This subchapter does not apply to:
(1) an extension of an existing sour gas pipeline facility that is in compliance with the railroad commission's rules for oil, gas, or geothermal resource operation in a hydrogen sulfide area if:
(A) the extension is not longer than five miles;
(B) the nominal pipe size is not larger than six inches in diameter; and
(C) the railroad commission is given notice of the construction of the extension not later than 24 hours before the start of construction;
(2) a new or an extension of a low-pressure gathering system; or
(3) an interstate gas pipeline facility, as defined by 49 U.S.C. Section 60101 and its subsequent amendments or a succeeding law, that is used for the transportation of sour gas.