cdc.gov/coronavirus

Available Data Tools: National Wastewater 

Surveillance System

Waterborne Disease Prevention Branch

Division of Foodborne, Waterborne and Environmental Diseases

15 June 2021
NWSS System overview

DCIPHER
Participation in NWSS is growing quickly

Cumulative Samples in DCIPHER

Since January 2021

Number of Samples

Ø Currently, 36 ELC-funded jurisdictions totaling 

$223M for wastewater surveillance activities

Ø Additional $34M pending award will increase 

number of jurisdictions

January February March April May

6000

5000

4000

3000

7000

9000

8000

Current
Data elements

1. Wastewater data – minimum requirement

– CSV upload

2. Sewershed spatial boundaries

3. Sewershed COVID-19 case data 

4. Laboratory protocols
DCIPHER features

§ Data Collation and Integration for Public Health Event Response platform

§ Unified system for data submission, management, and analysis

– Merging of multiple data submission flows 

– Integration of disparate data sources: HHS Protect, other DCIPHER surveillance systems

– Version control

– Build scheduling

– Analysis code

– Dashboards

– Document repository

– User access permissions 

– Built-in tools for quality control 

– Collaboration and communication
DCIPHER features: receive and merge multiple data 

streams
DCIPHER features: exploration and quality control
DCIPHER features: internal dashboard

1

2

3

4
Analytics: wastewater normalization

§ Current approach

– Flow and population normalization of SARS-CoV-2 RNA concentrations

– Adjusted by site-specific median RNA recovery

§ Standardization (and inter-laboratory comparison) need:

– Endogenous control 

– Matrix spike recovery control

– PCR type (RT-qPCR vs RT-dPCR) with common standards
SARS-CoV-2 

(million copies/person/day)

Analytics: overlaying wastewater & cases § Contextualizes wastewater data § Date considerations § Smoothing – data frequency 

impacts smoothing approach

§ Scaling – Currently believe shape of curve, not 

absolute values, is what’s reliable

– Additive (not just multiplicative) changes 

matter

Case incidence, per 100k
SARS-CoV-2 

(million copies/person/day)

Case incidence, per 100k

Analytics: wastewater trends & alerts § Trend analysis – Sustained trend: 5 measurements – Trend: 3 measurements – Linear regression – Log transform – Inverse variance weighting – Significance level: 0.05 § Alerts analysis – Value higher than expected given 5 

previous measurements

–1-sided prediction interval

Alerts
Analytics: wastewater spatial representation

§ Metric must be comparable 

across sites: trends

§ Sewershed boundaries used if 

available

§ Sampling location zip code 

used if not

SARS-CoV-2 wastewater trends
Analytics: under consideration § Measure of similarity between 

SARS-CoV-2 wastewater levels 

and case rates

§ Site-specific measure of 

relative SARS-CoV-2 level

SARS-CoV-2 in wastewater

Case incidence

Time
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.

NWSS@cdc.gov