It’s noticeable lots of places, but I am most sensitive to it when on a road trip. For example, on the Interstate across southern Idaho that follows the Salmon River through sage plains and various agricultural enterprises scattered around the small towns — I notice it. I also used to notice it when driving across North West Texas where the flat open lands and far horizon made grain silos visible for miles and miles.
Faint at first, it becomes more and more obvious until reaching a crescendo where the feed lots border the road. Cattle gather into long stretches of beef, vying for a place at the succession of feed troughs, some beneath a tin roof. Big yellow machines haul hay or other feed to be spread down the rows, and front-end loaders scrape the manure into piles or push it into an adjacent lagoon.
The mass of cattle reinforces the odor that wafts across the highway, the smell of decaying manure. In the summer, sometimes, we’d notice we were approaching a feed lot and close the windows before we got there. Usually, we forgot until too late. With air conditioning, we almost never thought to turn off the fan when passing and by then it was too late.
It’s not always cattle. Across the southern U.S., it was turkey, chicken or hog farms, often hidden among the trees, but still discernable from the highway.
I was as a suburbs kid, but no stranger to farms and ranches, since we fished and hunted on both thanks to my father’s ranching clientele. The stock pens would be lined with a layer of mixed manure and mud, and we tried to avoid the cow patties when walking around. You do get used to manure-laden boots after a while, though it’s never something you seek out. Backyard dog poop pales in comparison.
Most places pile up their manure and drain the lagoons occasionally then use the composted material to fertilize their fields, just like the farmers in the old days. Some outfits are more sophisticated now and they’re recovering methane from the waste to burn for heat or power.
The technology is simple. I have worked on many old landfills or landfills where old cells existed, where they drilled beneath the cover to pull out the methane created from the decaying organic matter. Most sewage treatment plants recover the gases from their anaerobic digesters. The recovered gas is often flared off, but sometimes, particularly recently, it is recovered for heat or power.
The flaring of oil field gas is considered to be a major contributor to global warming. Those layers of coal and oil are just the decaying organic matter from thick jungles of the distant past. The decay process is not much different from what happens at the feed lots and landfills — just on a different timeline and scale. Dan Charles quotes Kraig Westerbeek of Smithfields Foods, “The bacterial action releases a biogas that’s 60% to 65% methane.”
Charles reports on some attempts to corral the problem at feed lots. “On most farms, that gas just goes floating off into the air — and contributes to the overheating of the planet. Methane is a greenhouse gas with a warming impact at least 25 times greater, per pound, than carbon dioxide.”
Charles notes that at one facility, “the gas is trapped by a blanket of rugged black plastic that covers the manure pond. The gas lifts the plastic layer and makes it bulge like the floor of a child’s bouncy castle … The gas then gets pumped out to processing stations that remove water vapor and carbon dioxide. What’s left is almost pure methane, also called natural gas, ready to burn in any gas-fired home furnace or electric power plant.”
At a personal level, passing gas is a matter of courtesy or politeness. We joke about flatulence or complain if someone does so in public, and personally hope for one that is silent but not deadly. But imagine, if you can, the combined power of dozens or hundreds of beasts, confined in small areas and eating like crazy.
Recovering this gas could really make the world a better place, both locally and globally.
Dan Charles, Big Companies Bet on Cleaner Power From Pig Poop Ponds, November 22, 2019, All Things Considered, The Salt