Tap Water Trust

Increasing Trust in Tap Water in Los Angeles County (2018 event and current project)

Lead researcher and organizer: Gregory Pierce

Mistrust of tap water by residents is greater in Los Angeles County than in most of the U.S. Part of the reason is that there are well-documented accounts of discolored, foul-smelling, and poor-tasting water coming from taps in some communities ─ largely low-income communities of color across the county ─ served by publicly-regulated drinking water systems.

To address real and perceived risks, in 2018 LCI convened more than 100 community members and other stakeholders to discuss challenges and actionable next steps necessary to monitor, improve, and increase trust in tap water quality in the L.A. region for a more equitable and sustainable water future. The discussion, At the Tap, was made possible by support from the Water Foundation and the leadership of the Environmental Justice Coalition for Water, Environmental Justice Center for Water, Environment Now, LCI, and these units at UCLA: the Center for Neighborhood Knowledge, Sustainable LA Grand Challenges, the Water Technology Research Center, and the Water Faculty Group.

As a next step, LCI launched a working group to develop policy solutions to address drinking water contamination and mistrust due to premise plumbing, i.e., pipes that run from the lot line of a property to the tap which are the responsibility of property owners. With participants from water systems, state agencies, the county, and nonprofit groups, the working group plans to identify (a) the legal authorities of tenants and regulators to intervene in cases of premise plumbing contamination, and (b) financing program models targeted toward landlords to incentivize them to upgrade their premise plumbing infrastructure.

Tap Water Quality and Distrust in Los Angeles County: Strategies to Address Premise Plumbing (2024 report)

Researchers: Itzel Vasquez-Rodriguez and Gregory Pierce

Distrust of tap water is partly driven by undetected issues with “premise plumbing;” the pipes that move water from a distribution network to the tap in a home, school, or business. In partnership with the Los Angeles County Chief Sustainability Office, LCI researchers developed 22 specific recommendations, presented within five policy briefs, to guide 1) Los Angeles County; 2) the State of California; 3) landlords; 4) community water systems; and 5) advocacy organizations on how to reduce premise plumbing issues and help improve trust in tap water.

Fear at the Tap: Factors Contributing to Public Drinking Water Distrust in Latino Communities (2023 report)

Researchers: Silvia R. González, Ariana Hernandez and Gregory Pierce

This exploratory study presents research with parents and caregivers in Kern County on tap water usage, water disuse, and solutions to address distrust, including a tax on sugar-sweetened beverages. It finds that ~77% of all surveyed caregivers felt concerned with the safety of the tap water in their homes.

Stopping the Drain on Household Budgets: Addressing Tap Water Mistrust through Affordable Premise Plumbing Investments (2019 report)

Author: Peter Roquemore (advised by Professor Gregory Pierce)

Only about a third of Americans say they usually drink straight from the tap. There are costs associated with mistrust of tap water. This report, which focuses on tap water mistrust in the city of Los Angeles, found that L.A. households purchasing bottled water pay 25 to 125 times the cost of tap water. This can add thousands of dollars to household expenses each year. While recent research indicates that tap water is safe for customers of the Los Angeles Department of Water and Power, the L.A. region has one of the highest rates of tap water mistrust in the nation. This report identified that the main cause of water aesthetic issues is plumbing in the house and that the majority of complaints have low-cost solutions.

U.S. Households’ Perception of Drinking Water as Unsafe and its Consequences: Examining Alternative Choices to the Tap (2018 article)

Authors: Ariana Javidi and Gregory Pierce

This study generated the first national estimates of the use of drinking water alternatives among households who perceive their tap water to be unsafe. The researchers found that minority households more commonly perceived their tap water to be unsafe and chose bottled water because of it. While the perception of unsafe tap water is most prevalent among Hispanic households, among the population perceiving their tap to be unsafe, Black households more commonly buy bottled water.

The researchers estimated the minimum annual expenditure by all U.S. households who perceive the tap as unsafe and buy bottled water to meet necessary consumption standards at $5.65 billion annually. Novel secondary treatment interventions and education campaigns are needed to address the perception of tap water as unsafe and consequent alternative source reliance, while additional research is needed to document the active trade‐offs households make to manage their water sources, and to better understand determinants of the perception of tap water as unsafe within minority groups.

Mistrust at the Tap? Factors Contributing to Public Drinking Water (Mis) Perception across US Households (2016 article)

Authors: Gregory Pierce and Silvia R. González

This study provided the first national, rigorous assessment of individuals’ perception of their public drinking water supply. The researchers found strong evidence that perception of water quality is most influenced by individual and household indicators of socioeconomic status — education level, household income, racial or ethnic minority status, and most importantly, foreign-born nativity, especially from Latin America. The article outlines the implications of the study for proponents of enhanced tap water consumption, including public drinking water systems, county public health agencies, and environmental justice nonprofits.