Industrial Site Waste Soil Remediation

Our confidential client’s objective was to remove known refinery waste disposal areas, backfill and restore them during this phase of the project to prepare the site for sale and redevelopment as an industrial property.
 
Forgen’s client contracted our team as the prime contractor to realize their goals during this effort. The project involved implementing the remedial action (RA) for the waste pit and contaminated soil. The waste materials included other industrial waste (OIW), refinery waste such as tar and debris (e.g concrete, brick, metal, glass), potentially contaminated material (PCM), and environmental media contaminated with contaminants of concern (COCs) at concentrations above applicable surface water remedial action objectives (SWRAOs).
 
These waste materials pose serious environmental and health risks. OIW contains toxic substances like heavy metals (e.g., lead, mercury), Polycyclic Aromatic Hydrocarbons (PAHs), and Volatile Organic Compounds (VOCs). PCM requires assessment due to uncertain hazard levels, while COCs in soil, sediment, or water can harm ecosystems and human health through direct exposure or ingestion. This emphasizes the need for strict remediation efforts on site.

Under the construction contract, a wide array of tasks were completed to revamp the site and uphold environmental standards. Initiatives included constructing temporary access roads for logistical ease, excavating and disposing of waste from designated pits, and remediating asbestos disposal cells with rigorous safety measures. Additionally, a protective cover system was installed over the Southern Disposal Cell (SDC), and significant structures like Building 32 and the Wax Plant Basement were demolished. Utilities were identified, protected, and removed as needed, and water management involved dewatering and treatment processes. The project concluded with backfilling, grading, and meticulous site restoration efforts, all supported by detailed surveying to ensure compliance and accuracy throughout.

Our team successfully executed a comprehensive scope of work in heavy civil construction, starting with the clearing and grubbing of 38 acres of waste pits. We installed approximately 3,900 linear feet of temporary access roads and set up multiple load-out zones at each waste pit. This enabled the excavation and transportation of 350,000 tons of waste and impacted material from 19 waste pits and areas, accomplished over 15,500 truckloads.

Additionally, we managed the removal of 4,500 tons of Asbestos-Containing Materials (ACM) off-site and addressed Other Industrial Waste (OIW) and Potentially Contaminated Material (PCM) within active and inactive utility corridors and a street right-of-way. During the excavations, we effectively controlled stormwater and groundwater.

For the south disposal cell, which covered 10 acres, we installed an engineered cover system. This included a prepared subgrade, side slope repairs using geogrid and structural fill, a geocomposite layer, a low-density polyethylene geomembrane, a composite drainage net, and layers of soil and topsoil with vegetative cover.

Our team installed over 43,812 square feet of rip rap for drainage swales and letdown structures, and an operations layer of over 40,000 tons was placed on top of the liner, followed by 6 inches of topsoil. We hydroseeded over 12 acres on top of the landfill and fitted and raised the access road along the landfill to install three 24-inch HDPE culverts.

Approximately 350,000 tons of waste were generated during the project with the vast majority of waste consisting of non-hazardous contaminated soil generated by the excavation of waste pits onsite. Most excavated soils were direct loaded into trucks for transport to an offsite disposal facility. Segregation is critical at every stage of the project. Segregation of materials was completed to ensure comingling of distinct waste streams did not occur. Forgen optimized the recycling of reusable borrow, recoverable metals (steel, copper, stainless steel, etc.) and recyclable demolition debris (brick and concrete).

Forgen provided, operated, and maintained dewatering sumps of sufficient size and capacity to permit excavation and subsequent construction in the dry and lowered and maintained groundwater levels below the lowest point of excavation. Forgen treated the recovered water in a temporary, mobile Water Treatment System to meet water pre-treatment standards for discharge. Forgen conducted excavation to design lines and grades and coordinated with the post-excavation sampling and backfilling; this program many times required multiple excavation passes based on analytical results. The inordinately high frequency and magnitude of storm events created challenges to maintaining excavated waste pits in-the-dry while treating the associated volumes of stormwater; this was critical for completing the waste pit post-excavation sampling, analysis and backfilling.  

Our responsibilities also included vegetation clearing, stormwater and groundwater pretreatment and transfer, confirmation soil sampling, and the removal of inactive refinery-related pipelines. We backfilled 205,576 cubic yards of structural fill to 95% compaction, added topsoil, and restored each waste pit with hydroseeding. Additional tasks included removing 6 inches of topsoil from 10 acres of temporarily capped landfill, regrading the landfill for proper drainage, and constructing a drainage swale around its perimeter. Comprehensive site restoration also involved asphalt road reconstruction.

Our team’s work on this project promoted long-term environmental and health benefits. By addressing a variety of industrial wastes and potentially contaminated materials, including toxic substances like heavy metals and harmful chemicals, we’ve significantly reduced risks to local ecosystems and human health.

Installing an engineered cover system and removing large quantities of waste from multiple sites not only met regulatory standards, but also promoted environmental stewardship. This proactive approach safeguards the site for future generations by minimizing potential environmental and health risks and supporting sustainable land use practices. Through effective groundwater control, industrial site remediation, and hazardous material removal, we ensured the site was safe and ready for future redevelopment.

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