Soil Contamination 101: What Facility Managers Need to Know
By Bodhi Hale, Director of Environmental Science/Technology (Tulsa, OK)
Bodhi Hale holds bachelor’s degrees in both environmental biology and zoology from Oklahoma State University (Stillwater). His professional work centers on regulatory compliance, environmental risk mitigation, and the practical application of data-driven tools to support sustainable operations across industrial sectors. Hale emphasizes the integration of scientific rigor with real-world compliance solutions, advocating for proactive environmental management strategies that protect human health, preserve ecological integrity, and support long-term operational sustainability. His passion for environmental protection was instilled at an early age through exposure to horticulture and land stewardship, shaping a lifelong interest in the complexity and resilience of natural systems.
Soil contamination is one of the most persistent and underestimated environmental challenges facing industrial, commercial, and agricultural facilities today. Unlike air or water pollution, which is often visible or immediately regulated through continuous monitoring, soil contamination can remain hidden for decades, accumulating beneath the surface until it results in regulatory action, liability, or human health impacts. The purpose of this article is to provide a foundational, scientifically grounded overview of soil contamination, why it matters to regulated facilities, and how organizations can proactively manage risk through informed environmental stewardship.
As environmental regulations continue to evolve, facilities are increasingly expected to understand not only what contaminants are present in their operations, but also how those substances interact with soil systems over time. Soil serves as a critical interface between industrial activity, groundwater, ecosystems, and human exposure pathways. Failure to properly manage soil quality can lead to costly remediation, operational disruptions, and long-term reputational damage.
Understanding Soil Contamination
Soil contamination occurs when hazardous substances are introduced into the soil at concentrations that exceed natural background levels and pose risks to human health or the environment. These contaminants may originate from industrial processes, waste disposal practices, accidental releases, historical land use, or improper storage of chemicals. Common soil contaminants include petroleum hydrocarbons, heavy metals such as lead and arsenic, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and per- and polyfluoroalkyl substances (PFAS).
Once contaminants enter the soil, they do not remain static. Physical, chemical, and biological processes influence how contaminants migrate, degrade, or persist. Factors such as soil texture, organic matter content, pH, and moisture play a significant role in determining contaminant mobility and bioavailability. For example, sandy soils may allow contaminants to migrate more readily toward groundwater, while clay-rich soils may bind certain metals more tightly, reducing immediate mobility but increasing long-term persistence.
Sources of Soil Contamination at Facilities
Industrial and commercial facilities can contribute to soil contamination through both active operations and historical practices. Common sources include underground storage tanks, aboveground storage tank leaks, pipeline failures, loading and unloading areas, waste handling zones, and unpaved chemical storage areas. Even facilities that operate in compliance today may face soil contamination issues stemming from legacy operations conducted before modern environmental regulations were enacted.
In agricultural and land management settings, repeated application of fertilizers, herbicides, and pesticides can result in the accumulation of contaminants in soil over time. Similarly, landfills and waste disposal sites may release leachate containing hazardous constituents that migrate into surrounding soils.
Importantly, soil contamination is not always the result of a single release event. Chronic, low-level discharges such as drips, spills, or improper housekeeping practices can collectively create significant environmental liabilities if left unaddressed.
Regulatory Framework Governing Soil Contamination
In the United States, soil contamination is regulated through a combination of federal and state programs. At the federal level, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, establishes liability for releases of hazardous substances into the environment, including soil. The Resource Conservation and Recovery Act (RCRA) governs the management of hazardous waste and corrective action requirements for contaminated soil at permitted facilities.
State-level programs often impose additional requirements, including soil cleanup standards, site assessment protocols, and reporting obligations. Many states operate voluntary cleanup or brownfield programs designed to encourage the investigation and remediation of contaminated properties while limiting liability for responsible parties who comply with program requirements.
Facility management should also be aware that soil contamination can trigger obligations under other regulatory programs, including groundwater protection rules, stormwater permitting requirements, and property transfer disclosures. Understanding how these regulatory frameworks intersect is critical for effective compliance management.
Human Health and Environmental Impacts
The significance of soil contamination lies in its potential to create exposure pathways that affect both human health and ecological systems. Humans may be exposed to soil contaminants through direct contact, ingestion of contaminated soil or dust, inhalation of volatilized compounds, or consumption of food grown in contaminated soil. Workers at industrial sites and residents near contaminated properties are often the most at risk.
Environmental impacts can include reduced soil fertility, toxicity to plants and soil organisms, and contamination of surface water and groundwater resources. Once contaminants migrate into groundwater, they can spread far beyond the original source area, increasing the scope and cost of remediation efforts.
Because many soil contaminants persist for long periods, the impacts are often cumulative rather than immediate. This delayed risk profile makes proactive management essential, as problems discovered later are typically more complex and expensive to resolve.
Site Assessments and Soil Investigation
The primary method for identifying and evaluating soil contamination is the environmental site assessment process. Phase I Environmental Site Assessments (ESAs) are designed to identify recognized environmental conditions based on historical records, site inspections, and interviews. While Phase I ESAs do not involve sampling, they often serve as the gateway to more detailed investigations.
Phase II ESAs involve the collection and laboratory analysis of soil samples to confirm the presence, concentration, and extent of contamination. Data generated during this phase is used to compare contaminant levels against regulatory screening criteria and to assess potential risks. In some cases, additional delineation or Phase III remediation planning may be required.
Managers who conduct routine soil monitoring as part of their environmental management programs are better positioned to identify issues early and demonstrate due diligence to regulators and stakeholders.
Remediation and Risk Management Strategies
When soil contamination is identified, remediation strategies are selected based on contaminant type, concentration, site conditions, and intended land use. Common remediation approaches include excavation and disposal, soil stabilization, soil washing, bioremediation, and monitored natural attenuation. In some cases, institutional controls such as land use restrictions or engineering controls may be used to manage risk without full removal of contaminated soil.
From a compliance perspective, prevention remains the most effective strategy. Implementing secondary containment, conducting routine inspections, maintaining accurate chemical inventories, and training employees on spill prevention and response can significantly reduce the likelihood of soil contamination. Environmental management systems that integrate soil protection into broader compliance and sustainability efforts allow facilities to move from reactive remediation to proactive risk reduction.
Soil contamination represents a complex intersection of environmental science, regulatory compliance, and operational risk. For facility management, understanding the sources, impacts, and regulatory implications of soil contamination is no longer optional but a fundamental component of responsible environmental management. By proactively assessing soil conditions, implementing strong preventive controls, and responding decisively when contamination is identified, organizations can protect human health, safeguard environmental resources, and reduce long-term liability. Ultimately, informed soil stewardship is not only a regulatory obligation but a critical investment in sustainable operations and environmental integrity.