For more than 20 years, the harmful chemical perchlorate has seeped into San Bernardino County's groundwater. The seep is thought to have started at a local dump site; however, records about the site were lost in the late 1980s by "two state regulatory agencies." The problem wasn't reported again until 1997, but warnings were "dismissed" by the county. The site was "rediscovered" in 2001, but it wasn't until 2009 that the county got serious about stopping the chemical seep. It is estimated that the cleanup operation will be completed by 2013.