While you get ready to watch your town, fair or ballpark fireworks display this holiday, one community’s wondering if the rockets had a more lasting effect. EPA senior engineer Craig Smith recently visited Hills, a small town south of Iowa City, to talk with local residents about why a chemical called perchlorate turned up in their well water. The environmental protection agency’s been working on the case for almost there years and thinks the most likely cause is fireworks. “Duds that were unexploded or partially exploded and eft at the surface and caused the groundwater contamination that we’re seeing.” Perchlorate is best known as a rocket fuel and it’s been a mystery what might have led to its appearance in the rural east-central Iowa community. Smith says this is the first case they think is linked to a community fireworks display. In a few other cases it’s been blamed on the presence of a big fireworks factory. Two years ago investigators told Radio Iowa the chemical had been used years ago to fumigate grain in USDA storage bins but Smith says now they don’t think that was the source. The EPA engineer says the chemical’s found in fairly low levels that don’t pose much of a hazard to residents in Hills. He says the “action level” that triggers the agency to take action is just 18 parts-per-billion in the groundwater. Smith says they’ve found about 25 homes with shallow wells turning up groundwater contamination above that “action level.” They’ve provided bottled water to those residents, about a tenth of the homes in that community. The highest level found in any drinking-water well was 66 parts-per-billion, not significantly higher than the alert level. He says it’s probably never caused any health problems. Smith says providing bottled water to some residents is “primarily a precaution.” Smith says since the chemical first turned up in water tests, it seems to be declining and is gone from water sources in the area.
