The Nebraska Department of Environmental Quality says the Platte River, which carried contaminated floodwaters from Colorado into Nebraska, is no longer a public health risk.
The Nebraska DEQ made the determination on Friday.
The agency ramped up water testing after Colorado floodwaters were diverted into reservoirs and canals on the Platte River system in Nebraska. The public was warned to avoid the rivers until the floodwaters had passed through the state.
Initially, high levels of illness-causing bacteria were reported in central Nebraska, but have since returned to normal.