SARS-CoV-2 in Wastewater

COVID-19 Wastewater Surveillance

COVID-19 Wastewater Surveillance Trend

This map of Virginia shows the locations and overall viral load trends of the wastewater collection sites enrolled in the Sentinel Monitoring Program. The outlines represent the Virginia Health Regions. The trend is indicated by the color of the ‘dot’. See legend below. Not all sites produce data every week, so there may be gray ‘No Trend Available’ dots. You can zoom in on the map to see the area covered by each sewershed.

Select the week you wish to view from the ‘Sample Collection Week’ dropdown menu. The default display will be the most recent week. The colors of the dots vary depending on the change in the trend from the previous week. When you hover over a sample point, a tooltip will pop up and display the following information:

• Virginia Department of Health Region (underlined and bolded)
• Sewershed
• Approximate Population Served
• Start of Sample Collection Week
• 1 Week Trend

Note: If you select a point, click it again to deselect it.

COVID-19 Wastewater Surveillance Percentiles

There can be some variability within each site’s viral load every week, thus we determine if viral load is high (red) or low (blue) based on what we have seen in the past. What is high for one site may not be high for another. This visual is created every week to reflect whether the viral load that week is higher or lower than the viral load for that site in the past. Each sample is assigned to one of 5 groups (lowest, lower, middle, higher, or highest). It answers the question, “How high or low are current viral levels at Wastewater Treatment Plant X compared to previous sample collections at Wastewater Treatment Plant X?” ‘Insufficient data’ indicates there are not enough data points to appropriately bin the viral loads into the five categories:

• Lowest
• Lower
• Middle
• Higher
• Highest

One year’s worth of data is presented in the chart. Use the dropdown menu to select the ‘Most Recent 6 Months’ or ‘Prior 6 months.’

Note: If you select a point, click it again to deselect it.

COVID-19 Wastewater Surveillance Viral Load and Cases

Use the ‘Pick a Health Region’ control to select a specific region. The default setting is for all sewersheds within a selected region to be displayed on the same plot. The data can be filtered down to view data for just one sewershed by clicking on the list of sewersheds. Another option is to hold the ‘Ctrl’ key down while selecting multiple sewersheds within the same region.

Note: In December 2021, the Chesapeake-Elizabeth plant was closed and all of its wastewater is now treated by the Atlantic plant.

SARS-CoV-2 Viral Load in Wastewater 

This box shows all the viral load data points for a selected sewershed.

When you hover over a sample point, a box will pop up and display the following information:

• Sewershed
• Approximate (Approx.) Population Served
• Sample Type (grab vs. 24-hour composite)
• Sample Collection Date
• Viral Load (trillion copies/day)

Reported COVID-19 Cases within Sewershed 

This graph shows all COVID-19 cases known to VDH for the selected sewershed. Cases are presented as the number of new COVID-19 cases reported that day.

If the viral concentration is below detection, a ‘+’ sign is shown.

• The ‘Sewershed’ legend will present the sewersheds in order of smallest to largest population.
• Note that the scale on the y-axis will change depending on how high or low the viral loads are for the selected sewershed(s). The history goes back to the start of the Sentinel Monitoring Program, September 2021.

Note: If you select a point, click it again to deselect it.

Utility Partners

The wastewater surveillance program would not exist without the cooperation of our utility partners. Our utility partners donate staff time to collect and package the samples for shipping every week to the Virginia state laboratory, DCLS. Their support of this program is a testament to their ongoing goals of protection of public health and the environment.

Our participating facilities: