Dresser, LLC manufactured and repaired pressure relief valves from 1961 to 2016 at its facility in Pineville. The facility has been vacant for several years, and there is currently no equipment or chemical storage at the site.
The facility formerly used chlorinated solvents, including trichloroethene (TCE), in its manufacturing operations. It has been determined that chlorinated solvents are present in soils at the facility and have been found in the shallow groundwater at 14 to 65 feet below the ground surface in connection with historical operations.
An environmental assessment, monitoring, and remediation program is currently underway at the site.
Affected groundwater has been identified beneath a portion of the Aurora Park residential area and in a portion of the Timber Trails/Fairway East areas, both of which are in Rapides Parish, as well as in the Gray Stone subdivision in Grant Parish and adjacent rural areas to the northwest. This affected groundwater has migrated offsite to the north/northwest, south, and east.
Environmental activities were initiated voluntarily and proactively and continue to be conducted in close cooperation with the Louisiana Department of Environmental Quality (LDEQ). We are also working with the Louisiana Department of Health (LDH) and local officials.
These chlorinated solvents can, in some situations, evaporate from the groundwater and become vapors, traveling through the soils and into the air. If these vapors enter and collect in a home or other structure, this is referred to as vapor intrusion. Because the affected groundwater has moved offsite to the north/northwest, south, and east, an evaluation of the vapor intrusion pathway is ongoing. This includes the installation of monitoring wells to monitor the direction and concentrations in groundwater, as well as soil vapor monitoring points both at the Dresser facility and in adjacent areas.
We continue to monitor soil gas concentrations and ambient air quality in the potentially affected areas. In coordination with LDEQ, we are also testing the indoor air quality in some residences, where indicated, based on our groundwater and soil gas data. Depending on the indoor air results, we will determine if further action is needed, such as improved ventilation, vapor barriers, removal systems beneath the concrete foundations, or other remedies. Air purifier units have been offered to residents whose indoor air sampling results show detections of the chlorinated chemicals of interest.
Remediation activities for soils and groundwater will be ongoing at the Dresser site through 2021, in coordination with the LDEQ. This work includes a soil vapor extraction system which became operational in May 2020, following a successful field trial. We have also used an oxidation treatment process at the source area to begin reducing TCE concentrations in groundwater at the facility. The extent of affected groundwater has been evaluated with new groundwater monitoring wells on the Dresser property and in relevant adjacent areas. The area of affected groundwater has been delineated.