ZK6 and MJ9, and heptachlor expoxide only in ZK5. According to the Quality
Standards for Groundwater (GB/T14848–2017), the groundwater meets the standards for organochlorine and phosphorus pesticides.
• PAHs
The detected PAHs in groundwater are acenaphthene, dihydroanthracene and
fluorine with detection rates of 55.56%, 11.11% and 11.11% respectively. The
samples with acenaphthene were taken at ZK2, ZK3, ZK4, ZK5 and ZK6, and those
of dihydroanthracene and fluorine only at ZK2. According to the Quality Standards
for Groundwater (GB/T14848–2017), acenaphthene, dihydroanthracene and
fluorine in the groundwater exceed the limits, and the maximum excess, found in
ZK4 and ZK2, represented 1.62, 1.08 and 4.58 times of the standard values
respectively, which indicates serious pollution.
• Phenols and other components
2,4-chlorophenol and phenol were also detected in groundwater with detection rate
of 22.22% each. The detected samples were taken at ZK2 and ZK3 and ZK4 and
ZK5 respectively. According to the Quality Standards for Groundwater (GB/
T14848–2017), 2,4-dichlorophenol and phenol in groundwater exceed the standard
values (0.011 and 2.2 mg/L), to the maximum extent by 145.45 and 1.36 times (in
ZK4 and ZK2) respectively, which indicates serious contamination.
(b) Groundwater quality assessment
• Evaluation factors and method
Evaluation factors refer to the main elements of pollution that are representative to
characterize environmental quality for environmental quality assessment. The
appropriate selection of evaluation factors is essential to the reliability of evaluation
results. The selected evaluation factors should be representative and reflect the
environmental quality and status correctly and objectively. The standard index
method described in Sect. 2.2.7 is used for indicator-specific assessment and
comprehensive assessment.
• Results
As a number of items were tested for the nine sample groups in the lab, the
indicators adopted by the Quality Standards for Groundwater (GB/T14848–2017),
including ammonia, iron, manganese and 30 indicators, are used for groundwater
quality assessment. Where the limits are the same for indicators of different water
quality categories, the lower limits shall prevail (Grade I limits for undetected
indicators). The results of indicator-specific assessment and comprehensive
assessment are as shown in Tables 5.25 and 5.26 respectively.
According to the indicator-specific results (Table 5.25), eight of the nine sample
groups fail to meet the turbidity standard; seven fail to meet the chromaticity
standard; five fail to meet the standards for pH and permanganate index; four (all
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Standards for Groundwater (GB/T14848–2017), the groundwater meets the standards for organochlorine and phosphorus pesticides.
• PAHs
The detected PAHs in groundwater are acenaphthene, dihydroanthracene and
fluorine with detection rates of 55.56%, 11.11% and 11.11% respectively. The
samples with acenaphthene were taken at ZK2, ZK3, ZK4, ZK5 and ZK6, and those
of dihydroanthracene and fluorine only at ZK2. According to the Quality Standards
for Groundwater (GB/T14848–2017), acenaphthene, dihydroanthracene and
fluorine in the groundwater exceed the limits, and the maximum excess, found in
ZK4 and ZK2, represented 1.62, 1.08 and 4.58 times of the standard values
respectively, which indicates serious pollution.
• Phenols and other components
2,4-chlorophenol and phenol were also detected in groundwater with detection rate
of 22.22% each. The detected samples were taken at ZK2 and ZK3 and ZK4 and
ZK5 respectively. According to the Quality Standards for Groundwater (GB/
T14848–2017), 2,4-dichlorophenol and phenol in groundwater exceed the standard
values (0.011 and 2.2 mg/L), to the maximum extent by 145.45 and 1.36 times (in
ZK4 and ZK2) respectively, which indicates serious contamination.
(b) Groundwater quality assessment
• Evaluation factors and method
Evaluation factors refer to the main elements of pollution that are representative to
characterize environmental quality for environmental quality assessment. The
appropriate selection of evaluation factors is essential to the reliability of evaluation
results. The selected evaluation factors should be representative and reflect the
environmental quality and status correctly and objectively. The standard index
method described in Sect. 2.2.7 is used for indicator-specific assessment and
comprehensive assessment.
• Results
As a number of items were tested for the nine sample groups in the lab, the
indicators adopted by the Quality Standards for Groundwater (GB/T14848–2017),
including ammonia, iron, manganese and 30 indicators, are used for groundwater
quality assessment. Where the limits are the same for indicators of different water
quality categories, the lower limits shall prevail (Grade I limits for undetected
indicators). The results of indicator-specific assessment and comprehensive
assessment are as shown in Tables 5.25 and 5.26 respectively.
According to the indicator-specific results (Table 5.25), eight of the nine sample
groups fail to meet the turbidity standard; seven fail to meet the chromaticity
standard; five fail to meet the standards for pH and permanganate index; four (all
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133