HREC or Historical Recognized Environmental Condition is a sometimes misunderstood term used in Phase I Environmental Site Assessments and is commonly used to describe situations in which contamination is known to have occurred at a property and cleanup has been completed. In practice, the use of this term has resulted in (at least) two problems:

  • The owner of these properties may be required to comply with Continuing Obligations as a result of cleanup. If these obligations are not fulfilled, the owner may be liable for additional investigation or cleanup, as well as resulting personal injuries.
  • Consultants sometimes use the term to describe known or suspected contamination resulting from historical operations, even if the issue has not been investigated or cleaned up. Clients who believe that HRECs require no additional action may become liable by acquiring the property without conducting additional investigation or cleanup.

In most cleanups, some level of contamination is allowed to remain in place. It’s just not practical or cost effective to clean everything up to background levels. Cleanup is usually completed to acceptable concentrations predetermined by a regulatory agency, though a risk-based approach can be used to set higher cleanup goals for individual sites.

Cleanup objectives often depend on the use of a property, so that, for example, higher contaminant concentrations may be left in place at an industrial site than at a residential site. In these cases, Engineering Controls and Activity and Use Limitations may apply in order to control the risks of future exposure.

Engineering Controls are physical barriers to the spread of or exposure to contamination. For example, it is not uncommon to “cap” contaminated soils with pavement or clean fill to avoid exposing site occupants. Activity and Use Limitations are restrictions which prohibit certain activities; for example, a property may be restricted to non-residential use, or the installation of groundwater wells may be prohibited.

Failure to maintain Engineering Controls or comply with Activity and Use Limitations may result in exposure of site occupants to contamination, and could result in liability to correct the failure. The operator may also be liable for resultant personal injuries. As a result, it is important to understand continuing obligations associated with any past cleanup.

To complicate matters, the term HREC is used differently by different consultants. According to the ASTM standard (E1527-05) an HREC is a condition which would once have been considered to be a Recognized Environmental Condition (REC), but is not considered to be a current REC. Examples included in the ASTM definition of HREC make it clear that cleanup of past contamination constitutes a HREC, but the definition does not restrict the use of this term exclusively to these situations. 

A minority of consultants use this term to identify historical activities which may have resulted in contamination. For example, they may characterize a service station operation conducted from 1962 – 2001 as an HREC because the activity no longer takes place at the property. In these cases, since the HREC is not identified as a REC, the client may incorrectly conclude that there is no risk of contamination.

Revisions which may correct these problems are being considered for inclusion in a new version of the ASTM standard, though the full delineation of continuing obligations is expected to remain outside the scope of Phase I investigations. In the meantime, users of reports should carefully consider Historical Recognized Environmental Conditions to understand the extent of any investigation and cleanup as well as Continuing Obligations which may apply.