About
Why focus on the Central Valley?
Wastewater monitoring of infectious diseases has proven to be a powerful tool to inform public health. The Healthy Central Valley Together (HCVT) project aims to expand wastewater testing for infectious diseases in the Central Valley of California to support greater health equity. In 2021, we reviewed access to wastewater-based infectious disease data in California and found a need to extend wastewater monitoring to rural and disadvantaged communities in the Central Valley, a richly diverse agricultural region in the heart of California. HCVT launched with a mission to help fill this data gap.
HCVT began in Summer 2021 when partnerships were established between public health departments in three counties, wastewater facilities in eight cities, and researchers at the University of California campuses in Davis and Merced. HCVT adopted the highly sensitive wastewater monitoring approach and methods developed by WastewaterSCAN based at Stanford University. HCVT joined the WastewaterSCAN network in December 2022, enabling expansion of wastewater analysis in the Central Valley from COVID-19 to a broader suite of infectious diseases. Together, we are using wastewater to generate data on community prevalence of COVID-19, flu, RSV and other diseases that inform public health action in Merced, Stanislaus, and Yolo counties.
HCVT offers week-to-week statistical interpretations of wastewater data displayed on our website to inform public health action. If you are interested in receiving weekly updates about the data please email [email protected] with SUBSCRIBE ME in the subject line.
Lead Researchers
Heather N. Bischel
University of California, Davis
Dr. Heather N. Bischel is an Associate Professor of Civil and Environmental Engineering at UC Davis. Dr. Bischel’s research aims to support public and environmental health through safe and effective water and wastewater management. In 2020, Dr. Bischel launched the wastewater-based disease surveillance program of Healthy Davis Together (HDT), a collaboration between the City of Davis and UC Davis to combat COVID-19. The overall success of HDT and its wastewater program earned national recognition, with media highlights in WIRED, The Wall Street Journal, and The Washington Post.
Colleen Naughton
University of California, Merced
Dr. Colleen C. Naughton is an Assistant Professor in Civil and Environmental Engineering at UC Merced. Her lab co-designs sustainable and culturally sensitive Food-Energy-Water Systems for and with the UnderServed (FEWS-US) nationally and globally. Dr. Naughton is the Principal Investigator behind the COVIDPoops19 global wastewater monitoring dashboard and X, formerly known as Twitter, account @COVIDPoops19. The COVIDPoops19 dashboard has been internationally recognized, nationally awarded, and cited. Dr. Naughton is also part of Wastewater SPHERE, a global data center for wastewater and SARS-CoV-2.
Research Spotlight
Public Health Models and Forecasts
University of California, Davis
Led by Dr. Miriam Nuño, HCVT develops advanced mathematical tools that use wastewater data to model and forecast important public health metrics. Dr. Nuño’s research focuses on the application of statistics and applied mathematics to solve public health challenges, reduce health disparities, and improve patient health outcomes. Together, we have developed models for public health metrics for COVID-19, including hospitalization rates, test positivity rates, and case incidence. This research demonstrates the utility of wastewater data to inform our understanding of public health trends.
We use wastewater data on an ongoing basis to estimate effective reproductive numbers (Re). Re is a useful public health metric because it gives an indication of the transmission rate of the virus within a community at a particular point in time. It takes into account not only biological factors that impact transmission (e.g., the relative infectivity of a certain COVID-19 variant) but also behavioral factors that impact transmission in a community (e.g., masking behavior, physical distancing, hygiene behaviors, and vaccination and/or prior immunity status). Our research used wastewater data to calculate an Re through time. Our model is incorporated into the California Department of Public Health’s dashboard for R-effective trends by county.
Research Publications
Frontiers
Wastewater data for COVID-19 helped fill knowledge gaps in the Central Valley as individual testing rates declined and people shifted to at-home tests in 2022.
Read MoreMedRxiv
Our forecasts of COVID-19 hospitalization rates in California counties use wastewater data to inform strategic readiness.
Read MoremSystems
Our model of COVID-19 test positivity rates adapts through time to make use of the latest wastewater and case data.
Read MoreScience Direct
We estimate the COVID-19 effective reproduction number using wastewater and case data.
Read MoreScience Direct
Our 2021 review of wastewater monitoring for COVID-19 in California identified a need for more wastewater data to serve rural and disadvantaged communities.
Read MoreHealthy Davis Together
We developed a guide for cities, Monitoring Wastewater To Inform COVID-19 Public Health Response, based on lessons from Healthy Davis Together’s experience in Davis, CA.
Read MoreACS Publication