Analysis of the above data shows:
(1) The nonconforming indicators in the test of the 1st layer of groundwater,
including nitrate (as N), nitrite (as N), ammonia-nitrogen, total dissolved solids,
chloride, lead and manganese are characteristic pollutants of the leachate, which
indicates the 1st layer of groundwater of the surrounding area has already been
polluted by the waste soil leachate.
(2) The water quality of the samples collected in MW1
# at the western boundary of
the landfill (upstream of groundwater) is significantly worse than that of the
samples collected in MW2
# at the eastern boundary (downstream of groundwater). The first reason is that upstream well MW1
# is located too close to the
landfill, so that the landfill leachate is already directly connected with the 1st
layer of groundwater. Therefore, the upstream well MW1
# has been contaminated by the leachate and cannot represent the background value of surrounding
groundwater. The second reason is that the wasted are filled from west to east of
the field gradually, so that the waste at the western boundary had existed for a
longer period of time than at the eastern boundary and therefor the water quality
near the western boundary is significantly worse than that near the eastern
boundary. The third reason is that the well MW2
# (groundwater downstream) is
located 1 m to the west of the surface water of the pond. The leachate is directly
connected with the surface water and groundwater. Therefore, the water quality
here is better than the water quality at well MW1
#
.
Table 5.94 Statistical table of multiples by which the indicators of groundwater samples from the
1st aquifer exceed the limit
Exceeding item
Exceeding the
standard by
multiple
Exceeding by maximum multiple
MW1
MW2
Chromaticity (degrees)
3.0
/
3.0
Permanganate index (mg/L)
5.3
/
5.3
Nitrate (as N) (mg/L)
1.0
/
1.0
Nitrite (as N) (mg/L)
41.7
/
41.5
Total hardness (as CaCO 3 ) (mg/L)
1.8
/
1.8
Ammonia-nitrogen (mg/L)
67.5
/
67.5
Total dissolved solids (mg/L)
1.5
/
1.5
Fluoride (mg/L)
0.7
1.1
1.1
Sulfate (mg/L)
0.5
/
0.5
Chloride (mg/L)
0.9
/
0.9
Manganese (mg/L)
8.4
/
8.4
278
5 Application Cases
(1) The nonconforming indicators in the test of the 1st layer of groundwater,
including nitrate (as N), nitrite (as N), ammonia-nitrogen, total dissolved solids,
chloride, lead and manganese are characteristic pollutants of the leachate, which
indicates the 1st layer of groundwater of the surrounding area has already been
polluted by the waste soil leachate.
(2) The water quality of the samples collected in MW1
# at the western boundary of
the landfill (upstream of groundwater) is significantly worse than that of the
samples collected in MW2
# at the eastern boundary (downstream of groundwater). The first reason is that upstream well MW1
# is located too close to the
landfill, so that the landfill leachate is already directly connected with the 1st
layer of groundwater. Therefore, the upstream well MW1
# has been contaminated by the leachate and cannot represent the background value of surrounding
groundwater. The second reason is that the wasted are filled from west to east of
the field gradually, so that the waste at the western boundary had existed for a
longer period of time than at the eastern boundary and therefor the water quality
near the western boundary is significantly worse than that near the eastern
boundary. The third reason is that the well MW2
# (groundwater downstream) is
located 1 m to the west of the surface water of the pond. The leachate is directly
connected with the surface water and groundwater. Therefore, the water quality
here is better than the water quality at well MW1
#
.
Table 5.94 Statistical table of multiples by which the indicators of groundwater samples from the
1st aquifer exceed the limit
Exceeding item
Exceeding the
standard by
multiple
Exceeding by maximum multiple
MW1
MW2
Chromaticity (degrees)
3.0
/
3.0
Permanganate index (mg/L)
5.3
/
5.3
Nitrate (as N) (mg/L)
1.0
/
1.0
Nitrite (as N) (mg/L)
41.7
/
41.5
Total hardness (as CaCO 3 ) (mg/L)
1.8
/
1.8
Ammonia-nitrogen (mg/L)
67.5
/
67.5
Total dissolved solids (mg/L)
1.5
/
1.5
Fluoride (mg/L)
0.7
1.1
1.1
Sulfate (mg/L)
0.5
/
0.5
Chloride (mg/L)
0.9
/
0.9
Manganese (mg/L)
8.4
/
8.4
278
5 Application Cases