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Groundwater quality in Patna District
• Step 2: When the test value must not fall below the • ENVIS Centre on Control of Pollution Water, Air
objective: and Noise, Central Ground Water Board
Objective • ENVIS Centre, Bihar State Pollution Control
Excursion = −1 ; (IV) Board, Patna (Bihar)
Failedtestvalue • India Water Resources Information System,
Department of Water Resource, GoI.
• Step 3: The total sum of excursions (normalized
sum of excursions, nse) beyond compliance is 2.4. Software
determined using the following formulae: 2.4.1. QGIS
To analyze different spatial and non-spatial data, an
∑ n excursion open-source software named QGIS version 3.18.1
nse = = i 1 ; (V)
Number of test (Zürich) was used.
2.4.2. Microsoft office tools
nse
F = . (VI) For arranging and analyzing the data, some of the
3
001nse + 0 01. tools from Microsoft Office such as Word, Excel, and
.
PowerPoint were used in this study.
After establishing these factors, the CCME-WQI can
be computed using the following formula: 3. Results and discussion
2 3.1. Groundwater quality data collection
2
2
F
F
F
CWQI 100 1 2 3 . (VII) The data for several groundwater quality parameters
1 732
.
were collected from various central and state agencies
from 2004 to 2020. These data were further processed
The value derived from computing the index using in Microsoft Excel to use in the QGIS application as
the aforementioned formulae can classify the analyzed well as in the WQI calculation.
water into one of the specific quality categories outlined
in Table 1. 3.2. Physicochemical characteristics of groundwater
in Patna district
2.3. Groundwater quality data collection The secondary groundwater quality data collected from
All the information related to the present study such various sources includes the following water quality
as population data, groundwater quantity status, parameters: pH, electrical conductivity (EC), TH, TA,
groundwater quality status, drinking water quality TDSs, carbonates and bicarbonates, chloride, sulfate,
standards, and guidelines had been collected from nitrate, calcium, magnesium, sodium, potassium, and
various central and state agencies. Some of the fluoride concentrations. The statistical results of the
major agencies providing secondary data are enlisted physicochemical water quality parameters are tabulated
here: in Table 2.
• Ground Water Yearbook-India, Central Ground Based on Table 2, pH ranges from 6.90 to 9.20, with
Water Board (published from 2009 to 2020) some samples exceeding the permissible limit (6.5 – 8.5),
indicating alkaline water. High EC (242 – 2050 µS/cm)
Table 1. Water quality rating as per CCME WQI and TDS (114 – 1163.50 mg/L) in some locations suggest
method elevated dissolved ion concentrations. TH (90 – 816 mg/L)
Value of WQI Quality of water and alkalinity (112 – 694.90 mg/L) often exceed limits,
95 – 100 Excellent leading to potential scaling and taste issues. Higher
concentrations of chloride (up to 337.40 mg/L) and nitrate
80 – 94 Good (up to 111 mg/L) in some samples indicate contamination
60 – 79 Fair from sewage and agriculture. Calcium and magnesium
45 – 59 Marginal exceed the 75 and 30 mg/L limits, respectively, in several
0 – 44 Poor cases, contributing to water hardness. However, fluoride
Abbreviations: CCME: Canadian Council of Ministers of the concentrations are found to be mostly within safe limits
Environment; WQI: Water Quality Index. (0.08 – 1.05 mg/L), reducing fluorosis risk. While many
Volume 22 Issue 1 (2025) 137 doi: 10.36922/ajwep.8142
