Trihydro provided environmental support for the characterization, remediation, demolition, closure, and sale of a decommissioned fuel oil/natural gas power plant. Located in a high-traffic area surrounded by retail and dining outlets, the site was the subject of considerable public interest and regulatory attention. Trihydro partnered with the client and regulators under a Resource Conservation and Recovery Act (RCRA) voluntary clean-up framework and proactively established routine project meetings, which helped keep interested parties up-to-date and facilitated timely regulatory approvals.
To understand feature-specific impacts (e.g., fuel tanks, points of discharge, leach fields, and waste disposal areas) and site-wide conditions (e.g., pesticide use), Trihydro reviewed environmental data and site operations and performed a soil data gap analysis. Regulators accepted the resulting Soil Data Gap Investigation Work Plan ahead of schedule and with minimal comment. Trihydro then executed a soil investigation using a phased approach that reduced the number of drilling locations by more than 95%, saving the client an estimated $100,000. The soil investigation demonstrated that soil chemical conditions were suitable for commercial or industrial use across most of the site, including several areas with suspected impacts. The project team defined the nature and extent of soil impacts and proposed a remediation strategy (which regulators accepted without comment) that expedited beneficial reuse of accessible and valuable portions of the property.
Through a groundwater characterization program that included monitoring wells and routine sampling for metals, hexavalent chromium, and general minerals, Trihydro demonstrated that historical site operations did not cause unacceptable impacts to groundwater. In a Groundwater Current Conditions Report, Trihydro documented current hydrogeologic and water quality conditions and recommended no further groundwater investigation as well as phased well destructions. Regulators accepted the report with no comments.
Trihydro performed characterization and remediation activities in close coordination with a separate team that was concurrently demolishing the former power plant’s infrastructure. Trihydro partnered with the demolition team to address environmental issues that affected, or resulted from, demolition activities. After the demolition team demobilized, contamination was discovered in the surrounding soil. Trihydro demolished the power plant’s heavily reinforced foundation and several other features to access the soil.
Altogether, Trihydro removed multiple waste streams associated with investigation and demolition, including:
- 2,500 tons of hazardous and non-hazardous waste soil
- 2,600 tons of reinforced concrete debris (recycled)
- 470 tons of non-friable asbestos waste transite
- 100 tons of scrap metal (recycled)
- 15,000 gallons of hazardous and non-hazardous wastewater
Throughout investigation and demolition, Trihydro prioritized environmental protections and sustainability. For example, the project team selected drilling methods that minimized waste generation, identified waste reuse options (as opposed to landfill disposal), and supported the local economy by teaming with local subcontractors.
The project involved several other areas of environmental work, including:
- Performing biological surveys across the site to identify and implement protective measures for indigenous special-status plant and animal species
- Conducting a feasibility analysis of alternatives to off-site disposal for total petroleum hydrocarbon (TPH) impacted soil, including biological treatment and new thermal treatment technology available on a mobile platform
- Collecting and reporting greenhouse gas emissions (GHG) and other sustainability metrics, leading to the ability to document GHG reductions of 68 metric tons (as carbon dioxide equivalent)
- Establishing a waste management process through which hazardous and non-hazardous wastes were stored, transported, and disposed of efficiently and in compliance with laws, rules, and regulations
- Obtaining regulatory approval for a screening process that allowed for expedited decision-making for on-site reuse or off-site disposal of soil waste, which provided schedule, cost, and GHG emissions advantages over traditional waste management practices