SCAN Logo

What It Is

SEWAGE AS SENTINEL

SCAN’s monitoring provides a comprehensive view of COVID-19 in a community

What It Is

What We Flush Down the Toilet Can Tell Us a Great Deal

We call it “wastewater,” but we don’t want to waste it. The information it holds about COVID-19 is invaluable.

It can tell us about infection across an entire community within 24 hours.

In early 2020, scientists at Stanford, the University of Michigan, and Emory developed a method to find the COVID-19 virus (SARS-CoV-2) in sewage and to determine what it means about the level of infection in a community.

In November 2020, they partnered with wastewater treatment plants in eight California communities and the life sciences research company Verily to sample and analyze wastewater solids. Alexandria Boehm of Stanford and Marlene Wolfe of Emory lead the effort.

Proven Tool, Growing Use

Scientists have known the potential for wastewater-based epidemiology for decades. Israel has monitored wastewater for polio since the late 1980s. The COVID pandemic is the first time wastewater has been used to track a respiratory disease. SCAN has added to the field through its published papers and its protocols available online.

Other communities in North America are using a similar approach to wastewater monitoring, including the Yale COVID-19 Wastewater Tracker and Ottawa, Canada.

SCAN also is a centerpiece of the Wastewater Scan Consortium, whose academic, commercial laboratory, data, and pharmaceutical collaborators want to spread use of its analytic methods and public reporting models.

How It Works

Simple, Sensitive, Complete

SCAN’s process starts with easy-to-implement steps:

Pipe icon

Collecting samples that have settled in a treatment plant’s primary tank. The samples are stored and transported at near-freezing temperatures.

Virus icon

By testing solids, SCAN can identify as few as two infected people among 100,000. SCAN has found 1,000 times more virus genes in a solid sample compared to liquid wastewater.

Houses and Roads Icon

SCAN’s monitoring provides a comprehensive view of COVID-19 in a community. It isn’t tied to if individual COVID tests are available, who takes them, where they are available, or when they are offered. The if, who, when, and where of wastewater is almost everyone by necessity, almost every day, in almost every household and business.

What It Shows

Quick Turnaround

SCAN’s analysis is speedy, with results available within just 24 hours. An infected person’s waste shows genetic markers of the COVID virus that are contributed to the wastewater sample without the person needing to realize that they are ill, seek out a test, or wait for test results. 

Quicker turnaround for results and earlier signs of infection can warn public health officials of a coming rise in cases before those cases show up as clinical results. They can respond, for example deploying more diagnostic tests to identify individuals who are infected.

Early Warning 

Graphic of Early Indicator Results

Wastewater as an Early Indicator

Working closely with practitioners in sewage treatment and public health, SCAN developed a way to monitor levels of the COVID-19 virus (SARS-CoV-2) in wastewater that is simpler than large-scale diagnostic testing, gives an accurate population-level view, and delivers results more quickly. See how SCAN reports its data here.

Pipe connecting two houses icon


People excrete genetic markers of COVID-19 virus, often before they feel sick or seek a diagnostic test…

Water drain icon

Sewage System

Sewage Plant icon


Solids that settle in a Publicly Owned Treatment Works (POTW) tanks are sampled at least…

Delivery truck icon

Transport to Lab

Person in front of laptop next to test tubes icon


SCAN tests for virus RNA using digital droplet PCR technology. SCAN can identify as few as one…

Tech globe icon

Results Uploaded

Person using laptop icon


SCAN shares results with health and other officials and the public within 24 hours. Its dashboards…

 

How to Join

National Expansion

Verily Life Sciences LLC, the laboratory partner for SCAN’s research, is offering communities across the United States a new opportunity to monitor their own wastewater for COVID-19 using SCAN’s method. Participation in the program called WastewaterScan powered by Verily will last for at least one year. The program provides testing, sampling supplies and shipping free of charge to treatment plants.

Sewage treatment plants will get kits to sample wastewater solids three times a week and ship them for lab analysis at no cost. Verily will report results through an online dashboard within 48 hours of receiving samples.

Communities can sign up for WastewaterScan powered by Verily here.

Learn more about WastewaterScan by powered Verily here. See the sampling kit and process here.

See data from communities across the country here.


News & Events

Return to top

People excrete genetic markers of COVID-19 virus, often before they feel sick or seek a diagnostic test. A sewage system serves an entire community, so wastewater is a comprehensive sample created routinely – no one is left out.

Solids that settle in a Publicly Owned Treatment Works (POTW) tanks are sampled at least three times a week and sent for lab analysis. Solids carry 1,000 times more virus markers than liquid wastewater, which allows accurate results from small samples.

SCAN tests for virus RNA using digital droplet PCR technology. SCAN can identify as few as one or two cases per 100,000 people served by the wastewater treatment plant. SCAN can provide data on overall infection and trends over time, as well as on specific variants.

SCAN shares results with health and other officials and the public within 24 hours. Its dashboards show results over time in a way that’s comparable and understandable. Based on the information, health officials can plan and adjust tactics to reduce the spread of COVID-19.