ST. LOUIS — A recent assessment by the Environmental Protection Agency (EPA) has revealed that there has been little improvement in the pollution levels of rivers and streams across the country, particularly when it comes to nitrogen contamination. These nutrients, which stem from agricultural regions that drain into the Mississippi River, not only contaminate drinking water but also contribute to the creation of a vast dead zone in the Gulf of Mexico that significantly impacts aquatic life.
The assessment, which is based on samples collected between 2018 and 2019, highlights the persistent challenge of controlling nutrient pollution caused by farm runoff. Despite decades of efforts by federal and state authorities, farm runoff remains a significant source of pollution that is not subject to federal regulation. Compounding the problem, climate change is leading to more intense storms in the Midwest and South, washing away fertilizers and carrying them into nearby rivers.
Olivia Dorothy, director of river restoration with the organization American Rivers, expressed concern over the lack of progress made in meeting pollution reduction goals. The findings of the assessment revealed that over half of the rivers and streams in the Mississippi River basin were in poor condition due to nitrogen and phosphorus from fertilizer runoff. Additionally, around half of the river miles were deemed to have poor conditions for bottom-dwelling species, while approximately one-third were considered to have poor conditions for fish diversity.
The implications of nutrient pollution extend beyond the Gulf of Mexico. The excessive growth of bacteria resulting from the inflow of nutrients leads to oxygen depletion, creating what is known as a dead zone. This vast area, comparable to the size of Rhode Island or even New Jersey, poses significant challenges to marine animals trying to survive. Nancy Rabalais, professor of oceanography and wetland studies at Louisiana State University, explains that the dead zone not only impacts commercial fisheries but also damages marine life upstream.
Furthermore, excessive nitrate levels in drinking water can have detrimental effects on human health. High levels of nitrate can interfere with the oxygen-carrying capacity of blood, resulting in health problems such as headaches, nausea, and abdominal cramps. Infants are particularly vulnerable, with nitrate contamination potentially causing blue baby syndrome, a condition characterized by bluish discoloration of the skin.
Efforts to address nutrient pollution have been established through the hypoxia task force, initiated by the EPA in the late 1990s. However, these efforts primarily rely on voluntary actions to reduce farm runoff and have not significantly reduced the dead zone. Anne Schechinger, Midwest director with the Environmental Working Group, argues that stricter regulations are necessary, rather than relying on voluntary measures. While the Biden administration has made strides in improving drinking water quality, critics argue that more action is needed to address agricultural pollution.
Implementing measures to prevent runoff, such as creating buffers between farmland and waterways, establishing new wetlands for pollutant filtration, and reducing fertilizer application, are considered key steps in tackling the issue. However, addressing agricultural runoff remains a sensitive political issue, especially in major farming states in the Midwest that significantly contribute to the problem. While some states have implemented legislation requiring vegetation buffers along waterways, the interconnectedness of groundwater and surface water means that nutrient pollution can still find its way into streams.
To combat over-fertilization, Brad Carlson, an extension educator with the University of Minnesota, emphasizes the importance of educating farmers about nutrient pollution issues and striving to reduce excessive fertilizer application. He highlights that approximately 30% of farmers still apply more fertilizer than recommended.
The EPA assessment serves as a stark reminder of the challenges posed by nutrient pollution in rivers and streams across the United States. As climate change intensifies, it is clear that a more comprehensive and regulated approach is needed to address this persistent issue and safeguard both aquatic ecosystems and human health.
