The aims of this study are the characterization of runoff from nonpoint source, the
analysis of the pollutant loads and an establishment of a management plan for nonpoint
source of Okcheon. For this purpose the basin of the stream So-okcheon was selected to
the investigated. During the period from May 29 to July 21 in 2003, the water
automatic sampler system has been installed in Okkagkyo and parameters such as SS, COD,
TOC, TP and TN were analyzed. The pollutants of nonpoint source seem to be washed out
along the stream water in the beginning of rainfall, remain in water and cause the
stream pollution. The runoffs during heavy rainfall, especially, much higher
concentration of SS than those during dry period. With respect to the annual loading of
pollutants of the nonpoint source, the COD was 124 ton/yr, TOC 396 ton/yr, TN 1,429
ton/yr and TP 4.2 ton/yr in the year 2002. With respect to the pollutants loading of
the nonpoint source, the COD was 375 ton/yr(95percentage of the total COD loading of
394 ton/yr), TOC 844 ton/yr(96percentageof the tatal TOC loading of 876 ton/yr), TN
1,985 ton/yr(96percentage of the total TN loading of 2,062 ton/yr) and TP 37.1 ton/yr
(92percentage of the total TP loading of 40.3 ton/yr) in the year 2003.