In mid-December 2022, the Division of Drinking Water (DDW) released a Standardized Regulatory Impact Analysis (SRIA) for the future hexavalent chromium (CrVI) maximum contaminant level (MCL).
The SRIA presents an evaluation of the costs and benefits of a 10 µg/L MCL. Table 1, page 13, presents the anticipated compliance deadlines for different sized systems.
Beginning on page 32, DDW presents an evaluation of three alternate CrVI MCLs (12 µg/L, 8 µg/L, and 1 µg/L) and a discussion as to why DDW rejected those MCLs.