Design, construction and operation of a funnel and gate in-situ permeable reactive barrier for remediation of petroleum hydrocarbons in groundwater

A white spirit spill at a factory site located in a residential area of south eastern Australia led to contamination of shallow groundwater that fed into a nearby river. The contaminated groundwater contained toluene, ethyl benzene, and xylene and n-alkanes in the C(6)-C(36) fraction range. A funnel and gate permeable reactive barrier was designed and built, based on preliminary pilot scale tests using peat as the medium for the gate and the work conducted is presented as a case study. The technical effectiveness of the funnel and gate, over the 10 month operating period in which data was collected, indicates that peat represents an effective material for use in the gate component of funnel and gate remedial systems. The application of the funnel and gate technology represented a substantial saving to the client and was effective in preventing ongoing pollution of the nearby river. The construction of the funnel and gate system also incurred the minimum disturbance to the public access areas between the facility and the river.