Evaluation of a shoreline cleaner for enhanced removal of petroleum from a wetland

Abstract

The impact and performance of a shoreline cleaning agent in the environment, Corexit®9580 (EC9580®), was evaluated by conducting a controlled release of weathered crude oil (Arabian-light) in May 1998 at a well characterized and fully instrumented wetland research site. The research facility is located on the San Jacinto River near Channelview, Texas. It was originally set aside in 1994 to monitor intrinsic remediation and recovery subsequent to a catastrophic flood that ruptured four pipelines releasing petroleum products that impacted the shoreline. Since 1994, three controlled oil applications (1996 and 1997) were conducted to evaluate proposed remediation strategies for wetland environments including nutrient additions, oxidant additions, and bioaugmentation. This latest phase of research (1998) is a continuation of studies to evaluate non-invasive oil removal techniques from sensitive wetland environments. For this controlled oil release experiment, 21 plots were divided into three treatment regimes: six oiled, no-action control plots; six shoreline cleaner treated plots - high shoreline cleaner application dose; and six shoreline cleaner treated plots - low application shoreline cleaner dose. Three plots were also maintained as unoiled controls. The plots were separated into six blocks to achieve a randomized complete block design. To determine the effectiveness of the shoreline cleaner applications, triplicate sediment samples from all plots were taken as a function of time from May 15, 1998 until August 21, 1998. These samples were analyzed for petroleum hydrocarbons (TEM and GC/MS), toxicity, microbial counts, nutrient levels and redox potential. Target hydrocarbon concentrations were normalized to 17α, 21β-(H) hopane, a conservative terpenoid biological marker, to account for physical petroleum losses and to reduce the heterogeneity in the hydrocarbon data. The results show that the addition of a shoreline cleaning agent to an oiled estuarine environment does not inhibit the biodegradation of the oil. Additionally, the shoreline cleaner did not enhance the removal of the petroleum from the estuarine environment.