AMES, Iowa — Six plastic bags, swollen with trapped air, bounce around the back seat of the Buick. It's a good thing they're not leaking, Dwaine Bundy says as he drives, because the bags are filled with stink.
Bundy has just spent his lunch hour collecting the foul gases that hover over a lagoon brimming with 400,000 gallons of runny hog manure. He'll deliver the air to his lab at Iowa State University, where a team of trained sniffers will determine just how badly it reeks.
In the spare, bare-walled lab -- equipped with such instruments as the Nasal Ranger -- Bundy evaluates products designed to take the smell out of pig farms.
Today, he's testing whether a lagoon cover made of shredded tires traps manure odor before it can waft into the air. From orange-scented barn deodorizers to ultrasonic manure sterilizers, Bundy has no shortage of products to study.
As the pork industry has consolidated over the last two decades, with scattered barnyard farms giving way to city-sized compounds of 100,000 hogs, odor has become a critical social issue for rural communities from North Carolina to Utah.
Hogs emit at least 160 odorous compounds -- trace amounts of gases that rise off their skin and their waste. A few, like hydrogen sulfide and ammonia, can damage human health. Others simply smell bad.
"It stinks about enough to make you sick," said Kurt Kelsey, whose family has farmed near Iowa Falls since 1860.
The smell of swine was not overwhelming when most farms had a few hundred animals. But when thousands are packed into narrow confinement sheds, their meaty, musty, musky smell can saturate homes miles away.
Each pig produces as much waste in a week as three or four people -- eight liquid gallons of manure. It's too expensive to treat it in waste water plants that handle human sewage. So most pork producers store the manure in giant outdoor lagoons, some big enough to go boating on. They let it sit for up to a year until they can spread it on cropland before the spring planting.
Unless it is injected deep into the soil, manure fertilizer can smell awful. The lagoons are a potent source of stink too; bacteria feed on the waste, breaking it down to nutrients and releasing foul gases as they digest.
Even in a farm state like Iowa, which boasts five pigs for every person, many residents have had enough.
Making a Stink
By the score, they are suing confinement facilities as agricultural nuisances that drag down property values and make life downwind unbearable.
In some regions, suburban transplants expecting a clean, quiet country life have proved the toughest foes of big hog farms. In Iowa, many of the litigants are farmers themselves. They may have worked around livestock for decades but say they are physically sickened by the scale of modern agriculture. Blaming "factory farms" for their headaches, nausea and asthma, more than a dozen plaintiffs in Iowa have won damages ranging from $5,000 to $320,000.
That scares pork producers. "It's always in the back of your mind," said Gary Ledger, who raises 3,000 hogs near Williamsburg, a small town in east-central Iowa. "Someone could file a nuisance complaint that would destroy our business."
In such fear, entrepreneurs sense a gold mine.
They have developed lagoon covers made of clay pellets, straw and felt. They're tinkering with swine feed -- even adding extracts of yucca and sagebrush -- in hopes of making manure more fragrant.
At costs that range from a dime to several dollars per hog, they peddle devices to zap manure with electricity, blast-dry it at super heat, or bombard it with ultrasonic waves.
A Florida firm recently snagged $650,000 in state and federal grants to build an experimental chamber that will subject manure to temperatures as hot as the sun and atmospheric pressure equal to that on the ocean floor. A spokesman for Global Resource Recovery Organization said the "very violent environment" breaks down the waste so thoroughly that it emerges from the chamber 97% odor free.
Then there are the decidedly low-tech bugs-in-a-bucket products -- microbial mixtures designed to be dumped into manure pits. The microbes speed the breakdown of waste; in the process, they set the manure bubbling and burbling like witch's brew.
"We've got people out here in Kansas who talk about having to store their good clothes [in town] so they don't smell in church on Sunday. This is a phenomenal problem," said Stan Irvin, who promises less stink in 10 days with his Biozyme microbe mix, sold by Heartland Enterprises, an agricultural products company based in Hays, Kan.
So hot is the field of swine deodorizing that Premium Standard Farms, the nation's second-largest pork producer, fields hundreds of pitches a year from inventors hoping to test their products on the company's enormous farms in Missouri, North Carolina and Texas.
"I get a call about every day," said Dave Townsend, vice president of environmental affairs.