To manage environmental liability for oil and gas properties it was purchasing, Antero Resources contracted GZA to conduct ASTM 1527-13-compliant Phase I Environmental Site Assessments (ESAs) of 179 conventional well locations and ancillary facilities such as compressor stations and tank batteries. The turnaround time was less than three weeks.


GZA quickly mobilized two teams to the field. While a standard Phase I ESA would require individual environmental database and historic document searches for each of the 179 locations, GZA project managers realized that, due to the close proximity of these wells, they were able to expand the search radii and use GIS to effectively capture all the properties with only 45 database searches — dramatically reducing the cost to the client. Observations and data collected by GZA’s field teams were transmitted daily to GZA project managers who compiled them into the report deliverables. Data gaps were identified while the teams were still in the field, allowing them to be resolved without remobilizing. The final report was delivered on time and under budget.


GZA responded rapidly and with a cost-effective approach to accommodate the client’s pressing due diligence needs, which allowed Antero to better assess and alleviate their liability in the transaction.