• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.1-8
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• 2012

This study is to suggest a few efficient ways of rainwater utilization, through monitoring and analyzing 143 rainwater storage systems and 110 artificial recharge systems, which are installed in the recommended facilities by law, among the rainwater harvesting systems in Jeju Island. In the case that catchment facilities are damaged, rainwater could be contaminated by leaves and debris so that the rates of rainwater usages come to be lower. It is possible that contaminated rainwater could contaminate artificial recharge wells or rainwater discharging out of the rainwater harvesting system could result in flood and damage for the downgradient area. For maintaining high quality of rainwater and increasing rainwater utilization rate, it is necessary to install screening facilities and purification plant functioning precipitation and filtration. Also, in order to efficiently preclude the overflowing rainwater exceeding storage capacity, it is recommended to associate rainwater storage tanks with artificial recharge well or infiltration trench facilities.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.173-180
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• 2005

In this study, quantity and quality of collected rainwater by the ground collection system were investigated and the Rainwater Collection Prediction Model was developed to predict the amount of collected rainwater. The quantity of collected rainwater in the collection system was 9516 L(38.2%) and the quantity of infiltrated rainwater in the collection system was 9946 L(40.2%) through $25m^2$ area for the study period, respectively. Average turbidity of collected rainwater in collection system was 2.2 NTU, and average turbidity of infiltrated rainwater in collection system was 2.3 NTU for study period, respectively. The predicted amount by the model and the actual collected amount were 9842.4 L and 9516 L, which were very close showing that prediction was excellent. The optimal rainwater storage tank volume was simulated with a certain consumption condition for various cities with different rainfall patterns.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.1
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• pp.31-37
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• 2005

One of the major obstacles confronted in promoting the rainwater harvesting is the concerns of acid rain and heavy metals. Although there are many data concerning the quality of rainwater precipitation for the study of acid rain, the study on the quality of stored rainwater has been limited. In this study, we monitored the quality of stored rainwater at Galmoe middle school, where a rainwater harvesting system is installed and in use for more than two years. We measured water quality parameters such as pH, Electro Conductivity(EC), Dissolved Oxygen(DO), and some metals (aluminium (Al), chromium(Cr), manganese(Mn), zinc(Zn), copper(Cu), arsenic(As), cadmium(Cd), lead(Pb)). The monitoring period was during one year from September 9th 2003 to August 5th 2004. It was observed that the average pH of stored rainwater is neutral. DO is similar to tap water and EC is lower than tap water. Metal Concentrations are within the concentration specified in Drinking Water Quality Standard. Overall, the stored rainwater quality is good enough for sundry use and there's no threat of acid rain and air pollution, if the rainwater harvesting system is well designed and maintained.

• Environmental Engineering Research
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• v.18 no.2
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• pp.65-69
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• 2013

Despite the most severe weather and geological conditions, Korean people in earlier times were successful in maintaining sustainable water supplies because they understood the importance of rainwater management, and developed technologies and a philosophy which were needed to live under such circumstances. Recently, the Korean people have suffered frequent incidence of flood damage and drought, and have gradually started to remind themselves of the lessons of the past, which can be described as proactive, multipurpose rainwater management. Most of the problems associated with water and energy can be solved by the integration of rainwater management practices. The concept of multipurpose rainwater management and two examples of its practice are discussed. One is a design for a multipurpose rainwater tank which has been used in a building project, and is based on Korean philosophy. Secondly, a regulation was promulgated recently in Seoul that requires the building of rainwater tanks in new buildings over a certain size. The primary purpose is for the prevention of flooding, but water conservation is a secondary intention. Two examples of proactive rainwater management are discussed, one being public involvement in rainwater management, and the second being the rainwater piggy bank microcredit project. In order to maintain sustainability, to meet the requirements of the Millennium Development Goals, and to be prepared for the effects of climate change, it is expected that multipurpose and proactive rainwater management will be a very effective approach for both developing countries and developed countries. A worldwide network of scientific researchers, as well as a great number of professions, has suggested the promotion of rainwater management.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.1
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• pp.131-138
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• 2007

A rainwater utilization facility consists of its catchment area, treatment facility, storage tank, supply facility and pipes in general. The rainwater storage tank which occupies the largest area of the facility has been usually considered quantitatively for determining the storage capacity. Hence, there is little information on water quality improvement by sedimentation in a rainwater storage tank in operation. In this study, we measured the rainwater quality in a rainwater storage tank in operation during late spring and summer, and showed water quality improvement of turbidity removal of 25~46% by sedimentation in a rainwater storage tank under a fixed water level without inflow and outflow after runoff ceased. It is necessary to have a considerable distance between the inlet and outlet of the tank and, if possible, it is recommended that the design should allow for an effective water depth of over 3 m and supply rainwater near the water surface. The operation method which increases the retention time by stopping rainwater supply for insuring low turbidity is recommended when the turbidity of rainwater runoff is high. And also more efficient operation and maintenance of the rainwater utilization facility is expected through the tailored design and operation of the facility considering particle removal and behavior.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.230-238
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• 2008

This study evaluated the economic aspect of the rainwater harvesting facilities by hydrologically analyzing the inflow, rainwater consumption, rainfall loss, tank storage, and overflow time series to derive the net rainwater consumption and the number of days of rainwater available. This study considers several rainwater harvesting facilities in Seoul National University, Korea Institute of Construction Technology and Daejon World Cup Stadium and the results derived are as follows. (1) Increasing the water consumption decreases the number of days of rainwater available. (2) Due to the climate in Korea, a larger tank storage does not increase the amount and the number of days of water consumption during wet season (June to September), but a little in October. (3) Economic evaluation of the rainwater harvesting facilities considered in this study shows no net benefit (private benefit). (5) Flood reduction effect of rainwater harvesting facilities was estimated very small to be about 1% even in the case that 10% of all the basin is used as the rainwater collecting area.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.315-322
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• 2008

Recently there has been a great deal of interest in promotion of the utilization of rainwater. In this paper, we compared qualities of the rainwater collected from the top of vinyl houses to those of precipitated rainwater itself in Jeju Island. The pH of the collected rainwater was acidic and lower than the precipitated one. As a storm progresses, the pH of the collected water gradually increases. Ranges of EC of the precipitated and collected rainwater were 1-118 and $1-475{\mu}S/cm$. Most of Cl and turbidity values of the collected rainwater were less than 20 mg/L and 20 NTU, while those of the precipitated rainwater were less than 10 mg/L and 5 NTU. Differences in qualities between precipitated and collected rainwater indicate that qualities of the collected rainwater should be changed by the first flush effects, and imply that long term continuous monitoring for the qualities of collected rainwater is essential to quantify the first flush phenomenon more accurately.

• Journal of the Korea Institute of Building Construction
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• v.5 no.4 s.18
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• pp.165-171
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• 2005

Nowadays, a source of all water, which has been spent by a lot of people, is the rainwater The rainwater is directly relating human being' life. According to how to use rainwater. human being' life is abundant or poor. Due to the lack of underground filtration quantity, the water circulation of the city is discontinued and the underground ecosystem is destroyed. This study suggest that the unused underground space of building and temporary structure can be used into rainwater storage tank in the facility to use rainwater. Moreover, in this study, while the building is constructed, It is showed that the water used in construction can be replaced in the rainwater.

• Journal of Environmental Science International
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• v.12 no.3
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• pp.275-279
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• 2003

A water quality analysis of rainwater collected from catchment equipment(2m${\times}$1m) was conducted to determine its suitability for domestic purposes, in this study. As the results of analysis, the pH of rainwater was 6.3${\pm}$0.3, and the turbidity of rainwater was over the 5 times than drinking water guidelines. For the usage of rainwater as the domestic and drinking water, the rainwater is need to treat. The analysis value of BOD was about 3 mg/L and the values of heavy metal as the Pb, Cd, Fe, Mn, Cr$\sub$6/$\^$+/and Cu was satisfied with drinking guidelines. Overall results of analysis support the possibility of rainwater as the domestic and drinking water.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.11-20
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• 2012

The aim of this study is to accumulate the data about the roof-harvested rainwater quality characteristics for the better rainwater management. According to the results of rainwater quality indicators (pH, COD, TSS, T-N, T-P, $NH_4$-N, $NO_3$-N, enteric bacteria, heterotrophs, Pb, Cd, Cu), the rainwater qualities of the first flush of roof-harvested was the most polluted about 2 or 3 times (more than 100 times in microbial contamination) compared to the qualities of directly collected rainwater. In the first 10 min flush, over the 60% amounts of contaminant were released from the roof during 30 minute rainwater monitoring. Through statistical factor analysis, relatively close items(variables) can be categorized. It is expected that the continuous monitoring of the roof-harvested rainwater will help to design the safe and economical rainwater storage system in Korea.