Pollution

From 1944 to 1971, pump systems drew cooling water from the river and, after treating this water for use by the reactors, returned it to the river. By 1957, the eight plutonium production reactors at Hanford dumped a daily average of 50,000 curies of radioactive material into the Columbia. Timber industry activity further contaminates river water, notably in the increased sediment runoff that results from clearcuts.