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What is a Phase 3 Environmental Site Assessment?

What is a Phase 3 Environmental Site Assessment?

A Phase 3 Environmental Site Assessment (Phase III ESA) is a necessary step in the process of removing environmental contaminants and remediating a property – assuming that contamination is found on the site. This Phase can also include a plan for additional site investigations and evaluation of the most effective remedial options. The Phase 3 ESA is best understood by first reviewing the Phase 1 and Phase 2 ESA – studies that precede it and determine its direction. Then we can understand why the third-phase ESA is performed, what exactly it entails, and the key steps to performing one.

How Phase I & Phase II ESA’s Can Lead to a Phase III ESA

One way to understand the Phase III ESA is by comparing the scope of work typically completed during Phase 1, 2, and 3 Assessments. There is no sampling, laboratory testing, or physical evaluation conducted during the Phase I ESA. Instead, here is what is involved:

The objective of a Phase 1 ESA is to determine possible sources of contamination through the assessment of current and former property use. The assessment then includes recommendations to verify the extent of the contamination. To that end, a team performing this first-phase ESA will perform reconnaissance on the site, interview key personnel, and historically review the property. Adjoining properties can also be problematic, so they are also investigated for current and historical uses.

When would a Phase II or Phase 2 Environmental Site Assessment be needed? The second phase of the assessment is only needed if site contamination is deemed reasonably possible through Phase I or Phase 1 ESA. Here is how a Phase II ESA is different from Phase I:

The second-phase ESA moves on to sampling and laboratory analysis – in the interest of determining whether toxic substances exist on the property. It investigates contamination levels based on potential issues revealed in the Phase I ESA. Groundwater, soil, sediment, and surface water samples are collected as appropriate and analyzed in labs. By gauging how extensive contamination is in relationship to groundwater, soil, and sediment remediation guidelines, the Phase II ESA will determine what remediation strategies may be necessary.

Why is a Phase 3 Environmental Site Assessment Performed?

Just as the Phase 1 ESA will determine if a Phase 2 is necessary, the Phase 2 ESA will determine if Phase 3 is recommended. The testing completed during the second phase will verify if there is contamination; if there is, a recommendation for a Phase III ESA is made.

The basic objective of the Phase 3 ESA is to determine the extent of contamination discovered in the second phase. Phase III, is a critical precursor to any site remediation efforts, and it involves a much broader site investigation.

Results of a Phase 3 ESA will allow the development of a site remediation plan that is environmentally compliant at the federal, state, and local levels. The Phase 3 ESA will also include various specific remediation strategies, the costs to conduct them, and time estimates for completion.

To zero in on the property’s pollution levels, additional tests will need to be performed by environmental engineers. Individual or multiple tests within these categories are often needed:

  • Assessment of subsurface soil
  • Sediment testing
  • Groundwater testing
  • Determination and analysis of groundwater and soil contaminant pathways.

The overall cost of a Phase 3 Environmental Site Assessment will be significantly influenced by the testing and remediation techniques that are needed.

What is Involved in a Phase 3 ESA?

Phase 3 is the remediation phase and is only necessary if site contamination is verified by a Phase 2 investigation. The environmental engineering team will not only plan your property’s remediation, but they will also execute it.

The site’s current status and historical uses are available to the environmental remediation team from the Phase 1 and Phase 2 ESA’s. Using those assessments as a basis, the Phase 3 ESA quantifies the contamination and determines its boundaries through delineation. Calculations are made of how much soil is contaminated. Various monitoring efforts may be necessary, such as modeling and assessment of groundwater flow.

Using the characterization of the environmental impacts that have been revealed, the environmental team then analyzes remedial strategies that are most effective for the site and contaminants present. Regulations, timelines, and costs are considered to ensure that the site achieves regulatory compliance through the most appropriate means. Also, fundamentally guiding the remediation approach are the client’s core goals for the site.

An environmental remediation work plan will then be developed and executed. A single on-site day is often enough for simple soil contamination excavation and disposal. Groundwater remediation is more challenging and costly. Groundwater pump & treat, In-Situ Chemical Oxidation, bio-remediation, and other techniques can require months or even years to complete. The specific characteristics of your property may necessitate a longer, more complex remediation process.

In certain cases, the remediation approach developed through the Phase 3 Environmental Site Assessment is risk management-based and does not remove the contamination. Site-specific risk assessments (SSRA’s) and other remediation approaches can be used in those scenarios in which cleanup of a site is infeasible. Potentially feasible options include the creation of barriers and monitored natural attenuation. Having expert guidance from environmental engineers is invaluable for these processes.

A Phase 3 Environmental Site Assessment Report is then completed. This report includes the site’s current condition, treatment methods that were used, and confirmation of contaminant removal. Plus, it details any recommendations for ongoing monitoring.

The 5 Key Steps of a Phase III ESA

Although other steps may be involved, the five central steps of the Phase III Environmental Site Assessment process are as follows:

  1. Determine how extensive the contamination is that was discovered during Phase 2.
  2. Calculate an estimate of the volume of impacted groundwater and soil.
  3. To submit a proper notification to regulatory agencies, complete a site notification report.
  4. To clean up the site and remove contaminants, create a remedial action plan (RAP).
  5. Evaluate timelines, costs, and best options for remediation.

A Successful & Efficient Phase 3 Environmental Site Assessment

The results and speed of Phase 3 Environmental Site Assessment may differ based on the involved environmental services companies. At AOTC, we deliver environmentally compliant, cost-effective, efficient solutions for businesses across the Southeast. Contact us today to discuss our environmental services and how they can help your business.


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