CDPH: Chromium-6 in Drinking Water Sources: Sampling Results
CDPH (then the California Department of Health Services, DHS) adopted a regulation in 2001 that added chromium-6 to the list of unregulated chemicals for which requiring monitoring is required (UCMR).
Of the ~4,400 community systems and non-transient non-community systems that have ~12,000 drinking water sources, those that are vulnerable to contamination are subject to UCMR regulations. Systems with fewer than 150 service connections may be exempted from the monitoring requirement. Results of UCMR monitoring from over 7,000 drinking water sources showed chromium-6 at or above the 1-µg/L detection limit for purposes of reporting (DLR) in about one-third of them.
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