MANGALURU: Contamination in Karnataka’s drinking water has shown a marked decline over the last three years, according to data tabled in the Lok Sabha by the Union Ministry of Jal Shakti on February 12.
The number of samples found non-compliant with prescribed quality standards has fallen steadily. Chemical contamination cases dropped from 24,917 in 2023-24 to 17,261 in 2024-25 and further to 10,911 in 2025-26 (as on date). Bacteriological contamination has seen an even sharper fall—from 4,670 in 2023-24 to 2,574 in 2024-25 and just 452 so far in 2025-26.
A closer look at contaminant-wise data reveals both progress and persistent hotspots across districts. In 2023-24, nitrate and fluoride contamination were widespread. Nitrate-affected samples peaked in districts such as Chikkaballapur (563), Chitradurga (504), Vijayapura (340), Mandya (316), and Tumakuru (300). Fluoride was high in Chitradurga (437), Chikkaballapur (389), Raichur (320), and Tumakuru (211). Microbial contamination was significant in Bengaluru Urban (338 E. coli; 444 total coliform), Chikkaballapura (404 E. coli; 838 total coliform), Mandya (48 E. coli; 483 total coliform) and Hassan (81 E. coli; 182 total coliform).By 2024-25, overall contamination counts reduced across parameters.
However, nitrate levels remained elevated in Chikkaballapur (382), Vijayapura (359), Koppal (349), Mandya (373), Belagavi (302) and Tumakuru (198). Fluoride contamination continued in Tumakuru (248) and Chitradurga (252). Microbial contamination, though reduced at the aggregate level, persisted in districts such as Mandya (201 E. coli), Koppal (196), Mysuru (235), and Kolar (380 E. coli).
The 2025-26 data indicate a sharper contraction in both chemical and bacteriological non-compliance. Total nitrate-affected samples fell from 4,003 in 2023-24 to 3,129 in 2024-25 and 2,224 so far in 2025-26. Fluoride cases declined from 2,269 to 1,647 and then 1,169.
Bacteriological contamination reduced dramatically, with E. coli cases dropping to 315 and total coliform to 333 across the state so far this year. Yet, certain districts continue to show stress. In 2025-26, nitrate remains high in Mandya (336), Vijayapura (264), Koppal (285), Belagavi (230), Chitradurga (214) and Chikkaballapura (212). Fluoride persists in Chitradurga (241), Vijayapura (171), Raichur (125) and Tumakuru (100). Microbial contamination, though far lower overall, is still visible in Bidar (48 E. coli; 48 coliform), Kalaburagi (64; 64), Yadgir (53; 55) and Raichur (45; 45).
On the other hand, districts such as Dakshina Kannada, Udupi and parts of Bengaluru Rural show minimal or negligible contamination across most parameters in the latest year’s data. Bengaluru Urban saw high microbial contamination in 2023-24, which declined in 2024-25 and dropped to negligible levels in 2025-26, with only isolated chemical non-compliance reported this year.The Centre has said Karnataka has reported regular remedial measures, routine disinfection, district-level task forces and the use of community water purification plants in affected habitations.