Lubna landfill

More documents

Recommendations

Info

7 Groundwater modellingRecently, a 3-D groundwater model of the landfill including its vicinity was created, using theGroundwater Modelling System (GMS numerical program). GMS contains graphic environmentusers for groundwater flow and pollutant transport simulations. The system consists of a graphicuser interface and the following analysis codes: MODFLOW, MT3DMS, RT3D, SEAM3D,MODPATH, SEEP2D, FEMWATER, NUFT and UTCHEM. For the modelling of the secondgroundwater level (drinking) in the subsoil of the Lubna landfill, the set of MODFLOW was used(Fig. 14). For the modelling of the first groundwater level, the set of FEMWATER was applied (Fig.15). The modelling of groundwater flow was performed for 2-D and 3-D conditions. Thetransportation of pollutants in the first groundwater level was calculated taking into account theabsorption and dispersion phenomenon. The modelling results were compared to local monitoringobservations in piezometers.FIG. 14 Groundwater flow modelling in the second layer using MODFLOW numerical programFIG. 15 Groundwater flow modelling in the second layer using FEMWATER numerical program14
8 Remedial works8.1 Creation of landfill embankment with slope reinforcementsEspecially when the slopes are high and of considerable inclination, the construction of berms isthe most effective solution for slope stability reinforcement, however it requires area in the closevicinity of the landfill. Three technological roads are created on the landfill slopes at the levels of“130”, “140” and 160 m a. s. l. The crest of the landfill was designed at the level of 172 m a. s. l., i.e. approximately 60 m high (Fig. 16). By moderating and reinforcing the slope, the berm enablesthe achievement of additional capacity for waste disposal. The surface of the berm was made ofcohesive soil and compost. The construction of berms enables reaching additional capacityvolume for waste disposal.FIG.16 Designed Lubna landfill surface8.2 Cut-off wallThe bentonite cut-off wall barrier was constructed to protect the first aquifer against contaminationcoming from the landfill (Fig. 17). The permeability coefficient for the barrier wall is below 10 -9 m/s(resulting from the in situ BAT and laboratory tests). The initial hydraulic gradient for the bentonitewall is ca. i 0 =50, wheras the existing gradients in the field are i=2-3. In fact, the constructed cut-offwall is practically impermeable. The depth of the barrier wall was from 5.5 to 17 m, depending onthe subsoil conditions. Additional protection against migration of pollution is assured by directingthe flow from the vicinity to the leachate drainage system (Fig. 18). This would also protect thebentonite material against degradation caused by the leachate. Combination of a cut-off wall anda peripheral drainage system is safe and easy to build for the old sanitary landfill remediation. It isthe most effective and economic solution, if only applie on large areas.15
Page 1: GeoEnvNetStudy Panel 1 - LandfillsL
Page 4: FIG. 2 View of the landfill and nea
Page 8 and 9: 4.4 Permeability testsThe permeabil
Page 10 and 11: 205119.620455.212013020276.51 2 01
Page 12 and 13: Table 3. Annual water balance for t
Page 16 and 17: FIG. 17 Construction of cut-off wal
Page 18 and 19: FIG. 21 Mineral filter layers used
Page 20 and 21: FIG. 24 Zones with different moistu
Page 22 and 23: 9 Water monitoring systemThe local
Page 24 and 25: Table 4. Influence of a vertical ba
Page 26 and 27: Table 6. Results of quality tests o

Lubna landfill

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?