Illinois Nutrient Loss Reduction Strategy implementation drives success

Illinois nutrient loss reduction strategy: Successful implementation efforts

Nonpoint sources

The agricultural sector is the primary nonpoint source of nutrient loss via surface runoff and subsurface drainage. Agriculture conservation projects kept nitrogen and phosphorus -- 73,000 pounds and 30,000 pounds, respectively – out of waterways.

Successful implementation efforts include:

• Cover crops and reduced tillage.

  • The NLRS survey shows farmers are knowledgeable about cover crops and use the maximum return to nitrogen (MRTN) method to determine nitrogen fertilization rates.

  • In 2021, 1.39 million acres were dedicated to cover crops in Illinois.

  • Conservation tillage is practiced on nearly three-quarters of cropland, helping reduce soil loss and limiting the incorporation phosphorus fertilizer and manure into the soil.

• Edge-of-field practices.

  • In 2022, agricultural organizations sponsored more events discussing edge-of-field practices, such as bioreactors, wetlands, saturated buffers and stream buffers.

  • In 2022, water and sediment control basins were added as a recommended practice, which can lead to a 60% reduction in total phosphorus.

  • Grass buffers line 52.7% of rivers near Illinois croplands.

• Collaboration between farmers and agencies.

  • Between 2021 and 2022, more than 940 outreach events on nutrient loss were organized and attended by over 110,000 participants — the highest participation reported since 2015.

  • It is reported that 55% of surveyed farmers know about the NLRS strategy, an increase from 43% in 2020.

  • The survey highlighted a rise in fertilization practices' adoption rates for the 11 million acres of corn planted in 2021. In 2021, 76% of corn acres used the MRTN rate.

Point sources

By 2022, the point source sector exceeded the strategy’s 25% interim total phosphorus reduction goal for 2025. The Illinois Environmental Protection Agency’s (IEPA) National Pollutant Discharge Elimination System (NPDES) permit program has helped reduce phosphorus discharges by 6.2 million pounds, a 34% decline since 2011.

• Wastewater treatment plant upgrades.

  • In 2022, 101 major municipal facilities discharged an annual average phosphorus concentration of 1 mg/L or less. Of these facilities, 46 meet phosphorus discharge limits of 0.5 mg/L or less.

  • In Illinois, 38% of all major municipal wastewater treatment plants now have permit limits of 1 mg/L total phosphorus.

  • Facilities have also developed and submitted 210 nutrient reduction optimization studies and nutrient reduction feasibility studies since 2018.

• Watershed-based approaches.

  • Sixty-seven major municipal wastewater facilities are developing Nutrient Assessment Reduction Plans (NARPs) for phosphorus reduction. Another 89 are developing NARPs as part of a watershed group.

  • Since 2011, 143 watershed-based plans have been developed with cost-share funding from the Illinois EPA.

  • Facilities have also developed and submitted 210 nutrient reduction optimization studies and nutrient reduction feasibility studies since 2018.

Urban stormwater sector

In 2021-2022, an additional 14 urban stormwater best management practices were installed, which reduced total nitrogen by 4,192 pounds and total phosphorus by 1,033 pounds.

• Green infrastructure projects.

  • Eleven Illinois EPA Green Infrastructure Grant-funded projects prevented 1.2 million gallons of stormwater from entering waterways.

  • A new Green Infrastructure Inventory Tool maps the location and type of almost 2,000 stormwater best management practices across the state.

• Stormwater management practices

  • Seventy percent of communities with municipal separate storm sewer systems have adopted annual street sweeping and leaf collection practices.