The Elbert Files: Iowa’s bad water
When I think about how farm field runoff is polluting Iowa water systems, I picture someone using tissue paper to try to stop an overflowing toilet.
That’s because tissue paper can no more hold back the force of an overflowing toilet than Iowans can solve our growing water problems without addressing the issue of farm field runoff.
Problems associated with fertilizer runoff have been well known for a long time.
As far back as the 1950s, commercial fishers began noticing a “dead zone” in the Gulf of Mexico. All plants and animals in an area south of where the Mississippi River empties into the ocean died. Oxygen levels in the water were so low they could not support aquatic life.
By the 1970s, scientists had figured out what was causing the dead zone. It was created and fueled in large part by the increased use of nitrogen and phosphorous fertilizers on farms in the Mississippi River basin, which includes all of Iowa.
After World War II, commercial fertilizers were hailed as magic potions that increased output on land that would otherwise be less productive.
As ever increasing amounts of fertilizer were applied to the land, seasonal rains washed ever larger amounts of excess nitrates and phosphorous into streams and lakes. Those waterways emptied into the Mississippi River, which became a super highway, carrying boatloads of fertilizer runoff into the Gulf of Mexico, where it slowly suffocated the ocean’s plant and animal life.
Eventually, the problem spread.
A 2008 study found 405 dead zones along coastlines around the world, and that does not include inland lakes and rivers, which are now also being suffocated.
In Iowa, “No Swim” warnings at popular state parks and lakes are all too common today.
Although the sources of most of Iowa’s water quality problems are well known – runoff of commercial fertilizers from farm fields and manure from confined animal feeding operations – it is only in more recent years that we’ve begun to understand how insidious the problem is.
Throughout history, farmers believed that regular tilling of soil effectively broke it up, allowing farm fields to hold more water and effectively slow down flooding during periods of heavy rain.
That is no longer the case.
Fertilizers and other chemicals applied to farm fields compact the soil. Plus, they are harmful to many of the microscopic forms of life that live in the soil and help it breath and hold moisture.
The result today is that when rain falls on a farm field, instead of gradually soaking into the soil and revitalizing it, the water can cause the dirt to clump together and form cakes that prevent penetration.
Rather than soaking into the soil, rain now pools on top and runs off more quickly into streams and rivers, increasing flood potential and accelerating the process of carrying away the nutrients and other chemicals that farmers apply to the soil in hopes of producing more bountiful crops.
The solution to runoff problems is not rocket science.
As I noted, the two main causes of dead zone growth are runoff of fertilizer from farm fields and manure from contained animal feeding operations.
Better manure containment is one solution; more effective fertilizer application and containment is the other.
But Iowans lack the will to do what’s needed.
We need to rethink agriculture and move away from our current two-crop commodity model. That requires repositioning government incentives to minimize financial damage while creating more sustainable models.
Meanwhile, water problems are moving from dead zones in the oceans and unswimable lakes into groundwater supplies.
The nonprofit Environmental Working Group recently released a water atlas that reveals phosphorous water pollution in four Upper Mississippi River Basin states, including Iowa, that shows increasing groundwater pollution.
Two of those states, Minnesota and Wisconsin, have established standards to measure phosphorous pollution, but not Iowa.
In Iowa, we still think we can plug our overflowing toilet with tissue paper.