Assessment of contaminants in California drinking water by region and system size

Abstract

In this California‐wide spatial analysis, a cumulative ranking method and a trend test were used to estimate and compare concentrations of 12 contaminants and two drinking water standard violations by system size and region. The San Joaquin Valley, areas not served by water systems, and small water systems (less than 200 connections) had the highest cumulative rank with many high levels of contaminants. Large systems and the South Coast had the highest levels of disinfection byproducts and industrial contaminants. Based on a trend analysis, violations and concentrations of arsenic and cadmium decreased as system size increased, while industrial contaminant concentrations and disinfection byproducts increased as system size increased (p < .05). Although not indicative of violating drinking water standards, this study's results demonstrate where efforts to address specific contaminants can be targeted by region or system type. The results can help elucidate where contaminants may be elevated, from both an individual and multiple‐contaminant perspective.

Monitoring the human right to water in California: development and implementation of a framework and data tool

“…Our preliminary exploration of social equity indicates that systems serving socioeconomically DACs and those facing institutional constraints have some of the greatest water quality and affordability challenges (i.e., worse outcomes). These trends are corroborated by California studies in smaller geographic areas (e.g., Balazs et al, 2011Balazs et al, , 2012 and across the state (e.g., Bangia et al, 2020), though follow-up statistical analyses are in order.…”

“…Physical infrastructure used for water protection, treatment and transport can define water access (Stevenson, 2019). In California, where approximately 95% of residents obtain drinking water from public water systems via piped infrastructure (Bangia et al, 2020), physical accessibility is determined less by distance to water source than by physical and socioeconomic aspects associated with water infrastructure and institutions (Meehan et al, 2020a(Meehan et al, , 2020b. Physical accessibilityand community capacity to cope with related stressorsis largely influenced by water supply characteristics (e.g., infrastructure age) (National Research Council, 2007;Kayser et al, 2013) and the water service type (e.g., water system or domestic well) (Moore et al, 2011(Moore et al, , 2013.…”

An assessment of groundwater quality for drinking and agricultural purposes in Ca Mau peninsula, Vietnamese Mekong Delta

“…This makes it easy to express the comprehensive influence of various indices on groundwater and facilitate the comparison between samples collected from different regions. GWQI has been applied as an effective approach to communicate water quality information to decision makers and is widely used in many areas such as India [7], Iran [8], Palestine [9], USA [10]. The Geographic Information System (GIS) can support water quality assessment to understand clear picture of spatial variability of groundwater quality.…”

The Drinking Water Tool: A Community-Driven Data Visualization Tool for Policy Implementation

“…Approximately 10% of California's public water systems are currently out of compliance with federal regulatory standards for water quality [7]. Rural communities served by small water systems with fewer than 200 service connections experience a greater proportion of federal drinking water quality violations compared to medium and larger systems [8], as small systems face disproportionate challenges in meeting regulatory Maximum Contaminant Levels (MCL) due to a lack of financial, technical and economic resources to treat contaminated water or acquire new drinking water sources [9][10][11][12][13]. Communities served by water systems with elevated contaminant concentrations are disproportionately socioeconomically disadvantaged communities.…”