Ballast water - water carried in tanks on ships to help provide stability and aid steering - is likely the single greatest source for introduction of non-native and invasive aquatic species. Ballast water is collected in one body of water and discharged into another body of water, usually large distances apart. At least one new invasive species is found in the Great Lakes every year, with Lake Superior being particularly at risk. Scientists from the U.S.
The USGS and the MPCA will determine the relative contributions of endocrine active chemicals (EACs) and pharmaceuticals from WWTP effluent to aquatic ecosystems. The primary objective is to measure the concentrations of EACs and pharmaceuticals in water samples collected from the effluents from 20 WWTPs and at sites upstream and downstream of WWTP effluent discharge in Minnesota during 2009-2011.