Development and application of Total Coliform load duration curve for the Geum River, Korea

The load duration curve methodology was developed as a useful protocol to estimate the exceedence probability of pollutant loading to a river. The technique was applied to estimate the Total Coliform (TC) loading to a monitoring location in the Geum River, Korea. The daily mean flow rate and TC concentration data from January, 1996 to July, 2004 from a monitoring station in Gongju were used. A procedure to construct flow and load duration curves for the TC loading for Gongju is presented. A standard duration curve reflecting the water quality criteria was constructed to determine water quality compliance. A comparison of the load duration curve with the standard duration curve for Gongju revealed that the water quality did not meet the desired water quality for about 47% of the exceedance probability. From the analysis of the TC load duration curve and standard load duration curve, it could be inferred that diffuse pollution was mainly responsible for the water quality degradation at Gongju.