Journal of Korean Society of Disaster and Security ISSN:2466-1147(Print) 2508-285X(Online) 한국방재안전학회 논문집

Currently in 2018, Korea has over 600 operating sewage disposal facilities. The law requires a sewage treatment plant to treat 500 tons or more of water per day, and a small-decentralized sewage treatment facility in a community to treat 50 tons or more to less than 500 tons of water per day. However, most facilities fulfill neither the quantity nor the quality requirements from the original design for such reasons as inflow of rainwater and ground water due to deterioration of pipelines and unauthorized input of wastewater in the pipelines. The research has selected 2 representative cases among the technical diagnosif sewage pipelines in many regions within the country to use it as the baseline of: hourly flowrate and BOD water quality analysis in both clear and rainy days, proper plant operation through inflow rate and ratio calculation, and diagnostic evaluation for deterioration of the pipelines and their accessary structures. This also suggests facilities that treats 500 tons or more of inflow per day to sample and analyze the water hourly for 24 hours once a week in both clear weather and rainy weather considering the influence of rainfall on a regular basis.