Environmental justice implications of arsenic contamination in California’s San Joaquin Valley: a cross-sectional, cluster-design examining exposure and compliance in community drinking water systems

Table 1 Characteristics of community water systems (CWSs) in study sample compared to all CWSs in study region with geographic coordinates, 2005-2007, San Joaquin Valley, CA

Variable of interest	Active CWS with geographic coordinates n = 644	CWS in study: active, w/ coordinates and arsenic samples n = 464	CWS in study: < 200 connections n = 324	CWS in study: ≥ 200 connections n = 140
Total population (count)	3,037,785	1,134,017	49,340	1,084,677
Population Characteristics (%)
People of Color (Latinos and Non-Latinos)	53	55	38	56
White population	47	45	62	44
Population above poverty^a	57	54	60	54
Water System Characteristics (%)
Mean People of Color	42	39	35	50
Mean Home Ownership	67	70	72	67
Population served (mean/median)	4,717/163	2,444/180	152/100	7,748/2537
Incorporated ^b	10	9	1	29
< 200 Connections	72	70	100	0
Groundwater Alone (GW)^c	88	92	95	87
GW and surface water^c	7	4	2	9
Publicly owned^d	32	32	13	75
Privately owned non-PUC reg.^d	60	61	80	16
Water Quality Characteristics
Min-Max; mean (μg As/L)	NA	0-158; 6.0	0-158; 6.2	0-42; 57
IQR (μg As/L)	NA	1.4, 6.3	1.4, 6.2	1.4, 7.3
CWS with ³1 As MCL Viol	44	34	15	19

NA not applicable because not all active sources had arsenic samples, IQR interquartile range.
^a Above 200% the poverty level; ^b A water system that serves a city that is a legally recognized municipal corporation with a charter from the state and governing officials that is incorporated, as opposed to a water system that serves an unincorporated area; ^c Reference group=surface water only; ^d Reference group=privately owned and Public Utility Commission (PUC) regulated or unknown.

ISSN: 1476-069X