It doesn't really have a name, but the Big Stink -- which sometimes smells like sulfur, sometimes dog food, sometimes sewage -- is largely a combination of factory emissions from companies located within or near Commerce City.
Depending on weather conditions, this stinky gumbo can range from being a persistent nuisance for those who live nearby to a massive olfactory knockout that can be whiffed downtown. Yet decades of resident complaints and organized community efforts have yielded little success in forcing factories to reduce their odors. Instead, the chronic assault continues.
"It's like a rape," says Jarid Manos, director of the Great Plains Restoration Council, an environmental agency that has protested the problem through its Denver office. "It forces its way into your home and overpowers you with the most sickening smell imaginable. You can't think about anything else."
In a recent survey of northeast Denver residents, 55 percent say the putrid smell is "a problem," while 25 percent say it's a "major problem." As a local issue, residents ranked factory odors fifth -- beneath such concerns as education and crime, but above taxes, the economy and drug/alcohol matters.
Eldred Pate, a Denver youth-program manager, began talking about the odor issue with the young teens in his Youth Energy after-school program. On some mornings, the kids walk to school with their jackets pulled over their noses to block the stench. The Youth Energy group joined forces with the Great Plains Restoration Council, going door-to-door passing out local odor-complaint hotline numbers.
Among the young activists is thirteen-year-old Christopher Pride, who attends middle school in the Cole neighborhood, located downwind of the industrial zone. Pride knows far more about odors than he cares to; he says that ever since Pate began discussing the odor problem two years ago, he's become more aware of the pollution.
"I think it affects me more because I'm learning about it and where it's coming from," he says. "If it's a good day and then the smell comes along, then I just want to go into the house and be bored."
Others are not so alert. Pate was horrified to discover that residents nearest the factories were sometimes the least likely to notice the smell: They'd become desensitized.
"It angered me that some people didn't know what was going on -- and I hate saying this pun -- right under their nose," Pate says. "They can't smell it, and that's a shame."
When told that after years of non-compliance, Denver is on the verge of achieving compliance with the Environmental Protection Agency's clean-air standards, Pate is stunned.
"That's...," he struggles for the word, "...ludicrous."
"Are you ready to tour the plant?" Ken Kage asks.
It's a tricky question. Yes, there's nothing left to do after the interview but tour the plant. But it's doubtful that any novice is prepared for an inspection of National By-Products, a rendering plant at 5800 York Street, in unincorporated Adams County.
Kage, the company's district manager, claims that many of the odor complaints against his seventy-year-old company are a knee-jerk response to the grisly rendering process. "We know the type of business we are," he says. "Right off the bat, our public perception is not the greatest."
The plant grinds and cooks dead animals: spoiled meat from grocery stores, roadkill, slaughterhouse scraps, farm animals and euthanized pets. "We don't handle dogs, but we do pretty much everything else," Kage says.
The distinctive blend makes National By-Products the most offensive odor source, according to Lorraine Granado, a community activist for the nearby Swansea and Elyria neighborhoods. "You have to close your windows, doors, everything," she says. "It's just nauseating. We've seen dead pigs dumped on the tarmac. It's the most horrible smell."
Touring the plant provides a visceral demonstration of how some of the metro area's bad smells are born.
Kage begins at the end of the production line, showing edible and inedible tallow and meat-and-bone meal. The meal sits in large mounds and looks like dark oats with bits of white rock. The material is primarily used for livestock feed and pet food -- hence the National By-Products logo: two arrows in a perpetual circle. It may be a nauseating example of recycling, but it's a remarkably efficient process that dates back to ancient Egypt. Other rendering by-products are used to produce a variety of products, from pharmaceuticals to cosmetics, candles to Gummi Bears.
From 2 p.m. to 6 a.m., during normal operations, the rendering plant grinds the animal parts into smaller and smaller pieces, mixing them with used fry grease collected from restaurant kitchens and steam-cooking each batch at more than 250 degrees. The plant renders up to 5 million pounds of animal by-products per week. Kage claims to spend $200,000 annually to maintain air-stack scrubbers for the purpose of reducing odor emissions, adding that the company does as much as possible to reduce such discharges.