The Minnesota Health Department says it might have inadequately tested some water samples from municipal and other systems as far back as the 1990s, but it’s unlikely there is a significant threat to public health. The department’s Tom Hogan says they’re correcting procedures and hope to begin re-sampling within the next two weeks…

Officials say water samples were not held at correct temperature before testing for organic chemicals such as fertilizers and solvents, plus some inorganic compounds. They’re still trying to determine how the error began and why it went on for so long.