Nitrate Pollution

A barge sits in Missouri on the Mississippi River before it heads downstream to the Gulf of Mexico.
File: Abbie Fentress Swanson / Harvest Public Media

Chemical runoff from Midwest farm fields is contributing to the largest so-called ‘dead zone’ on record in the Gulf of Mexico.

Scientists have mapped the size of the oxygen-deprived region in the Gulf since 1985. This year’s is estimated at more than 8,700 square miles, which is about the size of New Jersey.

The amount and timing of rainfall contribute to the washing of chemicals from farm fields throughout the watershed into the Mississippi River and down to the Gulf.

Residents of Pretty Prairie, Kansas, are under pressure from regulators to reduce nitrates levels in their water.
Alex Smith / For Harvest Public Media

Pretty Prairie, Kansas, population 680, had a moment in the spotlight during the confirmation hearings for new Environmental Protection Agency head Scott Pruitt.

Kansas Sen. Jerry Moran mentioned Pretty Prairie as an example of a community that’s struggling because of EPA regulations that Pruitt could ease.

But residents of the tiny south central Kansas town are also concerned about how federal budget cuts might affect their ability to pay for a new water treatment system.   

The Brazile Creek Groundwater Management Area encompasses 756 square miles of north-central Nebraska.
Ariana Brocious / For Harvest Public Media

At a nitrogen management class in the small town of Creighton, Nebraska, Tanner Jenkins shows a chart of groundwater data to a group of about 40 farmers. He points to a red line, which shows the level of chemical nitrates in groundwater over time.

“You can see we’re on a pretty steady upward click,” Jenkins, who works for a local groundwater district, tells the farmers.

Decades of intensive farming have contaminated the groundwater across many parts of Nebraska. A new plan may help farmers in the northeastern part of the state address the problem.