High concentrations of iron have recently been observed in groundwater and soils around municipal solid waste landfills in Florida. The levels have been attributed to reductive dissolution from native iron in the soil perhaps caused by the presence of the landfill itself, which inhibits the reaeration of the shallow aquifer beneath the landfill. If the iron is associated with leaking of landfill leachate into the subsurface, then other more environmentally-significant contaminants associated with landfill leachate may also migrate downstream. The goal of this research was: 1) to investigate the key parameters governing reductive dissolution of iron that leads to release of iron downstream of landfills; 2) to develop a list of engineering management alternatives for controlling the release of iron in-situ; and 3) to conduct laboratory experiments on methods for iron and possible co-contaminant removal from groundwater at landfill impacted sites. A priori, the groundwater circulation well technology shows promise as a relatively low cost and potentially effective management technology for elevated levels of iron in the subsurface.  The technology introduces air into the zone of influence to stimulate microbiallymediated processes to biogeochemically convert dissolved iron to relatively immobile Fe(III) species. In the first year of the research, a bench scale model was developed to test multiple parameters such as aeration rate, soil type, removal efficiency, zone of influence,
etc. The models were tested using soil from Boca Raton and from Polk County.

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