Villädhe/Nastola was one of University of Helsinkis test sites in Finland. The contaminant was oil and the method tested was biostimulation with electro-kinetic pumping.

​The study site is located on an industrial area, within a 1-class ground water area The contamination is contaminated due to a filling accident of an oil tank in year 2003. The treatable part of the site is covered by concrete while the contamination is likely to have spread under buildings, some of them still in use. Asbestos exposure risk limits the accessibility of some of these premises. Oil contamination on the area been documented by sampling in 2012-2013, whereas apart from the hot spot near the origin of the spill, the concentrations appear rather low.

At this site the method used is biostimulation with electro-kinetic pumping to enable horizontal movement of the injected solution.
The in-situ treatment took 18 weeks in total, with weekly injections of a
solution with nitrogen, ammonium and nitrate mixed with water. Before the treatment there was a hotspot with high concentration of oil hyrdrocarbon. The treatment was successful and there was no hotspot left. The site is now considered clean by an external consultant and no further actions are required.