Ill. continues work to improve waterways by reducing nutrient pollution

The loss of nutrients into Illinois’ lakes, streams, and rivers harms water quality here and downstream all the way to the Gulf of Mexico. The Illinois Nutrient Loss Reduction Strategy, NLRS, was established in 2015 and is designed to reduce nutrient pollution in Illinois’ waterways and the Mississippi River and its negative impacts by exploring and recommending practical, research-based nutrient loss practices and collaborating with partners across the state.

The 2023 NLRS Biennial Report, now available at go.illinois.edu/NLRS, is the latest update to the strategy. It documents water quality updates and initiatives for 2021–22 that reduce the loss of the nutrients nitrogen and phosphorus across three sectors: agricultural, wastewater treatment facilities, and urban stormwater. The report also stresses the multifaceted challenges of confronting increasing nutrient loads in Illinois waterways.

The results of water quality measures taken in 2021-22 are mixed. While wastewater treatment facilities successfully reduced their total phosphorus discharges by 6.2 million pounds, or 34 percent, compared to the 1980-96 baseline measurements, nutrient levels in the state's waterways have continued their upward trend. The five-year average nutrient loads from 2017-21 show that nitrogen increased by 4.8 percent from baseline to 416 million pounds annually and total phosphorus increased by 35 percent to 46 million pounds annually. The primary goal of the strategy is a 45 percent reduction in both nitrogen and total phosphorus loads, with interim targets set at a 15 percent nitrate-nitrogen decrease and a 25 percent total phosphorus decrease by 2025.

A variety of factors contribute to rising nutrient loads, including increased streamflow, residual nutrients, nutrient management practices, and some unidentified sources. The impacts of climate change, particularly increased runoff and drainage, intensify river loads and more proactive measures are needed to achieve the strategy’s water quality goals.

Nutrient pollution promotes algal growth and impairs local ecosystems, making water unsuitable for drinking, recreation, fishing, and aquatic life. Excess nutrients also contribute to the “dead zone” in the Gulf of Mexico where aquatic life struggles due to depleted oxygen levels. Ill. is one of 12 states with nutrient strategies that are members of the U.S. Environmental Protection Agency Hypoxia Task Force created to address the issue. The NLRS is a collaborative effort involving the Illinois Environmental Protection Agency, IDOA, University of Illinois Extension, stakeholders, and experts from industry, science, and technology.

Nutrient pollution comes from a variety of sources. In Ill., the agriculture, wastewater treatment, and urban stormwater sectors all have crucial roles and unique challenges in reducing nutrient loss. The levels of nitrogen and phosphorus attributed to each sector vary and were published in the original strategy released in 2015. Fertilizer is the primary source of nutrient loss from agricultural production. Wastewater treatment facility discharge and urban stormwater runoff also contribute to nutrient loss.

The 2023 Biennial Report is the fourth update to the strategy since its inception in 2015. Implementation of the NLRS is guided by research to optimize nutrient loss reduction while fostering deep collaboration and innovation across academia, the private sector, non-profits, wastewater agencies, and local, state, and federal government agencies.

The 2023 Biennial Report outlines work done by NLRS partners across the state to mitigate nutrient loss through 78 distinct nutrient loss reduction programs and projects, including community outreach and engagement. University of Illinois Extension watershed outreach staff work with farm communities in priority areas to facilitate their engagement in watershed planning and to encourage farmers and landowners to put practices into place that reduce nutrient loss, such as growing cover crops or installing bioreactors to filter water running off farm fields.

Illinois Extension also has rainfall management staff and programs aimed at reducing nutrient loss in the urban stormwater sector by managing runoff and reducing the duration and intensity of flooding. The stormwater sector continues to provide public education on nutrient loss reduction, including the new website, IllinoisGroundwork, which provides information on green infrastructure research, tools, and resources.

Despite the ongoing implementation of nutrient loss reduction practices by each sector, challenges remain. The next Biennial Report will be published in 2025, which marks a decade since the strategy’s inception. Given the current rate of progress, the 2025 goals may not be achieved. More work is needed to encourage widespread adoption of agricultural conservation practices and foster deeper community engagement at the watershed level. Continued support for research, conservation initiatives, and education is essential.

The annual NLRS Partnership Conference on Jan. 25, 2024, in Springfield will explore the report and other elements of the strategy, including future developments. Visit the NLRS event registration website to sign up.