The aim of this final project was to made an environmental and health risk assessment of the oil-contaminated soil in the Haapamäki school area. The city of Keuruu was the client of the risk assessment and it was made in cooperation with Ramboll Finland Oy. The purpose of the risk assessment was to define the level of soil and groundwater contamination in the target and estimate the need for cleaning. The oil had leaked to the soil in consequence of overfilling the oil tanks.

The risk assessment was started by a further research in the school area. Groundwater pipes were installed around the school and soil samples together with ground water samples were taken. Based on the laboratory results it was possible to find out the spreading of hydrocarbons in the soil and groundwater. The risk assessment was made by accurate calculated evaluation for groundwater and indoor air diversion and the remainder of the assessment by accurate verbal evaluation. The method chosen for the calculated evaluation was the SOILIRISK program. The program took account of the properties, pathways and health and ecological risks of oil. Historical data and output values for sandy soils were used in calculation. The program calculated risks to surface and subsoil, indoor air and groundwater based on concentration and different fractions of oil.

Based on the calculated evaluation and groundwater samples taken the dissolving from the soil to the groundwater is minor. The most potential health risk was estimated to be the evaporation of harmful substances into the indoor air of the school building. The results from the evaluation showed that there are no significant risks to health or environment by the increased contaminant concentrations in the soil. There are no further soil remediation requirements.