DES MOINES — The Iowa Department of Natural Resources reported multiple discharges from sewage treatment plants and livestock facilities in recent days as systems got overwhelmed by large amounts of rain.
The DNR’s Scott Wilson says livestock facilities have struggled to handle the manure all spring. “Because of the wet weather, just bad farm conditions, ground conditions, and so right now with the extra rains they are full. Some have been overflowing,” Wilson says. “For some that’s a permit-allowable thing — for others it’s not.”
He says the DNR tries to help producers address the issue before it becomes a problem. “Yeah, we do like to talk to facilities about options for transferring manure, holding manure, putting it out on fields that are potentially full — but it buys us some time to let manure flow across fields,” Wilson says.
Wilson says there is not set rule or plan that can be used for every situation. “It really is very specific to each facility,” he says, “which is one of the reasons why we always like to asked people to call us when they are anticipating a problem, or they discover that they’ve already got a problem.”
The DNR had more than 70 reports of city sewage treatment plants discharging after having trouble handling the large volumes of water. “Sometimes those discharges that are being reported are coming from the wastewater treatment plants themselves. Where the treatment plant is getting influent that exceeds what they can handle,” according to Wilson. “It also is sometimes in what we call the collection system.”
Problems in the collection system include pipes that get plugged or overwhelmed with water. He says some systems still have sump pumps connected to them from houses and that additional water can overwhelm a plant. Wilson says they issue a warning to let the public know there might be sewage in the waterways.
“It’s the kind of thing for at least for the days which it is occurring and a few after — you’d want to be wary. There is potential for pathogens to be in the water. And also because of a flooding situation there’s other safety hazards in the water too, floating debris, force of the water moving,” Wilson says. He says the risk is a different for the animal manure that’s released from storage. But, he says there have been no reports of dead fish or other aquatic life.
Wilson says the immense volume of water helps dilute the risk. “When you have flooding situations, you do end up with a lot of dilution. That’s not an excuse to allow pollution — but it does frankly help out in this situation,” he explains. “Where you don’t see the impact that you might see otherwise if the wasterwater was going directly into a stream that was at low flow or normal flow.”
Wilson says livestock facilities that are discharging or expecting to discharge should contact their local DNR field office After hours, facilities can call the DNR emergency spill line at 515-725-8694. The DNR website has more information about spill reporting requirements.