Temporal variations in groundwater chemical composition of landfill areas in the vicinity of agricultural lands: a case study of the Zdounky and Petrůvky landfills in the Czech Republic

The issue of groundwater contamination is one of several major global concerns, especially in areas exposed to the impact of waste disposal. The present study investigated the potential of combining both direct monitoring activities with computer-based model simulations to predict and describe contamination sources from two landfills and surrounding land in the Czech Republic (CR). The results have shown that groundwater quality at the two monitored landfills in the CR falls within the requirements set for pH values. Electrical conductivity (EC) values for the Petrůvky landfill showed homogeneity, however for the Zdounky landfill EC values were significantly higher. The concentrations of nitrate (NO3– ) appear to have been affected both by the operation of the landfill and surrounding arable areas, although for both landfill sites, the average NO3 – values were seen to meet the CR water quality requirements. The contents of most of the monitored indicators were found to be at the level of the natural background, therefore not exceeding the critical values set by regulatory agencies. It was demonstrated that random high concentrations of pollution indicators can potentially be explained by runoff of contaminants from the section of both landfills where tires and/ or demolition wastes are stored. According to the Monte Carlo simulations it was also found that narrow contaminant plumes cannot be captured by a single downstream piezometer installed in the monitoring network. The outcomes presented in this work represent a novel aspect of environmental assessment as few studies have looked at groundwater quality in terms of temporal changes of contaminant indicators in locations where landfill facilities co-exist with agricultural lands.