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constant, metered flow of distilled water to the columns was built. The constant flow drip system was built from a peristaltic pump equipped with nine metered pump tubes with flow rates of 25 ml per hour. Three foot lengths of Tygon tubing with inside diameters of 2.5 mm were attached to the pump tubes. The delivery ends of the Tygon tubing were suspended 25 mm above each column. Distilled water, with an electrical conductivity of less than 2 umhos/cm @ 25°C, was pumped through the tubing and delivered into the column. Flow rates of water for several samples were required to be reduced due to less leachate volume being obtained versus the volume of water being added to the column. In these samples, sufficient water was kept in the column to keep the leach sample covered. Collection and Measurement t After the leach samples in the columns became saturated with water and leachate began to flow into the collection flasks, leachate fractions were collected every two hours. Volume and electrical conductivity ' measurements were made on the collected fractions. ' The fractions were then poured into one sample bottle for each leach column. The leaching process continued until the electrical ' conductivity readings for five consecutive fractions changed less than 30 umhos/cm @ 25°C. The leaching process varied in the amount of time ' for completion for each sample. This variation was dependent upon the texture of the sample and the amount of salts in the sample. ' Graphing of Leachate Analytical Data ' Once the leaching process was complete, graphs were made of the data obtained from the leaching process. These graphs, found in Tables 3 t through 11, Column Leach Analysis Data, compare electrical conductivity in umhos/cm @ 25°C of leachate fractions collected every two hours ' versus the volume of accumulated leachate per sample weight in ml/g of sample. These graphs also contain miscellaneous information regarding ' the leaching process. t -4-