Wastewater Surveillance Program Management and Execution: Lessons Learned from the COVID-19 Pandemic

Introduction
The Coronavirus Disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2), has exposed modern society's vulnerability to infectious diseases. Reliance on clinical testing of symptomatic individuals has proven challenging due to the inability to identify asymptomatic cases and time lags between disease onset and clinical reporting to public health agencies.
Wastewater surveillance is a disease-tracking tool that supports early response, such as public health decision making and vaccination efforts. Public health agencies have partnered with local officials, wastewater utilities, research institutions, engineers, and physicians to implement practical wastewater surveillance programs. CDM Smith has focused on building these partnerships to facilitate SARS-CoV-2 wastewater testing programs around the globe. Our work aims to support the use of wastewater data to inform specific public health interventions.
Program development involves careful planning of sampling sites via geographic information system (GIS) analysis, safe and efficient sampling support (Figure 1), analytical methodology development, data analysis and management, and collaboration between wastewater utilities and public health officials. The case studies describe each of these important aspects in the context of real-world programs developed at facility, neighborhood, city, and statewide scales. The primary goal of this report is to share lessons learned from these experiences to support further development of wastewater surveillance as a public health tool.
Wastewater Surveillance Program Planning and Analytical Support
Our approach to planning programs relies on early engagement of key stakeholders, including public health officials, utility leaders, and key research partners. The team defines program objectives, devises a cost-efficient approach to wastewater sampling and analysis, develops communication plans, establishes data presentation techniques, and informs on public health interventions.
State of Michigan The program between the Michigan Department of Health and Human Services (MDHHS), Michigan State University (MSU), Great Lakes Water Authority (GLWA), Detroit Water and Sewer District (DWSD), and CDM Smith relied on weekly collaborative engagements necessary for data sharing and understanding. The involvement of public health officials and utility leaders is essential for effective data analysis that supports public health action. For example, the team devised a best approach to sample from three distinct interceptors associated with three of the largest counties in the state of Michigan: the Detroit River Interceptor (DRI, Wayne County); the Oakwood-Northwest-Wayne County Interceptor (ONWI, Oakland County); and the North Interceptor-East Arm (NIEA) (Figure 2). Through GIS and hydraulic analyses, the team gathered census and hydraulic data needed to normalize SARS-CoV-2 wastewater data. Normalized data was then compared to local COVID-19 case data provided by the public health entities. This collaborative workflow helped show that wastewater data may provide an early warning of COVID-19 peaks by four weeks, as described in Miyani et al (2021).
State of Massachusetts In collaboration with CDM Smith, the Massachusetts Department of Health (MaDPH) implemented facility and neighborhood programs with the objectives of identifying COVID-19 cases sooner than clinical testing and confirming absence of disease. 24-hour composite wastewater samples were collected three days per week and analyzed for SARS-CoV-2 and other sewage markers. Results were communicated via email to state and city officials, and COVID-19 case data were evaluated for correlation with wastewater virus concentrations.
Collaboration with the MaDPH allowed our team to target sampling sites that corresponded with areas of concern. For example, wastewater samples from a smaller community (<1000 residents) showed a rapid rise in SARS-CoV-2 concentration (Figure 3). Public health officials in the area used these data to support interventions including educational campaigns, free masks, and mobile testing units. Within a few weeks of the interventions, SARS-CoV-2 concentration in wastewater receded (Figure 3).
US Agency for International Development Collaborating with the USAID, CDM Smith helped develop city-scale surveillance programs in Amman, Jordan and Cairo, Egypt. These program building projects focused on analyzing existing research infrastructure to support sampling campaigns and analytical testing, implementing wastewater monitoring and action plans, training seminars, and data visualization dashboards. Interestingly, our work suggested that grab sampling methods could be used to gather comparable analytical results to composite sampling (Figure 4). Grab sampling is easier and less costly to perform, indicating this simple method could support rapid program start-up in areas with limited access to funding. However, the projects also revealed that global supply chain shortages for analytical equipment could impact program development. Therefore, development of simple, widely available analytical methods is important to deliver programs throughout the world.
Wastewater Surveillance Sampling Support
After careful planning of sampling sites and analytical method development, program managers require sample collection services that are safe, reliable, and cost efficient. Our work from several programs has revealed methods to improve the efficiency of wastewater sampling logistics.
US Department of Veterans Affairs and City of Chicago The United States Department of Veterans Affairs developed a program to monitor eight conjugate living centers (CLCs) throughout the U.S (CA, NC, PA(2), TN, TX, WA (2)). The goal of the program was to provide an early warning system to prevent outbreaks in CLCs. From January to June 2021, CDM Smith assisted in sample coordination, collection, and delivery to the VA analytical laboratories. The City of Chicago, Current Water, and others developed a program to monitor the City's collection system for evidence of SARS-CoV-2 to prevent COVID-19 outbreaks. CDM Smith assisted in sample coordination, collection, and delivery to analytical laboratories. Planning the logistics of sample delivery were critical to the success of these projects. Program managers and delivery service providers must coordinate early to prevent issues in sample delivery.
Conclusions and Recommendations
Wastewater surveillance is an effective tool to measure community-level biomarker data. The approach is being used effectively at many scales for COVID-19. CDM Smith's wastewater surveillance work revealed several important findings:
A successful program starts with collaboration between public health agencies, local officials, research agencies, and their partners.
Normalizing viral concentration data to other wastewater data is helpful to mitigate competing influences in the sewer system.
Wastewater surveillance data was used to inform specific public health actions such as awareness campaigns. International development of wastewater surveillance programs requires low-cost sampling and analytical methods that are widely available in the host country.
Planning and coordination is a critical step to ensure wastewater samples are collected and delivered in a cost-efficient manner.
Future applications of the approach include early identification and understanding of disease outbreaks, understanding antibiotic resistance, and addressing health disparities Widespread development of programs could provide public health officials a proactive tool to respond to disease outbreaks. The Centers for Disease Control and Prevention (CDC) established the National Wastewater Surveillance System (NWSS) to improve acceptance of the approach. Wastewater surveillance is being funded through a combination of federal, state, and local support.