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Updated: June 25, 2026

What is Wastewater Surveillance?

Wastewater surveillance monitors community health by analyzing water from sewage systems. This method can detect genetic material from pathogens and other substances present in wastewater, helping public health officials understand disease presence and trends within communities. When used alongside other surveillance methods, this tool contributes to our understanding of community health patterns.

Why Monitor Wastewater?

Wastewater can:

  • Detect viruses from entire communities, including people without symptoms
  • Show changes in disease trends before we see increases in doctor visits
  • Provide an early warning system for public health

How Does It Work?

People infected with certain pathogens: germs that cause diseases, can shed genetic material in their waste, sometimes before, during, or after experiencing symptoms. Laboratory analysis can detect this material in wastewater samples, allowing public health officials to:

  • Monitor pathogen levels in communities
  • Track changes in detection rates over time
  • Study relationships between wastewater data and other public health indicators (like emergency department visits, hospitalizations, and clinical cases)
  • Support public health decision-making when combined with other surveillance data sources

Sample Collection and Analysis Include:

  • Automated 24-hour composite sampling
  • Advanced molecular testing methods
  • Quality control protocols
  • Standardized reporting procedures

South Carolina’s Wastewater Surveillance Program Current Monitoring

Our state conducts regular testing for multiple pathogens, including:

  • SARS-CoV-2 (COVID-19)
  • Influenza A/B
  • Respiratory Syncytial Virus (RSV)

Testing occurs at the South Carolina Public Health Laboratory using molecular detection methods. Additional surveillance at select sites through CDC-contracted laboratories includes monitoring for mpox.

Data Usage and Impact

The program provides:

  • The potential for early warning of disease outbreaks
  • Tracking of community transmission levels
  • Support for public health decision-making
  • Data sharing with CDC's National Wastewater Surveillance System

Results for South Carolina can be found at: Wastewater Monitoring Data.

Wastewater Surveillance Dashboards

This dashboard, a part of the Respiratory Disease Dashboard=, shows the Wastewater Viral Activity Level (WVAL) for COVID-19, Influenza A and RSV across South Carolina by week during the current respiratory season.

View the Respiratory Disease Wastewater Dashboard

This dashboard shows measles‑positive wastewater detections across South Carolina, providing weekly updates to support monitoring of measles activity statewide.

View the Measles Wastewater Dashboard

Dashboard FAQs

The Wastewater Viral Activity Level (WVAL) shows how much virus is currently in wastewater compared to typical baseline levels. Higher values suggest increased virus presence in the community.

The measure is calculated through a complex analysis of the raw data to determine how many standard deviations each sample is from what is historically typical. Values are categorized as Very Low, Low, Moderate, High or Very High.

WVAL levels are calculated by finding the number of standard deviations each sample is from what is historically typical. Values are categorized as:

  • Very Low: Minimal virus detected
  • Low: Low virus activity
  • Moderate: Moderate virus activity
  • High: High virus activity
  • Very High: Very high virus activity

Thresholds for each pathogen are:

  • COVID-19:
    • Very Low (≤2)
    • Low (2-3.4)
    • Moderate (3.4-5.3)
    • High (5.3-7.8)
    • Very High (>7.8)
  • Influenza A:
    • Very Low (≤2.7)
    • Low (2.7-6.2)
    • Moderate (6.2-11.2)
    • High (11.2-17.6)
    • Very High (>17.6)
  • RSV:
    • Very Low (≤2.5)
    • Low (2.5-5.2)
    • Moderate (5.2-8)
    • High (8-11)
    • Very High (>11)

Each line represents a different virus (COVID 19, Influenza A, RSV). Each point shows the median WVAL across all wastewater treatment plants in South Carolina for that week.

Important notes:

  • This data represents one part of disease surveillance and works alongside other health indicators
  • Data is updated weekly

Partnerships and Collaborations

  • Local utilities and municipalities
  • Academic institutions
  • CDC National Wastewater Surveillance System
  • Other state and territorial health departments, including the NWSS Centers of Excellence

Future Direction

  • Expand monitoring sites statewide
  • Implement a near real-time data reporting system
  • Expand pathogen monitoring capabilities

Frequently Asked Questions

Water samples are collected at the wastewater utility by machine or by hand. Samples are stored, packaged, and shipped to the laboratory for testing. The laboratory analyzes the sample and provides the concentration of certain infectious agents like SARS-CoV-2, the virus that causes COVID-19.

Wastewater surveillance provides community-level health monitoring without requiring individual testing. Key advantages include:

  • Cost-effective population monitoring compared to individual clinical testing
  • Early indication of disease presence in communities
  • Anonymous data collection that protects individual privacy
  • Detection of pathogens regardless of whether people seek health care
  • Ability to rapidly detect emerging health threats

Wastewater surveillance provides reliable trending data at the community level, validated against clinical metrics and other surveillance methods.

Sample processing and analysis typically takes 24-48 hours, with results reported to public health officials upon validation.

Public health officials analyze the data alongside other indicators to determine appropriate public health responses and resource allocation.

No. Wastewater surveillance only provides community-level data. It cannot identify individuals, households, or specific locations within a sewage system's service area.

Samples are destroyed after analysis following standard laboratory protocols. No wastewater samples are stored long-term.

The testing process uses chemicals called standard laboratory reagents to detect genetic material from viruses. These chemicals are contained within the laboratory and don't affect the water system.

Our program follows CDC guidelines and uses methods similar to other state programs. We regularly collaborate with other states to share best practices and improve our surveillance methods.

Yes. The CDC NWSS public dashboards for COVID-19, influenza A, mpox, and RSV show data for participating wastewater treatment plants. You can search by county or facility name to find information for your area.

While we currently focus on respiratory viruses, the technology could potentially monitor for:

  • Antimicrobial resistance
  • Foodborne illnesses
  • Emerging pathogens
  • Other community health indicators

For more information, please visit the CDC's National Wastewater Surveillance System (NWSS).