Sources of and solutions to mistrust of tap water originating between treatment and the tap: Lessons from Los Angeles County.

Tap water mistrust has adverse impacts on health and welfare. This study identifies, defines and motivates attention to cases of mistrust of tap water which originate between the treatment plant and the tap where people ultimately consume it. Between treatment and the tap, water quality contamination can be introduced within two segments of the built environment with two distinct responsible parties— community water system's distributional networks and property owner's premise plumbing. This contamination is considered secondary from a health perspective but elevates consumer concern. We use examples from Los Angeles County, an area with high resident tap water mistrust especially among disadvantaged communities, despite there being relatively few health-related water quality violations.