PROJECT SUMMARY
WHAT:
LNAPL Risk-Based Closure
WHO:
Hollis Millard, P.G.
Jennifer Rohrer, P.G
WHERE:
Oil and Gas Operations Pyote, Texas
WHEN:
2007 – 2012
BACKGROUND
ultiple operators conducted natural gas processing activities in close proximity to one another in an area south of Pyote, Texas. Natural gas condensate, a light non-aqueous phase liquids (LNAPL), was released to the subsurface from multiple areas resulting in commingled contaminant plumes. The operators formed a group (the Group) to jointly address the groundwater contamination and requested that CK be the representative consultant to complete the actions necessary to obtain the risk-based regulatory closure.
FINDINGS
K coordinated monthly teleconferences and annual meetings between the operators, the landowners (The University of Texas, University Lands Office), and the Railroad Commission of Texas (RRC) to discuss the project and formulate mutually agreeable plans to assess groundwater contamination.CK produced work plans and conducted subsurface investigations and groundwater monitoring to characterize the site and delineate contaminant plumes. A modeling study was conducted to evaluate recoverability and the potential for LNAPL to migrate. CK also conducted a thorough evaluation of the design, operation, and efficacy of the former recovery system to assess the feasibility of additional recovery of LNAPL from the subsurface. The primary conclusions drawn from the assessments, remediation and monitoring work conducted were that
- no on-going sources of contamination existed,
- contaminant plumes were stable within the delineated area, and that
- additional recovery would not be practical or reduce the risks to potential receptors.
RESOLUTION
K and the Group worked proactively with UT Lands and the RRC, to ensure that a prudent, mutually-agreeable risk-based approach to closure was achieved.The site was closed without further LNAPL recovery since it was shown that the plume was stable and additional recovery would not reduce the risk to potential environmental receptors. A restrictive covenant was placed on the land to protect receptors from contaminated groundwater within the delineated area.
PROJECT SUMMARY
WHAT:
LNAPL Risk-Based Closure
WHO:
Hollis Millard, P.G.
Jennifer Rohrer, P.G
WHERE:
Oil and Gas Operations Pyote, Texas
WHEN:
2007 – 2012
BACKGROUND
ultiple operators conducted natural gas processing activities in close proximity to one another in an area south of Pyote, Texas. Natural gas condensate, a light non-aqueous phase liquids (LNAPL), was released to the subsurface from multiple areas resulting in commingled contaminant plumes. The operators formed a group (the Group) to jointly address the groundwater contamination and requested that CK be the representative consultant to complete the actions necessary to obtain the risk-based regulatory closure.
FINDINGS
K coordinated monthly teleconferences and annual meetings between the operators, the landowners (The University of Texas, University Lands Office), and the Railroad Commission of Texas (RRC) to discuss the project and formulate mutually agreeable plans to assess groundwater contamination.CK produced work plans and conducted subsurface investigations and groundwater monitoring to characterize the site and delineate contaminant plumes. A modeling study was conducted to evaluate recoverability and the potential for LNAPL to migrate. CK also conducted a thorough evaluation of the design, operation, and efficacy of the former recovery system to assess the feasibility of additional recovery of LNAPL from the subsurface. The primary conclusions drawn from the assessments, remediation and monitoring work conducted were that
- no on-going sources of contamination existed,
- contaminant plumes were stable within the delineated area, and that
- additional recovery would not be practical or reduce the risks to potential receptors.
RESOLUTION
K and the Group worked proactively with UT Lands and the RRC, to ensure that a prudent, mutually-agreeable risk-based approach to closure was achieved.The site was closed without further LNAPL recovery since it was shown that the plume was stable and additional recovery would not reduce the risk to potential environmental receptors. A restrictive covenant was placed on the land to protect receptors from contaminated groundwater within the delineated area.