A federal study has proposed that several toxic substances released by wastewater treatment plants are being disposed in Columbia River.

Jennifer Morace, U. S. Geological Survey hydrologist who was lead investigator of the study, asserted that earlier, it was believed that water bodies have been polluted due to tall industrial chimneys emitting smoke on the river or due to dirty pipes.

He affirmed that the present problem is not just due to these industries only, but it has exaggerated due to a person's everyday life. He said, "What goes down the drain and to the wastewater treatment plant, and the fact they were not designed to remove the new or emerging contaminants".

It has been reported that during the course of study, water treatment plants' discharge was taken into consideration in nine cities, including Wenatchee, Wash., Longview, Umatilla, The Dalles, Hood River, Portland, Vancouver, and St. Helens.

In total, 112 toxic substances were recovered, out of which 53% were tested and were discovered to be including flame reducing products, pharmaceuticals, pesticides, personal care products, mercury and cleaning products.

Moreover, it has been subjected that compound diphenhydramine was found from all the nine sites and it was found that the compound was capable of making people drowsy.