• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.91-99
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• 2002

A recent survey investigated that there were over one thousand un-controlled closed landfills(1,072 sites) in Republic of Korea. Most of these landfills were constructed before 1986. Waste management act were not promulgated at that time, so they usually do not have dranage system and leachate treatment facility. Also, considerable attention has been received to landfill leachate pollution, leachate has an adverse impact on the surrounding environment such as soil, groundwater, and water supply source. According to the result of survey for closed landfill management, it was reported that 875 sites out of 1,072sites(81.6％) have no leachate treatment facility and 630 sites out of 1,072sites(58.7％) have been used for farm lands and residence. Consequently it is hard to do postclosure care continuously in most of cases and these uncontrolled landfills have contaminated farm lands and residence. The average age of these landfills are ranged mostly between 2 to 15 years. Much time and advanced technology are needed to remediate these uncontrolled landfills, therefore the survey for present status of closed landfill sites is required and suitable treatment processes should be prepared. With this point of view, We has been investigated to find out the present status of closed landfill, problems of post management and discussed plans for remediation and reuse. Remedial actions of un-controlled landfill have been carried out the many cities since 1997 upto now. Most frequently applied technology were reuse after excavation and there were several cases to capping in the surface of landfill and to construct subsurface barriers. It is considered that landfills in use have a possibility not to be controlled because of inadequate construction and improper management. Therefore remediation of uncontrolled landfills and recovery technology should be develop continuously Especially, it has been expected that resource technology of landfill gas as a energy has some advantages in controlling odors in the site area and accelerating stabilization of landfills with the energy.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.394-397
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• 2006

Hydrogeologic and hydrochemlcat conditions of two uncontrolled landfills without reliable underlying liners, leachate collection and treatment systems were compared. With similar weather conditions, spatial distribution and temporal variations of contaminants of concern and redox parameters were different for the two landfills. These differences are highly associated with ages and hydrogeologic settings of the landfills. Groundwater flow diverges from the Cheonan landfill while it converges to downgradient area in the Wonju landfill. Less permeable clayey silt layer or silty soil in the subsurface limited dispersion of leachate plume in the former landfill but highly permeable sandy soil with good lateral extent facilitated rapid plume dispersion in the latter landfill. In addition, hydraulic properties of the cover soil played a role in the different development of redox conditions, which resulted in significantly different concentrations of nitrates. Most problematic contaminants at downgradient wells of the landfills are ammonia and nitrate.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.432-435
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• 2006

To evaluate geology and extent of leachate migration around the landfills, electrical resistivity survey were conducted in area of uncontrolled landfills in Cheonan and Wonju. The Cheonan landfill is located above the paddy fields and the resistivity survey lines were crossed to confirm possible pollution of the paddy fields by leakage of the landfill leachate. In Wonju, the landfill and the downgradient paddy fields are divided by a concrete barrier wall. At the bottom of the landfill, there is a leachate settlement system but has not been in operation. And a total of 4 survey line installed (1 parallel and 3 perpendicular to mean groundwater flow direction). According to the resistivity survey results, the landfill leachate in Cheonan appeared to be restricted only within the interior of the landfill, not to migrate into the subsurface of the paddy fields. These results are well consistent with electrical conductivity values of groundwaters obtained from a periodic analysis of water qualities. In Wonju, however, it was inferred that the leachate emanating from the landfill migrated beneath the abandoned leachate settlement system and it would reach the downgradient paddy field.

• 한국농공학회지
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• 제43권6호
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• pp.44-53
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• 2001

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1994년도 봄 학술발표회 논문집
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• pp.75-82
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• 1994

Groundwater in waste landfills can be contarninated by leachates produced from wastes and flow down toward rivers. These accidents are easily discovered in uncontrolled landfill sites. In this study, applications for controlling groundwater pollution and protecting river pollution were studied using installation of cut-off walls around the waste landfill. Analyses for the efficiency and applicability of the cut-off wall were made under environmental, economical anc technical considerations. Cut-off walls were installed at the upgradient and the downgradient. prediction analyses for the hydraulic head distribution over the site were made for concerning with the final cover and without the final cover. Also, the hydraulic head distribution was predicted with well-pumping on both cases, upgradient cut-off wall and downgradient cut-off wall.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.260-263
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• 2005

Uncontrolled landfills have been a threat to surrounding environment and human health. To examine the effect of hydrogeological properties on plume migration caused by landfill leachate, two representative landfills in Cheonan and Wonju were selected. In these landfills, seven and eight groundwater wells were installed respectively to monitor water quality and waterlevel, and to perform hydraulic and tracer tests. This study reports preliminary evaluation results including site characteristics, waterlevel measurement and slug tests.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.398-401
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• 2006

Two landfills of this study containing municipal wastes without any bottom liner and leachate treatment system have different landfill age, waste volume and most importantly different hydrogeologic settings. The one (Cheonan) is situated in an open flat area while the other (Wonju) is located in a valley. In the interior of the landfills, typical anaerobic conditions revealed by low DO and ${NO_3}^-$ concentrations, negative ORP values, high $NH_3$, alkalinity and $Cl^-$ concentrations were observed. Generally higher levels of contaminants were detected in the dry season while those were greatly lowered in the wet season. Significantly large decrease of Cl concentration in the wet season indicates that the dilution or mixing is one of dominant attenuation mechanisms of leachate. But detailed variation behaviors in the two landfills are largely different and they were most dependent on permeability of surface and subsurface layers. The intermediately permeable surface of 1.he landfills receives part of direct rainfall infiltration but most rainwater is lost to fast runoff. The practically impermeable surface of clayey silt (paddy field) at immediately adjacent to the Cheonan landfill boundary prevented direct rainwater infiltration and hence redox condition of the groundwaters were largely affected by that of the upper landfill and the less permeable materials beneath the paddy fields prohibited dispersion of the landfill leachate into downgradient area. In the Wonju landfill, there exist three different permeability divisions, the landfill region, the sandy open field and the paddy field. Roles of the landfill and paddy regions are very similar to those at the Cheonan. The very permeable sandy field receiving a large amount of rainwater infiltration plays a key role in controlling redox condition of the downgradient area and contaminant migration.

• 환경위생공학
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• 제23권3호
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• pp.59-71
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• 2008

In this study, we intend to present the uncontrolled landfill maintenance plans by diversely reviewing the operating conditions of landfill and environmental effects and economical issues resulted from the operation of landfill for the purpose of suggesting the optimal maintenance plans applicable to the uncontrolled landfill and unused landfill located in Korea. We perform the basic and precise surveys against three landfill sites showing the biggest problem out of 8 unsanitary landfills sites located in Y County. We compare and review the treatment plans prepared and operated by the N Landfill. The compared and reviewed results show that the local stabilization plan is more effective than the excavation and transfer treatment plan when considering the economic efficiency only. However, the excavation and transfer treatment plan is valid when considering the diverse elements. The G Landfill is operated with separated into living waste landfill section and construction waste landfill section. However, some landfill gas collection bores or holes are installed in its living waste landfill section, which has not been used for about 20 years, as a part of follow-up control. The element causing the environmental damage is considerably reduced in its living waste landfill section. However, the effort to keep the follow-up control through the local stabilization work is required. The landfill is under processing in the construction waste landfill section. However, most of buried wastes are the inorganic wastes such as waste materials and concrete, so the maintenance plan focused on the use of top land by installing the local stabilization facilities is considered as an effective plan. The landfill is under processing in the K Landfill. It seems to be difficult to maintain this landfill through the local stabilization. The excavation and transfer treatment plan to completely remove the potential environmental pollution source is considered as the valid plan.

• 대한환경공학회지
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• 제29권8호
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• pp.895-903
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• 2007

매립지를 직접 생태학적으로 모니터링하는 방법을 개발하고자, 매립지 내의 생화학적 반응에 관여하는 세균들과 효소의 양을 정량함과 동시에 지하수 수질인자와 상호 연관성을 조사하여 생태학적 인자와의 연계 이용 가능성을 평가하였다. 이를 위하여 4개의 매립 종료된 비위생 매립지(천안(C), 원주(W), 논산(N), 평택(P) 매립지)에서 계절별로 지하수 시료를 채취하였으며 동시에 16S rDNA 방법을 사용하여 미생물 다양성을 분석하였다. 이를 기반으로, 매립지에서 주로 발견되는 세균과 효소를 대표하는 유전자를 정량하기 위한 특이 프라이머 쌍을 제작하였으며 상관계수에 기초하여 수질인자와 유전자 지표 인자간의 정량적 관련성을 비교하였다. 그 결과 DSR(황환원 세균) gene과 BOD(생화학적 산소요구량)사이의 상관관계는 0.8 이상인데 반해 NSR(질산화 세균-Nitrospira sp.) gene과 질산성 질소는 0.9 이상이었다. 안정화지표(BOD/COD)와 MTOT(메탄 산화 세균), MCR(Methyl coenzyme M reductase), Dde(Dechloromonas denitrificans) gene들은 0.8 이상의 상관관계를 가졌으나 3가 철과 Fli(Ferribacterium limineticm) gene은 0.7로 낮았다. MTOT gene의 경우, BOD/COD과의 관련성이 100%에 가깝게 높았다. 또한, 혐기성 유전자들(nirS-아질산 환훤효소, MCR, Dde, DSR)과 DO 역시 0.8 이상으로 나타나 일반적인 매립지 혐기성 반응들이 DO에 크게 의존함을 보였다. 결론적으로 분자생물학적 조사와 수질인자가 높은 상호연관성이 있었으며 real-time PCR이 전통적인 모니터링 인자들과 동시에 상호 보완적으로 모니터링에 사용됨으로써 매립지안정화 및 주변 영향을 평가하는데 효율적으로 사용 될 수 있음을 알 수 있었다.

• 대한환경공학회지
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• 제28권5호
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• pp.463-471
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• 2006

본 연구에서는 충남 천안시와 강원도 원주시에 위치한 불량매립지 일대에 대해 지구물리 탐사 중 전기비저항 탐사를 실시하였으며, 수집된 자료를 이용하여 2차원과 3차원 비저항 역산 모델링을 수행하여 매립지 주변 지질구조와 침출수 오염영역, 침출수 유동을 평가하였다. 천안 직산매립지는 매립지가 논 상부에 위치하고 있으며 매립지로부터 침출수로 인한 농지 오염의 가능성이 있어 물리탐사 측선 배열을 매립지를 기준으로 서로 교차하는 측선배열을 수행하였다. 원주 매립지의 경우 매립지와 주변 논밭의 경계가 매립지 옹벽으로 나뉘며, 매립지 경계로부터 침출수 침전시설이 위치하고 있으나 현재는 방치된 상태로 침출수 누출로 인한 농지 오염의 가능성이 있다. 이에 총 4개 측선에 대해 3개 측선은 매립지 경계로부터 일정거리를 두고 평행하게 배열을 하였으며, 나머지 한 개 측선은 이 3개 측선을 교차하도록 배열하였다. 2차원 비저항 역산모델을 수행한 결과 천안매립지의 경우 침출수가 외부 논으로 확대되지 않고 매립지 내부에 정체된 형태로 존재하는 것으로 평가되었다. 이는 지하수 관측정 정기 수질분석시 측정된 지하수의 전기전도도 값의 분포에서도 확인할 수 있다. 원주 매립지의 경우는 매립지로부터 유래된 침출수가 매립지 경계 부근 폐기된 침출수 처리시설 밑으로 흐르는 것으로 평가되었고, 매립지 주변 기존 저수지였던 곳에서는 매립지 주변에 위치한 계곡의 영향으로 계곡에서 흘러드는 지하수에 의한 흐름과 과거 저수지의 영향으로 지표 근처에서 낮은 비저항대를 형성하는 것을 확인할 수 있었다. 또한 저수지 제방에서는 하부 $7{\sim}8m$ 심도에서 지하수가 논으로 유입되는 것으로 추정되었다. 이하의 반응온도 기준으로 약 $10{\sim}80%$ 이상이었다. 따라서, CVOCs 제거반응을 위하여 널리 사용되고 있는 단일 $CrO_x/Al_2O_3$ 촉매보다는 $CrO_x$의 사용량을 최소화하면서도 우수한 반응활성을 얻을 수 있는 $CrO_x/TiO_2$-based복합 산화물 촉매가 보다 바람직하며 하나의 대안적인 촉매 디자인 방법으로 응용될 수 있을 것으로 생각된다.EX>을 효과적으로 처리할 수 있었다.문에, 이 연구에서 개발된 수치모델은 퇴적물에서 일어나는 미량 오염 물질의 거동을 파악하기 위해 유용하게 사용되어질 수 있을 것으로 사료된다.