Hillsboro Airport expansion phase I and ii ESA

Ash Creek completed ASTM 1527-05 Phase I Environmental Site Assessments (ESAs) at three contiguous properties as part of a proposed buffer expansion at the Hillsboro Airport.  The properties consisted of two agricultural parcels and one commercial operation.  Recognized Environmental Conditions (RECs) were identified on the commercial parcel related to prior underground storage tank (USTs) decommissioning and current waste handling, as well as data gaps related to agricultural chemical storage and usage. 

 A Phase II ESA was completed to address the RECs and data gaps.  The Phase II activities included sampling and analysis of former agricultural chemicals (metals, pesticides, and herbicides) on following DEQ’s Guidance for Evaluating Residual Pesticides on Lands Formerly Used for Agricultural Production, soil and groundwater investigation, and a geophysical survey

Former agricultural chemicals were largely not detected.  Low concentrations of 4,4-DDE were detected below the risk-based screening levels and metals were detected at concentrations consistent with background values. The residual contaminants did not pose an unacceptable risk to human or ecological health.  At the commercial property, concentrations of petroleum were detected in soil.  Ash Creek showed that the residual impacts could be managed, without remediation. 

Ash Creek recommended that the client require the owner to receive regulatory closure on all decommissioned USTs prior to closing on the property.  The parcels were purchased and incorporated into the airport property, and additional environmental issues were not identified during site redevelopment.