國內部分河川水質污染嚴重,不僅影響飲用水水源水質、公共衛生及環境品質,對兼具灌溉用途之河川,可能危害農作物之成長並造成土壤污染問題,更甚者會因污染物累積於農作物間接影響人健康。本文將以新竹茄苳溪流域為探討對象,彙整過去相關計畫及筆者參與其一計畫等之成果作一綜合討論,以瞭解該河川水質污染之種類與來源及作為農作物灌溉使用之適當性等,並提供有效解決河川水質污染之認知等。 由於茄苳溪源頭長期呈無水狀態,流域內之水源主要來自於新竹工業區污水處理廠之放流水及沿岸工廠之排放水,也受到生活、事業廢水等持續不斷排入之影響,其河川水質遭受嚴重污染,河水水體呈暗紅色,主要為新竹工業區污水處理廠排放具色度之放流水所致,而水質中SO4-2、CI-、鈉吸收率及電導度均超出灌溉用水水質標準,尤其是鈉吸收率及電導度兩項超出標準甚多,並不適於供農作物灌溉使用。因此,針對改善茄苳溪水質色度、鹽類等問題及檢討其灌溉用途而言,除建議可提昇新竹工業區污水處理廠處理能力並以灌溉用水水質標準為處理目標外,亦可由修改河川水體水質標準或灌溉用水水質標準著手,同時相關主管單位亦應積極協調尋求替代灌溉水源之可能性。
The pollution of rivers will affect not only the quality of drinking water sources, public health, and environmental quality, but for those with an irrigation purpose, it may also endanger the growth of crops and cause soil contamination problems. Furthermore, the pollutants accumulated in crops may possibly influence human health. With the Chei- Tong River at Shin Chu as an example, the authors collected data from relevant past research, discussed the water quality pol1ution problem of the river, and finally provided effective solutions for the problems. The water in this river mostly came from the discharge of some plants along the river and the wastewater treatment plant of Shin-Chu Industrial Park. It was found that the river water appeared dark red. This was primarily due to the discharge from the treatment plant and the SO4-2 and Cl- in the water. The conductivity and SAR (Sodium Absorption Rate) of the water, in particular, were much higher than irrigation water quality standards. Therefore, it was concluded that the water of Chei- Tong River was not appropriate for irrigation purposes. To solve these problems, the authors suggested that the treatment capability of the wastewater treatment plant should be improved, the water quality standards of the river or for irrigation usage should be revised, and the relevant governmental institutions should actively look for other alternative irrigation water sources.