Overview
The US Environmental Protection Agency Maximum Contaminant Level (MCL) for arsenic in drinking water is 10 parts per billion (10 µg/L), established in the 2001 Final Rule for Arsenic in Drinking Water and effective for compliance from January 23, 2006 (EPA arsenic (As) MCL). The 10 ppb MCL replaced a prior 50 ppb standard that had been in place since 1942 (EPA As MCL). The MCL applies to community water systems and non-transient non-community water systems under the Safe Drinking Water Act (EPA As MCL).
Rule
| Parameter | Value |
|---|---|
| MCL | 10 ppb (10 µg As/L) as total arsenic |
| Compliance effective date | January 23, 2006 |
| Prior MCL | 50 ppb (1942-2006) |
| Authority | Safe Drinking Water Act |
| Coverage | Community water systems and non-transient non-community water systems |
| Implementing rule citation | 40 CFR Part 141 (Phase II/V Rules) |
Sources
- EPA As MCL — EPA Office of Water. Final Rule for Arsenic in Drinking Water (2001).
References
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