A screening level ecological risk assessment (SERA) was completed to evaluate the potential risks of pesticides found in water in the lower Canal 111 (C-111) Basin and adjacent tidal zones in South Florida. This risk assessment was conducted under general U.S. EPA guidelines and focuses on effects of water exposure to the herbicides atrazine and metolachlor and to the insecticides chlorpyrifos, endosulfan, and malathion. Results found that the highest potential risk was associated with the acute effects of endosulfan to freshwater arthropods at sites near water control structure S-178 and Canal 111e, a branch of C-111. The highest potential risk of acute effects of endosulfan for saltwater organisms was in Joe Bay, which receives discharges from C-111. Results from evaluations of risk of chronic effects from pesticide exposure show that the highest potential risk is associated with endosulfan in freshwater.
