Twenty Iowa Democratic lawmakers are set to file legislation that would ban construction of large livestock confinements for five years, a measure that's repeatedly failed to gain support in the nation's largest pork-producing state.

This year's measure will be legislators' fifth attempt at getting a moratorium passed in the Republican-controlled Legislature.

Rep. Art Staed, a Cedar Rapids Democrat, said Monday in an online news conference that he believes more Democratic legislators will sign onto the bill, although he acknowledged few Republicans will join the call for a moratorium on large concentrated animal feeding operations, called CAFOs for short.

Most of the 50 million pigs marketed each year in Iowa are raised in the large feeding operations.

John Aspray, a Food & Water Watch senior organizer in Iowa, said the industry overapplies the manure from the pigs to Iowa cornfields, resulting in large amounts of nitrogen washing into the state's rivers, lakes and streams. It's hazardous in drinking water, and utilities like Des Moines Water Works spend millions on equipment to remove it.

“Factory farms are expanding unchecked in Iowa, and with it our water pollution is reaching crisis levels,” Aspray said Monday.

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Livestock producers did not immediately respond to a request for comment. Iowa agriculture groups have said their members are taking measures on their farms to protect water quality, including investing in saturated buffers, denitrifying bioreactors and construction of wetlands, all of which cut nutrient loss from farm fields.

In 2018, Iowa lawmakers agreed to pump $282 million into water quality initiatives over 12 years. The funding includes $156 million to help farmers adopt practices such as growing cover crops, building bioreactors and restoring wetlands, measures that can keep excess nutrients from polluting Iowa’s lakes and streams.

Fertilizer contributes to high nitrate levels in the state's water and feeds toxic algal blooms that can sicken people, pets and livestock. The blue-green algae also can create toxins called microcystins that drinking water utilities have limited capabilities to remove. 

Also, E. coli and other bacteria from manure in water can cause diarrhea and respiratory and other illnesses.

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Last year, conservation group American Rivers ranked the Raccoon River, a drinking water source to more than half a million Iowans, including much of the Des Moines metro, as one of the nation’s most endangered rivers.

Unlike past efforts, the proposed moratorium seeks to empower the Iowa Department of Natural Resources to fine large meatpackers when water quality violation, such as  manure spills, occur.

Tarah Heinzen, Food & Water Watch's legal director, said large meat processors are "really controlling the practices at these factory farms," providing farmers with everything from the animals to their feed and medicine.

Staed said the bill "will stymie corporate ag’s predatory growth in Iowa, confront our water quality crisis, and rectify the unfair treatment of contract growers — all by stopping the new construction of factory farms."

"Corporations need to be held accountable for their environmental degradation," he said.

Aspray said Iowa, which has an estimated 10,000 animal feeding operations, sees up to 500 new CAFOs built each year. "Time and time again, we've seen over-application of that manure and quantities far greater than the soil or the crops can possibly use," he said.

Aspray pointed to a 2019 John Hopkins survey that showed 63% of Iowa voters support a ban on concentrated animal feeding operations.

Heinzen said the legislation is aimed at temporarily stopping construction of facilities with 1,250 pigs or more.

This article has been edited to correct the name of Des Moines Water Works, and the size of the facilities for which the moratorium is proposed.

Donnelle Eller covers agriculture, the environment and energy for the Register. Reach her at deller@registermedia.com or 515-284-8457.