The main tasks of this project are the integrated management groundwater quality monitoring of the Environmental Protection Agency, the investigation result reviews, the investigation and evaluation of substances on the Contaminant Candidate List(CCL), the rolling review of the groundwater preliminary concern candidate list(PCCL), the research and analysis of continuous water quality monitoring applications, and the strengthening of communication of groundwater management. First, review and update of monitoring items and their frequencies of regional monitoring wells, suitability assessment of well location by a screening of those monitoring wells that are suspected to be affected by domestic sewage, with identification of the potential sources of industry, agriculture and residential in key nitrogen hotspots by buffer analysis. In addition, for the efficiency of monitoring resources, a joint groundwater early warning monitoring plan for nitrogen and arsenic has been proposed by identifying their sources and potential areas in both deep and shallow groundwater well networks’ data. Besides, to determine the relationship between agricultural fertilization behavior and groundwater ammonia nitrogen sources, automatic continuous monitoring equipment for water quality was employed to observe continuous data of surface and groundwater water quality, and a vertical infiltration model of surface ammonia nitrogen and a groundwater ammonia nitrogen solute transport model was established to estimate the production of agricultural activities of nitrogen transport.
Moreover, the recent years’ CCL’s substances investigation results of relevant environmental media are integrated. Their management recommendation is proposed by conducting a follow-up and supplemental investigations of Per-and Polyfluoroalkyl substances (PFASs) and pesticides and evaluating the domestic and foreign management status of these CCL’s items. Because the source of boron in groundwater may be affected by natural backgrounds or human activities, boron in groundwater investigation from industries, geological boring, and soil analysis has been conducted for better knowledge of boron distribution and its potential sources in domestic groundwater. A workflow to identify boron sources in groundwater with suitable management options has been proposed. A PCCL review mechanism in groundwater is built to optimize the management strategies in this project. Last, the integration of recommendations for groundwater management and issues of cross-unit cooperation through expert consultation meetings and public meetings is completed.