Pollution Snake River

dams milner dam divert water snake river irrigation, causes many of pollution problems in snake

much of return flows not issue directly snake river, rather feed snake river aquifer underneath snake river plain. water diverted river irrigation, after absorbing surface pollutants, re-enters ground , feeds aquifer. although aquifer has maintained level, has become increasingly laced contaminants. water in aquifer travels west side of snake river plain , re-enters river springs. throughout of snake river plain , hells canyon, excessive sediment recurring problem. in december 2007, u.s. environmental protection agency (epa) issued permit requiring owners of fish farms along snake river reduce phosphorus discharge 40%. pollutant levels in hells canyon upstream of salmon river confluence, including of water temperature, dissolved nutrients, , sediment, required meet levels.