Wells and Enteric-disease Transmission (WET) Trial

The Challenge

Approximately 48 million people in the US are served by private wells, many of which are untreated. We estimate that 1.29 million cases of acute gastrointestinal illness (AGI) per year are attributed to consuming water from untreated private wells in the US. These cases of AGI can cause a significant burden in terms of health care costs and lost work/school days. This impact is magnified when accounting for vulnerable populations such as children under the age of 5, the elderly and the immunocompromised.

Project Overview

We are conducting a randomized controlled trial (RCT) to investigate whether consuming water treated by ultraviolet light (UV) compared to consuming untreated private well water decreases the incidence of acute gastrointestinal illnesses (AGI) in children under 5. There are no prior RCTs or established causal links between AGI and the consumption of untreated water from private wells despite the fact that waterborne pathogens have been recovered in groundwater supplies, including in deep aquifers.

This trial is important as it will help to better understand the extent that child acute gastrointestinal illnesses (AGI) can be attributable to consuming untreated private well water and which viral, bacterial and protozoan pathogens are the most likely contributors of AGI in these water supplies. The results will help inform AGI burden estimates and policy decisions regarding the management of private well water supplies globally and across the United States.


Area of Research

Funding By

NIH R34 (trial planning)


2018-2019 (trial planning); 2020-2021 (pilot)

Team Members

Jingwei Wu
Debbie Lee
Miriam Wamsley

Partners and Collaborators

Mark Borchardt, Joel Stokdyk (USGS/USDA- Marshfield, Wisconsin)
Donna Denno (University of Washington)

Advisory Panel:
Phil Tarr, Lori Holtz (Washington University in St Louis)
Jack Colford (University of California Berkeley)
Tom Clasen (Emory University)
Tim Wade (EPA)


Pennsylvania (Berks, Bucks, Chester, Lancaster, Lehigh, Montgomery counties)