July 27, 2024

Much work remains to meet nutrient loss goals

SPRINGFIELD, Ill. — Progress, current and future challenges were highlighted in the Illinois Nutrient Loss Reduction Strategy biennial report.

Details of the report were unveiled during the Nov. 10 NLRS Partnership Conference.

The 2015 Illinois NLRS established a goal to reduce the amount of nitrogen and phosphorus in Illinois waterways by 45%, with interim reduction goals of 15% nitrate-nitrogen and 25% total phosphorus by 2025.

Implementation of the statewide strategy is guided by the Illinois Environmental Protection Agency, Illinois Department of Agriculture and University of Illinois Extension with the Policy Working Group and other stakeholder groups and councils.

Findings

Statewide nitrate-nitrogen and total phosphorus loads have been highly correlated with river flow, which in turn is highly correlated with precipitation.

For the five-year period of 2015-2019, the statewide river flow, nitrate-nitrogen and total phosphorus average loads were estimated at 25%, 13% and 35%, respectively, above the 1980-1996 baseline period.

The 2015-2019 averages were influenced by unusually high precipitation in 2019. Five-year average river flows have been greater than the baseline since 2008.

Greater runoff and drainage tend to increase nitrate-nitrogen and total phosphorus loads and, therefore, increases the difficulty of meeting the strategy’s water quality goals.

For some watersheds, however, nutrient loads remained constant or even declined despite increases in river flow. This indicates that other factors, such as nutrient management, may influence riverine nutrient loads.

The NLRS was built to incorporate flexibility into implementation, thus allowing the addition of two new practices — saturated buffers and terraces — to the list of recommended agriculture conservation practices.

The U of I Nutrient Loss Reduction Strategy Science Team estimates a saturated buffer has a nitrate-nitrogen loss reduction efficiency value of 40%, and terraces were given a 40% total phosphorus loss reduction value in non-tiled fields.

“This biennial report demonstrates the continued implementation of the strategy across agriculture, point source and urban stormwater sectors. Despite these efforts, nutrient loads increased, driven primarily by increases in precipitation and storm events. While progress toward the implementation of certain practices is evident, the scale and pace of adoption of all practices needs to accelerate in order to meet the interim nutrient loss goals by 2025,” the report noted.

“When I think about all the work you have done on soil health, all the work on precision ag and on better use of data, in many respects Illinois has been at the forefront of much of the work around nutrient reductions for a long time. Thinking about not only how you work with individual producers, but how do you target large landscapes, how do you work across multiple producers, how do you target the right practices to the right lands,” said Robert Bonnie, U.S. Department of Agriculture deputy chief of staff for policy and senior adviser for climate.

Agriculture

Brian Rennecker, Illinois Department of Agriculture Land and Water Resource Bureau chief, presented the agriculture sector overview with the following report takeaways:

• Sustained group effort despite historic rainfall in 2019 and a global pandemic in 2020.

• Agriculture sector spent nearly $27 million implementing the strategy outside of traditional government cost-share programs.

• Over 72,000 people attended more than 1,020 outreach events during 2019 and 2020, including field days, conferences and workshops to learn about practices that can be implemented to reduce nutrient loss from farm fields.

• Partners for Conservation cost-share program assisted farmers by redirecting funds to implement an additional 93,750 acres of cover crops after historic flooding in 2019.

• Fall Covers for Spring Savings supported 50,000 additional acres of cover crops in 2019.

• Illinois farmers reported increased knowledge of the NLRS, resulting in an increase in cover crops — 1.4 million acres planted — representing a 135% increase from 2011.

• Significant decrease in phosphorus fertilizer application rates in 2019 with 11.2 million acres of croplands reported as having less applied compared to 2011.

“While the biennial report highlights that the sustained effort of the agriculture sector has underscored several vital takeaways making an impact on the state’s nutrient loss reduction strategies, it is still critical that we keep an eye on the amount of nutrients leaving the state to help determine whether current strategy practices are enough to reach the reduction goals,” Rennecker said.

“Understanding the role climate change and its high-intensity storms play in nutrient loads could help insure the value of these efforts are not obscured by a wet year like 2019 and even the past year. Knowing that these types of storms will be more frequent gives the state ample time to adapt strategy practices to the changing climate.

“What we monitored and reported in the 2021 biennial NRLS report may not be sufficient in the future, while we can speculate that there will be more climate-related impacts on our Nutrient Reduction Loss Strategies will must remember that management strategies that worked in 2019 and 2020 and today may not be sufficient in the years ahead.”

Point Sources

Trevor Sample, Illinois EPA Bureau of Water Watershed Management Section, gave an overview of the point source sector in the NLRS.

Spending by the point source sector increased significantly from $65.1 million in 2019 to $185.2 million in 2020. Point source sector reductions are largely regulated through Illinois EPA’s National Pollutant Discharge Elimination System permit program, with 36% of major municipal wastewater treatment facilities having permit limits for total phosphorus.

Facilities are taking additional steps, and since 2018 have developed 71 nutrient reduction optimization studies and 59 nutrient reduction feasibility studies. Outreach and education have also continued in the point source sector with 13 events held, reaching more than 2,600 stakeholders.

Illinois EPA’s Water Pollution Control Loan Program continues to provide low-interest loans for wastewater treatment plant upgrades. In 2019 and 2020, Illinois EPA invested over $200.2 million to projects to improve nutrient removal, green infrastructure, urban storm water treatment and control of combined and sanitary sewer overflows.

Urban Stormwater

Eliana Brown, U of I Extension water quality specialist and Illinois-Indiana Sea Grant stormwater specialist, summarized the urban stormwater sector portion of the NLRS biennial report.

Thanks to online platforms, the urban stormwater sector continued to reach a broad audience of more than 14,000 stakeholders, sharing tips for homeowners to reduce nutrient loses from their property.

Additional practices from this sector showed more than 77% of Illinois’ Municipal Separate Storm Sewer system communities have implemented street sweeping and approximately 64% have implemented leaf collecting. With leaves representing a significant source of urban phosphorus loads, implementation of both practices results in decreased loading.

In 2020, Illinois EPA launched the Green Infrastructure Grant Opportunity program, providing funding to projects that reduce stormwater reaching Illinois waterways.

Illinois EPA saw great interest in the first year of the program and provided $5 million in funding, with an additional $4 million being provided by local match, which will support 11 projects.

Tom Doran

Tom C. Doran

Field Editor