Serving Southern California since 2003.  CSLB #926743 A-HAZ

Environmental Site Assessments

Hazardous Materials Inspections 

Environmental Contracting



  • Phase I ESA
  • Updated Phase I ESA
  • Limited Phase I ESA
  • Transaction Screen
  • Desktop Review

Other Consulting Services: Site AssessmentSite Cleanup


Environmental Due Diligence is the process by which environmental concerns, both present and historical, are researched and documented for a piece of real estate.  The Environmental Due Diligence process is usually initiated as a prerequisite for a property transfer or bank financing in an effort to document and explore known environmental concerns and, more importantly, to reveal any unknown environmental risk prior to any transfer or lending activity.

The Environmental Due Diligence process is typically initiated by conducting a Phase I ESA or a less comprehensive approach such as a Transaction Screen or Desktop Review.  If the Phase I ESA  identifies any environmental concerns, additional due diligence in the form of collecting subsurface samples (soil, soil-gas, groundwater) may be necessary to determine the extent of any potential contamination (see Phase II ESA, Subsurface Site Assessment).    


Our Phase I ESAs are conducted by an Environmental Professional as defined by 40 CFR 312.10 and include the following components for the subject property and adjoining properties, where applicable:

  • Regulatory Agency Database Review
  • Historical Aerial Photograph Review
  • Historical Topographic Maps Review
  • Sanborn Fire Insurance Map Review
  • Building Permit Records Review
  • Historical Street Directory Review
  • Site Reconnaissance
  • Interviews with Individuals Familiar with the Property
  • Environmental Lien and AUL Research
  • Environmental Questionnaires
  • Geologic and Hydrogeologic Data Review
  • Previous Environmental Investigations Review
  • Visual Inspection for Asbestos, Lead Paint, and PCBs
  • Tables and Figures Summarizing all Reviewed Data
  • Standard Digital Package and Delivery

FAQ Topics:

Regulatory Link Categories:


p. (818) 334-5414   p. (888) 663-1181   f. (818) 334-5413

© 2008 - 2017 Environmental One, All Rights Reserved

Terms of Use