D.C. Mun. Regs. tit. 16, r. 16-1704
Only the second sample from the underground storage tank that measures below the 0.5 tolerance shall be sent to the Motor Fuel Testing Lab of the Comptroller of Maryland or another testing lab authorized by the Director within twenty-four (24) hours of collection.
If the Motor Fuel Testing Lab of the Comptroller of Maryland or other testing lab authorized by the Director confirms that gasoline sample from the underground storage tank measures below the 0.5 tolerance of the automotive fuel advertised, the DCRA inspector shall return to the location where the sample was retrieved within twenty-four (24) hours or the next business day and repeat the procedure set forth in § 1702 to re-determine whether the gasoline measures below the 0.5 tolerance set forth in § 1700.1.
If the test performed pursuant to § 1702 re-confirms that the gasoline measures below the 0.5 tolerance of the automotive fuel advertised, the DCRA inspector shall condemn the service station dispenser nozzle where the fuel was retrieved.
D.C. Mun. Regs. tit. 16, r. 16-1704