This study investigated the levels of eight metallic elements in groundwater of 15 tap water treatment plants (TWTPs) located in the North of Jiangsu Province, China during 2007–2009, and evaluated the non-carcinogenic risks posed by the metals. Among the metals, Zn had the highest concentration (105.3 μg L−1), while Pb contributed most (40.3%) to the average hazard index (HI) of 15 TWTPs, followed by Cd (33.8%) and Mn (12.2%). Each metal, except Pb, had an average concentration below the permissible limit of China, WHO, EU and USA. Both hazard quotients of individual metals and HI of total non-carcinogenic risk in each TWTP were lower than 1, indicating that these pollutants provided negligible public health risk for local residents. Non-carcinogenic risks induced by metals showed temporal and spatial variations, revealing that low HIs occurred more frequently in high water seasons, and the three TWTPs of Xinan, Suqian and Biantang had relatively higher HIs.