affected by the transport of pollutants. In Q Village, 2200 m away from the landfill,
the time for NH 3 –N to reach Class III groundwater standard is 1730 days, and the
time for COD cr to reach the water quality standard for the secondary conservation
area of surface water sources is 1798 days. In K village 2600 m away from the
landfill, the time for NH 3 –N to reach Class III groundwater standard is 2076 days,
and the time for COD cr to reach the water quality standard for secondary conservation area of surface water sources is 2151 days, indicating that its impact is slow.
When leachate leaks, although its impact on groundwater is slow, the water
quality will deteriorate obviously when the groundwater is affected by it. Taking Q
Village as an example, the time for NH 3 –N and COD cr concentrations to reach the
standard is 1730 and 1798 days respectively, but the concentrations reach 28 and
350 mg/L in the 1900th day, which seriously exceed the water quality standards,
affecting the water quality for a long time, and posing great risks to the downstream
ecology and human health.
5.5 North China
Case 9 Groundwater pollution survey, source severity assessment and risk
assessment of an informal landfill in Beijing
1. Overview of the study area
(1) Overview of natural geographical conditions
The plot of land that the informal landfill site in Beijing occupies is located at the
middle and lower part of the Yongding River alluvial fan and has an overall terrain
relief higher in the northwest and lower in the southeast. The site is now built into a
suburb wild park. The terrain in the park show clear evidence of artificial modification. Artificial hills are heaped in the middle and an artificial lake is built in the west
side, resulting in greater fluctuation in overall terrain relief between 31.0–45.0 m.
7LPHIRU&2'FU DWGLIIHUHQWGLVWDQFHVWRUHDFKWKHZDWHUTXDOLW\VWDQGDUG
7LPHG
'LVWDQFHP
Fig. 5.41 Time for COD Cr at different distances to reach the water quality standards
254
5 Application Cases
the time for NH 3 –N to reach Class III groundwater standard is 1730 days, and the
time for COD cr to reach the water quality standard for the secondary conservation
area of surface water sources is 1798 days. In K village 2600 m away from the
landfill, the time for NH 3 –N to reach Class III groundwater standard is 2076 days,
and the time for COD cr to reach the water quality standard for secondary conservation area of surface water sources is 2151 days, indicating that its impact is slow.
When leachate leaks, although its impact on groundwater is slow, the water
quality will deteriorate obviously when the groundwater is affected by it. Taking Q
Village as an example, the time for NH 3 –N and COD cr concentrations to reach the
standard is 1730 and 1798 days respectively, but the concentrations reach 28 and
350 mg/L in the 1900th day, which seriously exceed the water quality standards,
affecting the water quality for a long time, and posing great risks to the downstream
ecology and human health.
5.5 North China
Case 9 Groundwater pollution survey, source severity assessment and risk
assessment of an informal landfill in Beijing
1. Overview of the study area
(1) Overview of natural geographical conditions
The plot of land that the informal landfill site in Beijing occupies is located at the
middle and lower part of the Yongding River alluvial fan and has an overall terrain
relief higher in the northwest and lower in the southeast. The site is now built into a
suburb wild park. The terrain in the park show clear evidence of artificial modification. Artificial hills are heaped in the middle and an artificial lake is built in the west
side, resulting in greater fluctuation in overall terrain relief between 31.0–45.0 m.
7LPHIRU&2'FU DWGLIIHUHQWGLVWDQFHVWRUHDFKWKHZDWHUTXDOLW\VWDQGDUG
7LPHG
'LVWDQFHP
Fig. 5.41 Time for COD Cr at different distances to reach the water quality standards
254
5 Application Cases