MCE Policy Team created this timeline in partnership with Missourian Cheryl Marcum

Missouri passed a corporate farming law that banned large corporations from owning land and operating industrialized farms within the state.  (“Animal Factory,” David Kirby, 2010, p. 193; Missouri Revisor of Statutes – Revised Statutes of Missouri, RSMo Section 350.015)

“[D]uring the final exhausting hours of the Missouri legislative session, a little-noticed amendment was piggybacked onto an economic development bill that would exempt Sullivan, Mercer, and Putnam counties from the corporate farming law for the raising of swine. . .  The amendment also gave Premium Standard Farms access to millions of dollars in new financing for their planned ‘Missouri operations” . . . They proposed a megacomplex consisting of 96 hog buildings and 12 lagoons with a total capacity of over 240 million gallons of feces and urine. It would house about 106,000 head and be built within a mile of nearly thirty family homes.”  (“Animal Factory,” David Kirby, 2010, p.193)

Hog market collapsed due to insufficient slaughter capacity.

Murphy Farms was raising about 900,000 pigs under contract in Iowa.

In September 1999, Smithfield Foods, the nation’s largest hog producer, began its pending purchase of Murphy Farms. (Murphy Farms sells for $460M – Triangle Business Journal (

January 2000, Smithfield Foods Inc. announced that it completed its acquisition of Murphy Family Farms Inc. (Smithfield Seals Merger with Murphy; The CAFO Industry’s Impact on the Environment and Public Health | Sierra Club)

“[T]he [EPA] 2008 final rule, unlike the 2003 rule, which categorically required a permit for any CAFO with a ‘potential to discharge,’ the revised regulations call for a case-by-case evaluation by the CAFO owner or operator as to whether the CAFO discharges or proposes to discharge based on actual design, construction, operation, and maintenance.” (Implementation Guidance on CAFO Regulations – CAFOs That Discharge or Are Proposing to Discharge)

In 2013, the Missouri legislature changed the statute that formerly outlawed foreign entities from owning Missouri farmland by slipping language into SB 9 at the end of the session so it received no public debate. SB 9, sponsored by Sen. Pearce (R) and Rep. Casey Guernsey (R), opened up 1% (289,000) acres of Missouri farmland to foreign corporate ownership. On Aug. 2, 2013, Gov. Nixon vetoed it. The Missouri legislature overturned the veto and two weeks after that, Chinese corporation Shuanghui International Holdings Ltd., now Shuanghui Group (later changed its name to WH Group), bought Smithfield Foods and began shipping as much as 25% of its pork to China. WH Group controls over 25% of U.S. pork and owns over 40,000 acres of Missouri farmland. They own Premium Standard Farms in northern Missouri, bought in 2006. 

In 2013, HB 28 became law, removing the requirement that CAFOs must obtain construction permits prior to constructing facilities. This had the effect of also changing the neighbor notice requirement for Class I CAFOs – only requiring notice for operating permits. This bill also changes what and how often operators of flush system animal waste wet handling facilities must inspect. 

Right to Farm constitutional amendment passed in the August primary election. It negates nuisance lawsuits against CAFOs.

April 14, 2015, Mo. Supreme Court issued opinion declaring CAFOs are permanent nuisances and eliminated citizens’ ability to make nuisance complaints for non-economic damages against CAFOs.

In 2015, the legislature changed the law and opened a large loophole that allowed foreign corporate interests to bypass reporting their land purchases to the Missouri Department of Agriculture. Omnibus SB 12, sponsored by Brian Munzlinger (R), created a loophole making it impossible or nearly impossible to track foreign land purchases. 

After the Clean Water Commission (CWC) denied two CAFO permits, Senator Munzlinger introduced House Bill 1713 which altered the composition of the Clean Water Commission, removing a requirement that reserved four of the seven seats for members of the general public. This bill became law, changing the composition to allow up to six of seven members on the board to represent agricultural interests. Shortly thereafter, a new commission was appointed.

“Congress removed the minimal regulations placed on agricultural air pollution in March 2018.” (

The Missouri Senate confirmed appointees to the CWC with close ties to the corporate, factory-farm agriculture industry. The new commission immediately issued permits to two CAFOs that were denied by members of the previous CWC. (MCE Fall 2018 Alert)

SB 782 became law in 2018, weakening Missouri’s Clean Water Law by limiting the DNR’s ability to intervene only after agricultural runoff pollution has been proven to “render such waters harmful, detrimental, or injurious to public health, safety, or welfare.” It essentially calls for cleaning up pollution after it happens instead of preventing it.

A CAFO is a “point source,” but all of the millions of gallons of waste they produce that is spread in our state are defined as “non-point source,” and therefore, not regulated. “States report that nonpoint source pollution is the leading cause of water quality problems.” (US EPA)

May 31, Governor Parson signed SB 391 into law, prohibiting county commissions and county health center boards from promulgating any orders, ordinances, rules, or regulations that “impose standards or requirements on an agricultural operation and its appurtenances that are inconsistent with or more stringent than any of law, rules, or regulations relating to the Department of Health and Senior Services, environmental control, the Department of Natural Resources, air conservation, and water pollution.”

Cedar County Commission and Cooper County Health Board et al. filed a lawsuit against the state to challenge SB 391. 

Legislature passed HB 574 which limits who can inspect agricultural facilities to state and federal agriculture and environmental officials and law enforcement in an apparent effort to bar local health departments from viewing the facilities. Considered an “Ag-gag Law” because it also prevents members of the public from testifying on conditions or events at agricultural facilities. (MCE’s “Policy, Politics, & CAFOs,” 2022.)

Legislature passed HB 271, prohibits local standards or requirements on “an agricultural operation and its appurtenances that are inconsistent with, in addition to, different from, or more stringent than state laws and regs.” This law particularly obstructs Cooper County’s new health ordinance which was “different from” applicable state law.