Site assessment is crucial for determining the extent and severity of contamination, which is necessary
for planning remediation or cleanup efforts. It helps identify hazardous substances that may be present,
the risk they pose to human health and the environment, and the best methods for removing or
containing the pollutants. In addition, site assessments are often required by local, state, or federal
environmental agencies to ensure that property transactions involving contaminated land comply with
environmental regulations.
Whether it is for the purpose of land development, real estate transactions, or environmental
protection, site assessment plays a key role in identifying and mitigating contamination risks.
Key Stages of Site Assessment
Site assessments are typically conducted in multiple stages to thoroughly evaluate the condition of the
land. These stages are designed to identify potential contamination, assess the risks involved, and
determine the necessary remediation actions. Below are the primary phases of a site assessment:
1.Phase I: Preliminary Site Assessment (Environmental Site Assessment)
The first step in the site assessment process is conducting a Phase I Environmental Site Assessment
(ESA). This phase involves a detailed investigation into the history of the site and its potential for
contamination. The key components of Phase I include:
Historical Research: A review of historical records to determine previous land uses and
activities on the site. This can help identify potential sources of contamination, such as former
industrial operations, waste disposal sites, or underground storage tanks.
Site Inspection: A physical inspection of the site to look for signs of contamination, such as
visible staining on the soil, dead vegetation, or discarded chemicals. The inspection also involves
examining neighboring properties for potential sources of pollution.
Interviews: Interviews with site owners, local residents, and employees who may have
knowledge of past activities or contamination incidents on the site.
The goal of Phase I is to identify potential risks and determine whether further investigation is needed.
If evidence of contamination is found, a Phase II assessment is initiated.
2.Phase II: Subsurface Investigation
Phase II involves a more detailed investigation of the site to assess the presence of contaminants in the
soil, groundwater, and other media. This phase includes the collection of soil, groundwater, and air
samples to determine the type and concentration of hazardous substances.
Soil Sampling: Soil samples are collected at various depths and locations on the site to analyze
for contaminants such as heavy metals, petroleum products, and pesticides.
Groundwater Testing: Groundwater wells may be installed to collect water samples for testing.
This is crucial in identifying whether the contaminants have spread into the groundwater, which
could affect drinking water supplies.
Air Quality Monitoring: Airborne contaminants, such as volatile organic compounds (VOCs),
may also be sampled to assess potential health risks from inhalation exposure.