On behalf of the state of Michigan, DLZ completed a remedial investigation at D&L Fuels. They are a bulk fueling and gasoline station facility, in Charlotte, MI. DLZ has been actively involved in the mitigation of high concentrations of petroleum impacts to soil and groundwater. The impact is a result of both underground and above ground releases at a former bulk oil distributorship. DLZ performed the remedial investigation of comingled plumes from both USTs and an AST bulk fuel facility at D&L Fuels.
Initially, DLZ monitored for the presence of gasoline, free product (LNAPL), impacted groundwater, and vapor intrusion risks to property occupants. Later, DLZ designed and oversaw source removal, using multi-phase extraction, to initiate the mitigation of LNAPL. DLZ then performed subsequent engineering design, oversight of the excavation, and disposal of the highly contaminated source soils. DLZ also directed the placement of MgSO4 (Epsom salt) to the base of the excavation and to the excavation periphery in order to enhance anaerobic biodegradation of residual petroleum impacts. Through the action of interim response activities, which included source excavation followed up with the in situ enhancement of biodegradation, over 95% of gasoline related impacts have been abated from the site. DLZ continues to monitor the levels of residual sulfate, and chemical parameters in the groundwater to assess the ongoing bioattenuation (contaminant reduction) process.