Life at the Intersection of Engineering and Public Health: Wastewater-based Disease Surveillance
By Jim Chastain, PE, PhD, BCEE, MPH | Principal/Senior Consultant
Public Health Week provides an opportunity to step back and recognize the value public health professionals contribute to our quality of life. Public health includes a broad mix of disciplines dedicated to identifying, preventing, and responding to threats to the health and well-being of our communities.
Without question, the most prominent example of a public health threat was the recent COVID-19 outbreak. While political factors created significant debate, the fact that the nation’s public health network was able to monitor and identify trends was a tremendous aid in assessing the overall impacts and trends in the disease. Did you know that wastewater engineers played an emerging role in providing real-time tracking of the disease in larger cities? Yes, indeed!
Early in the COVID outbreak, the CDC, in conjunction with major wastewater plants and state health departments, began to monitor plant influent for evidence of the COVID-19 virus. Infected individuals with and without symptoms shed viruses and discharge them in their domestic wastewater. With appropriate testing, these trace amounts can be detected to predict whether COVID levels were increasing or decreasing, thus providing an early warning system. Unlike other types of surveillance, this system works whether or not people have access to healthcare systems or choose to test. Because roughly 80% of the U.S. population is connected to municipal wastewater systems, it is exceptionally reliable
This process has been so promising that the CDC established a National Wastewater Surveillance System (NWSS) in September 2020 and is working to connect wastewater systems, health departments, and epidemiologists for a robust, sustainable national system. In its infancy now, wastewater systems may become the center for the application of whole-genome sequencing, which can be used to decode information on all manner of infectious disease pathogens. It’s only because these laboratory methods are increasingly available that this methodology is even possible. It’s still quite expensive and technically challenging to utilize, but those barriers are slowly coming down. This means that in the future, the humble wastewater plant that most people shun may once again become a centerpiece of community public health protection.
The initial success of the initiative has planners looking for other ways to use wastewater ‘fingerprinting’ as a means of understanding community health characteristics. Again, the wastewater system provides public health professionals with a potential composite record of what is happening within the sewer service area. With the experience gathered to date, the CDC notes the following:
1. Wastewater surveillance data is most useful used with other data.
Understanding the composition, location, and history of an area are essential attributes to understanding trends. This is especially important with comparing findings to other communities.
2. More data over time can give better, more reliable trends.
Correlation with changes in the community and the development of more robust detection databases can provide baseline and/or reference guidance to interpret new findings.
3. Early Warning Systems, such as wastewater surveillance, can detect small changes as a signal for early action.
Like other environmental metrics, when baseline levels are established and monitored, even small changes can translate into a call for action.
This novel application of laboratory science is only one example of how engineers provide important connections in the public health safety net. The fact that a wastewater system exists in the first place, is a prime example of a public health intervention provided by civil and environmental engineers. Previously known as ‘public health engineers’ these professionals are the primary reason that cholera, typhoid fever, and many other diseases, have been relegated to the history books in this country.
If you are interested in learning more about wastewater epidemiology or the National Wastewater Surveillance System (NWSS) follow the links below.
Wastewater Surveillance: A New Frontier for Public Health | Centers for Disease Control and Prevention
Wastewater network infrastructure in public health: Applications and learnings from the COVID-19 pandemic | PLOS Global Public Health
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About the Author
Dr. Jim Chastain, PE, MPH, BCEE, has over 50 years of professional experience in engineering and planning as a consultant to both government and private industries. His expertise includes computer simulation modeling of hydraulic systems, feasibility analysis, and water infrastructure design and permitting.
Jim currently serves as principal and senior consultant. On a day-to-day basis, he continues to work as an environmental engineer, focusing on studies related to water, wastewater, or water resource needs/strategies for clients. He also invests professionally in the entire Chastain-Skillman team and the clients he has spent his career working alongside.
About Chastain-Skillman
CS is a leading engineering firm headquartered in Lakeland, FL, with satellite offices in Orlando, FL, and Nashville, TN. Established in Lakeland in 1950, our company provides Civil Engineering, Water/Wastewater Engineering, Land Surveying, Geology/Hydrogeology, and Construction Management/Inspection services.
At CS, we treasure our role in creating thriving communities, always respecting the impact our work has on their foundations and their futures. For more information, visit chastainskillman.com.
