The Former Waddell Compressor Station, located southwest of Midland/Odessa, Texas, is impacted by light non-aqueous phase liquid (LNAPL) in the form of natural gas condensate and has over 20 years of groundwater monitoring data. The Site is regulated by the Texas Railroad Commission and is enrolled in the Operator Cleanup Program that allows for risk-based site closure.
GEI performed LNAPL transmissivity testing at five wells in 2018 using both oil/water ratio test methods and mobile dual-phase extraction data analysis. Transmissivity was calculated for both methods in accordance with ASTM E2856-13 indicating that LNAPL is not hydraulically recoverable. This finding was corroborated with less than 0.01 gallons of fluid phase LNAPL recovered during the MDPE event out of approximately 1,180 total gallons of water recovered.
A dissolved phase plume stability analysis was also performed using the Groundwater Spatiotemporal Data Analysis Tool (GWSDAT) (Jones et al. 2014). The dissolved-phase plume is stable to decreasing in mass and is not expected to migrate beyond the current extent. GEI’s work allowed for the immediate shut-down of the biosparge remediation system and preparation of site closure documentation with institutional controls to prevent future exposure.

Primary Author / Conference Presenter:
Thomas Daigle
Project Manager
GEI Consultants, Inc.
Denver, Colorado, USA

J. Michael Hawthorne, GEI Consultants, Denver, CO
Lisa Reyenga, GEI Consultants, Denver, CO
David White, Kinder Morgan, Houston, TX