Monsoon Recharges Pushing More Pollution Into Telangana's Groundwater

Hyderabad:Monsoon recharges of groundwater that are generally expected to help in improving the water quality are not having that impact thanks to human activities which include discharge of untreated sewage, industrial effluents coupled with excessive use of fertilizers, and pesticides in agriculture, with these factors actually resulting in deterioration of groundwater quality.

This was a disturbing finding revealed in the ‘Groundwater Quality Year Book of Telangana State, 2025’, released by the Union ministry of jal shakti recently.

Among the several aspects of groundwater the report focused on is the fluoride content, with the report revealing that it is not just Nalgonda district — infamous for its fluoride in groundwater problem — that suffers from this particular malaise.

Samples of groundwater even from Hyderabad showed excess fluoride above the desirable level of 1.0 mg/litre. Pre and post-monsoon studies showed that of the nine locations in Hyderabad, from where samples were drawn, quality improved only in three while in six others, the quality with respect to fluoride actually deteriorated post-monsoon. Three locations were found to have experienced significant deterioration.

The report, which provides data from 2017 and 2024 for pre and post-monsoon groundwater quality for various parameters in the state, said pre-monsoon excessive fluoride levels were found in Nagarkurnool, Rangareddy, Yadadri Bhuvanagri, Jangaon, Warangal, Hanamkonda, Hyderabad, Medchal Malkajgiri & Nalgonda districts.

Overall excessive levels, the report said, were predominantly found in parts of Hanamkonda, Warangal, Jagtial, Jangaon, Nagarkurnool, Karimnagar, Khammam, Rangareddy, Nalgonda districts.

It is clear that between 2017 and 2024, a significant increasing trend was observed with respect to the number of locations having fluoride more than the permissible limit. In addition to geological factors, the increasing fluoride content in groundwater in Telangana could be due to “anthropogenic (human) activities which include excess use of fertilisers, and industrialisation,” the report said.

Another vital parameter — electricity conductivity — in groundwater which is impacted by presence of total dissolved solids, also showed a rise post-monsoon. Of the 363 locations from where samples were analysed for this property, it was found that this rose in 170 locations.

Just as in the case of fluoride, the report said this rise too could well be a result of leaching of salts and minerals from the soil into the groundwater due to increased infiltration during the monsoon of agricultural residues, fertilisers, and urban pollutants into recharge areas.

Even with respect to nitrate pollution of groundwater, the report the causes for this too were the same as for the other parameters, adding that in the 2017-24 study period, more locations were found with nitrate levels with more than the permissible limit.

As per the BIS Standard for drinking water, the maximum desirable limit of nitrate concentration in groundwater is 45 mg/litre with no relaxation. “Though, nitrate is considered relatively non-toxic, a high nitrate concentration in drinking water is an environmental health concern arising from increased risks of methaemoglobinaemia, particularly to infants. Adults can tolerate little higher concentrations,” the report said.

The specified limits are not to be exceeded in public water supply. If the limit is exceeded, water is considered to be unfit for human consumption.