EPA-97-L101-02-203

098

17,167 千元

2009/01/01

2009/12/31

吳坤立

監資處

梁淑婷

清華科技檢驗股份有限公司

環境監測及檢測

水質監測，水質標準、方法偵測極限

Water Quality Monitoring, Water Quality Standards, Method Detection Limit

許姝羚

03-5545022#215

meg@tsing-hua.com.tw

本計畫主要針對中區六縣市各類水體水質監測，掌握各水體水質隨時間的變化趨勢，並進行各水體污染評估分析，以提供環保單位污染防治決策之參考。 河川水質計有19條河川主支流，75個監測站，每月監測一次。今年度監測結果顯示，西湖溪流域、大甲溪流域與大安溪流域水質狀況佳，未(稍)受污染等級全年比例均達88.8% 以上。而鹿港溪、新虎尾溪及北港溪流域屬中度污染至嚴重等級佔較高比例，於河川上游水質較佳，下游氨氮污染濃度較高。8月份莫拉克颱風過境，中部山區降下豪大雨，降雨延時沖刷河道，造成部分河川水質變動，如烏溪流域、新虎尾溪及北港溪流域等，水中懸浮固體濃度偏高，水質狀況不佳。濁水溪流域因流經地質特性之故，水質於平日即呈現灰色混濁。整體而言，今年度中部地區河川水水質屬未(稍)受污染等級佔最高比例為50.6%，中度污染等級佔次高比例32.5%，水質狀況較近 2 年略有轉好情形。 海域水質方面監測結果與海域海洋環境品質標準進行比較，新竹香山沿海、台中港沿海及彰濱沿海屬乙類海域環境水體，雲林沿海海域屬於甲類海域環境水體，今年度監測結果均符合所屬分類海域海洋環境品質標準。今年度水質普遍較歷年為佳，台中港沿海以南大多數測站第二季及第三季水中營養鹽含量為歷年監測之最低值，其餘監測結果與歷年差異不大。 海灘水質監測通霄海水浴場，由今年度11次監測結果顯示，通霄海水浴場水質狀況佳。試分級結果大致屬優良級，於7、8月採樣時，因鋒面過境受降雨及河川匯流之影響，海水浴場水質監測結果，略有轉差情形。 水庫水質計有8座水庫，每季監測一次。由今年度監測結果顯示，與甲類陸域地面水體水質標準比較，日月潭水庫均符合水體水質標準，其餘各水庫以pH值不符合甲類陸域地面水體水質標準項目所佔比例最高。各水庫水質以日月潭水庫水質最佳，全年屬貧養等級比例佔 100%，其次為霧社水庫，全年屬貧養等級比例佔 75.0% ，普養等級佔 25.0% ，以大埔水庫水質最差，全年屬優養等級比例佔 100%。其他如鯉魚潭水庫及德基水庫則屬貧養至普養等級，永和山水庫、明德水庫及頭社水庫屬普養至優養等級。 地下水水質監測計有 6 縣市，93個監測井，由今年度監測結果顯示，超過地下水第二類監測基準之項目與歷年結果相近，主要以氨氮、鐵及錳為主。而以彰化縣及雲林縣境內監測井之氨氮測值，較其他縣市之測值為高，應是該區域之地質特性因素所致。各監測井之水質，以Stiff水質形狀圖方式評估，屬Ca2＋及HCO3－+CO32－凸出型佔最高比例，為61.0%，Piper圖解則屬I區佔最高比例，為57.5%，與歷年評析結果大致呈現一致趨勢。

水質監測，水質標準、方法偵測極限

EAP97L10102203(98年度).pdf

14MB

98年期末報告

2010/3/1 上午 12:00:00

The aim of this project was to monitor the water quality of rivers, ocean, reservoirs and groundwater in the six counties located in the central part of Taiwan. The monitoring data obtained in this work could be used to evaluate the current condition and to predict the quality changing trend of the water systems, and to provide information for the Environmental Protection Organization to make the pollution control policy. A total of 75 water-monitoring stations spread among the 19 rivers of the six counties were established, and the monitoring frequency was set to be once per month. The data obtained this year showed that the water quality of the Si-hu, Da-jia and Da-an River Basins were good among the rivers monitored, with an annual proportion of more than 88.8% to be of no (or slight) pollution. Meanwhile, the Lu-gang and Sin-huwei Rivers as well as the Bei-gang River Basin had a higher percentage, ranging from medium to high levels of pollution, with better water quality in their upper streams, but higher concentrations of ammonia and nitrogen contaminants in lower streams. In August when typhoon Morak hit Taiwan, mountain areas in central Taiwan experienced torrential rains, which had washed away the riverbeds, resulting in a change of water quality to some rivers, such as Wu River Basin, Sin-huwei River and Bei-gang River Basin, with higher concentrations of suspended solids in water, deteriorating their water quality. Because of geological characteristics in the Zhuoshui River Basin, its water quality appeared grey and murky. On the whole, among 50.6% of the 19 rivers surveyed this year were found to be of no (or slight) pollution, and 32.5% fell into the medium pollution level. The result was somewhat better than those of the past two years. The ocean water quality in the central part of Taiwan was also monitored. According to the data collected, the water quality near the seashores of Hsiang-shan (in Hsin-chu County), Tai-chung Harbor, and Chang-hwa all met the Water Quality Criteria of category B, while that of Yun-lin seashore met the Criteria of category A. The results monitored this year were satisfactory to quality standard for the marine environment quality for categorized sea waters. Water quality this year was generally better than the past years. At most monitoring stations to the south of Taichung Harbor, the content of nutrition salt in the water was found at the lowest level in the second and third seasons. Other monitored results were about the same as those in past years. For monitoring of water quality on beaches, Tung-hsiao Beach was chosen as a target. The area was monitored eleven times this year and results showed that the water quality of Tung-hsiao Beach was good. It may be rated as superior as a result of preliminary grading. When samples were taken in July and August, due to passing fronts and rainfalls, and the effect of merging of river waters, the result monitored at beaches showed somewhat deteriorated water quality. The water quality monitoring of the eight reservoirs was conducted once per season. As shown by the results of this year’s monitoring, with comparison made to the water quality standard for Category A land area and ground level water bodies, the results showed that the water quality of Sun-Moon Lake reservoir met the criteria. The other reservoirs were found to have failing pH values, not satisfying Category A water standards for land area and ground level water bodies. Of all reservoirs in central Taiwan, the water quality of the Sun Moon Lake Reservoir was the best, rated as 100% oligotrophe; followed by the Wushe Reservoir having a rating of 75.0% oligotrophe and 25.0% mesotrophe. The water quality of the Ta-pu Reservoir was the worst, rated as 100% eutrophe year round. The water quality of the Li-yu-tan Reservoir and Te-chi Reservoir was rated as oligotrophe to mesotrophe. The water quality of the Yung-ho-shan Reservoir, Ming-ter Reservoir and Tou-ser Reservoir was rated as mesotrophe to eutrophe. Finally, the monitoring of groundwater was conducted through 93 wells spread across the six counties. The data show that, among the monitoring items, ammonia nitrogen, iron, and manganese were found to be in excess of the Quality Control Criteria, and the same results were also observed in past years. It is worth to noting that ammonia nitrogen in the groundwater in Chang-hwa County and Yun-lin County, which could be attributable to the local geological characteristics, was substantially higher than that in the other counties. From graphical analysis of the monitoring items of groundwater obtained from each well using Stiff-plotting and Piper-plotting, the Stiff-plotting method shows that Ca2 and HCO3-+CO32- have the highest percentage, which is 61.0%, while the Piper-plotting method shows that the Area I has the highest percentage, which is 57.5%. A general trend similar to those in the past three years was observed, indicating that the groundwater quality in the area has no substantial changes.

Water Quality Monitoring, Water Quality Standards, Method Detection Limit