How Big Would a Pyramid of Iowa Pig Poop Be?
Iowa has over 23 million pigs. That's a lot of pigs. Heck, even for other states that raise a lot of pigs, that's a lot of pigs:
Obviously, we were curious how much those pigs poop compared to humans. Twice as much? Three times as much? Nope. A pig creates about 30 times as much waste as a human:
85 billion pounds of poop sure sounds like a lot, but it's hard to imagine. So we wanted to take that weight and calculate the volume so we could build something with that poop. Enter cottage cheese:
Okay, so now we know that Iowa produces 1.5 billion cubic feet of poop in a given year. How big is that? Are we talking an Empire State Building's worth of poop?
Ha! In 9 days Iowa would fill it! The state could 40 Empire State Buildings out of poop every year! Put that on the welcome sign!
Okay, let's get crazy: let's take the volume of the Empire State Building, the Great Pyramid of Giza, the Burj Khalifa, and Boeing's Everett Factory (the largest building int he world in terms of volume), would those hold a year worth of Iowa poop? Nope:
Iowa would fill them all in only 5 months?!
We need something even BIGGER. We need to build our own Pig Poop Pyramid. So we take our volume and find that 1.5 billion cubic feet fits into a pyramid that is about 1,200 feet tall:
Even a 1,200 foot tall pyramid is hard to imagine, so here is what it looks like when laid on top of downtown Des Moines:
Des Moines' skyline would be like the crunch inside a gooey exterior if a giant poop-loving Godzilla tried to eat our pyramid!
From above, you can see that in 4 years, downtown Cedar Rapids would be a little less walkable:
But the good news: in only 12 years, we'd have a mountain of poop the same height as the elevation of Vail from base to summit. Someone get a trail map ready!
Oh, we almost forgot water sports! At about 1.5 gallons of liquid waste per pig per day, Iowa has enough liquid pig waste to fill Clear Lake in only 1 year.
Did we say "water sports," we meant liquid sports!
As we played around further with our numbers, we wondered what is the human equivalent to all that pig poop, and the number is almost hard to believe. 235 billion pounds of poop is what would be generated by 676 million people.
That is like 2 USA's pooping on Iowa every day, forever!
Hold the phone, RAYGUN: How is that right? Our friend and Swine Republic author Christopher Jones, estimated that Iowa's animal waste is the equivalent of 168 million people.
Over 600 million seems unbelievable, so let's look at our numbers:
If we know how much poop is produced by pigs and people, the math is pretty easy. The error would be if our underlying daily poop weights were wrong.
To get pig poop weight and human poop weight we pulled data from several places including National Hog Farmer, American Cattleman, Hobby Farms, a 2008 Government Accounting Study, Live Science, and a UK study of human waste.
Where does the poop go? Onto the ground!
This isn't an expose or a new revelation. Animal manure can be fertilizer and so it's used as fertilizer.
Agriculture has done this since the beginning of time. The process occurs naturally in nature, and that's what most farm advocates will fall back to:
If you are an industrial agriculture scientist like Daniel Anderson or an industry group like the Farm Bureau, you have almost rolled your eyes so hard at our blog post, you've almost fallen out of your chair ("Shut up and make t-shirts!").
Dr Anderson will tell you that since Iowa grows so much corn and soy beans, it has high nutrient replenishment needs, thus 23 millions pigs is only a quarter of what Iowa's current agricultural system could handle:
Hoo boy! Think of how big our poop pyramid would be with 100 million pigs making cottage-cheese-like blocks for us!
But Dr Andersen is correct that Iowa's agricultural system requires so much fertilizers that 85 billion pounds of pig poop from 23 million pigs isn't even enough, it's just the tip!
That pig poop is a minority of Iowa fertilizer and may not even be the biggest problem when it comes to nitrate contamination in water.
Chemical fertilizers and lightly regulated top-applied-dry fertilizers (think of bird poop cereal) and may be a bigger part of the problem.
In recent years, over application of nitrates during a period of drought may put Iowa on track to discharge more nitrates into the water than ever.
Most frustratingly, as Iowa has been pumping so many nitrates into our soil that excess runs off, our soil is still losing its richness:
And still Iowa has helped create a Dead Zone the size of Connecticut in the Gulf of Mexico.
Our soil isn't retaining it nutrients.
And we're killing the water and our soil at the same time?
"Current agricultural system" is the demarcation. Agriculture has changed from small, quaint farms to massive, industrial operations. These are operations of unprecedented size that operate at scales states didn't imagine when setting up rules about waste and drainage.
As pigs are confined, fed antibiotics and engineered feed, the content of their manure has changed.
What we put on the ground today may have unintended consequences:
Putting antibiotics and heavy metals aside, you also need to just try and make sure that regular-old poop and urine don't flow into your rivers.
Agricultural run-off is the also a major source of water impairments.
The sheer scale of the system in Iowa means that small mistakes can still be huge amounts of feces!
Iowa could handle 95% of its pig poop properly, but that 5% error rate is equivalent to 10 million people's poop. And, remember, all of that poop is only about 20% of the fertilizer we are using!
This a fraction of a fraction is a massive problem:
As we look downstream, we can see that something is not quite right in Iowa. The water quality issues in Iowa persist even after changes have been made.
For example, there was the years-long cleanup effort at Lake Darling that concluded in 2014.
Sitting among one of the highest concentrations of hog confinements, Lake Darling's sky-high bacteria levels and poop-colored water were only cleaned up after the lake was drained and dredged. When it was finished, it was considered a major success for Iowa's DNR:
Additional mitigation efforts were put in place and farmers were invited to voluntarily use best practices for fertilizing surrounding land.
But within a year of completion, Lake Darling's bacteria levels were rising again:
Since 2014, water quality at Lake Darling has continued to decline, and in 2021 it violated three state swimming standards in a single round of tests -- a record!
Lake Darling is one small example of the issues Iowa experiences ongoing water quality issues.
Because our current agricultural cycle is set up to create water quality issues.
We over apply fertilizers to grow crops to feed the animals that don't even make enough fertilizer for our crops to grow them, and while degrading our soil at the same time, making farming in the future less viable without new chemicals.
Run-off is just part of the cycle now.
Iowans, and Americans, live inside an industrial agricultural machine.
That machine's productivity is measured by a few inputs and outputs -- not by community health, or environmental health, or individual health.
And the machine's technical issues -- leaks, spills, and growth -- are not closely monitored or reported.
There is a path forward, but it starts with seeing the pyramid for the poop. It starts with seeing the scale. Then realizing the pyramid of poop is jut the tip of a bigger pyramid!
