• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.2
• /
• pp.265-274
• /
• 2011

Nowadays, the importance of non-point source pollution treatment is being emphasized. Especially, the easy runoff characteristic of highly concentrated pollutants in the roads makes the circumstance more complicated due to impermeability of roads. When the pollutants flow into steam it could make water quality in stream worse and it also causes a bad influence in the aquatic ecosystem because the effluents of rainfall-runoff may contain indecomposable materials like oil and heavy metals. Therefore, we tried to figure out the property of non-point source pollution when it is raining and carried out an assessment for the property of runoff for non-point source pollution and EMC (Event Mean Concentrations) of the essential pollutants during this study. As the result of the study, the EMC was BOD 5.2~21.7 mg/L, COD 7.5~35.4 mg/L, TSS 71.5~466.1 mg/L, T-N 0.682~1.789 mg/L and T-P 0.174~0.378 mg/L, respectively. The decreasing rate of non-point pollutant in Chungyang-Hongsung road indicates the maximum decrease of 80% until 5 mm of rainfall based on SS concentration; by the rainy time within 20~30 minutes, the decreasing rate of SS concentration was shown as 88.0~97.6%. Therefore it was concluded that it seems to be possibly control non-point pollutants if we install equipments to treat non-point pollutants with holding capacity of 30 min. It is supposed that the result of this study could be used for non-point pollutants treatment of roads in Chungyang-Hongsung area. We also want to systematically study and consistently prepare the efficient management of runoff from non-point source pollution and pollutant loading because the characteristics of non-point source pollution runoff changes depending on different characteristics and situations of roads and rainfall.

• Journal of Wetlands Research
• /
• v.18 no.1
• /
• pp.94-99
• /
• 2016

Non-point source control has been issued and intensively studied for the control of water quality in streams and rivers. In this study, non-point source pollutants monitoring was conducted at the end of five small streams which were connected to a main stream in three stages including Phase I (one hr before the rainfall), Phase II (one hr after the rainfall), and Phase III (six hrs after the rainfall). For all five small streams, the concentrations and loading rates of non-point source pollutants significantly increased due to the rainfall. As a result of this, priority control streams and priority pollutants were suggested to prepare for future plans of the non-point source control.

• Journal of Environmental Impact Assessment
• /
• v.20 no.5
• /
• pp.651-661
• /
• 2011

The purpose of this study is to estimate the characteristics and pollutant loadings of non-point pollutants that flowed in the streams on precipitation for pollutant loading reduction of Hwa-sung lake inflow streams. Although it has been made an effort to improve the water quality of Hwa-sung basin through the strategies for the preservation of water quality, it is shown that the water quality is not greatly improved. Because it has been industrialized and urbanized near Hwa-sung basin so that it is difficult to reduce the water pollution due to the increase in pollutant loadings of point and non-point sources. In this study, it is investigated the outflow characteristics of non-point pollutants that discharged with storm runoff and estimated the effect of runoff on Hwa-sung basin. The final goal of this study is to utilize the basic information for proper management and strategies of non-point sources on Hwa-sung basin. At the result of inflow streams, Ja-an stream that has the greatest pollutant loadings on precipitation is strongly influenced on the water quantity of Hwa-sung basin. On the other hand, it is shown that Nam-yang stream is strongly influenced on the SS concentration of Hwasung basin among them. Also, all streams; Nam-yang, Ja-ahn, Ah-eun stream; has the degree of slope more than or near 1 in the correlation results so that they have strong pollutant loading impact and the concentration of SS is the highest among other pollutants. So, specific studies on initial rain phenomena are more necessary to manage the pollutants economically. Also, the proper control of SS concentration is required to manage the effluent pollutants effectively on precipitation. So, it is necessary to consider the strategies for non-point pollutants as well as point pollutants when the new management is imposed to reduce the pollutant load for improvement of Hwa-sung basin.

• Journal of Environmental Impact Assessment
• /
• v.17 no.1
• /
• pp.1-9
• /
• 2008

Non-point pollution is caused by many diffusive sources, unlike a point pollution derived from industrial wastewater treatment plants or sewage treatment plants. Runoff of non-point pollutants is originated from rainfall or thawing in short period of time moving over and through the a ground surface. They cause ill effect on the quality of neighboring aquatic environment. To prevent effectively the wash off from non-point pollutant, it should be immediately reduced at the source or be treated after gathering of runoff water. This study has been carried out for the best width of riparian buffer zone. So we implemented the experiment in terms of its depth, width and kind of vegetations and calculated the reduction of pollutants loading. The experimental zone encompasses the watershed of Namhan River (Kyunggido Yangpyunggun Byungsanri). The region was divided into 5 land cover sectors : grass, reed, pussy willow, mixed(grass+pussy willow) and natural zone to compare effectiveness of vegetation. Water samples from four points have been collected in different depths. And the pollutant removal efficiency by sectors with different plant species was yielded through influent with one of each sample. And we obtained the correlation between the width of riparian buffer zone and the removal efficiency of pollutants. Using correlation result, the width of riparian buffer zones which needs to improve the water quality of river could be derived.

• Korean Journal of Ecology and Environment
• /
• v.34 no.1 s.93
• /
• pp.62-69
• /
• 2001

This study was investigated discharge and water quality for rainy days at the inflow streams (Gog-Kyo, Mu-Han, Sap-Kyo and Nam-Won) into Lake Sap-Kyo from June to November of 1999. The eventual aim of this study was to improve the water quality of Lake Sap-Kyo. Therefore, in order to reduce inflow pollutants loading into Lake Sap-Kyo, we investigated characteristics of stormwater runoff and estimated pollutant loading for the rainy season. The results of that Sap-Kyo stream is $5.75\;m^3/sec$ flow and influences water quantity of Lake Sap-Kyo greatly during the dry weather. Gog-Kyo stream influence to quantity of Lake Sap-Kyo greatly for the rainy days. Gog-Kyo stream and Sap-Kyo stream are $12.13\;m^3/sec$ and $8.49\;m^3/sec$, respectively. The reason is that the watershed area of Gog-Kyo stream is larger than other streams. When we prepare to plan management to improve the water quality of Lake Sap-Kyo, we have to consider that runoff characteristics by land use. Among the annual total pollutants loading inflow Lake Sap-Kyo, the ratio of non-point pollutants loading estimated that SS, BOD, T-N and T-P are 62%, 43%, 41% and 27%, respectively. Therefore, in order to improve water quality of Lake Sap-Kyo, we have to reduce non-point pollutants loading.

• Journal of Wetlands Research
• /
• v.13 no.2
• /
• pp.161-169
• /
• 2011

The objective of this study was to evaluate the efficiency of a modified filtration system treating non-point source (NPS) pollutants. The developed Best Management Practice (BMP) technology was designed based on the geographical and climatic characteristics of the site. A lab-scale test experiment was conducted using three different hydraulic loading rates representing the first flush flow, average flow and overflow conditions during a rainfall event. Water quality analysis was performed on the water samples taken at the inflow, outflow and infiltration during the test experiment of the lab-scale BMP. Also, the water and mass balance at different hydraulic loading rates was determined. Results from the lab-scale test experiment showed that the lab-scale BMP had a high removal efficiency of 80-90% for all NPS pollutants. The overflow test condition obtained the lowest removal efficiency among the hydraulic loading rates because it gave less opportunity for the pollutants to be filtered and retained inside system. The infiltration ratio was approximately 1 % of the inflow and outflow. Increasing the infiltration ratio requires technical approach of soil amendment where the BMP is installed.

• Journal of environmental and Sanitary engineering
• /
• v.22 no.4
• /
• pp.87-104
• /
• 2007

The objective of this study is to estimate the load of pollutants caused from the forest area among non-point pollutants within the Juam lake. The surveyed forest area was classified into broad-leaved, conifer, mixed and herbage area by forest tree type. Water quality and flux were investigated under rainfall and non-rainfall, respectively. Then, pollutant loading was evaluated by using the values of unit pollutant loading factor of each point and area of forest zone. Water quality analysis results of runoff by forest tree types were as follows. - Annual BOD, $COD_{Mn}\;and\;COD_{Cr}$ concentration of runoff in conifer area was high, and particle and biological recalcitrant compounds were flowed highly. - SS, T-N and T-P concentration was high in runoff from broad-leaved area, and biological degradable compounds was flowed. - Water quality of water from valley was maintained good under non-rainfall and could be utilized as fresh drinking water. Through water quality standard investigation, a countermeasure establishment was necessary to secure a good quality of drinking water - BOD, $COD_{Mn},\;and\;COD_{Cr}$ concentration of Bo-sung river was higher 1.5 times than other 2 streams, and because of high T-N, and T-P concentration in Songgwang stream, the management for this was necessary.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.3
• /
• pp.407-417
• /
• 2011

Nowadays, the high land use, mainly used for urbanization, is affecting runoff loads of non-point pollutants to increase. According to this fact, increasing runoff loads seems like to appear that it contributes to high ratio of pollution loads in the whole the pollution loads and that this non-point source is the main cause of water becoming worse quality. Especially, concentrated pollutants on the impermeable roads run off to the public water bodies. Also the coefficient of runoff from roads is high with a fast velocity of runoff, which ends up with consequence that a lot of pollutants runoff happens when it is raining. Therefore it is very important project to evaluate the quantity of pollutant loads. In this study, I computed the pollutant loadings depending on time and rainfall to analyze characteristics of runoff while first flush storm water and evaluated the runoff time while first flush storm water and rainfall based on the change in curves on the graph. I also computed contribution ratio to identify its impact on water quality of stream. I realized that the management and treatment of first flush storm water effluents is very important for the management of road's non-point source pollutants because runoff loads of non-point source pollution are over the 80% of whole loads of stream. Also according to the evaluation of runoff loads of first flush storm water for SS, run off time was shown under the 30 minute and rainfall was shown under the 5mm which is less than 20% of whole rainfall. These are under 5mm which is regarded amount of first flush storm water by the Ministry of Environment and it is judged to be because run off by rainfall is very fast on impermeable roads. Also, run off time and rainfall of BOD is higher than SS. Therefore I realized that the management of non-point source should be managed and done differently depending on each material. Finally, the contribution ratio of pollutants loads by rainfall-runoff was shown SS 12.7%, BOD 12.7%, COD 15.9%, T-N 4.9%, T-P 8.9%, however, the pollutants loads flowing into the steam was shown 4.4%. This represents that the concentration of non-point pollutants is relatively higher and we should find the methodical management and should be concerned about non-point source for improvement on water quality of streams.

• Journal of Korean Society on Water Environment
• /
• v.29 no.1
• /
• pp.97-106
• /
• 2013

The temporal and spatial variations of water quality in a stratified reservoir are fully dependent on the characteristics of inflow loading from its watershed and the transport regimes of pollutants after entering the reservoir. Because of the meteorological and hydrological conditions in Korea, the pollutants loading to reservoirs are mostly occur during rainfall events. Therefore it is important to understand the characteristics of pollutants loading from upstream rivers and their spatial propagation through the stratified reservoir during the rainfall events. The objectives of this study were to characterize the water quality variations in upstream rivers of Imha Reservoir during a rainfall event, and the transport and spatial variations of pollutants in the reservoir through extensive field monitoring and laboratory analysis. The results showed that the event mean concentration (EMC) of SS, BOD, $COD_{Mn}$, T-N, T-P, $PO_4-P$ are 8.6 ~ 362.1, 2.5 ~ 5.1, 1.5 ~ 5.1, 1.1 ~ 1.9, 8.3 ~ 57.1, 5.6 ~ 25.7 times greater than the mean concentrations of these parameters during non-rainfall period. The turbidity and SS data showed good linear correlations, but the relationships between flow and SS showed large variations because of hysteresis effect during rising and falling periods of the flood. The ratio of POC to TOC were 12.6 ~ 14.7% during the non-rainfall periods, but increased up to 28.2 ~ 41.7% during the flood event. The turbid flood flow formed underflow and interflow after entering the reservoir, and delivered a great amount of non-point pollutants such as labile and refractory organic matters and nutrients to the metalimnion layer of reservoir, which is just above the thermocline. Spatially, the lateral variations of most water quality parameters were marginal but the vertical variations were significant.

• Journal of Korean Society on Water Environment
• /
• v.24 no.1
• /
• pp.69-77
• /
• 2008

This study was conducted to know the characteristics of agricultural non-point source pollutants runoff by rainfall events at the upper catchment of Goseong reservoir in Gonjy city, Chungnam Province. For this study, the monitoring sites of the research catchment were set nineteen during the research period (between June 2005 and October 2006). Average runoff coefficient were observed 0.51 in 2005, 0.71 in 2006, respectively. The correlation coefficient (r) between the rainfall and peak-flow was investigated 0.787. By rainfall events, the water quality of the sites were shown like this : BOD 0.555~9.60 mg/L, T-N 0.01~13.50 mg/L, T-P 0.002~2.952 mg/L, and SS N.D~820.0 mg/L. The strong rainfall intensity was the most important factor of the soil erosion. The gabs of the arithmetic mean concentrations and the flow weighted mean concentrations were observed as the followings : BOD 0.0~29.2%, T-N 0.1~11.4%, T-P 0.4~95.2%, and SS 1.7~57.0% in 2005, and BOD 1.0~11.9%, T-N 0.7~7.3%, T-P 9.9~36.5%, and SS 6.6~36.5% in 2006, respectively. The BOD pollution load was 2,117 kg (36% of the total BOD loading of survey periods) while, T-N was 3,209.0 kg (27.9% of the total T-N loading of survey periods), T-P was 136.4 kg (37.4% of the total T-P loading of survey periods) and SS was 72,733.8 kg (51.8% of the total SS loading of survey periods) in the year 2005. In case of 2006, BOD load was 1,321.7, T-N was 2,845.8, T-P was 42.9, and SS was 16,275.8 kg, respectively.