Brockovich assisted in the filing of a lawsuit against Prime Tanning Corp. of St. Joseph, Missouri in April 2009. The lawsuit claims that waste sludge from the production of leather, containing high levels of hexavalent chromium, was distributed to farmers in northwest Missouri to use as fertilizer on their fields. It is believed to be a potential cause of an abnormally high number of brain tumors (70 since 1996) around the town of Cameron, Missouri, which is currently being investigated by the EPA.