in Sect. 2.2.7 is used for indicator-specific evaluation and comprehensive evaluation (Table 5.5).
• Results
As a number of items were tested for the three sample groups in the lab, the
indicators set in 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 groundwater quality evaluation are as shown in
Table 5.6.
As shown in Table 5.4, groundwater in G1, G2 and B1 is not contaminated and
reaches the Grade I standard for majority indicators. Groundwater in G1 and G2
overall reaches Grade II standard, in terms of ammonia nitrogen, nitrate nitrogen
and TDS in G1 and in terms of sulfate, TDS and total hardness in G2. The overall
Table 5.2 Test items specific to sample group
Sample group
Test items
G1
All 49 indicators
G2
All 49 indicators
B1
23 conventional indicators and 5 types of monocyclic aromatic
hydrocarbons
L1
All 49 indicators
L1’ (selective
retest)
Ammonia, permanganate index, arsenic, iron, manganese, and 5 types of
monocyclic aromatic hydrocarbons
S1
23 conventional indicators and 5 types of monocyclic aromatic
hydrocarbons
Fig. 5.7 Sampling preparation
5.1 Central China
101