Variation Tendency of Drinking Water Source Qualities in Taipei Metropolitan

• Main Authors: Chang-Ming Wu, 吳昌明
• Other Authors: Ting-Chi Hsu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/43171103714252500342

碩士 === 淡江大學 === 水資源及環境工程學系碩士班 === 96 === The Nan-shi creek and Bei-shi creek are the main drinking water source for 5 million people in Taipei metropolitan. Using water quality data monitored during 1990-2006, this study evaluated the variation tendency of source drinking water qualities in Taipei metropolitan. The biochemical oxygen demand (BOD), ammonium nitrogen (NH4+) and total phosphate (TP), and coliform bacteria are represented for organic, nutrient and bacterial pollutants, respectively. The result shows that the annual average BOD of both Nan-shi creek and Bei-shi creek is less than 1.0 mg/L. This indicates that water quality of these creeks meet the water quality classification standards of A category. However, the NH4+ and TP increase 0.85 times and 0.35 times in Bei-shi creek, respectively, while they are 2.33 times and 1.23 times in Nan-shi creek during the past decade. Comparing water qualities between these two creeks, it shows that the BOD, TP and coliform bacteria concentrations of Nan-shi creek are 1.31 and 1.90 and 8.05 times, respectively, as that of Bei-shi creek. The results imply that the water pollution in Nan-shi creek is heavier than Bei-shi creek. Furthermore, the water qualities of three monitor stations at the upstream of Bei-shi creek show that the BOD decreases dramatically, while the increases of TP range from 1.07 to 1.49 times. The Calson trophic state index was used to evaluate the trophic state of water quality of Feitsui reservoir. Based on the water qualities of seven monitor stations at upstream of Feitsui reservoir, it shows that the water quality is in mesotrophic state for most time. However, the TP concentration increases from 9.2-16.96 μg/L to 20.51- 26.38μg/L during the past decade. The increase of TP concentration enhances the potential of eutrophication on Feitsui reservoir. Therefore, it is necessary to conduct eutrophication control strategies for protecting drinking water source.