The amount of municipal waste produced worldwide has seen a significant increase in recent years. The need to store waste is a significant problem in the context of environmental threats and spatial development. Due to the fact that the easiest way to reduce the amount of waste is to incinerate it, and despite the fact that waste incineration plants have existed since the late 1800s, the amount of illegal waste burning and landfills has also increased. Subsurface landfill fires are particularly dangerous, as they can affect the structure of the landfill. Methane also plays an important role in fires as it is flammable and contributes to the spread of fire. In addition, the leachate from incinerated waste is much more dangerous than the leachate from waste in its natural state. The effluents from incinerated waste include heavy metals and persistent organic pollutants, as well as sulphates, chlorides, and polycyclic aromatic hydrocarbons. Other pollutants also end up in the atmosphere. The aim of this article is to present the problem of landfill fires and their impact on air, soil, and water, based on a review of the selected documented fires as well as indicators of fires in the areas in which the authors of this article conducted their research. The article presents an overview of methods and tests, such as dynamic leaching tests, monitoring tests, and lysimetric tests, all of which can be implemented to prevent fires as well as for research purposes after a fire has occurred, so that this article can be utilitarian not only for researchers, but also for decision makers.

Landfill fires pose a real threat to the environment as they cause the migration of pollutants to the atmosphere and water sources. A greater risk is observed in the case of wild landfills, which do not have adequate isolation from the ground. The aim of this article is to present the results of studies on the toxicity of waste from a fire in a landfill in Trzebinia (southern Poland). Both soil and waste samples were investigated. The samples were analyzed using the GC-MS method and the leachates using ICP-OES. A total of 32 samples of incinerated waste and soil were collected. The organic compounds included naphthalene, fluorene, phenanthrene, anthracene, acenaphthene, acenaphthylene, fluoranthene, pyrene, benzo (c) phenanthrene, benzo (a) anthracene, chrysene, benzo (ghi) fluoranthene, benzo (b + k) fluoranthene, benzo (a) fluoranthene, benzo (c) fluoranthene, benzo (a) pyrene, benzo (e) pyrene, perylene, indeno[1,2,3-cd] pyrene, benzo (ghi) perylene, and dibenzo (a + h) anthracene. Among the inorganic parameters, sulfates, chlorides, arsenic, boron, cadmium, copper, lead, and zinc were taken into account. Phenanthrene reached values exceeding 33 mg/L. Fluoranthene dominated in most of the samples. Sulfates and chlorides were present in the samples in concentrations exceeding 400 and 50 mg/L, respectively. Compounds contained in burnt waste may have a negative impact on soil and water health safety. Therefore, it is important to conduct research and counteract the negative effects of waste fires.

The groundwater risk assessment in the vicinity of landfill sites requires, among others, representative monitoring and testing for pollutants leaching from the waste. Lysimeter studies can serve as an example of dynamic leaching tests. However, due to the bacteriological composition of the municipal waste, they are rarely carried out. These tests allow for the proper design of the landfill protection system against migration of pollutants into the ground, assessment of bacteriological, biochemical and chemical risk for the groundwater, determination of the water balance of leachate as well as examination of the course of processes taking place in the waste landfill with a diversified access to oxygen. This paper addresses the issue of performing lysimeter studies on a sample of municipal waste in various scientific centers. It analyzes the size of lysimeters, their construction, the method of water supply, the duration of the experiment, the scope of research, and the purpose of lysimeter studies.

An Environmental Risk Assessment is an efficient technical and analytical method for analyzing environmental impacts and it supports the decision-making process connected with projects variants by using historical data collection, identification of regional risk sources, probability and impact estimation of signal risk type. In this article, an Environmental Risk Assessment was performed for groundwater quality in the region of municipal landfills in Tychy-Urbanowice (Southern Poland) to assess the impact of various factors on the quality of groundwater in the region. The assessment used qualitative and quantitative risk analysis methods, including cause and consequence analysis, completion of an effect/probability matrix and utilization of the SWOT analysis method. The results of the assessment indicate that use of the SWOT analysis was the best method for groundwater risk assessment in the examined area. The analysis included an assessment of the spatial and temporal variability of leachate and groundwater quality (using data from a groundwater monitoring system), simulation of the longevity of both the top and bottom security system, spatial planning and an assessment of the impact of other parameters on groundwater, terrain and climatic conditions. The overall result for this analysis for the likely potential groundwater hazard was a score of -4. For the purposes of further risk analyses, it is possible to consider additional factors that are likely to affect the water quality of the area under investigation or to use other methods that will be based on a time series analysis.

The quality of groundwater in the source area of pollution depends on many factors, including the weather and hydrogeological conditions within the given area. Anassessment of water quality can be carried out based on data obtained from sensors placed in boreholes. This research examined the influence of air and water temperature, groundwater table position and precipitation on the value of electrical conductivity in groundwater in a selected piezometer belonging to the monitoring network of the Quaternary aquifer in the area of a waste landfill site in Tychy-Urbanowice in southern Poland. The influence of individual factors was checked by using twenty neural network architectures of a Multilayer Perceptron Model (MLP). Each of these indicated factors were selected as input variables. Ultimately, three neural networks were selected, which were characterized by the smallest validation and test errors and showed the highest learning quality. The significance of individual variables for the effectiveness of the model was checked using a global sensitivity analysis. Three selected MLP models contained seven to nine neurons in the hidden layer and used a linear or exponential function as the hidden and output activation. The maximum test quality was 0.8369, while the smallest test error was 0.0011. The results of the sensitivity analysis highlighted the important role of water temperature and water table position on the conductivity value. The obtained goodness of fit results of the models to the input data allowed us to conclude that the MLP was applicable to such forecasts and can be extended by the analysis of further factors.