Environmental Protection's how-to on soil exposure.  

More information about Brownfields and Land Revitalization from the EPA


Corridor Research

Environmental Contaminants

Communities wishing to convert rail corridors into multi-use trails sometimes find themselves in the difficult position of dealing with known, potential or perceived contamination along a railroad corridor. However, contamination does not usually prevent the development of rail-trails as long as necessary steps are taken to ensure safety to trail users. Whenever there are environmental concerns about land acquisition, an expert in the field should be consulted.

What types of contamination are along rail corridors? The type and extent of contamination falls into two general categories: residual contamination that may be found along any stretch of corridor, and contamination associated with industrial uses along the corridor. When acquiring a railroad corridor, you will want to be aware of the following contaminants:

  • Railroad ties, usually treated with chemicals such as creosote
  • Coal ash and cinder containing lead and arsenic
  • Spilled or leaked liquids such as oil, gasoline, cleaning solvents, etc.
  • Herbicides
  • Fossil fuel combustion products (PAHs)
  • Roofing shingles (asbestos)
  • Air compressors
  • Transformers and Capacitors
  • Metals

Steps to take

  1. Conduct due diligence and inventory potential hazards along the corridor. This could include a Phase I and Phase II environmental assessment.
  2. Analyze the potential adverse health effects caused by found substances.
  3. Determine what, if any, mitigation steps need to be taken and examine the risks and benefits of remedial alternatives.
  4. Provide information needed by regulators and the public.
  5. Design and route the trail to avoid dangers.
  6. Follow state and federal laws.
  7. Create a comprehensive management plan that includes risk management for the open trail.
  8. A qualified person should regularly inspect the trail to identify potential hazards and maintenance problems.
  9. When needed, use signage and fencing to protect trail users.

Addressing Common Concerns 

When converting a railroad corridor into a trail, the chemicals that railroad ties are treated with often pose a problem. One common treatment is creosote, which is a commercial wood preservative. It is used as an insecticide, sporicide, miticide and fungicide that penetrates deeply into pressure-treated wood for a long time. If the railroad ties are old, creosote may ooze out, leeching the soil and killing plants, insects and small animals. Creosote also pollutes the local watershed and can be dangerous to health with prolonged or frequent contact. Wood oozing creosote should be treated as hazardous waste. Such materials should be disposed of immediately, either by burning them at high temperatures or having them crushed at a municipal waste facility. Some trail managers cite using in-tack ties in landscape construction. This should be done minimally, carefully and in full awareness of the dangers of creosote.

Chromated copper arsenate (CCA)-treated wood, which appears green, can be even more dangerous. This preservative protects against rotting with chromium, copper and arsenic. It once had residential uses but was then deemed too dangerous. However, it is still used in some commercial structures, including railroad ties. The arsenic in the wood is acutely toxic, making it a danger to consume in any way: through ash, sawdust, leeched water, etc. CCA- treated railroad ties should be disposed of immediately through municipal means. For more information about this pressurized wood treatment, see the EPA's overall CCA risk assessment.

Soil surveys may come back with another severe issue—lead and arsenic. These harmful chemicals can be left behind in once busy corridors, as they are produced from coal ash and cinder. Severity and depth can be determined by continued soil surveys. Solutions range from removal and replacement of top soil or clay, to the construction of an impervious surface over the area. This remediation can prevent further leeching or harmful contact for trail users and trail neighbors.

For more information, refer to Rails-to-Trails Conservancy's report, Understanding Environmental Contaminants: Lessons Learned and Guidance to Keep Your Rail-Trail Project on Track .

Return to Toolbox >>

Rails-to-Trails Conservancy
The Duke Ellington Building
2121 Ward Ct., NW
5th Floor
Washington, DC 20037