Why did the customer contact us?
Ensolum personnel were retained to investigate the source, magnitude and extent of petroleum hydrocarbons in on-site soil and groundwater, and to conduct response actions to mitigate on-site contamination and its off-site migration. Based on Site conditions a Remedy Standard B closure has been selected utilizing a Plume Management Zone for the affected area. The excavation and bioremediation of source area soils, installation of a permeable barrier wall, and recovery of non-aqueous phase liquids (NAPL), soil vapor, and impacted groundwater utilizing dual-phase extraction (DPE) were selected as the appropriate response actions.
Ensolum personnel provided environmental consulting services in association with a release of crude oil from a pipeline pump station. The scope included subsurface investigation, risk-based assessment, and remediation utilizing the Railroad Commission of Texas (RRC) Field Guide for the Assessment and Cleanup of Soil and Groundwater Contaminated with Crude Oil/Condensate From a Spill Incident and Texas Risk Reduction Program (TRRP) regulatory guidance. During initial spill response activities, soil was excavated at the release source and placed into treatment cells constructed on-site. The affected soil was treated using a balanced fertilizer to enhance biodegradation of the crude oil. Treated soil was periodically tilled for a period of three (3) weeks to increase oxygen availability and stimulate naturally occurring bacteria in the soil which metabolize organics including petroleum hydrocarbons. An interceptor trench was installed between the source area and a nearby tributary. Two (2) underflow dams and absorbent booms were installed within the tributary to restrict the flow of crude oil in the creek. A permeable reactive barrier wall was installed to reduce the mass and restrict the downgradient migration of petroleum hydrocarbon compounds detected in on-site groundwater. Activated carbon was injected into the subsurface and was amended with a sulfate-reduction mechanism (BOS-200®) to take advantage of both aerobic and anaerobic environments. BOS-200® is a blend of select nutrients, a cultured mix of bacteria (symbiotic facultative microbes) that are known petroleum hydrocarbon degraders, gypsum, activated carbon, and iron. Approximately 193,241 gallons (4,601 barrels) of crude oil have been recovered to date utilizing vacuum trucks and mobile dual- phase extraction units. DPE, also known as multi-phase extraction, vacuum-enhanced extraction, or sometimes bio-slurping, is an in-situ technology that draws a vacuum on the formation and removes contaminated groundwater, phase separated hydrocarbons, and hydrocarbon vapor from subsurface soil. Extracted NAPL and impacted groundwater are collected for recycling or disposal and extracted vapor is consumed by the normal combustion process of the engine. Ensolum is currently conducting groundwater monitoring to ensure plume stability and the effectiveness of the soil and groundwater response actions. Additional DPE events will be conducted at the Site prior to filing a restrictive covenant limiting the future use of the initial groundwater bearing-unit and requesting regulatory closure from the RRC.
Crude Transmission Pipeline Corrective Action