(CNN) Sara Ganim, November 12, 2018 — For 10 years, some residents in Denmark, South Carolina, have been suspicious of the rust-colored water coming from their taps. They’ve been collecting samples in jars and using bottled or spring water, even though the local and state government assured them it was safe.
But through a Freedom of Information Act request and a one-year investigation, CNN has found new information that may cast doubts on those assurances.
The state government was adding a substance to one of the city’s four wells, trying to regulate naturally occurring iron bacteria that can leave red stains or rust-like deposits in the water. The substance, known as HaloSan, was not approved by the US Environmental Protection Agency to disinfect drinking water.