MOHALI: Groundwater in Derabassi and Zirakpur is highly affected by chemical weathering of rock minerals, is hard and alkaline in nature and not fit for drinking and irrigation in many pockets, according to a study conducted by an independent agency.
The results -- all the water samples were below the acceptable limit of BIS (2012) and WHO (2006) -- have been sent to Central Pollution Control Board and ministry of environment, forest and climate change.
The agency had taken the samples from 30 locations and aquifers to assess hydro-chemical parameters of groundwater in February 2020.
The study said Derabassi has around 300 industries and brick kilns. Waste water from some of these industries is flowing into a drain crossing between Derabassi and Bhankarpur, the study said, terming industries the main cause of groundwater contamination.
96% of sampling sites in very hard water category: Study
The study found the levels of magnesium, calcium, sodium and potassium within the permissible limits but on the higher side, except alkalinity, whose value fell above the permissible limit at a few sites.
The study said as per TH classification, 96% of the sampling sites fell in the category of very hard water. The total dissolved solids (TDS) concentration in the groundwater samples varied from 337 to 937 mg/L, with an average value of 555.7 mg/L. The TDS concentration of 16 samples was within desirable limits and the rest on higher side.
Alkalinity of water samples varied from 305 to 980 mg/L. Out of the 30 samples, 23 samples fell between desirable and permissible limits and the rest above the permissible limit of 600 mg/L. The minimum concentration of sodium was 3.4 mg/L, and maximum 64 mg/L in the samples.
The concentration of total hardness in the water varied from172 to 555 mg/L. The values of total hardness for only three samples were below desirable limit and the rest between desirable and permissible ranges.
Ghaggar pollution
The study said people living in the Ghaggar river basin are facing waterborne diseases as effluents from chemical units have polluted the river, considered a major aquifer for groundwater recharge. The quality of Ghaggar river water was not suitable to withstand aquatic life and not fit for domestic uses, the study said