EPA-97-L101-02-203

099

17,167 千元

2010/01/01

2010/12/31

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、大安溪流域及大甲溪流域水質狀況佳，未(稍)受污染等級全年比例均達80.2% 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。中區河川大致以上游水質較佳，下游氨氮污染濃度較高。今年度4月至9月份中部地區累積降雨量較高，河道受沖刷影響，造成部分河川懸浮固體偏高，如烏溪流域、新虎尾溪流域及北港溪流域等，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47.4%，中度污染等級佔次高比例34.3%，水質狀況與近 2 年差異不大。 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。整體水質，第二、三季水質狀況大多較第一、四季為佳，水質趨勢與歷年相似。 海灘水質監測通霄海水浴場，由今年度10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，海灘水質易受降雨及河川匯流之影響，造成水質結果變動。 水庫水質計有8座水庫，每季監測一次。各水庫均有部分測點不符合甲類陸域地面水體水質標準。中區水庫以日月潭水庫水質最佳，全年屬貧養等級比例佔 100 % ，其次為德基水庫及鯉魚潭水庫，全年屬貧養等級比例佔 50.0 % ，普養等級佔 50.0 % ，以大埔水庫及明德水庫水質最差，全年屬優養等級比例佔 100 % 。其他如霧社水庫則屬貧養至普養等級，永和山水庫及頭社水庫屬普養等級。 地下水水質監測計有 6 縣市，95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65.0%，Piper圖解則屬I區佔最高比例，為58.9%，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

EPA97L10102203.pdf

18MB

2011/3/1 上午 12:00:00

The aim of this project was to monitor the water quality of rivers, oceans, reservoirs and groundwater in the six counties located in the central part of Taiwan, to properly understand the changing trend of water quality in those types of water bodies over the passage of time, and evaluate and analyze the pollution to all water bodies that was conducted 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 Si-hu , Da-an, and Dajia River Basins was good, with an annual proportion of more than 80.2% to be of no (or slight) pollution. Meanwhile, Lu-gang, Sin-huwei and Bei-gang River Basins had a higher percentage, ranging from medium to high levels of pollution, with better water quality in their upper streams of the rivers in the central region, but higher concentrations of ammonia and nitrogen contaminants in lower streams. From April to September this year, higher rainfall had accumulated in the central region of Taiwan, where riverbeds were washed away, resulting in slightly high concentrations of suspended solids in some rivers, such as Wu River Basin, Sin-huwei River Basin and Bei-gang River Basin, deteriorating their water quality. Because of geological characteristics in the Zhuoshui River Basin, its water quality was grey and murky on regular days. On the whole, 47.4% of the 19 rivers surveyed this year were found to be of no (or slight) pollution, and 34.3% were found to be of medium pollution level. There was not much difference of water quality between that period and the past two years. The monitored result of water quality in oceans was compared with the standard of environmental quality of seas and oceans. The water quality of offshore Hsiang-shan (of Hsinchu County), Taichung Harbor and Chang-hwa Coastal area was rated Class-B ocean environment water body, and offshore Yun-lin was rated Class-A ocean environment water body. The results monitored this year were satisfactory to quality standard for the marine environment quality for categorized sea waters. On the whole, water quality in the second and third seasons was better than that in the first and fourth seasons, and the trend of water quality was similar to the past years. Water quality of Tung-hsiao Bathing Beach was monitored. The area was monitored ten times this year and results showed that the water quality of Tung-hsiao Bathing Beach was good. It may be rated as superior as a result of preliminary grading. Water quality of beaches may be affected by rainfall and merging river flows, resulting in changes to their water quality. Water quality of eight reservoirs was monitored once each season. At certain survey points of all reservoirs, water quality was found unsatisfactory to the standards for Class-A land surface water body. Among reservoirs in central Taiwan, the water quality of Sun Moon Lake Reservoir was the best, rated at 100% oligotrophe all year round; followed by Te-Chi Reservoir and Li-Yu-Tan Reservoir having a rating of 50.0% oligotrophe and 50.0% mesotrophe. The water quality of Ta-pu Reservoir and Ming-de Reservoir was the worst, rated at 100% eutrophe all year round. Others, such as Wu-she Reservoir was rated in a range from oligotrophe to mesotrophe. Yong-he-shan Reservoir and Toushe Reservoir were rated at mesotrophe. The monitoring of underground water quality was conducted through 95 wells spreading across six counties. The data obtained this year showed that, items exceeding underground water Class-B monitoring criteria were about the same as results found in previous years, mainly ammonia nitrogen, iron, and manganese. It is worth noting that ammonia nitrogen in wells in Chang-hwa County and Yun-lin County was higher than in other counties, which may be due to local geological characteristics. According to the assessment of water quality of all monitored wells, using Stiff-plotting analysis, the highest percentage was 65.0% for Ca2+ and HCO3-+CO32- , while the Piper-plotting method showed that Area I has the highest percentage, which was 58.9%. The trend was found to be consistent with the results of analysis conducted in the past years.

Water Quality Monitoring, Water Quality Standards, Method Detection Limit