Nitrogen is a powerful nutrient. It can make grass green and dramatically increase corn yields. Yet when too much of it reaches our rivers and streams, it threatens human health, chokes out aquatic life, and fouls our coastal waters.

For example, there is abundant scientific evidence that nitrogen contributes to the growing “Dead Zone” in the Gulf of Mexico . In 2001, the U.S. Environmental Protection Agency (EPA) determined that the nation needs to reduce excess nutrients, such as nitrogen, in our streams and rivers.

Currently, state EPAs are mandated by the federal EPA to write and enact water quality standards for nitrogen and phosphorus or to adopt the proposed federal criteria. In response, Illinois water reclamation districts predict¹ it will cost their ratepayers more than $5 billion to install the best technology available—and $500 million annually to operate—yet even this investment will not produce water that meets the proposed federal criteria. Nor will it address the region’s needs for open space, wildlife habitat, and flood control.

The Wetlands Initiative and its partners have developed an alternative: Restored wetlands, financed by the purchase of nutrient removal credits, either through an open market or through long-term contracts. We call this strategy “nutrient farming.” In addition to removing nutrients, the restored wetlands will provide important environmental benefits for humans and wildlife—benefits that are unavailable through the use of traditional treatment technologies.

The potential market for nutrient credits is huge. For example, an immediate market could be industrial and municipal dischargers. Annual operating and maintenance costs at upgraded treatment plants are estimated to be $4.8 billion nationwide (extrapolated from Illinois per capita costs). This money would be better spent re-creating wetlands, which provide many other environmental benefits. 

Nutrient farming could be conducted throughout the Mississippi River Basin and other watersheds across the United States where high nutrient concentrations are of concern.

Problem

The regions with the highest losses of presettlement wetlands are also the areas with highest fertilizer usage and nitrogen yields. In the past 200 years, for example, three Midwestern states ( Iowa , Missouri , Illinois) in the Upper Mississippi River Basin drained 85 to 90 percent of their wetlands. More than 4 million acres of wetlands were destroyed in the Illinois River watershed alone. Not surprisingly, these areas also have the highest nitrogen concentrations in their rivers.

The modern, highly modified aquatic ecosystems of the upper Midwest can no longer purge themselves of excess nitrogen. By dredging, channelizing and leveeing off rivers from the ir backwater lakes and floodplain wetlands, we have crippled the river’s natural ability to denitrify its waters. Today, the nutrient-rich water reaching the Gulf of Mexico's coastal shelf, triggers excessive algal growth. This results in low oxygen levels (called hypoxia), causing fish, shrimp, crabs, and zooplankton to die. Scientists also have linked excess nitrogen to bladder cancer and blue-baby syndrome.

The altered river systems of today cause billions of dollars in flood damage as well. According to the U.S. Weather Bureau, national flood damages now average $3.5 billion; earlier in the century (1903-1933), damages averaged $1.4 billion (both sums are adjusted for inflation). This increase is in spite of— or because of—ever-rising federal spending on levees and other structures.

Solution

Nutrient farming is a control strategy that seeks to optimize the natural chemical and biological reactions in created and restored wetlands to remove nitrogen and phosphorus from the water and carbon from the air. Landowners then sell nutrient reduction credits to other farmers, municipalities, or industries that release excess nutrients to surface waters and cannot cost-effectively remove these nutrients themselves .

The Wetlands Initiative is developing the Goose Pond Nutrient Farming Pilot Project to test and demonstrate the economic efficiency and environmental benefits of nutrient farming. This new way of managing the quality of our nation’s waters will be less costly than conventional treatment methods, reduce demand on energy resources and provide additional benefits for biodiversity and wildlife.

Nutrient farming must be viewed as a business enterprise—an economically efficient means to manage environmental problems. This economic efficiency will be established only by using solid biogeochemical and economic data.

¹Zenz, D. R. 2003. Technical feasibility and cost to nutrient standards in the state of Illinois, Report commissioned by the IL Assn. of Wastewater Agencies.