Innovative Strategy and A Case Study For Implementing Watershed Nutrient Management

Introduction
Wisconsin enacted legislation that allows regulated point sources to partner with stakeholders to implement watershed-wide strategies to reduce nutrient and sediment loadings to surface waters. This strategy can be a more cost-effective way to meet water quality and total maximum daily load (TMDL) goals than traditional construction of treatment facilities. The options include a 'multi-discharger variance' that requires watershed best management practice implementation, water quality credit trading that has similarities to other trading programs across the country, and watershed adaptive management that is unique to Wisconsin and has been viewed as a model for other nutrient reduction strategies that challenge the status quo for implementing cost effective pollutant reductions (Figure 1). Each of these options allow more than one implementation strategy with each having unique advantages and disadvantages. This paper will provide a summary of the phosphorus permitting framework in Wisconsin along with a case study. The case study highlights key decision criteria for the utility selecting adaptive management and the innovative, technology-driven approach to program implementation.
Case Study
NEW Water, the brand of the Green Bay Metropolitan Sewerage District in Green Bay, Wisconsin, operates two treatment facilities with a combined 38 million gallons per day (MGD) average annual flow and a permitted treatment capacity of 59.2 MGD. NEW Water discharges near the Bay of Green Bay to the Lower Fox River in the Lower Fox River Basin which is impaired for phosphorus and sediment (TSS) with an approved TMDL. To satisfy Wisconsin's phosphorus and TMDL regulations, NEW Water conducted an alternatives evaluation in 2018 as part of its phosphorus Final Compliance Alternatives Plan. NEW Water evaluated current operations at the treatment facilities, planned optimizations that were under way, and estimates of further mass reductions required to achieve low-level effluent phosphorus concentrations using 2040 flow projections. The analyses demonstrated NEW Water cannot achieve low effluent limits without constructing tertiary treatment or implementing a watershed-based permit compliance strategy. An economic evaluation assessed adaptive management as a low-cost alternative (Figure 2). A multi-attribute utility analysis concluded that adaptive management provides the greatest nonmonetary benefits (Figure 3). Additionally, a sensitivity analysis demonstrated adaptive management did not carry significant long-term risk as permits are reassessed every 5 years.
The adaptive management program, titled the NEW Watershed Program (Program), is part of the current discharge permit and is anticipated to span four, five-year permit terms. The Program focuses on phosphorus and TSS reductions in a defined Action Area of the Ashwaubenon and Dutchman Creeks sub-watersheds that covers 38,700 acres and requires a TMDL reduction of approximately 19,000 pounds of phosphorus and 3.9 million pounds of TSS per year. The Program is partnering with several entities to install agricultural and urban conservation Best Management Practices (BMPs) to reduce phosphorus and TSS nutrient loading, with the goal to achieve TMDL reductions and water quality standards in the Action Area (Table 1). A core part of adaptive management is to form partnerships between point- and nonpoint sources to work towards achieving phosphorus and TSS reductions beyond what current permits, regulations, or watershed initiatives have been able to achieve. NEW Water has chartered a diverse team that includes County conservationists, agronomists, the Oneida Nation, stormwater engineers, municipal separate storm sewer systems, a regional airport, and several non-governmental organizations. Jacobs Engineering supported a 7-year pilot project for NEW Water in the Silver Creek watershed and is now providing program management assistance to support all aspects of the full-scale Program. Because significant work is required to achieve these goals, the Program needs to delegate workloads across a highly diverse team, identify and prioritize installation of BMPs, coordinate with landowners and agricultural operators, manage grants, and write and manage contracts of individual BMPs. In addition, progress made by team members is tracked in real-time and compared against regulatory requirements and Program goals. Jacobs developed several digital solutions to address large complex datasets and program management. Watershed-based programs are new, unfamiliar endeavors for wastewater facilities and can seem daunting to manage. By efficiently leveraging data and utilizing tools like GIS, custom mobile applications, real-time dashboards, and automated workflows, managing a program of this size is more attainable than before. For NEW Water, the backbone of this complex data system is a Spatial Database Engine (SDE), which is a type of database for GIS datasets that contain spatial data and related tabular data (Figure 4). The SDE supports a variety of data-related tools for the Program, including: - Custom ArcGIS Field Maps Applications that allow for field teams to collect geolocated data using a tablet-based mobile application that directly stores and organizes data as it's collected (Figure 5). - PowerBI, PowerApp, and Mapbox Dashboards for reporting and visualizing data in real-time as collected (Figure 6). - Custom database views (stored queries that are updated in real-time as data changes) that transform data, process data, and/or display as overlays on mobile GIS applications and maps (Figure 7, Figure 8). - Web maps and web-applications for viewing maps and related data (Figure 8). - Python scripts for automating email notifications based on triggers when data is entered, or notifications scheduled on a recurring basis (Figure 9). - Python scripts that write and update data to HyperText Markup Language reports and reattach to geolocated records in the SDE which are then available for downloading and distribution. - PowerApps applications that allow users to enter and update data in the GIS from within a PowerBI dashboard. The tools support a wide variety of staff, workflows, reporting, budget management, contracting, and communication that is customized and unique to each use-case, with levels of permission and security that ensure confidential information is protected. Using digital solutions has allowed personnel at all levels to effectively contribute to the overall project successes, including workload planning with key staff, collaboration in the multiple facets of BMP implementation, and monitoring progress against regulatory requirements, all in real‐time.
Summary
Adaptive management and other watershed-based approaches can be lower-cost and provide additional environmental benefits beyond constructing a tertiary treatment system. Wisconsin state regulations include watershed options for point source dischargers to comply with phosphorus and TSS permit requirements. A case study of NEW Water's adaptive management program demonstrates a watershed approach for permit compliance, the decision-making criteria that supported this approach, and the innovative technology-based solutions that have enabled success. Watershed approaches can be scaled for facility sizes and needs, and the tools to implement watershed projects are flexible and adaptable. Adaptive management provides opportunity for partnerships between point- and nonpoint sources to work towards achieving phosphorus and TSS reductions beyond what current permits, regulations, or watershed initiatives have been able to achieve.