National pilot projects for management of diffuse pollution in Korea

Extensive effort through point source controls, such as the construction of wastewater treatment plants, has been continuously made not only to improve the water quality but also to protect the water resources since 1990 in the Han River basin, Korea. However, it is difficult to maintain biochemical oxygen demand (BOD) concentration below 1.0 mg/L and not able to meet the standard for drinking water sources. One of the main reasons for not achieving the target of water quality management is pointed out as to take insufficient measures toward diffuse pollution, particularly in the control of stormwater discharge. In March 2004, the Comprehensive Measures for Non-point Source Pollution Management in the Four Major Rivers were established under the leadership of the Prime Minister’s office and through the cooperation of related ministries. The effective control of Non-point Source (NPS) holds the key to the success of fulfilling total maximum daily loading (TMDL) program. As a part of carrying out policies on NPS pollution management, various types of NPS pollution pilot facilities were installed in the Han River basin at the end of 2005 and are continuously being installed in the other major rivers. The research program will be used to identify and design the Best Management Practices for the Han River and other river basins in Korea.

The Ministry of the Environment in Korea has established the Comprehensive Measures for Non-point Source Pollution Management in the Four Major Rivers in 2004 and approximately 12.1 US$ million over the previous 4 years have been invested to determine catchment areas, collect runoff characteristics and evaluate the treatment performance of 25 BMPs. From the feasibility study, it is concluded that site-selection criteria should consider local hydrology, land use, receiving water characteristics and specific requirements of the BMP types. Although not all BMPs have been evaluated, early results suggest that media filters are capable of producing substantial water quality improvements, while BMPs requiring vegetation present challenges for management and requiring longer start-up time, necessitating longer monitoring program to obtain representative results. The results of pilot facilities will be used to identify, to design BMP types and to optimize NPS management polices of Korea.