Procedures and Methods. Each utility or gas master meter operator shall establish procedures for making periodic gas leakage surveys as specified in these regulations. For residential customers with meters located outdoors, leakage surveys shall be performed up to the building entry. The leakage surveys shall be conducted by one or more of the following methods: Flame ionization; Combustible gas indicator and bar hole; Optical methane detector; or Other method approved by the Commission. Frequency of Surveys. Leakage detection surveys shall be made at frequencies that comply with 49 CFR §§192.706 and 192.723, as amended, which are incorporated by reference, and the requirements of §B(2) and (3) of this regulation. Places of Public Assembly. Service lines to places of public assembly shall be leakage surveyed at least once each calendar year, but with intervals not exceeding 15 months. The customer shall cooperate with the company in the conduct of these tests as regards accessibility to meters and service lines. Cast iron, ductile iron, and cathodically unprotected steel pipelines shall be leak surveyed at least once every 3 years. Except as provided in §B(1) of this regulation, segments of these pipelines located inside a building shall be leak surveyed at least once every 5 years. Field Operations. After a leak repair, a leakage survey shall be performed in accordance with COMAR 20.55.02.02B(1). When a utility service person enters a customer's premises for the purpose of inspecting or servicing any gas equipment (excluding meter reading), a leakage survey shall be conducted at appropriate locations, including atmosphere samples, and at all utility service entrances. In multiple-occupancy buildings, an individual apartment or dwelling unit shall constitute the customer's premises specified above. The customer shall cooperate with the company in the conduct of the tests as regards accessibility to meters and service lines. Leakage surveys shall be conducted on each new or replaced service line before being placed in service but after backfilling and after a reasonable period of gas pressurizing. Leaks Without Presence of Odorant. A review system shall be established to continuously analyze and monitor the results of all leakage surveys specified in these regulations to determine any areas where leaks were detected without presence of odorant. Any areas so determined shall be leakage surveyed immediately to determine the possible extent of the area, and shall then be leakage surveyed at least annually as long as the condition of odorant absorption exists. Leak Repairs. Leaks located by leakage surveys shall be investigated promptly and corrective action initiated. Records of Surveys. Each utility or gas master meter operator shall maintain a record of each leak survey showing by location and date: Leaks detected; Severity of each leak; and Action taken to repair leaks. These records are to be kept as long as the segment of pipeline involved remains in service.