The Keelung River catchment protected area and sections of Dahan Creek downstream of its rear detention pond were studied in this project. The project objectives included 1)water quality trend analysis and supplementary sampling to better understand pollution distribution and loading within the studied area; 2)formulating water quality goals and strategies by stages, and selecting the best solutions ; and 3)constructing Danshui River’s environmental information webpage and other visual presentations. Firstly, water quality data from the past 10 years were used for trending analysis, and sampling was undertaken to identify critical water quality issues in order to help estimating pollutant loading in the river water quality model constructed. According to the analysis outcomes, the critical factor for water quality in the Keelung River catchment protected area was ammonia nitrogen, and the critical river section was that downstream of Jieshou Bridge, which was mildly to moderately polluted. Between Dahan Creek’s rear detention pond and Banshin reservoir, the critical water quality factor was suspended solids, and was overall none or mildly polluted only. Downstream of Banshin reservoir intake, suspended solids and ammonia nitrogen were both critical, and the river section was mostly moderately to highly polluted.By referring to the water utilisation and relevant regulatory requirements, and considering the current water quality, management and oeprational objectives, and economic and financial feasibilities, short, mid, and long term water quality improvement goals can be developed. The short-term goal was mostly related to improving the river pollution index (RPI), and mid and long-term goals were to achieve the water quality classification level. Finding an optimal solution to pollution reduction was mainly based on following the existing point source pollution control implementation plan, and evaluating costs and benefits of pollution control measures. Options considered included more stringent control and auditing for quarry wastewater discharge, speeding up construction of sewerage infrastructure, on-site treatment for moderately polluted river branches, and interception of highly polluted sections.To let general public access the Danshui River information, all the study results in this report are exhibited in the Environmental Information WebPages and diagrams

Pollution Control, Keelung River, Dahan Creek