To conduct an environmental risk assessment for metals in the groundwater of a site in Jiujiang City, Jiangxi Province, we analyzed seven metals (Cr, Zn, Pb, Ni, Sb, Cu, and Tl) that exhibited higher detection rates among the elements we measured. For example, in our measurement data, the average concentration of the element cobalt (Co) is less than 2 × 10^–3 μg/L, and the average concentration of the element cadmium (Cd) is less than 5 × 10^–3 μg/L. The purpose of this environmental risk assessment was to provide a scientific basis for site remediation and subsequent construction. The risk assessment was carried out using the single-factor pollution index, the Nemerow comprehensive pollution index (Pn), and potential ecological hazard index methods. Principal component analysis and correlation analyses were used to investigate the sources of metal pollution in the groundwater. The results indicated the following: (1) The average concentrations of the seven metals in the groundwater of the study area did not exceed the Class IV groundwater quality standard limits. The highest average concentration was for Zn (38.08 μg/L), indicating that metal concentrations in the groundwater were relatively low. (2) The Pn for the seven metals was below 0.7, indicating that the study area was at a non-polluted level. (3) The correlation and principal component analyses of the metals indicate that the sources of these metals may be residues from material stored in the raw material warehouse of the former iron smelting plant at the site. The results show that the level of groundwater contamination at the site falls within an extremely low range; thus, the focus on groundwater pollution can be reduced in subsequent site remediation and construction activities.