New data shared in Parliament this week reveal high level of contamination in drinking water samples in Haryana and Punjab over the past five years. Records from the Ministry of Jal Shakti show that Haryana tested 3,35,334 water samples during this period, of which 20,334 were found bacteriologically contaminated and 5,691 chemically contaminated.Punjab tested 2,05,053 samples, of which 5,109 showed chemical contamination and 389 were bacteriologically contaminated.Himachal Pradesh tested 11,78,436 samples, the highest among Indian states, with 110 found chemically contaminated and 163 showing bacteriological contamination.Bacteriological contamination poses the highest risk during monsoon and in areas with old or leaking pipelines. Chemical contamination implies excess of fluoride, arsenic, nitrates and heavy metals — challenges most prevalent in areas dependent on groundwater.The data was presented in the Rajya Sabha this week in an answer to a question by AAP member Raghav Chadha. An analysis shows the picture for Haryana is particularly alarming in terms of bacteriological contamination that can cause waterborne diseases, including diarrhoea, typhoid and cholera.Kerala, Bengal top contamination chartAcross India, the highest bacteriological contamination over the five-year period was reported in Kerala, while West Bengal recorded the highest levels of chemical contamination.In 2021-22, out of 96,910 samples tested in Haryana, 497 were bacteriologically contaminated and 397 had chemical contamination. The situation worsened in 2022-23 as out of 82,725 samples tested, bacteriological contamination jumped to 12,657 samples — the highest in any single year for Haryana — while chemical contamination rose to 3,689.The upward trend continued in 2025-26 up to March 11, with 25,240 samples tested, of which 325 were found to be bacteriologically contaminated and 71 chemically contaminated.So far as Punjab is concerned, 2,05,053 samples were tested, with chemical contamination emerging as a major concern. The state’s water quality data also show a steady increase in the number of samples tested — from 14,930 in 2021-22 to 67,481 in 2024-25 — a sign of expanding surveillance.However, contamination concerns remain. In 2021-22, of the 14,930 samples tested, 815 showed chemical contamination and 36 bacteriological contamination. In 2025-26, up to March 11, 2026, of the 64,919 samples tested, 753 showed chemical contamination and 57 bacteriological contamination.Overall, of the 2,05,053 samples tested by Punjab over five years, 5,109 showed chemical contamination and 389 bacteriological contamination.Himachal Pradesh reported relatively low levels of toxicity.Nationally, too, the problem is significant. Of the 3,27,52,723 samples tested for quality over five years, 14,51,009 showed chemical contamination and another 11,74,266 were bacteriologically contaminated, taking the overall contamination rate to over 8 per cent.The government, meanwhile, maintains that drinking water is a state subject, with responsibility for planning, implementation, operation and corrective action resting with the states.States can use up to 2 per cent of their annual allocation under the Jal Jeevan Mission for water quality monitoring and surveillance activities. In December 2024, the government released a Concise Handbook for Monitoring Water Quality of Piped Drinking Water Supply to Rural Households. The department also issues periodic advisories to states to obtain and maintain accreditation for their drinking water testing laboratories.