(423h) Jet Fuel Remediation at Paulinia Refinery (Replan), Sao Paulo, Brazil

During a site investigation performed in Paulinia Refinery, in 2003, monitoring wells intercepted aquifer contaminated with jet fuel, which leaked from storage tank for jet fuel.

Detailed studies were conducted to furnish 3D configurations of free and dissolved phases, as well as local geology, in order to design a remediation system to remove the contaminants. Initial estimate of 500 m3 of oil is thought to have spilled from tanks.

The remediation system in operation since June of 2005 is composed of 4 pumping wells and 41 monitoring wells. Oil/water emulsion is pumped and sent to oil separators, after which oil is sent to the refining processes and water phase to wastewater treatment plant. Water table level and oil thickness variations are monitored using interface meter and pressure transducers, providing an estimate of oil volume infiltrated into the ground, through the entire remediation process, as well as spatial change of LNAPL plume configuration.

Free phase plume configuration varies with water level change, which is intrinsically related to intensity of rain precipitation. During dry season plume expands, while in the rainy season it reduces to the point where in many wells free phase became extinct.

Despite pumping was initiated in June, oil production only occurred 3 months later, after October. Peak production occurred in January, ending in March, after that only dissolved phase was produced.

Rain precipitation, volume of recovered oil, free phase thickness, water level fluctuation and plume dispersal were examinated, which led to the conclusion that seasonal water table level variation is the main factor controlling mobility, stability and oil volume recovery in the contaminated site.