Environmental Site Assessment

The phrase “environmental site assessment” (ESA) can refer to anything from a cursory review of past site uses, to a formal Phase I Environmental Site Assessment, to a focused suite of soil and/or groundwater sampling, or to anything in between. If any type of sampling occurs, the project may be referred to as a Phase II ESA. The purpose of an ESA is to determine whether petroleum products and/or hazardous materials have negatively impacted a site.

A Phase I ESA is perhaps the most well-known type of ESA. Phase I ESAs are frequently done prior to the purchase of a commercial piece of property, and should adhere to the procedures in the American Society for Testing and Materials’ (ASTM) Standard E-1527-21. Phase I ESAs generally exclude sampling. Sprecher Group has conducted numerous Phase I ESAs over the years, and currently offers review and comment on Phase I ESAs as requested by site owners.

With the exception of our water rights work, nearly all of Sprecher Group’s projects are ESAs that involve some degree of soil sampling and/or groundwater sampling. Our webpages for emergency response incidents, groundwater investigations, and Underground Storage Tank, contain a brief discussion of these specific project types.

Oregon Department of Environmental Quality’s Risk-Based Decision Making (RBDM) guidance, available on DEQ’s website, is sometimes referred to as “risking away a release”.  Applying this guidance involves comparing soil and/or groundwater sample analytical results with DEQ’s Risk Based Concentrations (RBCs; updated by DEQ in May 2018) for various exposure pathways in order to decide whether a site is “clean enough”. The RBDM process was initially intended for use at petroleum contaminated sites, but has been expanded by DEQ to include numerous other types of releases, including metals, polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), and many more. Sprecher Group has authored numerous Risk-Based Assessment Reports since our inception.


Push probe rig collecting soil and groundwater samples for a risk-based assessment project.


Soil sample in push probe liner.