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Environmental Contaminants

Delaware & Lehigh Trail | Photo by Thom Carroll

Railroads are required to submit an environmental report to the Surface Transportation Board (STB) when they begin the process of abandoning a corridor. If the STB finds that salvaging the line will result in significant environmental impacts, they can impose conditions on the abandoning railroad requiring them to address the issues before abandonment can proceed. Nevertheless, communities developing rail-trails occasionally have to deal with known, potential or perceived contamination along the corridor.

Fortunately, contamination does not necessarily prevent the development of rail-trails as long as appropriate 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.

Types of Contaminants

The type and extent of contamination along rail corridors fall into two general categories: residual contamination that may be found along any stretch of corridor and contamination associated with industrial uses alongside it. Before and after acquisition, you should be aware of the following potential contaminants:

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. Designate a qualified person to regularly inspect the trail to identify potential hazards.
  9. Use signage and fencing, where needed, to protect trail users.

Addressing Common Concerns 

The chemicals that railroad ties are treated with can pose a problem to trail development. One common treatment is creosote, 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 disposed of immediately as municipal solid waste. Railroad ties coated in creosote are not intended for use in landscaping and should not be used along the trail.

Wood coated in chromated copper arsenate (CCA), which appears green, can be even more dangerous. This preservative protects against rotting with chromium, copper and arsenic, and it is a common alternative to creosote for treating railroad ties. The arsenic in the wood is toxic, making it a danger to plants and wildlife that have prolonged contact with it. CCA- treated railroad ties should be disposed of through municipal means.

Soil surveys may come back with other severe issues such as lead and arsenic. These harmful chemicals can be left behind in freight 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.


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.


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

‣ Manual – Best Management Practices for Controlling Exposure to Soil during the Development of Rail-Trails

‣ Article – Considering Contamination in a Rail-Trail Conversion

TrailNation Collaborative

TrailNation Collaborative is a nationwide peer learning community from Rails-to-Trails Conservancy that brings together advocates, leaders and professionals from across disciplines to establish and accelerate trail networks across America. The collaborative provides proven tools, methods and resources, combined with RTC’s expertise and network of partners across the country, to accelerate the development of connected trail systems. When trails are connected across regions and states, trail networks have a proven transformative impact—they are essential infrastructure that creates thriving, healthier communities.

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