Hyderabad: Groundwater in most part of Telangana may not be safe for drinking, unless purified before consumption, due to excessive concentration of nitrates because of unrestrained use of fertilisers for crop production in the rural areas, and, in urban areas, untreated water percolating into the ground.
There is not a single district, out of the 33 in the state, which is not plagued by the problem of excessive nitrate concentrations, the levels being more than the permissible limits.
According to the Central Ground Water Board (CGWB), Rangareddy district is at No. 3 among the top 15 districts in the country where groundwater has extensive nitrate levels. Adilabad is at No. 11 followed by Siddipet at No. 12 while Palnadu district in Andhra Pradesh is at No. 8.
In its annual groundwater survey report 2024 released in the last week of December, the CGWB said that nitrate contamination of ground water is “primarily linked to agricultural run-off and overuse of fertilisers.”
The CGWB report said that 27.48 per cent of the samples it studied from across Telangana had nitrate levels in excess of 45 micrograms per litre, the Bureau of Indian Standards (BIS) safe limit for presence of this group of chemicals in groundwater.
“We have been seeing a rise in paddy cultivation over the years, and typically in paddy, just 30 per cent of the urea applied by farmers is actually absorbed by the plants while the remaining compounds leach into the ground because of the standing water in paddy fields. And nitrate rich groundwater that results because of this seepage, is simply unfit for human consumption,” Ravi Kanneganti of Rythu Swarajya Vedika explained.
Nitrogen comprises some 46 per cent of fertiliser urea that farmers use for their crops.
In a possible indication that increased fertiliser use could be a cause for high nitrate levels in 32 districts of Telangana, the CGWB report said that post monsoon season recharge of groundwater tables in the state – when surface water percolates more because of accumulation from rainfall - actually witnessed deterioration of water quality – as in discovery of higher nitrate content – in 123 of the 148 locations from where it drew samples for study.
Telangana has among the highest fertiliser use per hectare with the National Academy of Agricultural Sciences, New Delhi’s State of India Agriculture report for 2024, pegging the average fertilizer consumption at 297.5 kg per hectare for 2021-22.
According to the Fertiliser Association of India’s 2022-23 annual review of fertilizer production and consumption, fertiliser use in Telangana saw a 4.7 per cent growth between 2021-21 and 2022-23.
High fertiliser use a contributing factor
Infograph:
States Samples– High nitrate - percentage
Telangana 1,150 316 27.48
Andhra Pradesh 1,149 270 23.5
TG/AP in top 15 high nitrate-level districts
District – All India Rank - Samples– Above safe level
Rangareddy – 3 70 44
Palnadu (AP) 8 70 36
Adilabad 11 51 24
Siddipet 11 51 24
