The landfills for six ferrous foundries in Wisconsin were instrumented with suction lysimeters to sample leachate directly from the waste above the zone of saturation. All landfills disposed of only foundry process solid wastes had minimal known changes in processes and waste over the period of landfilling in the areas tested and were not located in ground water. The quality of leachate from the lysimeters was compared to the quality of leachate obtained by laboratory leach testing of the auger cuttings obtained during lysimeter installation and to leach tests performed on composite raw waste samples obtained directly from the foundries.
It is concluded that, even though the (EP) (acid) test was able to predict the presence or absence of a contaminant in landfill leachates over half of the time, the test was inaccurate, in some cases grossly inaccurate, in predicting the actual field concentrations. It is also concluded that the EP (water) test was basically equal to the EP (acid) test in being able to predict the presence of absence of a contaminant in landfill leachates.