E.coli found in Pala water samples as Kerala fights growing groundwater safety issues

UPDATE - follow-up to Why Kerala's groundwater is increasingly at risk of contamination | Explained: Water quality tests in flood-hit areas along the Meenachil river in Pala found E. coli bacteria in 67% of tested samples. Researchers connect this high level of bacterial contamination to recent floods that allowed dirty surface water to mix with local drinking sources. Around 62% of the State population depends on groundwater from roughly 6.5 million open wells for daily needs. A 2024 study in the Journal of Environmental Management warned that 7.4% of the population could be using poor quality groundwater, putting about 0.59 million people at risk across 252 local bodies due to a lack of regular chlorination.

Causes And Spread

A mixture of high population density, unscientific building of septic tanks close to shallow wells, and changing rainfall patterns due to climate change drives the crisis. A 2018 study in Thiruvananthapuram found coliform in 73% of wells, with most having septic tanks within a 7.5-meter radius and acidic water averaging 5.4 pH. Only 5% to 6% of major urban areas use a central piped sewerage network, leaving the State dependent on individual soak pits. Unpredictable heavy rains overflow these systems and push pollutants directly into unconfined shallow aquifers. Pipe leaks in rural small water supply schemes also let sewage mix with drinking lines, leading to regular outbreaks of Hepatitis A, Shigellosis, and norovirus. ICMR and Health department studies trace amoebic meningoencephalitis cases to non-chlorinated well water rich in E. coli.

Infrastructure Progress

Projects are underway through the Central AMRUT 2.0 Mission to upgrade sewerage systems, but a CAG 2025 report showed the earlier AMRUT mission ended with just 11.25% overall achievement and only 0.13% households receiving sewerage connections. Public protests against proposed treatment plants near homes and financial shortages have caused major project delays.

Context

Groundwater supplies shallow aquifers that are easily refilled by rain and surface water, meaning pollution on land quickly reaches drinking sources. Safe water access remains a challenge in parts of India where decentralized sanitation sits close to domestic wells.