Developing a Regional Biosolids Master Plan for the North Shore Water Reclamation District

In 2023, the North Shore Water Reclamation District (NSWRD) developed a comprehensive Biosolids Master Plan (BMP) to leverage opportunities for the regionalization of solids handling facilities that were in need of renewal and modernization. The BMP addressed operational and maintenance challenges, optimized resource recovery, and made plans for current and future regulations, within the framework of stakeholder goals and values. The NSWRD BMP planning process is complete, and a discussion of the planning approach, considerations, and the selected alternative will be presented. This approach to biosolids master planning could be implemented by any water resource reclamation facility seeking to take a holistic approach to their biosolids management program, solids handling technology, and the operational requirements of their solids processing. The NSWRD serves around 300,000 residents north of Chicago and processes a total average of 63 million gallons and 7,785 dry tons of Class A Exceptional Quality (EQ) biosolids per day. The NSWRD is composed of three water reclamation facilities (WRFs), Gurnee WRF, Waukegan WRF, and Clavey Road WRF, and a regional biosolids drying facility (Figure 1). The drivers for completing this BMP included the following: Capacity constraints , aging assets, operational challenges associated with the drying and marketing of unstabilized solids, and other regulatory considerations. At the onset of the planning effort, a collaborative effort was undertaken by the NSWRD and the Brown and Caldwell team to develop a set of guiding principles to keep the plan aligned with the long-term goals of the NSWRD's. Those program goals and objectives are listed below: - Modernize NSWRD's aging solids handling assets in a cost-effective manner that balances program goals with stakeholders' financial interests. - Create solids handling solutions that can incorporate innovation and are operation and maintenance (O&M) friendly/easy to own. - Improve regulatory and market resiliency by creating solutions that lend themselves to program flexibility and redundancy. - Set a course that supports environmental stewardship, including reduction or recovery of energy, and the creation of marketable biosolids products. - Create an adaptable plan that can be implemented to leverage current assets and address near-term challenges, while prioritizing those projects that address the NSWRD's goals for the future. The preferred alternative was selected through a two-phase planning process, with numerous collaborative and iterative rounds of analysis and screening. In Phase I of the planning process, the planning team established the operational, economic, and environmental baseline for the existing biosolids management program at NSWRD and performed a regulatory and market assessment of the current biosolids land application landscape. In Phase II, the team performed a biosolids stabilization and biogas management technology pre-screening and an intensive three-round alternatives analysis, Each round of the analysis provided some clear trends. An outline of the number of alternatives, the objective of each round, and a summary of those takeaways are presented in Figures 2-5. The selection of the preferred alternative was made through a multi-criteria decision-making process in which the alternatives from round 3 were compared on cost and relative benefit. This process facilitates the selection of the program that provides the best value to the District by considering a variety of specific factors that the District's staff weigh in order of importance. A dashboard of these results is shown in Figure 6. The preferred alternative implements an advanced regionalized digestion and drying program that generates renewable energy and a high-quality Class A EQ product. It also consolidates solids management at the Gurnee WRF over the next 20 years. The regionalized thermophilic anaerobic digestion (TAD) and belt drying program will be located at the Gurnee WRF, with pipeline injection of the upgraded biogas or renewable natural gas (RNG). At full implementation, solids from Waukegan WRF and Clavey Road WRF would be conveyed via tanker or forcemain to Gurnee WRF for fully regionalized digestion, dewatering, and drying, with the option to convert to a Class A temperature-phased anaerobic digestion system in the future. A process flow diagram of the preferred alternative is shown in Figure 7. The preferred alternative maximizes operational resiliency and resource recovery while reducing costs through consolidating solids processing and utilizing existing assets. After the selection of the preferred alternative, an implementation plan was developed for the biosolids program by dividing the BMP into sub-projects to distribute construction costs across the twenty-year planning time frame. During the BMP process, the NSWRD staff identified several concerns that could arise from regulatory changes, community impacts, and market conditions. The team prepared conditional projects in response to those concerns. They are not part of the core BMP, but were identified, discussed, modeled, and cost estimates were prepared. The intent was to give NSWRD some insight into what changes may need to occur to mitigate the risks of those future challenges. The preferred alternative and conditional projects for the BMP are summarized in Table 1. The NSWRD selected a new biosolids management program that addresses the drivers and issues as well as meets the stated goals by reducing solids, providing resiliency, adding redundancy, and creating renewable energy. Results and takeaways from throughout the planning process will be presented.