TITLE:
Assessment of Groundwater Quality in a Tidal River Basin of the Ganges Delta in Bangladesh
AUTHORS:
Sadhon Chandra Swarnokar, Nazia Hassan, Masudur Rahman, Md. Muhyminul Islam, Mosummath Hosna Ara
KEYWORDS:
Geochemical Process, Major Ions, Tidal Delta, Hydrogeochemistry, Groundwater Quality, CCME WQI, Bangladesh
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.5,
May
30,
2019
ABSTRACT: At Shailmari River basin, located in the central
Ganges Delta and the southwestern coastal Bangladesh, groundwater is the only
potable source for water supply due to incompatible surface water sources.
However, salinity degradation along with arsenic and iron contamination poses a serious health threat to the basin
community. Considering this, an investigation was carried out along both
banks of the river to assess groundwater vulnerability and its quality for
drinking by conducting multi-seasonal water sampling campaigns from 20 domestic
wells and analyses (both in-situ and laboratory) for several physico-chemical
(pH, EC, TDS and major ions) and biological (coliforms) parameters. The results
show slightly alkaline groundwater in the study area with largely variable chemical composition, i.e. EC varies from around 1900 to 2700 μS/cm. The abundance of major ions indicates as Na+ > Ca2+ > Mg2+ > K+ for cations and > Cl- > > > for anions. As per the Canadian water quality index (CCMEWQI), almost all groundwater samples
concentrate in the marginal category meaning that groundwater is frequently
threatened. Besides, it is not fully safe for drinking as revealed from
comparison of geochemical data with national and WHO water quality standards.