The Petro-Processors site remediation activities continued to progress towards site closure during the past year.
NPC completed annual long term monitoring activities at the Brooklawn and Scenic Operable Units (OUs). Based on the annual review of performance monitoring data and annual inspection of cover areas, each of the selected remedies for the impacted environmental media was found to be protective of human health and the environment. The USEPA completed the fourth Five Year Review of the site and issued its Fourth Five-Year Review Report in 2021. Workplans and submittals to address the Five-Year Review findings were submitted in 2021 and 2022 and remaining work under the workplans is ongoing.
Subsurface conditions in the alluvial sediments at the Brooklawn OU continue to be supportive of the anaerobic biodegradation processes necessary to reduce groundwater contaminant concentrations to levels predicted by the groundwater flow and solute transport model upgradient of the point of compliance monitor wells. Enhanced in-situ reductive dechlorination is the approved remedial action at the Scenic OU. Remedial injections of extracted groundwater amended with molasses to 0.3% solution were completed at the source treatment zone to promote and sustain geochemical conditions necessary for enhanced reductive dechlorination. Remedial injections at the distal treatment zone are planned to be performed during 2024.
An interim remedial action (activated carbon treatment of the downgradient plume) was initiated downgradient of the Scenic OU distal treatment zone in 2016 and continued through 2020. Data analysis has shown this interim remedial action to be effective in remediating the transitional plume downgradient of the distal treatment zone. In December 2020 USEPA and LDEQ approved discontinuing the pumping from the four (4) extraction wells and pumping ceased in December 2020. Beginning in March of 2021, the wells have been sampled quarterly for four quarters. The Constituents of Concern (COC) were below the remedial standards (MCLs) in three of the wells for four (4) consecutive quarters. Only a single COC was slightly above the MCL for the first three (3) quarters in the fourth well but was below the MCL in that well in the fourth quarter. Quarterly sampling of this well continued in 2023. Results have been below the MCL for three (3) consecutive quarters and this well will continue to be sampled quarterly until below the MCL for four (4) consecutive quarters. USEPA and LDEQ have approved annual sampling for the other three (3) extraction wells.
The site completed 23 years and over 723,000 man-hours with no recordable injuries.
Details of all approved plans and reports can be inspected at the Louisiana Department of Environmental Quality EDMS website (www.deq.louisiana.gov/page/edms). These reports include groundwater contaminant plume maps. The Agency Interest Numbers are 2469 for the Brooklawn OU and 83225 for the Scenic OU. We welcome your questions or comments at any time.
J.O. Collins, President
Disclaimer: Unsolicited applications for employment or resumes are not maintained by NPC Services, Inc. NPC accepts applications on company-supplied forms only, and will not accept applications except for a specific position, and then only when an opening is advertised. All applications that do not meet this requirement will be returned.