Frequent Questions

What are the five constituents of the haloacetic acids (HAA5) group and what is the maximum contaminant level (MCL) and maximum contaminant level goal (MCLG) for this group of constituents?

The five haloacetic acid constituents are monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid. The MCL for HAA5 is 0.060 mg/L (40 CFR 141.64). This MCL is based on the sum of the concentrations of the five constituents (63 FR 69390, 69396; December 16, 1998). There is no MCLG for HAA5 as a group; however, two of the five constituents, dichloroacetic acid and trichloroacetic acid, have individual MCLGs of zero and 0.3 mg/L, respectively (40 CFR 141.53).

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