Preparing for Uncertainty: Climate Resilience Assessment and Adaptation Planning for Water Resource Recovery Facilities

Introduction
Changing climate can affect wastewater systems in many ways, through changes in temperature, precipitation intensity, duration and frequency (IDF), and magnitude of extreme weather events, and the associated secondary implications such as flooding and wildfires, and sea level rise and coastal storm surge. This paper presents two case studies, focusing on how utilities prepare for the uncertainties of future climate by incorporating climate resilience assessment and adaptation planning into the long-term facility plan of water resource recovery facilities. In addition, one of these case studies addresses greenhouse gas mitigation aspect of climate action planning.
Case Study 1: WSSC Climate Change Vulnerability Assessment Adaptation and Planning
The Washington Suburban Sanitary Commission (WSSC), a water and wastewater utility located in the suburban Maryland outside Washington, D.C., completed a five-year Climate Change Vulnerability Assessment, Adaptation and Mitigation Plan (CCVAAMP) project in 2020. The project included the development of future climate scenarios, modeling of future flood conditions near WSSC facilities, assessment of facility vulnerability and risk, and development of adaptation strategies and cost benefit analysis. The presentation will focus on the study methodology and results from the vulnerability assessment and flood adaptation analysis for the wastewater pumping stations and treatment plants, including:
-Vulnerability analysis, which resulted in a calculated cumulative risk avoided value for each facility based on planning timeline, flood risk, asset replacement costs, and probability of failure of selected strategies (see Figure 1).
-Development of design guidelines for protecting facilities from future climate extremes.
-Annual updates to the WSSC greenhouse gas (GHG) inventory and Action Plan, including GHG mitigation strategy implementation and monitoring (see Figure 2).
Case Study 2: JEA Wastewater/Water System Resilience Plan
JEA is a community-owned electricity, water and wastewater utility located in Jacksonville, Florida. In 2020, JEA completed a System Resilience Plan to further advance its water and wastewater systems toward the goal of being a benchmark resilient utility. This System Resiliency Plan provides enhanced design standards and forward‐looking adaptation strategies that will allow JEA to maintain a high level of service (LOS) and minimize system interruptions during extreme weather events across all of its 1,700 facilities, including water, wastewater, reclaimed water and chilled water systems. While JEA has already addressed many of the high-priority and straightforward enhancements, a comprehensive adaptation plan focused on risk reduction, aggressive design standards, and forward-looking capital improvement plan (CIP) investment was developed to further advance JEA's system reliability and resilience.
The presentation will summarize the results of the key tasks completed in preparation of the System Resilience Plan, focusing on findings for the wastewater system, including:
-Vulnerability assessment and risk analysis (see Figure 3)
-Development of mitigation and adaptation strategies, including economic impact and benefit-cost analysis to prioritize implementation (See Figure 4).
-Development of design and construction standards.