cdc.gov/coronavirus

National Wastewater 

Surveillance System

Implementation for COVID-19 and Beyond

Amy E. Kirby, PhD MPH

National Wastewater Surveillance System Program Lead

Waterborne Disease Prevention Branch

Division of Foodborne, Waterborne and Environmental Diseases

Standards to Support an Enduring Capability in Wastewater 

Surveillance for Public Health Workshop

June 14, 2021
Wastewater Surveillance | Public Health Toolbox

§ Captures sub-clinical infections

§ Independent of healthcare-seeking behavior 

and testing access

§ Wastewater serves as an efficient 

pooled sample of community infection 

levels

§ Data available within days of viral shedding 

onset versus up to 2-week lag for other 

surveillance data
SARS-CoV-2 Wastewater Surveillance Evaluation

Reported wastewater data associated with reported cases ~6 days in the future. 

Timeseries Leading Indicator Analyses

Confirmed Cases SARS-CoV-2 in Wastewater
National Disease Surveillance | CDC‘s Role

§ Ensure data comparability across 

jurisdictions

§ Analyze data to provide public 

health interpretation and guidance

§ Summarize and make national data 

available for states and public

§ Support inter-health agency 

communication for public health 

action

NWSS DCIPHER Results Dashboard

1

3

2 4
Participation in NWSS is growing quickly

Cumulative Samples in DCIPHER

Since January 2021

Ø Currently, 36 ELC-funded jurisdictions totaling 

$223M for wastewater surveillance activities

Ø Additional $34M pending award 

Number of Samples

January February March April May

6000

4000

2000

10,000

8000

June
NWSS Communities of Practice

Health Departments

Host: CDC

106 participants from 21 

jurisdictions

§ Peer-to-peer learning

§ Data coordination, 

submission, & 

interpretation

§ Public health action

Laboratories

Host: Association of 

Public Health Laboratories

37 participating labs 

in 27 jurisdictions

§ Best Practices and Lab 

Startup Guides

§ Corporate pricing 

agreements

§ Workflow pilot projects

Utilities

Host: Water Environment 

Federation

517 registered facilities 

in 44 jurisdictions

§ Discussion board at 

nwbe.org

§ NWSS workshop at 

WEFTEC in October

§ Autosampler program
Successful Use of Wastewater Data for Response

State and local jurisdictions have used wastewater data to 

inform response decisions:

üIndependent confirmation of true increases or decreases 

in cases

üDistribution, siting of test capacity

üSurveillance data in communities where clinical testing is 

limited or not available

üNear-term forecasting of cases or hospital utilization

üMonitoring the impact of home testing
Targeted Use Cases | Potential early warning

Building-level applications:

§ Long-term care facilities

§ University dormitories

§ Correctional facilities

Potential benefits:

§ Early warning for new cases

§ More efficient 

§ Cheaper for routine surveillance

The Washington Post

CNN

Coloradoan
NWSS | Facility-Level Surveillance

Prisons

§ At least 4 states include prisons in 

their current surveillance network

§ Evaluation project of on-site 

wastewater testing for 

correctional facilities through 

December 2021. Coordinated by 

Water Environment Federation 

Long Term Care Facilities

§ Internal method evaluation 

study initiating early 2021

§ Contract with University of 

Kentucky to evaluate impact 

of plumbing design and 

sampling strategy at LTCFs

Universities

§ ~30 universities 

§ Providing TA to universities 

§ Webinar to facilitate information 

sharing between universities
SARS-CoV-2 Variant Tracking in Wastewater

§ Interpretation is limited by 

– fragmented genomes present in wastewater 

– unknown method sensitivity

– potential variation in shedding dynamics 

between variants

§ Wastewater sequencing may be useful for variant detection and tracking but 

unlikely to be useful for variant discovery

§ Pursuing multiple avenues to secure wastewater sequence data for evaluation

§ Working with NCBI to establish database and preliminary analysis pipeline for 

wastewater SARS-CoV-2 sequence data
NWSS| Challenges

§ Decentralized wastewater systems will not be captured

– ~25% of US residences are not connected to sewer

– Onsite treatment increasingly common at correctional 

facilities, universities

§ Appropriate interpretation of data in low incidence 

settings

– Negative results do not indicate absence of cases

§ Barriers to implementation and sustainability

– Hesitance to implement a “pilot” program

– Building testing capacity in public health labs
NWSS | Beyond COVID

Flexible surveillance platform for 

multiple health targets

• Antibiotic resistance

• Foodborne infections

• Emerging infections

Potential additional targets
Emergency Response

Local or regional activations in the wake 

of natural disasters to detect outbreaks

Emerging Infections

Short-term activations to assess the 

prevalence and distribution of emerging 

threats

Pandemic Preparedness

Rapid activation and increased sampling 

frequency to detect pandemic spread into 

communities to target mitigation efforts

Bioterrorism

Rapid local or regional activation with 

increased sampling frequency to detect 

and track bioterrorism threats

NWSS | Beyond COVID

Nimble structure to rapidly adapt to changing 

public health needs

For more information, contact CDC

1-800-CDC-INFO (232-4636)

TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the 

official position of the Centers for Disease Control and Prevention.

Contact the NWSS team at 

NWSS@cdc.gov