Naseem, S.; Husain, V., and Bano, S., 2018. Origin of salinity and other constituents in Indus deltaic plain groundwater, Thatta District, Pakistan.

Physico-chemical and microbiological analyses of 32 groundwater samples from the Sujawal and Makli areas of Thatta District, Sindh Province, Pakistan, were carried out to reveal the source of major ions and high salinity. Data reveal that aquifers in the study area show high salinity due to various geochemical phenomena, including cation exchange, mineral dissolution, evaporation, seawater intrusion, and anthropogenic activities. Shallow wells in the area are highly polluted due to unlined sanitation ponds, fish ponds, and waste dumps, as shown by microbiological data. Minerals found in subsurface soil are quartz, calcite, calcian-albite, muscovite, and phlogopite, which could be sources of high salinity and fluoride in groundwater. High arsenic in subsurface soil can be related with Holocene aquifers. However, the alkaline pH and oxic nature of the aquifers are not favorable for the release of arsenic in the groundwater of the study area. Therefore, most of the aquifers in the area are free from arsenic.