Method of evaluating the impact of landfill leachate on groundwater quality

Lecture Notes in Civil Engineering

Municipal solid waste disposal in a non-engineered landfill is one of the serious threats to groundwater quality deterioration. In fact, the leachate generated from landfill percolates the strata and reaches to aquifer causing groundwater contamination. The paper aims to analyze the characteristics of landfill leachate along with groundwater quality at various locations in the vicinity for some selected parameters. The grab samples of leachate and groundwater sample have been collected and analyzed as per standard procedure. All the parameters except the pH and electrical conductivity have been observed to be more than the typical values of municipal wastewater. In groundwater, the pH, coliform bacteria and nitrate content have been found to be within the permissible limit at all locations, however, rest of the parameters exceeded the permissible limit. This may happen because of the percolation of leachate through strata. The influence of leachate on groundwater decreases drastically with an increase in distance from landfill site. Maximum contamination has been observed in north and northwestern areas of landfill, especially, at locations GW4 and GW5. The groundwater quality in vicinity of landfill site revealed the unsuitability for both household and commercial uses.

The paper aim is to critically review an existing literature on impact of landfill leachate on groundwater quality in order to identify various extent of groundwater contamination at different distances between the landfill and the water well during the dry and rainy season. To address the aim more than ten (10) academic articles were reviewed. According to the different analysis results from different sources revealed that, the landfill leachate impact is slightly higher during the raining season and the extent of the contamination is also depends on the closeness of the groundwater to the landfill. As far studies of Kassega & Mbuligwe, (2009) results during the dry and wet season were found to be no significant difference between dry and wet season results in terms of heavy metals based on ANOVA analysis meaning having almost the same levels of contamination.

International Journal of Environmental Science & Technology, 2007

The influence of local hydrogeology on natural attenuation of contaminants from landfill leachates in shallow aquifer underlying the active Olusosun landfill base in Lagos was investigated. In addition, the level of groundwater contamination in the vicinity of the landfill and of leachate migration pattern in groundwater down gradient of the landfill base was equally assessed. Landfill leachate and groundwater samples were collected and analyzed and characterized. Physico-chemical analyses of sampled water followed standard analytical methods. Analytical results showed a measurable impact of leachate outflows on groundwater quality. Elevated levels of anions: nitrate, chloride and sulphate in the groundwater body and heavy metals: Cr 3 , Cd and Cu, were detected at measurable levels in groundwater down gradient of the landfill location without any particular attenuation pattern. The migration pattern and dispersion of leachates down gradient, 750 m away from the landfill location are irregular and difficult to predict as depicted by levels of contaminants present in groundwater. The study highlighted the importance of soil stratigraphy beneath the landfill base as an important factor in the natural attenuation of leachate constituents in the groundwater body.

Archives for Technical Sciences, 2015

Regional Landfill Brijesnica is located in the northeastern part of Bosnia and Herzegovina, and the western part of the municipality of Bijeljina, and began work in 2010, with an approximate area of 4.5 ha. The sanitary cells are built with protective insulating materials-special geomembranes and other materials that guarantee the protection of groundwater. The landfill has a system to collect leachate and biogas collection system. An equalization pool was built to accept leachate with a recirculation system with the return of leachate into the cell. Leachate from the equalization basin is in the monitoring period directly discharged into surface flows (Majevički kanal). In this study, to determine the state of pollution of surface and groundwater first a hydrogeological analysis of the immediate area of the landfill was done. The analysis of the results of the monitoring of leachate, surface water and groundwater in this dump for a period of four years was done. Monitoring of these waters was made in all four seasons during several hidrological years in order to define a degree of pollution of surface and groundwater. Based on the results of analysis the undeniable impact of leachate from the landfill to the surface was determined but not in groundwater.

… monitoring and assessment, 2006

Leachate and groundwater samples were collected from Gazipur landfill-site and its adjacent area to study the possible impact of leachate percolation on groundwater quality. Concentration of various physico-chemical parameters including heavy metal (Cd, Cr, Cu, Fe Ni, Pb and Zn) concentration and microbiological parameters {total coliform (TC) and faecal coliform (FC)} were determined in groundwater and leachate samples. The moderately high concentrations of Cl -, NO 3 -, SO 4 2-, NH 4 + , Phenol, Fe, Zn and COD in groundwater, likely indicate that groundwater quality is being significantly affected by leachate percolation. Further they proved to be as tracers for groundwater contamination. The effect of depth and distance of the well from the pollution source was also investigated. The presence of TC and FC in groundwater warns for the groundwater quality and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures are suggested to reduce further groundwater contamination via leachate percolation, the present study demand for the proper management of waste in Delhi.

Sains Malaysiana

In this study, leachate collection and processing system in Ampar Tenang Closed Landfill (ATCL) and its impact on both groundwater and surface water was evaluated. Samples from three locations in leachate processing system (Collection, aeration and stabilization ponds), groundwater and surface water were collected and tested for twenty-one parameters covering nine heavy metals (Fe 2+ , Zn 2+ , Cu 2+ , Cr 2+ , Cd 2+ , Pb + , As 3+ , Co 2+ and Mn 2+) and twelve physiochemical parameters (Mg 2+ , Ca 2+ , Na + , chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), electrical conductivity (EC), pH, ammoniacal nitrogen (NH 3-N) and dissolved oxygen (DO). Correlation analysis for landfill leachate ponds, groundwater and surface water showed different patterns of relationships between all possible combinations of two parameters. Similarity and dissimilarity were studied through cluster analysis, three clusters were found to entirely separate the collection pond (cluster 1) while the two ponds were clustered with groundwater samples (cluster 2) and the third cluster is for the surface water. This study shows the benefit of statistical analysis such as correlation analysis and cluster analysis for evaluation and interpretation of landfill data to understand the behavior of the selected parameters and to have a clear picture about the pattern of the relationship for effective landfill management.

Landfills are a source of groundwater pollution in Gaza Strip. This study focused on Deir Al Balah landfill, which is a unique sanitary landfill site in Gaza Strip (i.e. it has a lining system and a leachate recirculation system). The objective of this article is to assess the generated leachate quantity and percolation to the groundwater aquifer at a specific site, using the approaches of (i) the Hydrologic Evaluation of Landfill Performance model (HELP) and (ii) the water balance method (WBM). The results show that when using the HELP model, the average volume of leachate discharged from Deir Al Balah landfill during the period 1997 to 2007 was around, 6800 m 3 /year. Meanwhile, the average volume of leachate percolated through the clay layer was 550 m 3 /year, which represents around 8% of the generated leachate. Meanwhile, the WBM indicated that the average volume of leachate discharged from Deir Al Balah landfill during the same period was around 7660 m 3 /year-about half of which comes from the moisture content of the waste, while the remainder comes from the infiltration of precipitation and re-circulated leachate. Therefore, the estimated quantity of leachate to groundwater by these two methods was very close. However, compared with the measured leachate quantity, these results were overestimated and indicated a dangerous threat to the groundwater aquifer, as there was no separation between municipal, hazardous and industrial wastes, in the area.

Journal of Ecological Engineering, 2015

The monitoring that was carried out at the landfill specialized in leachate, groundwater and surface water. There were 6 sampling sites. The observed parameters were pH, BOD 5 , COD Cr , conductivity. Leachate reached the high values in all observed parameters. Groundwater samples were collected at two monitoring wells and the sampling site (A, B, C). Surface water was collected from two sampling sites (D, E). The pH showed slightly acid values at all sampling points. The pH of surface water was slightly acid to neutral. Both BOD 5 and COD Cr values remained stable over the reporting period. The average conductivity value at sampling points D, E remained constant. In line with the Czech National Standard ČSN 75 7221 "Classification of Surface Water Quality" sampling point D belongs to II Water Quality Class-slightly polluted water and sampling site E to Class I water quality-unpolluted water. The authors believe that the fluctuations occurring with regard to the values of certain samples were not caused by the operation of the landfill itself, but were a result of the intense agricultural activity nearby the landfill.

Asian Journal of Chemistry, 2014

One of the important environmental issues and problems that the country's big cities are facing with them including urban, industrial, medical and dangerous solid waste management. Meanwhile, industrial and hazardous waste management or so-called special wastes is very important because the lack of proper planning and management that can cause pollution of surface and underground water resources, soil and air widely. According to the mentioned subjects above and the overall approach of waste management , one of the basic steps and the main axes in integrated waste management is special waste management, which special attention has demanded and it is necessary to be considered the management and control systems. Subjected records review of plans and structural projects implementation in developing countries shows that in the past program-the importance and values of natural resources and environmental is hidden from the perspective of decision makers and many of them have been designed and utilized, without regard to environmental considerations. The outcomes and consequences of such measures have been various pollution outbreak and degradation and severe depletion of environmental resource in countries. Certainly the urban landfill sites can be considered also among the plans and constructional projects, having the short

Physico-chemical and microbiological parameters were analyzed in leachate and groundwater samples obtained at different locations adjacent to a municipal solid waste landfill in order to assess the impact of leachate percolation on groundwater quality. Total dissolved solids (TDS), electrical conductivity (EC), and Na+ exceeded the World Health Organization (WHO) tolerance levels for drinking water in 62.5, 100, and 37.5% of the groundwater samples, respectively with pH and Fe exceeding WHO limits in 75% of the samples. Significant negative correlations of -0.839, -0.590, and -0.590 were shown by Na+, TDS, and EC respectively to distance from landfill. A high population of Enterobacteriaceae ranging from 4.0 x 103 ± 0 to 1.0575 x 106 ± 162,705 CFU/ml was also detected in the groundwater samples, indicating contamination. The results show that the leachate from the landfill has a minimal impact on the groundwater resource and this can be attributed to the existing soil stratigraphy a...