Adaptation of water quality index (WQI) for groundwater quality assessment near the landfill site

In this paper the level of groundwater contamination near the municipal landfill site is examined. A modified WQI was used to determine the change in groundwater quality. A total of 127 groundwater samples were analyzed for pH, EC, PAH, TOC, Pb, Cu, Cd, Cr, Zn, Hg. The mean value of the WQI for groundwater outflow from the landfill was 8.01, which means a very high landfill impact. Most contaminated water was in piezometers P2 and P3 located to the east from the landfill border with the WQI value of 9.12 and 10.48, respectively. The WQI in the P1 piezometer, situated to the north-west of the landfill reached a value of 4.41. The highest WQI value in analyzed water was recorded in summer (mean: 10.59); the lowest in March (mean: 4.57). The trend line equation point to a stabilizing water quality in P1 and P2 and a growing trend in P3.