Slowing the Flow: Wetlands Work As Filters

Algae crowing in constructed wetland

Nestled along farm fields on the banks of Money Creek, a series of wetland projects aims to improve water quality in McLean County.

“One of the big goals for this wetland is to reduce the amount of nitrates flowing into Lake Bloomington,” says McLean County farmland owner Tim Kraft, who installed a wetland on his land in 2014.

Money Creek is the main tributary to Lake Bloomington, one of the reservoirs used as a water supply for the city of Bloomington. The constructed wetlands act as filters, removing excess nutrients that can have a negative impact on water quality if they reach a high enough level.

Nitrates are a water soluble form of Nitrogen, an essential nutrient for plant growth. When heavy rains saturate the soil, nitrates can be washed away.

Nitrates occur naturally in the absence of agriculture, but fertilizer use can contribute to increased levels. Nutrient loss can be an unintended side effect of fertilizer needed for crop production and field tile drainage that make much of Illinois’ soggy soils farmable.

“Everyone has the same goal to keep the nitrogen in the field and out of the water,” says Rick Twait, Superintendent of Water Purification for the city of Bloomington. “The export of nitrates in tile drainage water doesn’t do anybody any good.”

In looking for solutions to keep nitrates out of the water, the city partnered with McLean County Soil & Water Conservation District, Nature Conservancy and the Environmental Defense Fund to explore wetlands. To learn more, check out this video on a similar project along the Mackinaw River:

As part of the ‘Drinking Watersheds’ project, monitoring equipment at the inlets and outlets of each wetland collect data for researchers to analyze how well the process is working.

“We’re seeing reductions of about 50 to 60 percent,” says University of Illinois Ecological Specialist, Mike Wallace, who visits each wetland about once a week to collect data and water samples. “No matter how much nitrate is in the water, the wetlands remove about half.”

In addition to reducing nutrients in water, wetlands serve can also serve a secondary purpose.

“The big emphasis is water quality, but a great side benefit is wildlife habitat,” Kirkham says.

To learn more, read the full article here.

The Friday Five: Trash Talk

2013 soybeans, landscape

We’ve probably all done it. Forgotten something in the back of the refrigerator and then had to deal with the stinky, rotten or moldy consequences.

As Americans we’re also pretty bad at throwing away ‘good’ food, too – items that would be safe to eat but end up in the garbage can for whatever reason. In fact, the USDA estimates we throw away 133 billion pounds of edible food every year at a cost of $370 per person.

Food waste has environmental costs, too – both in terms of wasted production and emissions from food waste in landfills. To get a grip on the food garbage problem and ways to combat it, take a look at our fresh picked tidbits for this week’s Friday Five:

  1. For starters, ‘Let’s Talk Trash’ from USDA helps put the problem in perspective with a few numbers & pictures. The 90 billion pounds depicted here is a little less than the 133 billion reported elsewhere, but that may be because it can be difficult to get an accurate count (see #3)
  2. Last week, USDA & EPA announced plans to cut food waste 50% by 2030, as reported by the Washington Times.
  3. For a deeper look at the food waste numbers and the challenge of tackling the problem, check out this article from Wall Street Journal.
  4. Perhaps the U.S. needs to takes some cues from Denmark, which is leading the way in reducing food waste, as reported by NPR’s The Salt.
  5. And for a few ways to get you started in curbing food waste in your own kitchen, check out these 10 Tips to use food you might consider tossing, also from NPR’s The Salt.

What can you do to reduce food waste?