Dangkor Landfill
Dangkor Landfill is in the south of Phnom Penh, approximately 30 minutes away from the city center.
The project was drilling boreholes and installing ten gas wells. The wells were drilled using a rotary drilling rig with a diameter of 130mm and constructed using slotted HDPE casing. The wells were packed with gravel, sealed with bentonite and had a cement grouting cap layer. The wells were supervised by a civil;l engineering company geotechnical engineer
Leachate or water table levels were found to be relatively high during drilling; they were roughly four meters below ground level at the closed landfill and ten meters below ground level at the operational landfill. Elevated leachate concentrations in closed landfills suggest the buildup of residual fluid, which may increase the risk of leachate migration and affect the quality of groundwater. Gravel packing stops waste material intrusion while preserving borehole stability, and slotted HDPE casing permits gas migration while shielding the borehole structure. Cement grout caps and bentonite seals are used to hydraulically isolate the wells and stop fugitive emissions and surface infiltration.
The high water levels suggests that at wet times of the year the gas production is loess. Restrictions of water inflows and clay capping will reduce the flows and lower levels increasing production
Dangkor Landfill gas wells
Drilling Gas well
Gas well
Gas Results
Methane (Landfill gas) is being produced by gas wells 7, 8, 9, and 10, which all seem to be in the peak gas production phase. With a good methane to carbon dioxide ratio of about 60:40, the landfill gas testing results are excellent. Because of the deeper water table, generally low oxygen levels, and stable CO2 levels (around 40% for all wells), higher pumping rates were possible. The amount of H2S is extremely high. Wearing the appropriate PPE and limiting exposure time near wells and during upcoming activities (such as studies and gas extraction) are crucial.
