June 7, 2021

Introduction to Ohio’s Water Quality Problem

In 2014, a toxic algal bloom in Lake Erie caused nearly half a million people in the Toledo area to be without tap water for two days. The water crisis generated headlines around the world, drawing attention to an increasingly serious problem with the quality of Ohio’s water, specifically in the Western Lake Erie Basin.

While there are many factors contributing to harmful algal blooms (see sidebar), scientists agree the biggest culprit is excess dissolved phosphorus, which is found in animal manure, many commercial fertilizers and municipal wastewater. Phosphorus is essential to producing food, fuel and fiber but can drain from fields and feed the growth of harmful algal blooms. Before 1972, point-source pollution from factories, for instance, was the main source of the phosphorus load into Lake Erie. A reduction of that pollution resulted in harmful algal blooms not being a problem until recently. Today, experts estimate up to 93% of the phosphorus load comes from nonpoint sources such as agriculture.*

As the state’s largest land user, agriculture has shouldered a majority of the blame. For decades, the agriculture industry has been working to reduce sediment loss from fields, and technology advances have improved the way nutrients are managed. A study by the U.S. Department of Agriculture shows 99% of cropland acres in the Western Lake Erie Basin are managed with at least one conservation practice. Despite these efforts, an increasing amount of dissolved reactive phosphorus has been entering Lake Erie.

Determined to be proactive, Ohio’s agriculture industry has stepped forward, acknowledging its role in the problem and desire to find workable solutions. With scientists agreeing that a multipronged approach is needed to protect Ohio’s water, Ohio Farm Bureau and the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) joined forces to address the issue. Concentrating their efforts on the Western Lake Erie Basin, they came up with the idea of the Blanchard River Demonstration Farms Network in northwestern Ohio. Its ultimate goal is to show how clean water and productive agriculture can coexist.

What are harmful algal blooms?

Harmful algal blooms are mostly caused by excess nitrogen and phosphorus, nutrients found in many sources including animal manure and many commercial fertilizers. Nutrient pollution flowing in Lake Erie and other bodies of water come from farm field runoff, sewer overflows, leaking septic systems and wastewater treatment plant discharges among other sources. The thick slimy blue-green algal blooms have closed Lake Erie beaches, caused illness in humans and animals and negatively impacted the lake’s $11 billion tourism industry. The Ohio Phosphorus Task Force has concluded that agriculture is a major source of phosphorus for Lake Erie with some experts saying agriculture contributes as much as two-thirds of the phosphorus load.


*Source: Achieving phosphorus reduction levels in the Lake Erie in the Journal of Great Lakes Research

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