Manure Matters

Water contamination is a danger when more animals are raised on fewer acres.

By Brian DeVore

On a June evening in 1997, Dennis Barta took his son Nathan down to Beaver Creek, a stream that snakes through their Renville County farm. They were looking to pass a few hours catching chubs, just as the Barta family had done many times over the years. But the fish weren’t biting this particular evening.

"I think they were too busy fighting for air," Dennis Barta recalls. Chubs, bullheads, minnows, and other fish were at the surface, struggling. Even more troubling was the sight of crayfish—tough bottom dwellers—crawling up the banks to escape the water.

"Then the creek turned white with the bellies of dead fish," Barta says.

After following a putrid smell about 10 miles upstream, the farmer and his neighbors discovered the source of the trouble: Some 100,000 gallons of hog manure had washed into the creek, killing an estimated 690,000 fish. At this writing, it is the largest documented manure-related fish kill in Minnesota.

The manure was produced by a farm that was using a liquid system to manage the waste of some 9,000 pigs in three barns. Minnesota Pollution Control Agency investigators later learned that a faulty timer had sent water, manure, and urine overflowing into the stream.

The Beaver Creeks of the world make one thing clear: Though manure has long been a valuable crop fertilizer, too much manure in too small a space is bad for the environment. Recent changes in the animal agriculture industry—the concentration of more animals on fewer acres among Minnesota’s 38,000 livestock farms—pose a serious threat to the state’s waters.

Unfortunately, not all sources of livestock-caused water pollution are as easily pinpointed as the Beaver Creek spill. The threat is spread among thousands of businesses that are key elements of the state’s economy and rural communities. As a result, the solution to water-quality problems posed by ever-larger livestock farms is anything but clear.

New Impact Statement

How big of an issue is manure in Minnesota? Big enough that in 1998 the state Legislature commissioned the first-in-the-nation Generic Environmental Impact Statement on Animal Agriculture. This study (www.eqb.state.mn.us/geis/  ), coordinated by the Environmental Quality Board, is supposed to help officials and private citizens resolve the controversy over the growth of large-scale livestock farms.

Besides animal agriculture, only one other Minnesota industry has been the subject of a GEIS: logging. Like logging, animal agriculture is spread among many operations over a large area. And, like logging, it is a major force in the state, particularly in the southern third. Minnesota is the nation’s third-largest hog-producing state, first in turkeys, and fifth in dairy cows. Livestock produce $3.9 billion in farm revenues each year; and Minnesota’s dairy industry alone employs more local workers than Northwest Airlines, 3M, and Target combined. What’s more, livestock adds value to the surplus of corn and soybeans produced here.

"If we don’t at least see a steady amount of livestock in Minnesota, it affects not only livestock; it affects grain farmers," says Gene Hugoson, Minnesota agriculture commissioner.

Greater Concentrations

Since the early 1980s, the makeup of the livestock industry has shifted dramatically. Between 1982 and 1997, the number of Minnesota farms with hogs declined by 64 percent, but the average number of hogs on each swine farm increased by 254 percent (from 215 to 762), according to the U.S. Census of Agriculture. At the same time, the number of dairy farms dropped 60 percent, but the number of cows per dairy increased 62 percent (from 72 to 117). The bottom line: Minnesota has higher concentrations of animals than ever.

A concentration of animals means a concentration of manure. It can’t be spread on growing crops and should not be applied when the ground is frozen, so large livestock farms must store millions of gallons of manure for months at a time. Earthen lagoons, some larger than a city block, have proven to be a relatively cheap way to store manure. In 1998 Minnesota placed a moratorium on construction of open-air earthen lagoons for swine facilities, partly because it was hoped the GEIS study would help determine how much of an environmental threat they pose. (The GEIS has recommended extending the moratorium indefinitely.) These days, the livestock industry is increasingly using concrete pits or above-ground tanks to store manure. Whatever the vessel, these facilities use massive amounts of water to move, store, and otherwise manage manure. The 161 million gallons consumed by Minnesota livestock farms daily represents 5 percent of the state’s water usage.

All that liquid makes animal waste mobile and, at times, difficult to keep out of waterways. In Minnesota, about 60 percent of surveyed rivers and streams and 17 percent of surveyed lakes do not meet state and federal water quality standards. Of waterways that fail to meet those standards, 90 percent of the stream miles and 64 percent of the lake acreage owe their polluted status to agriculture.

Chronic Runoff

Spills are the most dramatic form of animal-waste pollution. About 20 documented manure spills occur annually in the state, according to the GEIS. Their causes range from equipment failures—like the one on Beaver Creek—to heavy rains after field applications.

But catastrophic manure spills are probably less of a threat than chronic nutrient runoff. In a paper written for the GEIS, University of Minnesota soil scientists say the routine application of too much manure on too little land poses the biggest overall risk to water. Ideally, farmers inject or work manure into fields at "agronomic rates"—rates at which the plants can efficiently use nutrients such as phosphorus. But there isn’t always enough farmland nearby to adequately utilize large influxes of manure.

According to another paper written for the GEIS, which studied nearly 4,000 feedlot permits, small farms actually ran a phosphorus shortage. Feedlots with 100 to 300 animal units (one mature dairy cow equals 1.4 animal units or one hog weighing more than 300 pounds equals 0.4 animal units) had a slight surplus. The largest feedlots studied produced 38 pounds of excess phosphorus for each acre of manure-fertilized land. Why the difference?

Joseph Schimmel, a PCA nonpoint pollution educator who coauthored the study, says the difference comes down to what a farm’s animals-to-acres ratio is. Large feedlots averaged 503 animal units and 558 acres of land available for manure disposal; smaller ones averaged 55 animal units and 220 acres of land. Small and medium-sized farms are more likely to grow crops, providing fields where manure can be spread nearby. And nearby is key: It doesn’t pay to transport liquid manure much more than a mile.

Overwhelming Process

Riding herd on manure at the state level is mostly left in the hands of the PCA. The Department of Natural Resources may collect information on manure-related fish kills, provide input on an environmental review of a proposed feedlot, or help with enforcement of pollution rules. But the PCA has responsibility for making sure large-scale manure-handling facilities are built to industry specifications and that farmers are applying manure at rates that don’t overwhelm the system. The PCA’s handling of this job has drawn plenty of criticism.

The livestock industry says the permitting process for a large feedlot takes too long, drives up costs at a time of record-low commodity prices, and is based on a shaky scientific foundation. "Our fear is regulations with expensive price tags that are based on emotion rather than good information will show up on our doorstep," says Dianne Bettin, president of the Minnesota Pork Producers Association.

But neighbors to large-scale feedlots, as well as environmental and small-farm groups, say that the PCA takes few enforcement actions against livestock farms (about 15 fines in each of the past six years), and has never ordered an environmental impact statement for a livestock operation. Indeed, the courts recently have twice found the agency should have ordered EIS studies—one in the case of a dairy and the other for a hog operation.

"Where were the PCA experts working on the citizens’ behalf, representing the public’s interests, researching the science and engineering for our point of view?" asks John Gaterud, who, along with about 45 other citizens in Waseca County, last year filed a lawsuit against the PCA after it failed to order an EIS for a proposed 1,600-cow dairy that would have required a 25-million-gallon manure system. (The project is now on hold.)

A 1999 legislative auditor’s report found that the PCA’s feedlot program had a number of weaknesses, including inadequate rules, insufficient site visits to inspect proposed projects, and untimely service to farmers seeking permits.

The new GEIS report echoes these concerns and says the PCA does not order enough environmental assessments, which are less extensive than environmental impact statements.

Myrna Halbach, PCA feedlot program manager, says legislators, citizens, and industry all have a say in how the PCA regulates livestock operations. However, she says, it’s difficult to keep tabs on 38,000 feedlots. "I’m not guaranteeing we didn’t make any mistakes."

Halbach sees penalties and prosecution as last resorts. "We try to achieve compliance cooperatively with the producer at first."

New feedlot rules were developed in 2000 in response to years of criticism from the public and legislators. The rules require registration but reduce permitting requirements so that county and PCA staff can spend more time in the field doing inspections and working directly with producers. The PCA now concentrates on large feedlots, especially those with more than 1,000 animal units.

"We have shifted from permitting almost 40,000 facilities to about a couple thousand," says Halbach. "During the previous permitting process, we were spending as much time on a 50-animal-unit facility as we were on a 400-animal-unit facility."

It’s too early to tell how the new regulations will work; full implementation has been delayed as the PCA works to register feedlots throughout the state. And tougher feedlot rules being proposed by the federal Environmental Protection Agency might override some PCA rules.

By December 2001, the animal agriculture GEIS had developed 77 policy recommendations, many of which have the potential to significantly reduce the environmental threat of livestock agriculture. For example, the document recommends developing and requiring the use of a "phosphorus index" to determine appropriate manure application rates based on how much a crop needs on a particular soil type. The GEIS also recommends increasing financial and technical support for farmers seeking to adopt environmentally friendly livestock systems.

But more than six months after the study was scheduled to be approved by the Environmental Quality Board, it remained in "draft" form as the Minnesota Department of Agriculture and the PCA wrangled over its final content.

Tweaking Feed

Some townships and counties have taken matters into their own hands and turned to stricter zoning to keep large-scale livestock farms from being built near vulnerable areas such as sinkholes and wetlands. (Local units of government in Minnesota are allowed to implement stricter siting requirements than the state requires.) A few local governments have placed moratoriums on the construction of such facilities while they hash out what the future of animal agriculture should look like in their community.

Scientists are working on several fronts to reduce the threats posed by handling huge amounts of manure. The research ranges from tweaking feed rations to cut the excretion of excess phosphorus, to using zebra mussels and aquatic plants to filter manure. Near the east-central Minnesota community of Princeton, the manure from an 850-cow dairy farm is producing electricity through anaerobic digestion. Similar "methane digesters" are in operation on more than 30 swine and dairy farms throughout the country. Besides serving as a renewable source of electricity, these digesters reduce manure-related odor. Researchers are now trying to figure out if digested manure is taken up more readily by growing plants, thus reducing excess runoff of nutrients.

Alternative Systems

What about alternatives that reduce the need to store and get rid of millions of gallons of manure in the first place? The animal agriculture GEIS barely touches on alternative production systems. George Johnson, project manager for the GEIS, says that’s because there simply isn’t a lot of solid information available on alternatives, and the study lacked the time and resources to dig further into the issue.

But some Minnesota farmers and researchers have already done a little digging, and are unearthing a few nuggets. Management intensive rotational grazing, for example, moves cattle through a series of paddocks, naturally spreading manure at a rate pasture plants can use efficiently. University of Minnesota case studies show this system can dramatically reduce nutrient runoff while producing milk and meat profitably. And it isn’t just a small farm enterprise: One of the largest dairies in Wisconsin rotationally grazes its cows.

Alternatives in hog production are attracting attention as well. The University of Minnesota’s West Central Research and Outreach Center in Morris recently set up an alternative swine research center that is generating a lot of interest among area farmers. Among those farmers are Jim and LeeAnn VanDerPol, who, with their son Josh and his wife, Cindy, have been producing pork since the mid-1990s using methods borrowed loosely from Sweden. The Chippewa County farmers pasture hogs during the warm months. They have also built two "hoop houses"—Quonset-hut-shaped structures of fabric stretched over steel frames. The floors are bedded with straw or cornstalks, making for a composting "nest" that generates enough heat to keep pigs warm even on the coldest days. After a group of pigs is sent to market, the mass of dry bedding and manure is pushed outside to compost further. Several months later the VanDerPols spread the composted fertilizer on fields and pastures.

The family produces 800 pigs annually —a drop in the bucket compared with larger farms that measure production in the thousands or tens of thousands. But what the VanDerPol hog enterprise lacks in girth, it makes up for in affordability. Iowa State University estimates that a hoop-house system can be established for a third the cost of a full confinement setup. Because they save money on fuel, manure management, and other expensive inputs, Jim VanDerPol says, his family is producing pigs more cheaply than many larger operations. The VanDerPols market their antibiotic-free hogs for a premium through the natural foods market. This has helped their 320-acre farm do the unthinkable in this modern age: support two families.

This system supports the environment as well. When applied in the right amounts, manure’s biological qualities can help build soil quality in a way that commercial fertilizers cannot, according to field trials. University of Minnesota soil scientists have found that well-balanced manure applications can reduce soil erosion. In Connecticut, the spreading of composted manure along roadways cut erosion by more than 90 percent. Organic farms in Nebraska and North Dakota that used manure as a fertilizer had 22 percent more organic matter in their soils than did conventional farms.

VanDerPol says his own observations show that organic matter content in his fields is higher than before, more earthworms are present, and rainwater and snowmelt tend to infiltrate the soil rather than run off the surface.

Using Iowa State calculations, the VanDerPols make sure the composted manure is applied based on nutrient content, not just on how much they need to get rid of. When the pigs are out on pasture, the family moves them frequently to spread the manure evenly. Could they raise more hogs? Sure, but such an expansion could upset their animals-to-acres ratio, VanDerPol says.

"We treat manure as an asset rather than as a liability," he says. "All of a sudden we don’t have to worry as much about regulation or expensive safety inputs because we aren’t producing a threat to the environment in the first place. It’s really exciting."

Brian DeVore is the editor of the Land Stewardship Letter and recently collaborated on The Farm as Natural Habitat, a book published in April by Island Press.