• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.647-654
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• 2009

Since the end of the 1990s, sewer pipe improvement works have been going on: most septic tanks have been thrown away and discarded. These discarded septic tanks amounts up to 370,000 based on the project plan 2005-2008: it is a serious squander of nation's resources, a contaminating means that buries toxins under soil, and a cause of a expensive waste. Research on recycling of discarded septic tank as a new resource is in urgent need. This research suggests plans to recycle discarded septic tank as a rainwater management facility, solutions to water cycle recovery in the limelight, and economic analysis of the plan. In the case of a recycling discarded septic tank as a rainwater management facility will socially benefit to support economical adequacy, discard cost saving of septic tank and water supply and sewage cost reduction will come out. Consequently a rainwater management facility converted from a discarded septic tank leads to decentralization of the rainwater management system, which anticipates a positive effect on recovery of urban water cycle.

• KIEAE Journal
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• v.6 no.3
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• pp.27-34
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• 2006

The recent emphasis on ecological urban development has led to the need to maintain a hydrologic cycle in urban areas. As such, this study proposes decentralized rainwater management, a concept of onsite rainwater management that involves the utilization, infiltration, detention, and retention of rainwater. The main objective of this research is to estimate the proportion of decentralized rainwater management that is needed. From the research that was conducted in this study, it was found that the total runoff quantity increases by 10-20% after district lands are developed, when the probable rate of precipitation every 10 years is within this range. Thus, the runoff rate can be reduced by 10~20% of the total runoff quantity through decentralization. On the other hand, in the scale of housing complex development, the total runoff quantity increases by as much as 10~40% due to the changes in the rate of the impervious surface area. If 10-40% of the total runoff quantity was processed through decentralized rainwater management, the rate of infiltration, detention, retention, and runoff in precipitation prior to development could be recovered.