D.C. Mun. Regs. tit. 25-D, § 702
702.1 All handwashing sinks, including those in toilet rooms, shall be equipped to provide water at a temperature of at least one hundred degrees Fahrenheit (100° F) (thirty-eight degrees Centigrade (38°C)) through a mixing valve, a combination faucet, or tempered water and a single faucet.
702.2 A steam mixing valve shall not be used at a handwashing sink.
702.3 A self-closing, slow-closing, or metering faucet shall provide a flow of water for at least fifteen (15) seconds without the need to reactivate the faucet.
702.4 An automatic handwashing facility shall be installed in accordance with the manufacturer's instructions.
Source: Final Rulemaking published at 56 DCR 7975 (October 9, 2009).