Digging Deep
June 03, 2025
When the Orlando Utility Commission (OUC) needed to repurpose a historic site for a new electrical substation, the challenge of clearing decades-old debris required expertise, precision and innovative problem solving. Pece of Mind Environmental, an NDA member headquartered in Orlando, Florida, rose to the occasion and delivered a project that met the high standards of safety, sustainability and efficiency.
OUC tasked Pece of Mind Environmental with clearing the remnants of an old power plant, demolished and buried on-site over 35 years ago. The project began in February 2021 and was completed in January 2022. While the power plant’s history and remnants posed significant challenges, Pece of Mind Environmental’s team utilized ingenuity and cutting-edge equipment to navigate the complexities.
One of the unique aspects of this project was the absence of as-built plans to delineate the limits of the former power plant. Pece of Mind Environmental relied on old aerial photos, surveys and even newspaper archives to determine the extent of the buried debris field. Once the outer limits were identified, the team conducted test pits to confirm the depth and size of the basement structure — ultimately revealed to span 200 feet wide, 500 feet long and 15 feet deep.
The team then phased debris removal to manage the vast area efficiently, maintaining a staging area for screening debris and maximizing soil reuse for backfilling.
A range of heavy equipment was mobilized to tackle the project:
- Volvo 480 excavator
- 2 Cat 336 excavators
- Kobelco 210 excavator
- Cat D5 dozer
- Komatsu D51 GPS dozer
- Cat 730 end dump truck
- McCloskey R230 screen plant
This fleet enabled efficient excavation, debris screening and site grading.
Execution Steps
- Site clearance: The team began by removing all known infrastructure, including underground stormwater piping, electrical duct banks, and various concrete slabs and footers.
- Excavation and investigation: Careful excavation exposed the limits of the basement and debris field, followed by the installation of a dewatering system to ensure proper compaction during backfilling.
- Recycling and soil reuse: Pece of Mind Environmental screened the debris, achieving an impressive 99.99% recycle rate, including 45,000 cubic yards of concrete.
- Safety and structural integrity: Sheet piling was installed in areas with significant elevation changes to prevent undermining adjacent properties. Additionally, a 90-inch stormwater outfall pipe, abandoned for 40 years but still connected to a lake, was meticulously inspected using robotic technology and permanently capped to prevent flooding.
Overcoming Challenges
Several hurdles tested the team’s expertise:
- Petroleum contamination: Localized contamination required a carefully designed dewatering system to avoid discharging polluted effluent.
- Elevation variations: Significant elevation changes necessitated sheet piling to stabilize the site.
- Stormwater pipe risks: Ensuring the integrity of the outfall pipe was critical to avoid turning the site into a lake.
A Model of Success
Pece of Mind Environmental’s team of 10 crew members logged 10,000 manhours with zero injuries, completing the project on time and within budget. The company also imported 55,000 cubic yards of clean fill to return the sitwe to its original elevation, ready for the new substation.