EPA-97-L101-02-203

097

17,167 千元

2008/01/02

2008/12/31

吳坤立

監資處

梁淑婷

清華科技檢驗股份有限公司

環境資訊系統

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

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，以西湖溪流域水質狀況最佳，而鹿港溪及北港溪流域屬嚴重污染等級佔較高比例。 7至9月數個颱風過境，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，如大甲溪流域、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。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47.3%，中度污染等級佔次高比例35.3%，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8月第三季監測期間因颱風過境降雨量增加，水溫、鹽度及部分重金屬測值與歷年略有差異，第四季監測時水質測值已回復至歷史監測範圍。 近岸休憩海域計有3個測站，由今年度7次監測結果顯示，以通霄海水浴場之水質狀況較佳。於6、7月採樣時，因鋒面過境受降雨及河川匯流之影響，各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，日月潭水庫各監測項目均符合甲類陸域地面水體水質標準。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42.9%，另以大埔水庫水質最差，全年屬優養等級比例佔85.7%。鯉魚潭水庫、德基水庫之水質變動較大，水質屬貧養至優養等級，其他水庫如明德水庫及頭社水庫則屬普養至優養等級，永和山水庫及霧社水庫屬貧養至普養等級。 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62.0%，Piper圖解則屬I區佔最高比例，為53.6%，與近 3 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

KM-99976946-7.pdf

8MB

[期末報告]公開完整版

2009/2/1 上午 12:00:00

The aim of this project was to monitor the water quality of rivers, ocean, reservoir dams and groundwater in six counties located in central Taiwan. The monitoring data obtained in this work can be used to assess the current condition, to predict the changing trend of the water system quality and to provide information for the environmental protection research to develop pollution control policies. A total of 75 water-monitoring stations were established, spreading along 19 rivers in these six counties, and the monitoring frequency was set as once per month. From the data obtained, the result shows that the water quality of the Si-hu River was the best among the rivers monitored, while the Lu-gang and Bei-gang Rivers were found to contain a relatively high degree of pollution. As to the suspension solids concerned, the density measured from July to September in the Sin Huwei, Bei-gang, Da-jia and Wu Rivers was remarkably higher than that in other months. This is possibly due to a large quantity of rainfall in the mountain areas of these six counties and the landfall of several typhoons during summer season. In summary, 47.3% of the 19 rivers surveyed this year found no pollution, and the rest of other 35.3%, contained medium levels of pollution. The result was slightly better than those during the past two years. The ocean water quality in 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 met the Water Quality Criteria of Category B, while that of Yun-lin met the Criteria of Category A, and the result shows that the water quality all met the criteria this year (2008). Due to increased rainfall brought by the landfall of a typhoon in August of the third quarter this year, a certain degree of difference was monitored in terms of water temperature, salinity and some heavy metals; however, the monitored water quality value of the fourth quarter returned to the historical monitoring scope. In this task, three ocean water monitoring stations were established. The water quality of Tung-hsiao Beach Resort was found superior than others based on the results from 7 rounds of sample taking. However, the data obtained in June and July was obviously worse than others, and this fact could be attributed to heavy rainfall and the conflux of rivers. The water quality monitoring of the said 8 reservoir dams was conducted once per quarter. The results show that the water quality of the Sun-Moon Lake Reservoir Dam, which met the Water Quality Criteria of Category A, was the best among all reservoirs monitored. It belonged to oligotrophe, taking about 42.9% of the year. In addition, the water quality of Ta-pu reservoir, which was the worst among all reservoirs monitored, belonged to eutrophe, taking about 85.7% of the year. In this respect, the Li-Yu-Tan Dam and Der-Ji Dam showed bigger fluctuation of water quality, which ranged from oligotrophe to eutrophe levels. As for other reservoir dams, the Minder Reservoir Dam and Tousher Reservoir Dam belong to mesotrophe to eutrophe levels; whereas, Yunghoshan Reservoir Dam and Wusher Reservoir Dam belong to oligotrophe to mesotrophe levels. Finally, groundwater monitoring was conducted for 93 wells spread throughout these six counties. The data shows that, among the monitoring items, ammonia nitrogen, iron, and manganese were found to be off from the Quality Control Criteria of Category B, and the same results were also observed during these past years. It is worthy to note that the ammonia nitrogen content of the groundwater in Chang-hwa County and Yun-lin County, which could be attributable to local geological characteristics, was substantially higher than that in other counties. From graphical analysis result of the groundwater monitoring items obtained from each well using Stiff-plotting and Piper-plotting method, the Stiff-plotting method shows that Ca2＋and HCO3－+CO32－ have the highest percentage, which is 62.0%, while the Piper-plotting method shows that the Area I has the highest percentage, which is 53.6%. A general trend similar to those during the past three years was observed, indicating that the groundwater quality in the area has seen no substantial changes.

Water Quality Monitoring, Water Quality Standards, Method Detection Limit