Phase I Environmental Site Assessments

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Phase I  ESA

A critical step in environmental due diligence for commercial and industrial real estate is the Phase I Environmental Site Assessment commonly referred to as a Phase I ESA or simply, a Phase I. The purpose of a Phase I is to provide a preliminary assessment of a property's potential environmental liabilities for prospective buyer or current site owner.  Guidelines for conducting a Phase I are provided by ASTM International in Standard E1527-21.  Phase I assessments typically do not involve sampling of groundwater, soil or other media. Such efforts may be reserved for a more detailed Phase II if the potential for adverse impact has been identified.

When to Consider a Phase I

Several reasons for requiring a Phase I include:

  • Property aquisition or divestiture
  • Mergers and acquisitions
  • Refinancing
  • Redistribution of ownership

What is Included

A Phase I typically involves a site walk through, careful review of existing site environmental documents, a review of various databases, interviews and a review of existing State environmental agency files.  An evaluation is then made of current and historical site environmental conditions in addition to an evaluation of risks from nearby and adjoining properties.

Tasks performed in an ASTM 1527-21 Phase I typically include:

  • Conducting an on-site visit to view present site conditions and document potential environmental issues.
  • Evaluation of potential risks to the subject property from adjoining and nearby properties.
  • Review of Federal, State, Local and Tribal databases to specified distances.
  • Review historical aerial photography of the vicinity to identify historic land uses and changes.
  • Review historical topographic maps which include the property to identify changes to topography, drainage patterns and development.
  • Review of historical fire insurance maps.
  • Examine chain-of-title for Environmental Liens and/or Activity and Land Use Limitations (AULs).
  • Interview individuals familiar with the property history (past owners, present owner, key site manager, etc).
  • Contact with public agencies (fire department, county health department, etc.) with knowledge of site history and potential environmental issues.
  • Conduct a review of existing files at the State environmental agency.

Contact GSI Environmental Services for a Phase I Environmental Site Assessment

A Phase I Assessment must be prepared by a qualified individual, typically an environmental scientist, professional geologist or environmental engineer. Our staff of qualified environmental professionals has been providing quality Phase I ESAs for over 20 years. Contact GSI today for additional information or to schedule your Phase I.


What Our Customers Have to Say

"Groundwater Services, Inc. has been our “go-to” team for Phase I work for all of our real estate development projects. Having a firm like them that understands the importance of high pressure deadlines and complex grant requirements has been invaluable. Their communication, competence, and timeliness have been outstanding every time. We couldn’t be happier with their services."

David Butcher , President & Partner WCI Partners, LP