The territory of Halda Poldi is one of the largest and most risky environmental burdens in the whole Czech Republic. The project is focused on remediation of tar ponds and their surroundings and subsoil. The primary contaminant is tars and their mixtures containing high concentrations of PAHs, C10-C40 hydrocarbons, phenols and BTEX. Implementation of corrective measures will eliminate health and ecological risks resulting from the existence of surface tar ponds, their contaminated subsoil and migration of pollution into groundwater.