# Bacterial contamination in Swedish private wells > Live situation record from CLSTR: https://clstr.news/situations/bacterial-contamination-in-swedish-private-wells > Updated: 2026-09-27T10:11:53.000Z. Sources: 4. Developments: 2. Data from the Geological Survey of Sweden (SGU) has identified significant bacterial contamination in private wells across multiple Swedish regions. Initial findings in Kalmar County showed that 38 percent of tested private wells contained high bacterial levels, rendering the water either unfit for consumption or suitable only with remarks. Subsequent reports expanded these concerns to other areas, noting that 34 percent of tested wells in Halland and approximately 24 percent in Värmland faced similar contamination issues. Experts note that environmental factors such as drought, flooding, heavy rain, or changes in nearby land use can alter water composition. Because of these risks, the Swedish Food Agency recommends testing wells at least every three years, with annual testing advised for households with children under five. Contaminants of concern include E. coli, which can cause gastrointestinal illness, as well as chemical substances like manganese, lead, and arsenic. Vulnerable populations, including the elderly, the sick, and young children, are noted to be at higher risk. ## Timeline ### 2026-09-27: Private well water contamination reported in Halland and Värmland Recent data shows high bacterial contamination in private wells in parts of Sweden, with 34% of tested wells in Halland and 24% in Värmland deemed unfit or requiring remarks. 2 sources. https://clstr.news/cluster/private-well-water-contamination-reported-in-halland-and-vrmland ### 2026-09-20: Kalmar County private wells show high bacterial levels Recent data shows 38 percent of tested private wells in Kalmar County, Sweden, have bacterial levels making the water unfit or questionable for consumption, prompting calls for more frequent testing. 2 sources. https://clstr.news/cluster/kalmar-county-private-wells-show-high-bacterial-levels --- Cite as: Bacterial contamination in Swedish private wells. CLSTR, https://clstr.news/situations/bacterial-contamination-in-swedish-private-wells