At PAB Oil, cleanup left a cap to maintain and limits on land use

Nearly four decades after PAB Oil stopped accepting oilfield waste north of Abbeville, its cleanup still required inspections, groundwater monitoring and restrictions on disturbing the ground. EPA’s April 11, 2022 review describes what remained after contaminated material had been treated and capped.

The fifth five-year review, page 4, places the 16.7-acre site about three miles north of Abbeville on Route 167. PAB Oil operated there from 1978 to 1983, disposing of wastes from oil and gas exploration and production, including drilling muds and fluids. Pits, ponds and their associated levees and berms once occupied nearly 82 percent of the property, EPA reported.

The remedy did not remove everything from the site. EPA’s review summarizes the work as dewatering and backfilling the saltwater pond, then excavating and stabilizing contaminated soil and sludge for placement in an on-site disposal unit. A cap covered that material; monitoring and maintenance continued afterward.

The agency’s 2022 finding was reassuring within those limits. Its approval memorandum said monitored groundwater constituents had remained below federal maximum contaminant levels since 2016, and there were no known exposures to contaminated material. EPA determined that the remedy was protective of human health and the environment in the short term.

Land-use safeguards were part of that protection. The review’s account of an October 2007 notice filed in the parish records describes restrictions on excavation or drilling that could expose contaminated material or damage the cap. The notice also restricted groundwater extraction to monitoring or remediation purposes.

EPA found that institutional controls were already in place but had not been required in the remedy’s decision documents. It recommended evaluating how to formalize them as part of the cleanup for long-term protection. The review also explained why periodic oversight remained necessary: material was still present above levels that would allow unrestricted use and exposure.

The maintenance plan described in the same report made that oversight concrete: inspections of the cap, drainage ditches, fences and wells; mowing; settlement surveys; and groundwater sampling. At PAB Oil, the cleanup’s lasting work included keeping the barrier intact and watching what happened beneath it.