• Korean Journal of Ecology and Environment
• /
• v.55 no.2
• /
• pp.111-119
• /
• 2022

The occurrence of cyanobacterial blooming and the contaminant sources were analyzed in the downstream of Jecheon Stream, a tributary of Chungju Reservoir. The concentrations of chlorophyll a at the Myungseo Fishing Point (GPS; 37°03'25.5"N, 128°03'13.6"E) were 399.2 and 184.8 mg m^-3 on October 18, 2015 and September 25, 2016, respectively, and the concentrations of total microcystins, a cyanobacterial toxin mainly produced by Microcystis, were 124.09 and 79.71 ㎍ L^-1, respectively. The occurrence of cyanobacterial blooming at the downstream of Jecheon Stream was closely related to the water level of Chungju Reservoir. The cyanobacterial blooming occurred after the increase of water level in Chungju Reservoir, when the water body stagnated. As a result of analyzing National Water Quality Monitoring Data of the upper region of Jecheon Stream, the main source of pollutant was Jangpyeong Stream, the tributary of Jecheon Stream, and the discharge water from Jecheon Wastewater Treatment Plant located in Jangpyeong Stream was considered to be the most important source of contaminant.

• Journal of the Korean Society of Groundwater Environment
• /
• v.4 no.3
• /
• pp.122-129
• /
• 1997

Spills or leaks of hazardous organic. compounds from underground storage tanks (USTs) are common contaminant sources of soil and groundwater. It would aid in managing USTs to assess and rank the potential environmental hazard posed by the USTs. Therefore, a preliminary hazard ranking system of USTs is developed in this study. The system is combined with GIS and consists of five steps: 1) selection of significant factors, 2) determination of the hierarchy of the factors. 3) determination of the weights, 4) calculation of the potential hazard, and 5) hazard assessment. The system is applied to the gas stations in Kwanak-gu, Seoul. The results indicate that the gas stations can be categorized in three groups as highly hazardous, less highly hazardous, and weakly hazardous. Seven gas stations belong to the highly hazardous group. Through the sensitivity analysis, four stations appear to possess high hazard potentials regardless of weights assigned to the factors. It appears that a user can make flexible application of the hazard ranking system with the user's experience and particular purposes. However, the system still needs validations against field survey data.

• Journal of the Korean Geophysical Society
• /
• v.4 no.4
• /
• pp.267-285
• /
• 2001

This study has tried to develop the modified DRASTIC Model by supplying the parameters,such as structural lineament density and landuse, into conventional DRASTIC medal, and to predict the potential of groundwater contamination using GIS in Whanam 2 Area, Gyeonggi Province, Korea. Since the aquifers in Korea is generally through the joints of rock-mass in hydrogeological environment, lineament denisity affects to the behavior of goundwater and contaminated plumes directly, and land-use reflect the effect of point or non-point source of contamination indirectly. For the statistical analysis, lattice layers of each parameter were generated, and then level of confidence was assessed by analyzing each correlation coefficient. Composite contamination map was achieved as a final result by comparing modified DRASTIC potential and the amount of generation load of several contaminant sources logically. The result could suggest the predictability of the area of contamination potrntial in the respects of hydrogeological aspect and water quality.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.215-218
• /
• 2002

The purposes of this research are to identify the source and the extent of contamination of nitrate in groundwater in a typical agricultural area. The study area has many livestock raising facilities, rice paddies and grape farms. In order to identify the hydrogeological character, we sampled groundwater and surface water in 27 locations and performed chemical analyses. Nitrate-nitrogen is the major contaminant in this area. Approximately 32 ~ 42% of groundwater samples are over the drinking water limit(10 mg/L) and 77% estimated to be entered from artificial sources. The nitrogen isotope analysis indicates animal waste being the major source of nitrate in water samples. Not only presently operating livestock facilities but also abandoned ones influence groundwater quality for a long time.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.5
• /
• pp.352-357
• /
• 2001

Cadmium (Cd) has been identified as a potential contaminant in agricultural and environmental soils. Ionic condition in the soils is an important factor to influence Cd availability. In this study, the effect of sulfate or nitrate application on Cd sorption in acidic and calcareous soils was investigated. The Cd, sulfate $(SO_4)$, and nitrate $(NO_3)$ sources were solutions of $CdCl_2$, $K_2SO_4$, and $KNO_3$, respectively. The soil-solution system pH was affected by the application of sulfate or nitrate in both acidic and calcareous soil system, but there was not clear pH difference between pre- and simultaneous applications of sulfate or nitrate (PAS/PAN or SAS/SAN). Solution ionic strength (I) values were similar between the acid and calcareous soil systems after applying the Cd even though it was significantly different in the untreated control soils. However after applying the sulfate or nitrate, the I values increased and were always higher with SAS/SAN treatments. Solution Cd concentration also increased with the application of sulfate or nitrate. However, the Cd concentration in soil solution controlled by Cd sorption in the systems was different between PAS/PAN and SAS/SAN treatments only in the calcareous soil system, but not in the acidic soil system. The difference in Cd concentration between SAS/SAN and PAS/PAN in the calcareous systems may be caused by system pH, ionic strength, complexation, and predominately, competition of the $Cd^{2-}$ with the index $K^+$ ion. Potassium ion-Cd competition in the acidic soil system may be minimized because of the abundance of hydrogen ions.

• Korean Journal of Environmental Agriculture
• /
• v.35 no.1
• /
• pp.15-23
• /
• 2016

BACKGROUND: Water quality is of concern to water utility operators, public health officials, and populations using the water. If any contaminant is released from a point of entry, it could be spread rapidly throughout the water stream. So the identification of the location of the points of entry and its release history are critical informations to establish the management strategy.METHODS AND RESULTS: Aniline, nonylphenol, pentachlorophenol and formaldehyde in 39 surface water samples were analysed using Gas chromatography-mass spectrometry (GC-MS) methods. Formaldehyde, aniline and nonylphenol were mainly detected in the near sites where industrial waste water and domestic sewage were discharged into stream. But pentachlorophenol was detected in the downstream samples where pulp manufacturing plants were operated.CONCLUSION: Results indicate that pentachlorophenol found in main stream of Guem river was mainly introduced from pulp manufacture industries. Otherwise, formaldehyde, aniline and nonylphenol were mainly contaminated from the industrial waste water and domestic sewage.

• Journal of Environmental Impact Assessment
• /
• v.25 no.1
• /
• pp.41-50
• /
• 2016

Environmental impact assessment has been implemented for more than 30 years in Korea. During that period, various amendments were carried out about target plan and assessment factors. However, in current environmental impact assessment act, only a few factors has been considered for soil environment assessment. This study analyzes the national and foreign environmental impact assessment guidelines on soil related factors and figures out the problems and implications of Korean environmental impact assessment. In Korea, water quality, topography and geology, hydraulics and hydrology, and soil contamination were analyzed as a soil related factors. The main assessment targets were pollution related factors such as soil pollution levels, amount of rainfall runoff, and non-point sources. However, in the case of foreign guidelines, soil compaction, soil sealing, and soil salinization is being analyzed for evaluating function and quality of soil environment. The revision of soil-related factors are needed for sustainable development of Korea.

• Journal of Korean Society on Water Environment
• /
• v.23 no.6
• /
• pp.822-828
• /
• 2007

Perchlorate is an unregulated contaminant but recently many cases of perchlorate contamination have been reported in the US. In Japan, also, a couple of contamination incidents caused by perchlorate occurred. Against this backdrop, investigation on perchlorate was urgent for Korea. Accordingly, perchlorate investigation in tap water and river water was conducted one time a week for seven consecutive weeks at major water sources of Korea including Han River, Guem River, Yeong-san River, and Nak-dong River. Perchlorate was not found at Han River, Guem River, and Yeong-san River. However, all the 4 tap water samples in Nak-dong River recorded high level of perchlorate. Among others, NT1 located at Daegu posted the highest value of $22.3{\mu}g/L$. This level is lower than $24.5{\mu}g/L$, the threshold recommended by US EPA. Still, perchlorate contamination in drinking water can deal a heavy blow to nerve development of infants and children by causing iodine deficiency. At the 1st and 2nd investigations, perchlorate concentration reached $18.7{\sim}95.6{\mu}g/L$ and $4.0{\sim}25.6{\mu}g/L$ respectively, both of which are relatively higher. The high perchlorate concentration in Nak-dong River was possible because of the waste water discharged from LCD manufacturing factory which was located at NS3 in Gumi, Korea. Perchlorate concentration of waste water from the factory was $730{\sim}1,858{\mu}g/L$.

• Journal of Soil and Groundwater Environment
• /
• v.20 no.4
• /
• pp.83-89
• /
• 2015

Soil samples collected in an area of Gahak Mine were investigated for the characterization of mineralogical and physicochemical properties of contaminants in soils. It is found that soils in the study area are contaminated by lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), in which their concentrations are 595.3 mg/kg, 184.9 mg/kg, 712.8 mg/kg, and 10.64 mg/kg, respectively. All the concentrations exceed the concern criteria of Korean standard. Upon distribution patterns of metals identified by the sequential extraction procedure, our results show that more than 50% of metals are found as a residual type, and 30% are accounted for the association of Fe/Mn oxides. Interestingly, XRD results show that minium (Pb₃O₄) and cuprite (Cu₂O) are identified in the soil samples, suggesting that the sources of the contaminants for Pb and Cu are these minerals. In SEM images, tens of µm of Pb oxides and Pb silicate-minerals are observed. We, therefore, note that the contamination of metals in the study area results from the direct influx and disturbance of tailings. Our findings indicate that the characterization of physicochemical and mineralogical properties of contaminated soils is a critical factor and plays an important role in optimizing recovery treatments of soils contaminated in mine development areas.

• Advances in environmental research
• /
• v.2 no.2
• /
• pp.81-98
• /
• 2013

Mercury (Hg) dynamics in the boreal environment have been a subject of concern in recent decades, due to the exposure of local populations to the contaminant. Land use, because of its impact on mercury inputs, has been highlighted as a key player in the sources and eventual concentrations of the heavy metal. In order to evaluate the impact of watershed disturbances on Hg dynamics in frequently fished, large boreal lakes, we studied sediment cores retrieved at the focal point of eight large lakes of Qu$\acute{e}$bec (Canada), six with watersheds affected by land uses such as logging and/or mining, and two with pristine watersheds, considered as reference lakes. Using a Geographical Information System (GIS), we correlated the recent evolution of land uses (e.g., logging and mining activities) and morphological characteristics of the watershed (e.g., mean slope of the drainage area, vegetation cover) to total Hg concentrations (THg) in sedimentary records. In each core, THg gradually increased over recent years with maximum values between 70 and 370 ng/g, the lowest mercury concentrations corresponding to the pristine lake cores. The Hg Anthropogenic Sedimentary Enrichment Factor (ASEF) values range from 2 to 15. Surprisingly, we noticed that the presence of intense land uses in the watershed does not necessarily correspond to noticeable increases of THg in lake sediments, beyond the normal increment that can be attributed to Hg atmospheric deposition since the beginning of the industrial era. Rather, the terrestrial Hg inputs of boreal lakes appear to be influenced by watershed characteristics such as mean slopes and vegetation cover.