In recent years in Poland, there has been an increasing issue with waste management. Despite waste sorting and fees paid by residents for waste collection, many of these waste materials are illegally disposed of. Such formally unclassified waste poses a significant threat to the surrounding residents and exerts toxic effects on soil and as well as surface- and groundwater and also fauna and flora in the vicinity. Due to the significant number of illegal storage site fires in Poland, the authors of this article assessed the impact of five different fires at illegal waste storage sites in Poland on the soil by analyzing the composition of the ashes remaining after a fire. Based on the chemical evaluation of the ashes, it was found that there are substances present in quantities exceeding permissible concentrations. Therefore, the authors concluded that some of these substances may have a negative impact on human health and degrade the surrounding flora and fauna in the storage areas. Consequently, it is essential to exercise stricter control over waste storage locations, classifying the waste left there to prevent adverse environmental and human impacts in case of a fire. Further research is necessary to assess the influence, for example, of leachate following a fire on the quality of the natural environment.