Water quality was monitored for one year at a hillfill, a balefill, a millfill, a strip mine landfill, and a permitted sanitary landfill to determine the impact of each on water quality. The leachate generated by the hillfill was the strongest during initial decomposition. However, during the study period, it was in the final stages of anaerobic degradation and therefore was of low strength. The balefill produced a low strength leachate since this method of landfilling results in channeling of water through the landfill. The millfill generated the strongest leachate among the leachates analyzed during the study period as a result of the decomposition of the refuse which was accelerated by milling. The strip mine landfill generated a leachate of moderate strength. The permitted sanitary landfill also produced a leachate of moderate strength.