6209. TIERS 1 AND 2 STANDARDS

6209 TIERS 1 AND 2 STANDARDS 6209.1 The Tier 1 and 2 standards for water, soil, soil vapor, and indoor air shall be the levels specified in the Department’s RBCA technical guidance, which is available on the Department’s website at https://doee.dc.gov/page/lust-forms-guidance-and-public-documents. 6209.2 Indoor air sampling shall be used in conjunction with sub-slab soil gas and ambient air sampling in a multiple lines of evidence approach to evaluating vapor instrusion risk. SOURCE: Final Rulemaking published at 40 DCR 7835 (November 12, 1993); as amended by Final Rulemaking published at 46 DCR 7699 (October 1, 1999); as amended by Final Rulemaking published at 67 DCR 1778 (February 21, 2020). District of Columbia Municipal Regulations Environment 20 DCMR § 6209