Industrial sites often carry a legacy of soil contamination – a critical concern for developers, regulators, and environmental consultants. From heavy metals to hydrocarbons, these pollutants can impact human health, delay construction, and increase remediation costs. This article answers five commonly asked questions about what causes soil contamination in industrial areas.

What Are the Most Common Sources of Soil Contamination?

Industrial activities like manufacturing, fuel storage, and chemical processing are leading sources of contamination. Historical land use plays a big role – former gasworks, tanneries, and workshops often leave behind heavy metals, petroleum hydrocarbons, solvents, or polycyclic aromatic hydrocarbons (PAHs) in the soil. Improper waste disposal and leaky underground storage tanks are also major contributors.

How Do Contaminants Enter the Soil?

Contaminants reach the soil through direct spills, leaks, or improper storage of hazardous materials. Rain can wash surface pollutants into the ground, and some substances seep downward from old infrastructure or stockpiles. In some cases, soil was imported from offsite locations already contaminated. Over time, pollutants can accumulate at harmful concentrations, especially if unnoticed or unmanaged.

Why Are Industrial Areas at Higher Risk?

Industrial zones often have long operational histories, minimal historical regulation, and complex chemical use. This increases the likelihood of legacy contamination. Many older facilities operated before current environmental standards were introduced, meaning past activities went undocumented or unregulated – a major risk factor for contamination hotspots today.

What Are the Typical Contaminants Found?

Common soil contaminants in industrial areas include:

• Heavy metals like lead, arsenic, and cadmium
  
  
• Petroleum hydrocarbons (e.g. diesel, oil)
  
  
• Volatile organic compounds (VOCs) and solvents
  
  
• Polycyclic aromatic hydrocarbons (PAHs)
  
  
• Asbestos, especially in fill material or demolition debris

The exact profile depends on site history, nearby industries, and past waste management practices.

How Is Contamination Confirmed?

Environmental consultants use Preliminary Site Investigations (PSIs) and Detailed Site Investigations (DSIs) to assess contamination. These include reviewing historical land use, sampling soil and groundwater, and comparing results against National Environmental Protection (Assessment of Site Contamination) Measure (NEPM) health screening levels. Once identified, contamination can be assessed for risk and managed accordingly.

Understand the Source, Plan the Solution

Knowing what causes soil contamination in industrial areas is the first step toward safe development. Whether you’re redeveloping old factory land or conducting due diligence, accurate site investigations help avoid costly surprises.

Need expert insight into industrial soil risks? Get in touch with our expert team today.