Environmental site assessment

An environmental site assessment is a report prepared for a land holding that identifies potential or existing environmental contamination liabilities. The analysis, often called an ESA, typically addresses both the underlying land as well as physical improvements to the property. A proportion of contaminated sites are “brownfield sites.”

The actual sampling of soil, air, groundwater and/or building materials is typically not conducted during a Phase I ESA. The Phase I ESA is generally considered the first step in the process of environmental due diligence. Standards for performing a Phase I site assessment have been promulgated by the US EPA and are based in part on ASTM in Standard E1527-13.

If a site is considered contaminated, a Phase II environmental site assessment may be conducted, ASTM test E1903, a more detailed investigation involving chemical analysis for hazardous substances and/or petroleum hydrocarbons.

Scrutiny of the land includes examination of potential soil contamination,  groundwater quality, surface water quality and sometimes issues related to hazardous substance uptake by biota.

The examination of a site may include: definition of any chemical residues within structures; identification of possible asbestos containing building materials; inventory of hazardous substances stored or used on site; assessment of mold and mildew; and evaluation of other indoor air quality parameters.

Asbestos-containing materials are not typically surveyed during a Phase I site inspection, but suspect building materials may be noted

depending upon precise protocols utilized, there are a number of variations in the scope of a Phase I study.

The tasks listed here are common to almost all Phase I ESAs:

  • Performance of an on-site visit to view present conditions (chemical spill residue, die-back of vegetation, etc.); hazardous substances or petroleum products usage (presence of above ground or underground storage tanks, storage of acids, etc.); and evaluate any likely environmentally hazardous site history.
  • Evaluation of risks of neighboring properties upon the subject property
  • Review of Federal, State, Local and Tribal Records out to distances specified by the ASTM 1528 and AAI Standards (ranging from 1/8 to 1 mile depending on the database)
  • Interview of persons knowledgeable regarding the property history (past owners, present owner, key site manager, present tenants, neighbors).
  • Examine municipal or county planning files to check prior land usage and permits granted
  • Conduct file searches with public agencies (State water board, fire department, county health department, etc.) having oversight relative to water quality and soil contamination issues.
  • Examine historical aerial photography of the vicinity.
  • Examine current USGS maps to scrutinize drainage patterns and topography.
  • Examine chain-of-title for Environmental Liens and/or Activity and Land Use Limitations (AULs).

In most cases, the public file searches, historical research and chain-of-title examinations are outsourced to information services that specialize in such activities. Non-Scope Items in a Phase I Environmental Site Assessment can include visual inspections or records review searches for:

Asbestos Containing Building Materials (ACBM).

  • Lead-Based Paint
  • Lead in Drinking Water
  • Mold
  • Radon
  • Wetlands
  • Threatened and Endangered Species
  • Mercury poisoning
  • Debris flow
  • Earthquake Hazard
  • Vapor intrusion
  • Emerging contaminants

Observations of Non-scope items can be reported as “findings” if requested by the report user, however, these items do not constitute recognized environmental conditions.