Appraisal and
comparison of contamination in potable water sources during pre, syn and post monsoon
periods in Southwest Lawngtlai district, Mizoram, India
Blick John, Verma Rahul, Malsawmtluanga and Lalfakawma
Res. J. Chem. Environ.; Vol. 29(9); 75-85;
doi: https://doi.org/10.25303/299rjce075085; (2025)
Abstract
The quality of groundwater South-west Lawngtlai district, Mizoram has been assessed
in the present work using the samples from ground water sources (WL) in three different
seasons as pre-monsoon, monsoon and post-monsoon. The main objective of this study
is to investigate the physico-chemical, bacteriological, estimation of heavy metals
or trace elements and other cations and anions characteristics used for domestic
and household purposes. The main sources of heavy metals/ trace elements along with
different parameters in potable water were controlled by the geological composition
of the host rock and with other local anthropogenic activities due to increasing
urbanization, agricultural runoff containing fertilizers, pesticides, insecticides
and industrial effluent. Turbidity has been found exceeding the permissible limits
of 5 NTU in some stations.
The concentration of Aluminum (Al), Barium (Ba), Gallium (Ga), Iron (Fe), Lithium
(Li), Strontium (Sr) and Zinc (Zn) is well within the prescribed limits recommended
by BIS and WHO. In all the samples the concentration of Silver (Ag), Cadmium (Cd),
Cobalt (Co), Chromium (Cr), Copper (Cu), Molybdenum (Mo) and Nickel (Ni) is found
below limit of detection (BLD). The concentration of Arsenic (As), Manganese (Mn)
and Lead (Pb) in some stations has been recorded exceeding the permissible limits
of 0.05 mg /me, 0.3 mg /me and 0.05 mg /me respectively. especially in the low-
lying area of reducing environment such a high concentration of Arsenic in potable
may be induced due to the dissolution of rocks, minerals and ores. The occasional
high concentration of lead in water sample may be due to gasoline coming out of
vehicles as most of the water sources are situated on or near the highway. Most
of the value of total coliforms (MPN) has been found exceeding the permissible limits
of 10 MPN/100 ml in water sample from all the water sources. The higher value of
coliforms in water samples may be attributed to the use of pit latrines, piggeries
and poultries, which are predominant in the study area. The total hydrochemistry
of the area under study is dominated by alkaline earths and weak acids. Most of
the surface, sub-surface and groundwater in the study area can be classified as
Ca-Mg-HCO3 facies while in some samples calcium or magnesium is sometimes replaced
by sodium. It is highly recommended that the drinking water of the affected areas
should be filtered and should be treated chemically or physically for toxic metals.
