Nutrient Reduction Planning: Illinois' Journey and Lessons Learned

INTRODUCTION:
Efforts to reduce nutrient loading from both point sources and non-point sources are intensifying to tackle major environmental issues. These issues include hypoxia in the Gulf of Mexico, harmful algal blooms in Western Lake Erie, and various nutrient-related problems in local water bodies across the U.S. The Illinois Nutrient Loss Reduction Strategy aims for a 45% reduction in total phosphorus and nitrogen loading by 2045. A key tool in this strategy is the Nutrient Assessment Reduction Plan (NARP), which is a special condition included in National Pollutant Discharge Elimination System permits for major wastewater treatment plants with a design flow of one million gallons per day.

OBJECTIVE:
The primary purpose of the NARP is to identify phosphorus input reductions and other necessary measures to address phosphorus-related impairments. The NARP special condition requires permittees to develop an implementation plan and schedule for the identified measures to address water quality impairments effectively. The WWTPs are required to achieve an annual geometric mean effluent TP target of 0.5 mg/L by 2030. The NARP determined whether a local TP effluent target was required to address the phosphorus-related impairments in receiving waters

IMPLEMENTATION STRATEGIES:
The NARP development NARP was tailored to the unique characteristics of each wastewater treatment plant (WWTP) and watershed. At WEFTEC 2022, various approaches to NARP development were presented (Mahajan et al., 2022). This presentation will cover implementation plans for three completed NARPs: one for a headwater stream by a single WWTP, another by a large regional utility for a network of receiving water bodies, and a watershed-wide NARP by a group of WWTPs.

STAKEHOLDER ROLE:
The Water Research Foundation Project #4974 has identified three pillars for nutrient management: Practice, Policy, and Partnerships (Clark et al., 2023). Partnerships with relevant stakeholders are a critical aspect of nutrient reduction efforts and are often overlooked. The NARP development included many stakeholders, including government agencies, municipalities, non-profits, environmental groups, and the community. This presentation will discuss the role of different stakeholders in the NARP development, and the strategies used to solicit input from them. Example strategies utilized in the NARP development included public meetings, watershed group meetings, surveys, and workshops. Engaging stakeholders ensures that diverse perspectives are considered, and collaborative solutions are developed.

OBSTACLES TO IMPLEMENTATION:
The NARPs were due by the end of 2024. This presentation will discuss the obstacles to the NARP implementation recommendations. These include, but are not limited to:
1. Financial Constraints: Many WWTPs in Illinois, especially smaller ones, face financial constraints in meeting the NARP TP effluent limits of 0.5 mg/L. The State Revolving Fund (SRF) in Illinois does not have enough funds to assist with upgrading all the major WWTPs to meet the effluent TP target of 0.5 mg/L. Another example is the funding for dam removal recommended in some NARPs for addressing phosphorus-related impairments.
2. Technical Constraints: An example of a technical constraint is the inability of a large WWTP to meet the effluent TP target of 0.5 mg/L due to the industrial nature of a large proportion of its effluent. This presents a significant challenge in achieving the desired nutrient reduction goals.
3. Uncertainty about the Role of Environmental Groups' Comments for NPDES Permit Renewal: Environmental groups were part of the NARP development process. However, they provided comments urging the Illinois EPA to set the target effluent TP concentrations to 0.1 mg/L or below. It remains to be seen how the Illinois EPA will respond to these comments during the NPDES permit renewal process, adding a layer of uncertainty to the implementation.
4. Public Engagement: During the NARP development, WWTPs found it challenging to engage with the public on wastewater topics. This is likely to remain a challenge for implementation, as it is difficult to generate public interest and excitement about 'wastewater' issues. Effective public engagement strategies are essential for gaining community support and ensuring successful implementation.

PATH FORWARD: This presentation will discuss the recommended path forward to overcome the described obstacles. Adaptive management is an iterative process that involves continual monitoring to assess the performance of management actions and enable responsiveness to potential challenges. The NARP implementation would need to include adaptive management to address the implementation challenges. The NARP implementation will also focus on the three Ps of nutrient management: incorporating technological advancements and cost-efficient WWTP upgrades, flexible regulatory policies that encourage innovation, and continuing to foster partnerships to achieve the nutrient reduction goals. By adopting an adaptive management approach, stakeholders can ensure that the NARP implementation remains effective and responsive to changing conditions and new information.

SIGNIFICANCE:
The lessons learned from the development of Illinois NARPs will be invaluable to stakeholders in other states as they address nutrient-related impairments in receiving waters.