(a) The railroad commission shall adopt rules under which an owner, operator, or manager of a mobile home park or apartment house may purchase natural gas through a master meter for delivery to a dwelling unit in the mobile home park or apartment house using individual submeters to allocate fairly the cost of the gas consumption of each dwelling unit.
(b) In addition to other appropriate safeguards for a resident of a mobile home park or apartment house, the rules must provide that the owner, operator, or manager of the mobile home park or apartment house:
(1) may not deliver natural gas for sale or resale for profit; and
(2) shall maintain adequate records relating to that submetering and make those records available for inspection by the resident during reasonable business hours.