D.C. Mun. Regs. tit. 20, r. 20-6001
The owner or operator of each UST shall maintain records demonstrating compliance with this chapter in accordance with this section and § 5602.
All written performance claims pertaining to any release detection system that is in use, including a description of the manner in which those claims have been justified or tested by the equipment manufacturer or installer, shall be maintained for at least ten (10) years after the date of installation.
The results of any sampling, testing, or monitoring conducted under this chapter shall be maintained for at least ten (10) years, except as provided in § 6001.4.
The results of tank tightness testing conducted in accordance with § 6007 shall be retained until the next tightness test is conducted.
Written documentation of all calibration, maintenance, and repair of release detection equipment permanently located at the UST facility shall be maintained for at least three (3) years after the servicing work is completed.
All schedules of required calibration and maintenance provided by the release detection equipment manufacturer shall be retained for at least ten (10) years from the date of installation of the release detection system.
No later than October 13, 2021, an owner or operator using groundwater or vapor monitoring for release detection shall maintain a record of the site assessment conducted pursuant to §§ 6009.7 or 6010.7 for as long as the method is used. Records of site assessments developed after February 21, 2020 must be signed by a professional engineer or professional geologist, or equivalent licensed professional with experience in environmental engineering, hydrogeology, or other relevant technical discipline acceptable to the Department.
D.C. Mun. Regs. tit. 20, r. 20-6001