[en] The potential for using zero-valent metals to remediate contaminated groundwater has been recognized since the early 1990s. This paper reports on possible enhancements achieved by plating small amounts of nickel onto the iron surfaces. The half-life for trichloroethene, for example, was shown to decrease from about 30 min in the presence of granular iron to about 3 min with the enhanced iron. Based on the results of the laboratory tests, an above-ground pilot-scale field test using the enhanced iron was initiated in New Jersey in July 1996. Groundwater at the site contains dissolved tetrachloroethene, cis 1,2-dichloroethene and trichloroethene at concentrations of up to 15, 1 and 0.5 mg/L, respectively. A granular iron treatment canister has been in operation at the site since November 1994. Performance of a canister containing only iron, but the performance was substantially below expectations based on the results of the laboratory tests. Investigations are continuing in an attempt to determine the cause of the difference in laboratory and field performance