| Contents Notes |
"Laboratory and field investigations were conducted to study factors affecting the mobility of metals in soils.The project focused on subsoils associated with waste disposal sites and examined a wide range of conditions that might be present influencing movement of metals. Field and laboratory work demonstrated acidic wastes associated with a battery recycling operation has combined with the relatively poor metal retention properties of the soils in the area to transport excess lead to the shallow groundwater zone in a southeastern Louisiana location. Conversely, field and laboratory data indicate a soil with a higher clay content and a near neutral to slightly alkaline pH can effectively immobilize high levels of metals such as now-closed disposal pits used for metals plating and other waste at an Oklahoma Air Force base. The study showed Important interactions between soil types, metals, metal concentrations, and the presence of additional nonmetallic waste materials (co-wastes) on the movement of metals in subsoils. Disregarding any of these factors when evaluating the potential for metals leaching at a contaminated site could result in large errors in predicting metal mobility and the potential for groundwater contamination. The most significant new information from this project pertains to the effects of co-wastes, when present, on facilitating the movement of trace and toxic metals in subsoils. The findings of this project lead to the recommendation that more research should be done to: (1) identify the important characteristics of various types of co-wastes that facilitate metal mobility, and (2) quantify these effects to aid in development of models predicting metal mobility in subsoils. The particular metals present, the amounts of metals present, and soil properties must also be considered as all of these parameters interact in affecting metal mobility in subsoils." |
