Remediation, abatement, environmental demolition. Scopes like these require technical expertise to remove unwanted material. While it may seem straightforward, the rise of sustainable practices in the environmental industry as a whole raises concepts of waste reduction or waste recycling. The initial response may be, “How are we supposed to incorporate that concept?” into a scope with a goal of mitigating unwanted material due to potential hazards to public health or the environment. Actually, various methods exist to reduce the volume of material originally destined for waste streams.
The following project is a great example of utilizing multiple approaches to impact various materials being removed from the worksite. The scope was abatement, environmental demolition, and soil excavation to prepare the property, a former railroad right of way (RR ROW), for the construction of a bike and walking path. Work included demolishing approximately 6 miles of railroad track, railroad ties, railroad ballast, and signal equipment. Over 2.5 miles (by 18 feet wide and approximately 24 inches deep) of soil was excavated. Signal equipment was removed from 23 intersection crossings.
Our team provided project, construction, and subcontractor management.
We completed the project on time and under budget. Key to success was open and frequent communication with the entire project team and the community. We held weekly meetings with the project team and more frequent focused meetings with subcontractors. Agency documentation was completed accurately, and community concerns were addressed in coordination with the client community relations team.
Railroad ROWs typically have elevated arsenic and lead levels, and this ROW was no different. Our approach included treating the impacted soil onsite and transporting it as non-hazardous material offsite.
The materials scheduled for removal were diverse, voluminous, and sometimes regulated. Whether the project budget is limited or not, spending is always a primary concern, and this project was no different. Our budget was limited, and we intended to squeeze as much work as possible to clear the RR ROW for future heavy civil construction. At this stage, we evaluated each potential waste material.
By approaching each material and assessing its potential value, we accomplished some fairly incredible feats to keep material out of landfills.
First, the railroad equipment. As it turns out, there is a market for recovered railroad equipment.
The rail ribbons (the “rails”), ties, and ballast can be reused on active RR ROWs. The materials are identified in the field and evaluated for fitness before being recovered. Separating the fit materials from the unfit became a step in our procedure, but our teams were experienced and worked efficiently, and the majority of railroad equipment was put back into service.
The metal recovered included rail ribbons and metal supplies like tie plates, stakes, and signal equipment. The rail ribbons were assessed for fitness and cut into 39-foot sections for reuse. Other metal material was collected for metal recycling. All in all, approximately 556 tons of metal was diverted from landfills.
The RR ROW used heartwood ties. These, too, were evaluated during removal and separated for reuse and solid waste. The project recovered about 522 tons of wood to be put back into service.
The ballast was also assessed onsite. Ballast is an engineered material used to build and provide stability for RR ROWs and therefore has value as a material. Extra processing was required to prepare the material, but we established an efficient and effective method to shake the material to separate the ballast from the soil, thereby increasing the reuse potential. The project recovered 1,360 tons of ballast for reuse.
The soil excavation brought different challenges. Railroad ROWs typically have elevated arsenic and lead levels, and this ROW was no different. Our approach included treating the impacted soil onsite and transporting it as non-hazardous material offsite. The treatment unit held a temporary permit to operate and used a proprietary customized formula to achieve target concentration levels. The soil hauled offsite was valued as cover material for landfills. Over 20,000 tons of impacted soil was delivered to landfills as cover.
This is an impressive diversion rate for a demolition and excavation project!
It took vision to design the scope with the concept in mind, planning to evaluate the potential waste streams and understand which may have a market, planning to devise methods to extract the materials so that they CAN be diverted from a landfill, field management to ensure the methods are followed, and project management to follow through, laying the rules for the project, documenting processes along the way, and drafting summary reports to document the materials’ destinations.
Also, recovering and recycling actually saved the project budget! The soil alone is a great example. Had the project disposed of 20,000 tons of impacted soil without treating it, the project would have spent approximately $1.5M more. The moral of this project is to stay open to alternative methods of your scheduled waste materials. Don’t sleep on the potential of secondary markets, recycling, or onsite treatment.
