Hamburg, Iowa

Agricultural runoff contaminants (Nitrogen and Phosphorous) are carried via water and spread throughout Iowa.

These contaminants effect the quality of drinking water in cities like Hamburg especially when they flood.

We found this to be one of many consequences of the larger systemic issue of agriculture.

 
 

Iowa is 90% farmland where farmers use insecticides, herbicides, and fungicides to kill agricultural pests. These chemicals can enter and contaminate water through direct application, runoff, and atmospheric deposition. They can poison fish and wildlife, contaminate food and water sources, and destroy the habitat that animals use for protective cover.

Iowa Cropscape

Iowa Land & Vegetation

Farmers apply nutrients such as phosphorus, nitrogen, and potassium in the form of chemical fertilizers, manure, and sludge. When these sources exceed plant needs, or are applied just before it rains, nutrients can wash into aquatic ecosystems. The gray circles on this map represent sites where phosphorus is at high levels, which can lead to algae blooms that produce algal toxins which can be harmful to human and animal health. The colors represent what types of vegetation has historically grown in that location.

 

Examining the CropScape

Using Hamburg Iowa as a case study

Hamburg CropScape

In this image the city of Hamburg is shown in grey and the surrounding land is almost all farm. The main crops grown near Hamburg are corn and Soybeans. Corn is a dangerous crop - it needs more fertilization because it can’t produce it’s own nitrogen, and harvesting the crop usually requires taking most of the plant, which results in more nutrients being removed from the field at the end of the season that must be replenished. Corn, soybeans, wheat, and cotton combined receive approximately 60 percent of all nitrogen, phosphorus, and potassium (NPK) fertilizers. Around 40 percent of total commercially applied NPK is put on corn, whose production is largely concentrated in the Midwestern states.

 
 
 
 

Corn is grown with very large amounts of nitrogen applied to it because it cannot produce its own. It also requires high levels of phosphorous. It is also important to note that farmers are payed government subsidies for growing corn. This chart represents corn (blue) and soybean (orange) crops’ use of NPK fertilizers.

Iowa Water

This map represents groundwater vulnerability - or similar potentials for contamination of groundwater. Deeper blues tend to represent higher contamination risk, while lighter greens are safer. The green dots are dams, and blue dots are agricultural drainage wells which can effect the quality of drinking water.

 
 

Hamburg, Iowa

To explore the real effects of this potential risk we investigated a flood that happened in 2019 that devastated the small town of Hamburg, Iowa. Hamburg is home to two contamination sites - one of which is the site of a fertilizer company.

 
 

The flood destroyed part of the levee and trapped water on the other side of it contaminating the drinking water for weeks after. The levees are meant to protect Hamburg from the flooding of the Missouri and Nishnabotna Rivers. One levee was damaged and water was trapped on the wrong side of it - further harming the quality of water.

Private Well Contamination in Hamburg

Iowa has a private well tracking system that monitors the levels of Nitrogen (fertilizer runoff) and Coliform (bacteria that are present in the digestive tracts of animals). High concentrations of nitrate in drinking water can cause methemoglobinemia, a potentially fatal disease in infants, also known as blue baby syndrome. Many private wells fail these tests due to runoff from surrounding farms, and are therefore drinking contaminated water. This chart shows all of the private wells in Fremont county that were tested since that flood, and what amount of them failed those tests.

Private Well Contamination in Fremont County and Hamburg

  • The “nitrate” layer shows Iowa private wells that had average nitrate concentrations at or above 5 mg/L between 2002 and 2017, excluding 2014, but not any positive tests for bacteria.

  • The “bacteria” layer has private wells that had one or more tests positive for bacteria between 2002 and 2017 but had average nitrate concentrations below 5 mg/L.

  • The “bacteria nitrate” layer displays the private wells that had both their average nitrate concentrations at or above 5 mg/L and at least one positive test for bacteria.

Many private wells have been contaminated with agricultural runoff in Hamburg and greater Iowa

Agricultural runoff of nitrogen, phosphate, and animal waste has ended up in many Fremont country resident’s private drinking water. This problem is only made worse by the flooding of the Missouri and Nishnabotna Rivers which carry even more agricultural runoff with them. We then examined why people grow crops like corn if they need that much harmful fertilizer added to it.

 

This led us to a bigger systemic issue in agriculture and this chart shows the unbreakable cycle of the corn crop. We pay a huge price for corn; we pay directly - through taxes, and indirectly - through poor quality food options, agricultural runoff, and greenhouse gas emissions. Unfortunately the government subsidizes corn to ensure it is grown in excess. This makes food cheaply available, and largely unhealthy.

About a third of Iowa’s corn crop is used as “carbs” in animal feed while soybeans provide protein. It takes a few bushels of corn to make a corn fed steak, and a beef cow can eat about a ton of corn if raised in a feedlot.

Corn is also used in fuel. Another third of Iowa’s corn crop is used to make ethanol which serves as a “renewable” fuel additive to gasoline.