Background and purpose: Groundwater resources are one of the most important water sources for domestic,agricultural and industrial sectors especially in arid and semi-arid environmental area. The main purpose of this study was to investigate the quality of groundwater in a semi-arid environment area in Malayer,Hamedan Province, with respect to a four-year monitoring data using water quality index(WQI).
Materials and methods:The monitoring data related to 14 water quality parameters associated with 26 sampling wells in 2012-2013 and 19 sampling wells in 2010-2011 were provided. The trend of pollution was considered by a paired-sample t-test between these two time periods. Spearman correlation coefficient was utilized to study the interrelationship among the water quality parameters.The overall quality of water was considered using water quality index.
Results: The amount of chlorine residue in 50 percents of the stations was zero. In addition the fluoride in 14 stations was less than 0.5 mg/l and for 80.7 percents of the stations the nitrate values were higher than 13 mg/l. Although there was a significant difference between the level of some parameters between these two time periods however this difference was not that much noticeable.76.9 percents of the stations were slightly to moderately polluted based on the results of water quality index.
Conclusion: Although the overall quality of groundwater has not deteriorated according to WQI but there is a health risk of water for local people especially associated with the results of nitrate in the study area.