The occurrence of cyanobacterial blooming and the contaminant sources were analyzed in the downstream of Jecheon Stream, a tributary of Chungju Reservoir. The concentrations of chlorophyll a at the Myungseo Fishing Point (GPS; 37°03′25.5″N, 128°03′13.6″E) were 399.2 and 184.8 mg m-3 on October 18, 2015 and September 25, 2016, respectively, and the concentrations of total microcystins, a cyanobacterial toxin mainly produced by Microcystis, were 124.09 and 79.71 μg L-1, respectively. The occurrence of cyanobacterial blooming at the downstream of Jecheon Stream was closely related to the water level of Chungju Reservoir. The cyanobacterial blooming occurred after the increase of water level in Chungju Reservoir, when the water body stagnated. As a result of analyzing National Water Quality Monitoring Data of the upper region of Jecheon Stream, the main source of pollutant was Jangpyeong Stream, the tributary of Jecheon Stream, and the discharge water from Jecheon Wastewater Treatment Plant located in Jangpyeong Stream was considered to be the most important source of contaminant.

Abstract
서 론
재료 및 방 법
    1. 시료 채취
    2. 수질 분석 항목 및 방법
결과 및 고 찰
    1. 제천천 하류의 녹조 발생 현황 분석
    2. Microcystins 농도 분석
    3. 수질측정망 자료를 통한 오염원 유입 현황 분석
결 론
적 요
REFERENCES

• 전유호(충북대학교 공과대학 환경공학과) | Yu-Ho Jeon (Department of Environmental Engineering, Chungbuk National University)
• 김도환(충북대학교 공과대학 환경공학과) | Do-Hwan Kim (Department of Environmental Engineering, Chungbuk National University)
• 오경희(충북대학교 공과대학 환경공학과) | Kyoung-Hee Oh (Department of Environmental Engineering, Chungbuk National University)
• 조영철(충북대학교 공과대학 환경공학과) | Young-Cheol Cho (Department of Environmental Engineering, Chungbuk National University) Corresponding Author