UI scientists: Corps should consider livestock, not just geese, as Red Rock pollution source

By: - July 21, 2021 1:33 pm

The U.S. Army Corps of Engineers has blamed geese for fecal bacteria problems at Lake Red Rock near Pella. University of Iowa scientists say livestock most likely were the source. (Photo courtesy of U.S. Army Corps of Engineers)

The U.S. Army Corps of Engineers’ attempt to blame geese for dangerous fecal bacteria in an Iowa reservoir ignores the possible role of widespread livestock manure applications, two University of Iowa water quality experts said Wednesday. 

Water-quality records kept by the Des Moines Water Works show a spike of E. coli bacteria last week in the Des Moines River, upstream from Lake Red Rock, the Iowa Capital Dispatch found. 

KCCI reported that Corps staffer Chelsea Tyler attributed an outbreak of fecal bacteria at Lake Red Rock to Canada geese and seagulls. 

“E. coli is high here right now and that’s caused by the seagulls out here and the fecal matter getting stirred up when they defecate on the beach and that gets in the sediment and the sand and that gets stirred up when there’s a lot of traffic through it,” Chelsea Tyler, a natural resource specialist at Red Rock, told KCCI.

That brought immediate pushback from two University of Iowa water quality experts. Both said Iowans need to acknowledge the role of hog and cattle manure in fouling Iowa’s waterways. 

“I don’t understand how we can’t have more frank conversations,” David Cwiertny, director of the University of Iowa’s Center for Health Effects of Environmental Contamination, said in an interview. “(UI research engineer) Chris Jones just talked about in his blog recently about there being a reticence in Iowa to link our water quality problems to agriculture, even though it’s hard to deny that is one of the root causes,” Cwiertny added. 

Cwiertny said the sheer number of animal confinements in the Des Moines watershed means it’s unlikely geese are the main source of the bacteria. 

Jones agreed. In a tweet, he wrote that “high end estimates” of the number of Canada geese in Iowa run about 100,000, “and many of these are not resident. We have 25 million hogs, each of which has 10x the mass of a goose,” Jones wrote.

“The day pigs fly will be the day Ag quits blaming their pollution on geese (in other words, never),” Jones wrote.

In an interview, Jones noted that a DNR study of the Raccoon River, which drains to Red Rock, found at Van Meter that 46.4% of the fecal bacteria was from hogs, 51.3% from cattle, 2% from chickens, 0.2% from turkeys, 0.1% from septic systems, and less than 0.1% from wildlife. He added that it takes elaborate scientific testing to trace a specific source, and he doesn’t have data from Red Rock.

Cwiertny said there is often political pressure when someone ties farm pollution to water quality issues. In a recent example, the Cedar Rapids Gazette reported that state Rep. Chad Ingels of Randalia said he would reconsider funding at UI, and his support for tenure. That comment came after Jones and UI engineering professor Larry Weber made comments in print and on TV about problems with livestock manure runoff.

Livestock manure is routinely spread on Iowa crop fields as manure. Bacteria from the manure can run off when it rains. 

Data from Des Moines Water Works’ website shows that within the past 10 days, fecal bacteria levels in the Des Moines River at Des Moines were as much as six times the health limit for swimming. That water runs downstream to Pella and Red Rock.

It wasn’t the first time the Corps blamed geese for fecal bacteria in its reservoirs — Saylorville, Rathbun and Red Rock. Saylorville is north of Des Moines, Rathbun near Moravia and Red Rock near Pella. 

A U.S. Army Corps of Engineers official in 2020 suggested geese regularly cause bacteria problems by using the reservoirs as a pit stop.

The Iowa Department of Natural Resources checks state-park beach swimming areas for fecal bacteria and toxic algae in summer. The Corps tests its own reservoirs. 

DNR’s website lists multiple sources of fecal bacteria. “Fecal bacteria, and sometimes pathogens, are present in the intestines of warm-blooded animals, including humans. They are carried into the water with fecal material. Fecal contamination can occur due to improperly constructed and operated septic systems and sewage treatment plants, manure spills, storm water runoff from lands with wildlife and pet droppings, or direct contamination from waterfowl, livestock, or small children in the water,” DNR reports. 

Fecal bacteria aren’t necessarily a threat themselves, but high levels usually mean a good chance that pathogens are present that can make people sick. Diarrhea and skin rashes or infections are among the most common issues, especially among the very old, the very young, and others with suppressed immune systems.

There have been cases in which DNR blamed geese for local pollution problems. After a swimmer got sick in Clear Lake two decades ago, some officials initially blamed geese for high E. coli levels. A 2001 study by Iowa State University said sources of bacteria pollution in the lake could include livestock manure, septic tanks, city sewage systems and wildlife. 

Scientists found some of the the greatest pollution was coming from farm fields northwest of the lake.

In some local situations, including George Wyth State Park, DNR has said geese are a major source of the fecal bacteria at the beach. 

University of Iowa graduate student Reid Simmer wrote a doctoral thesis in 2016 that found that geese were “the main cause of bacterial contamination” at Kent Park Lake. 

The World Health Organization has reported that bird feces pose less of a health threat to humans than human sewage or cattle manure, Simmer found. Dogs and horses on the beaches also were a significant source of the pollution.

The Iowa Environmental Council has noted that livestock in Iowa now produce wastes equal to 134 million people.

Michael Schmidt, an attorney for the nonprofit, gave a simple warning in a blog post last last year: “If you wonder if there’s poop in the water, the answer is probably yes.”

The question seems to be what kind of poop.

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Perry Beeman
Perry Beeman

Perry Beeman has nearly 40 years of experience in Iowa journalism and has won national awards for environmental and business writing. He has written for The Des Moines Register and the Business Record, where he also served as managing editor. He also is former editorial director of Grinnell College. He co-authored the recently published book, "The $80 Billion Gamble," which details the lottery-rigging case of Eddie Tipton.