Wastewater is used water that flows down the drains and enters the sewer system from homes, businesses, and other facilities. It often contains a mix of substances, including:

• Human waste (urine and feces) that may carry bacteria and viruses

• Pharmaceuticals

• Personal care products

• Chemicals

• Nutrients

• Other materials from household or industrial sources

Wastewater surveillance is a public health tool used to track the presence of pathogens and substances in a community. It involves collecting samples from wastewater treatment plants and testing them for genetic material from viruses, bacteria, and other substances shed by people who are infected.

Wastewater surveillance helps track infections in a community and provides valuable data to inform early warning efforts and guide public health actions.

Viruses and bacteria can enter the sewer system after a person uses the bathroom or other running water. The used water and sewage then travel through pipes to a wastewater treatment plant, where wastewater surveillance begins.

Here, wastewater treatment plant operators collect wastewater samples and ship them to laboratories. Then, laboratory staff process the samples and analyze them for the presence of pathogens like viruses and bacteria. This data is sent to epidemiologists at health departments, who interpret the data and share the results with the public through dashboards, reports, and alerts.

Wastewater surveillance helps measure pathogens and substances, such as the viruses that cause COVID-19, influenza, RSV, polio, and hepatitis, within the area served by a wastewater treatment plant (known as a sewershed). Conducting wastewater surveillance allows public health officials to monitor disease trends, detect outbreaks early, and make informed public health decisions to protect community health.

Wastewater data is used alongside other public health data to inform decision-making and prompt early action. Because wastewater surveillance allows for early detection of pathogens in communities, it helps guide preventative actions and alerts the public of potential outbreaks.

Public health officials use wastewater data to:

• Respond to outbreaks

• Decide optimal locations for disease testing

• Notify hospitals and health care facilities when there might be more patients

• Direct health departments’ resources to areas of greatest need

Wastewater surveillance enhances our ability to understand and predict infections within communities. This is possible by comparing wastewater surveillance data with other data metrics like clinical cases and hospitalizations data.

Wastewater surveillance can offer early detection of some diseases at a community-level, without relying on people having symptoms or getting tested.

Wastewater surveillance is an efficient process. A single sample represents the entire community. Data results are available 5-7 days after samples are collected, allowing health departments to analyze and interpret disease trends in a timely manner.

Wastewater surveillance is adaptable. In the event of an outbreak, a wastewater surveillance network can increase sampling frequency in high-risk areas and neighboring communities. Wastewater surveillance can also be done upstream from a wastewater treatment plant to better understand the risk of a community. In addition, analysis of one wastewater sample can be expanded to track the presence of multiple pathogens and substances. This was demonstrated during the 2022 polio outbreak in New York.

Wastewater surveillance does not capture households outside of public sewer systems. This is because samples from wastewater treatment plants do not typically include wastewater from septic tanks. However, around 80% of U.S. households are served by public sewer systems, so wastewater surveillance is feasible and implementable in many communities.

Wastewater surveillance data cannot tell us the number of infected individuals in a community. Instead, it provides community-based data on the fluctuating levels of viruses or bacteria present in a population, allowing public health officials to monitor infection trends and identify potential outbreaks.

Wastewater surveillance data is affected by tourism and travel. Wastewater samples are representative of all people within a treatment plant’s service area, or sewershed, at a given time. As people leave or enter a sewershed, the population represented by its wastewater samples changes accordingly.

Wastewater surveillance programs need funding and support for their long-term sustainability. Investing in wastewater surveillance is cost-effective - It just takes one wastewater sample to gain insight on the current state of a community’s health and test for the presence of multiple pathogens and substances.

No - Wastewater surveillance does not pose a risk to individual privacy. Wastewater data is anonymous and cannot be traced back to specific people or households. Each sample contains combined wastewater from an area served by a treatment plant. Since the samples represent an entire community, individual information cannot be identified. This means that wastewater surveillance can be conducted with no burden to individuals while fully protecting their anonymity.

Yes, there are ethical guidelines for public health wastewater surveillance. In 2020, the Canadian Water Network published “Ethics and communications guidance for wastewater surveillance to inform public health decision-making about COVID-19." This document references the World Health Organization’s 2017 publication on ethical guidelines for public health surveillance, highlighting specific principles that are applicable to wastewater surveillance. Additionally, in 2025, the Association of State and Territorial Health Officials released the report “Framework for Addressing Ethical Considerations in Infectious Diseases Public Health Wastewater Surveillance.” Key topics outlined in this framework include discussions of privacy, stigma, and data stewardship in wastewater surveillance.

For New York State wastewater surveillance data, click the links below:

• COVID-19 Wastewater Concentration Dashboard

• COVID-19 Wastewater Variant Dashboard

• COVID-19 Wastewater Surveillance Weekly Summary Report

• NYS COVID-19 Wastewater Surveillance Open Data

• NYS Wastewater Surveillance Network GitHub

For national wastewater surveillance data, navigate to the CDC National Wastewater Surveillance System (NWSS) links below:

• CDC’s National Wastewater Surveillance System (NWSS)

• COVID-19 National Wastewater Data

• Influenza A National Wastewater Data

• RSV National Wastewater Data

• Measles National Wastewater Data

• Mpox National Wastewater Data

• CDC COVID-19 Wastewater Surveillance Open Data

For New York State, you can find more information and resources about wastewater surveillance by clicking the links below:

• Main pages:

  • NYS Wastewater Surveillance Network

  • NYSDOH Wastewater Surveillance

• Additional Resources:

  • Communications Library

  • Our Recent Publications

  • Informational Wastewater Surveillance Video

The National Wastewater Surveillance System (NWSS) is a CDC-coordinated program that supports wastewater surveillance efforts across the United States. Health departments report their local COVID-19, influenza A, RSV, and mpox wastewater data to NWSS. This data is then shared with the public through the CDC NWSS website.

The CDC provides funding to support health departments’ wastewater surveillance efforts through the Epidemiology and Laboratory Capacity for Prevention and Control of Emerging Infectious Diseases (ELC) Cooperative Agreement. In addition to financial support, NWSS offers technical assistance to health departments that are implementing or developing their wastewater surveillance programs. The CDC NWSS team also facilitates the Health Departments Community of Practice (CoP), which allows the sharing of best practices and advancements in the use of wastewater surveillance data.

A NWSS Center of Excellence (CoE) is a regional leader in wastewater surveillance. NWSS Centers of Excellence are led by public health departments in partnership with an academic institution, and they support states and territories through trainings, consultations, and technical assistance. The six NWSS Centers of Excellence are:

• California Center of Excellence

• Colorado Center of Excellence

• Houston Center of Excellence

• New York Center of Excellence

• North Carolina Center of Excellence

• Wisconsin Center of Excellence