Raw sewage is still being dumped into the Big Sioux River at Sioux Falls after heavy rain and flooding overwhelmed the system two weeks ago. That waterway flows into the Missouri River at Sioux City, but officials do -not- see a threat to clean water in river cities in Iowa and Nebraska.
Ken Hessenius, a regional supervisor with the Iowa Department of Natural Resources, says flooding is taking care of most of the pollutants. Hessenius says, “Those sewer systems get so overwhelmed and so surcharged with fresh water mixing with the sewage, we find the actual amount of pollution in those discharges is very, very minimal.”
He says the sewage is heavily dilulted by the flooding to the extent that a mile downstream from the dumping point, there’s no pollution being found in most cases. Hessenius says people always hear to avoid rivers when they’re flooding — due to dangerous currents and debris. Now, here’s another reason why.
“The river becomes virtually unusable for a lot of uses, particularly canoeing, kayaking, swimming,” Hessenius says. “All of those public uses are curtailed or virtually stopped during flooding conditions so what that does do is remove the potential for human contact.”
Hessenius says the DNR notifies any towns or cities downstream of any wastewater malfunctions that bring this sort of a discharge. Facilities are put on notice but even in those cases, they haven’t had to change their treatment at all to take care of any additional pollutants.
Compounding problems, a sewer line collapsed in Sioux Falls on August 4th, backing up likely a million gallons of sewage, which also had to be dumped into the river.
By Jerry Oster, WNAX, Yankton