Using COP Model to Map the Vulnerability of Groundwater Wells Adjacent to Landfills

Protecting the quality of the groundwater is of the utmost importance, particularly in countries such as Jordan, where the groundwater comprises a significant portion of the total water resources. A groundwater vulnerability assessment is one of the viable preventive measures that is normally used to preserve this strategic water resource. Groundwater vulnerability maps provide information on the groundwater basins that are vulnerable to contamination, particularly those coming from the landfills, and thus, they can be used for sustainable land use planning. The general goal of this study was to map the groundwater vulnerability to contamination and evaluate the impact of landfills on the groundwater quality at five landfill sites in Jordan, i.e., Akaider, Al-Husaineyat, Madaba, Dair Alla, and Azraq by using a COP hydrogeological model. The COP method is an European approach for aquifer vulnerability in the karst regions. This method uses the parameters: C—Concentration of flow; O—Overlying layers; P—Precipitation. Unlike the other methods, the COP model allows for us to assess the impact of the karst systems if they exist. For the study area, daily rain records from three weather stations surrounding each landfill were used. Along with the vulnerability maps, Peizometric maps for Akaider, Azraq, Dair Alla, Madaba and Al-Husaineyat were produced that assisted in our efforts to determine the wells located in the upstream and downstream of each targeted landfill. The water quality was tested two times in the upstream and downstream wells of each targeted landfill to explore the potential impacts of the landfills on the groundwater wells. The developed vulnerability maps show that most of the lands surrounding the landfills’ areas, within a diameter of 15 km, are located in low to very low vulnerability areas, except for the Al-Husaineyat landfill in Mafraq where a significant part of it lies in a moderate vulnerability area across a fault section. Additionally, the results of the water analysis from the surrounding wells indicated that there was no clear evidence of the contamination of the groundwater resulting from surrounding landfills, which was in agreement with the produced vulnerability maps.