My Healthy Community

Overview

Wastewater monitoring is an early detection tool that can help communities prepare for and respond to increasing cases of infectious diseases. People with certain infections shed pieces of the virus when they use the bathroom, shower, or wash their hands, even if they don't have symptoms. Those pieces of virus travel down the drain through the sewage system. Before wastewater is treated, operators take samples to send out to a laboratory. Labs test these samples to detect and report on different types of infection circulating in a community. Public health officials use wastewater data to better understand disease trends in communities and target interventions, such as providing guidance on how to prevent infections or increasing testing or vaccination options.

The Scoop on Poop

We can test more, for less money

Wastewater surveillance is a cost-effective tool to passively and equitably test communities for diseases and pathogens. In 2020, it cost Delaware $30 million for 200,000 COVID-19 tests.

View DHSS Wastewater Surveillance Infographic

Key Data & Reports

Wastewater Surveillance in Delaware

Key Wastewater Surveillance Indicators

Delaware

COVID-19 Wastewater Viral Activity Levels

5/11/2025 - 5/17/2025

Low

viral activity level of 1.7

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In Delaware, levels of COVID-19 in wastewater are currently low.

Very Low Moderate Very High

Delaware

Flu Wastewater Viral Activity Levels

Week 20 (5/11/2025 - 5/17/2025)

Very low

viral activity level of 1.3

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In Delaware, levels of Flu in wastewater are currently very low.

Very Low Moderate Very High

Delaware

RSV Wastewater Viral Activity Levels

5/11/2025 - 5/17/2025

High

viral activity level of 4.7

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In Delaware, levels of RSV in wastewater are currently high.

Very Low Moderate Very High

About the Data

Wastewater monitoring can detect viruses spreading throughout the community earlier than clinical testing and before people who are sick go to their doctor or hospital. It can also detect infections without symptoms. It can also detect infections without symptoms. If you see increased wastewater viral activity levels, it might indicate that there is a higher risk of infection.

About the Wastewater Viral Activity Level

The wastewater viral activity level (WVAL) indicates whether the amount of virus in the wastewater is very low, low, moderate, high, or very high. The wastewater viral activity levels may indicate the risk of infection in an area. The wastewater viral activity levels are categorized as follows:

Up to 1.5 - Very Low
Greater than 1.5 and up to 3 - Low
Greater than 3 and up to 4.5 - Moderate
Greater than 4.5 and up to 8 - High
Greater than 8 - Very High

Calculating Wastewater Viral Activity Level

The Wastewater Viral Activity Level is a calculated measure that allows us to aggregate wastewater sample data to get state/territorial, regional, and national levels and see trends over time. For more information about how Wastewater Viral Activity Level is calculated, please see the CDC's website.

Data Sources

Wastewater Data

Citation: Centers for Disease Control and Prevention (CDC). National Wastewater Surveillance System (NWSS). https://www.cdc.gov/nwss/

View or download this dataset

Explore Wastewater Monitoring Data

Wastewater Levels for COVID, RSV, and Influenza (2022-2025)

viral activity level

Delaware

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Please note: Counts of less than 11 are suppressed. If the population is sufficiently large, 0 counts may be shown. Rates based on counts less than 20 may be unstable.

About the Data

Wastewater monitoring can detect viruses spreading throughout the community earlier than clinical testing and before people who are sick go to their doctor or hospital. It can also detect infections without symptoms. It can also detect infections without symptoms. If you see increased wastewater viral activity levels, it might indicate that there is a higher risk of infection.

About the Wastewater Viral Activity Level

The wastewater viral activity level (WVAL) indicates whether the amount of virus in the wastewater is very low, low, moderate, high, or very high. The wastewater viral activity levels may indicate the risk of infection in an area. The wastewater viral activity levels are categorized as follows:

Up to 1.5 - Very Low
Greater than 1.5 and up to 3 - Low
Greater than 3 and up to 4.5 - Moderate
Greater than 4.5 and up to 8 - High
Greater than 8 - Very High

Calculating Wastewater Viral Activity Level

The Wastewater Viral Activity Level is a calculated measure that allows us to aggregate wastewater sample data to get state/territorial, regional, and national levels and see trends over time. For more information about how Wastewater Viral Activity Level is calculated, please see the CDC's website.

Data Sources

Wastewater Data

Citation: Centers for Disease Control and Prevention (CDC). National Wastewater Surveillance System (NWSS). https://www.cdc.gov/nwss/

View or download this dataset

Investigate Wastewater Viral Concentration by Infectious Disease (Last Week)

Map of Delaware showing Wastewater Viral Concentration per Sewershed (5/11/2025 - 5/17/2025)

Select Investigation

Map Results Data Table

Sewersheds	COVID-19 Wastewater Viral Concentrationweekly averages of million viral copies per person per day
MOT Middletown WWTP	31.1
Seaford WWTP	24.7
Lewes WWTP	22.9
Kent County WWTP	8.8
Wilmington WWTP	6.2
Georgetown WWTP	2.9
Selbyville WWTP
Delaware City WWTP
Port Penn WWTP

About the Data

Wastewater monitoring can detect viruses spreading throughout the community earlier than clinical testing and before people who are sick go to their doctor or hospital. It can also detect infections without symptoms. It can also detect infections without symptoms. If you see increased wastewater viral activity levels, it might indicate that there is a higher risk of infection.

About Sewersheds

A sewershed is the area served by a wastewater treatment plant (WWTP).

Data Sources

Wastewater Data

Citation: Centers for Disease Control and Prevention (CDC). National Wastewater Surveillance System (NWSS). https://www.cdc.gov/nwss/

View or download this dataset

Sewers in Delaware

Here are images of sewer manholes from different sewersheds in Delaware.

Dover

Laurel

New Castle County

Seaford

Rehoboth Beach

Sanitary Sewer

Sussex County

Wilmington

Additional Information

Wastewater Surveillance in Delaware

Resources

National Wastewater Surveillance System (NWSS)

CDC's NWSS works with health departments to track viral levels in wastewater so communities can act quickly to prevent the spread of infectious diseases. NWSS is transforming independent local efforts into a robust, sustainable national surveillance system.

CDC Wastewater Viral Activity Level

CDC’s National Wastewater Surveillance System (NWSS) collects, analyses, and shares data on multiple viruses and bacteria in wastewater, including SARS-CoV-2, influenza A, and mpox. CDC updates the data on public wastewater data dashboards.

Data Sources

Wastewater Data

Citation: Centers for Disease Control and Prevention (CDC). National Wastewater Surveillance System (NWSS). https://www.cdc.gov/nwss/

View or download this dataset

Privacy

In releasing this information, Delaware aims to provide information that can be helpful to local communities as they work to improve public health. However, the protection of the confidentiality of our citizens is of paramount importance. To that end, counts of less than 11 are not presented. An outside expert has reviewed the platform to ensure it complies with the HIPAA privacy rule (45 CFR 164.§514(b)).