Modeling Leachate Migration from a Landfill
MODELING LEACHATE MIGRATION FROM A LANDFILL
December, 2003
1 INTRODUCTION
A two-dimensional, steady state transport modeling using MODFLOW/CTRAN was carried out following the particle tracking calculations to simulate potential contamination for leachate migration from Gibraltar landfill.
Gibraltar landfill was a disposal waste site in Bogotá (Colombia) until 1988. The site presented problems related to contamination for leachate migration after its closure, since the operation of the site did not meet all the technical requirements for waste disposal.
A technical study was conducted in 1997 to propose alternatives for contamination control and posterior land use. The information gathered during that study is the base for the modeling presented in this report.
According with the results of modeling the flow velocity is very low with an average of 4 mm/d, therefore the leachate migration movements is slow. The advective transport of a contaminant from the landfill to the river and west drainage takes 90 years.
2 SITE CHARACTERIZATION GIBRALTAR
The Gibraltar Landfill is located in Bogotá, capital of Colombia (Figure 1), and has presented problems related to contamination for leachate migration since its closure in 1988.
A technical study was conducted in 1997 to propose alternatives for contamination control and posterior land use. The information gathered during that study was the base for the modeling presented in this report.
The Gibraltar site has an extension of 80 Ha. The layout of the site, base for the conceptual model, is presented in Figure 2. The limits of the site are the Bogotá River and two drainages.
The composition of the wastes disposed in Gibraltar was the typical for domestic residue. The characteristics of the leachate are presented in Table 1.
TABLE 1
TYPICAL COMPOSITION OF THE GIBRALAR LEACHATE - 1985
Parameter Unit Value
Biochemical Oxygen Demand (BOD)
Chemical Oxygen Demand
Totals Solids
December, 2003
1 INTRODUCTION
A two-dimensional, steady state transport modeling using MODFLOW/CTRAN was carried out following the particle tracking calculations to simulate potential contamination for leachate migration from Gibraltar landfill.
Gibraltar landfill was a disposal waste site in Bogotá (Colombia) until 1988. The site presented problems related to contamination for leachate migration after its closure, since the operation of the site did not meet all the technical requirements for waste disposal.
A technical study was conducted in 1997 to propose alternatives for contamination control and posterior land use. The information gathered during that study is the base for the modeling presented in this report.
According with the results of modeling the flow velocity is very low with an average of 4 mm/d, therefore the leachate migration movements is slow. The advective transport of a contaminant from the landfill to the river and west drainage takes 90 years.
2 SITE CHARACTERIZATION GIBRALTAR
The Gibraltar Landfill is located in Bogotá, capital of Colombia (Figure 1), and has presented problems related to contamination for leachate migration since its closure in 1988.
A technical study was conducted in 1997 to propose alternatives for contamination control and posterior land use. The information gathered during that study was the base for the modeling presented in this report.
The Gibraltar site has an extension of 80 Ha. The layout of the site, base for the conceptual model, is presented in Figure 2. The limits of the site are the Bogotá River and two drainages.
The composition of the wastes disposed in Gibraltar was the typical for domestic residue. The characteristics of the leachate are presented in Table 1.
TABLE 1
TYPICAL COMPOSITION OF THE GIBRALAR LEACHATE - 1985
Parameter Unit Value
Biochemical Oxygen Demand (BOD)
Chemical Oxygen Demand
Totals Solids