The vertical and horizontal migration patterns of zinc, cadmium, copper, and lead through the soil and shallow aquifer systems at two secondary zinc smelters were defined by use of soil coring and monitoring well techniques. The vertical migration of the same elements at a third zinc smelter also was defined. The migration of metals at the three smelters has been limited by attenuation processes to relatively shallow depths in the soil profile. Cation exchange and precipitation of insoluable metal compounds, resulting from pH changes in the infiltrating solution, were determined to be the principal mechanisms controlling the movement of the metals through the soil. Increased metal contents in the shallow groundwater systems have been confined to the imnediate plant sites. Soil coring was found to be an effective investigative tool but was not suitable by itself for routine monitoring of waste disposal activities. It should be used to gather preliminary information to aid in determining the proper horizontal and vertical locations for monitoring wells. The analyses of water samples collected in this project generally did not yield a stable, reproducible pattern of results. This indicates the need to develop techniques to obtain representative water samples. The failure of some well seals in a highly polluted environment also indicates the need for additional research into monitoring well construction.
This investigation is part of a state - wide investigation of groundwater resources being conducted by the State Water Survey Division. Records of more than 1400 wells have been tabulated. These wells penetrate one or more of three separate and distinct aquifers within the glacial drift . The three aquifers penetrated by wells in this are a have unrelated hydrostatic heads. The average daily pumpage from the middle deposits, the major producing aquifer considered in this report, was 7.917 million gallons. It was estimated that a total of 67,812 million gallons of water has been pumped from this aquifer. Water level pressure contour maps of the upper and middle waterbearing deposits show no similarity. Sufficient data are not available to permit the construction of a pressure contour map of the lower deposits. Values of the coefficients of transmissibility and storage have been determined. Values of the coefficient of transmissibility ranged from 10,000 to 400,000 and averaged about 40,000. Values of the coefficient of storage ranged from 0.00024 for short periods to 0.0065 for a 46 year period, the longest for which records are available. Using a coefficient of storage of 0.0065 it was determined that the amount of water removed from storage since pumping began was about 3,187 million gallons or about 5 percent of the total amount of groundwater withdrawn. The amount of inflow into the heavily pumped area at Champaign-Urbana is about equal to the 1948 rate of withdrawal indicating little if any recharge within the 630 contour of the cone of depression. The steep hydraulic gradient and low water levels near the area of heavy withdrawal, together with continued water level recession, suggests that the middle deposits at Champaign-Urbana have been developed to their maximum transmission rate and that some lessening of the rate of withdrawal would be necessary to maintain constant operating water levels.