Skip to content 
At Essel, we’re often asked the question, “how is a Phase 2 ESA different from a Phase 1 ESA?” We get it, it’s complicated. Hopefully this article will start to provide answers to some of your Phase 1 & 2 ESA questions.
What is a Phase 2 ESA?
Development projects often require a Phase 2 Subsurface Investigation to identify any potential contamination present in soil, soil vapor, and/or groundwater. When residential properties are being converted from commercial uses, for example, planning commissions will require investigations to be performed before project approvals are provided.
Subsurface investigations consist of:
- Drilling of soil borings around the area of suspected impacted soil
- Collection of soil, soil vapor, and groundwater samples
- Soil lithologic classification
- In-field screening for undifferentiated volatile organic compounds
- Laboratory chemical analysis of samples
- Evaluation of data and report preparation.
Okay, but how is a Phase 2 Subsurface Investigation different from a Phase 1 ESA?
To put it simply, a Phase 1 ESA assesses the likelihood of contaminants being present, while a Phase 2 Subsurface Investigation assesses whether or not the contaminant is present in the area. Phase 1 ESAs review records, involve visual inspections of the property, and interview current and past property owners to determine the likelihood of contamination. A Phase 1 ESA often leads to the need for a Phase 2 Subsurface Investigation, if it looks like contaminants might be
present in the area.
Got more Phase 1 & Phase 2 questions? Reach out to us at 1-800-595-7616 to speak with one of our experts!