Wastewater Sampling for COVID-19
In September 2020, the CDC launched the National Wastewater Surveillance System (NWSS) to coordinate and build the nation’s capacity to track the presence of the virus that causes COVID-19, in wastewater samples collected across the country. Sampling efforts around the country have determined that by measuring COVID-19 in wastewater on a routine basis allows predictive trends to be observed. Any increases or decreases in COVID-19 in the samples are 'leading indicators' of increases or decreases in active cases of COVID-19 in the population being studied.
CDC expanded the program nationally in February and is working with health departments around the country, including the NH Department of Health and Human Services (DHHS) to track COVID-19 virus levels in wastewater so communities can act quickly to prevent the spread of COVID-19.
NH DHHS launched a program in May 2022 to regularly test wastewater levels at around two dozen of the 78 municipal wastewater treatment plants in New Hampshire. Portsmouth is one of those municipalities.
Both of the City’s Wastewater Treatment Facilities (WWTF) -- Peirce Island and Pease -- are participating in the NH DHHS project. Initially a lab at UNH is processing the samples and NH DHHS expects to process samples in its own labs eventually. The University of New Hampshire has been testing its own samples independently since the summer of 2020. Their researchers have also shared their method with long-term care facilities and other wastewater treatment facilities in the state.
Peirce Island WWTF sent its first sample for testing on June 7, 2022. The Pease WWTF started sampling the week of June 13, 2022. Each facility will be sending out weekly samples until the project ends.
While it is not possible to determine trends until several weeks of reports are collected, the first Peirce Island WWTF test results are posted on below, and future test reports will also be posted to this page.
A few notes on reading the reports:
- The N1 and N2 will rise and fall as the community increases or decreases in infection levels.
- As this is the first report Portsmouth has received it is impossible to show trends. But the longer the City monitors, the more useful the wastewater COVID trends will be in predicting what’s to come during the week in terms of new infections and what the timing is to compare community infections in relation to detection in the wastewater.
- For this first report, SARS-CoV-2 viral biomarkers were detected in the wastewater at levels above method detection limits. With future reports, conclusions from the data can be drawn.
- For the latest report on the CDC assessment of community risk and NH DHHS data, in order to compare community infections and the wastewater sampling, go to the COVID-19 INFO page, and refer to the Regional COVID-19 bulletin board, posted to each Wednesday.