(a) Complete exemption. The following underground tanks and containment devices (including any connected piping) are completely exempt from regulation under this chapter:(1) farm or residential tank with a capacity of 1,100 gallons or less used for storing motor fuel for noncommercial purposes;(2) tanks used for storing heating oil for consumptive use on the premises where stored;(3) septic tank;(4) surface impoundments, pits, ponds, or lagoons;(5) stormwater or wastewater collection systems;(6) flow-through process tanks;(7) tanks, liquid traps, gathering lines, or other facilities used in connection with an activity associated with the exploration, development, or production of oil, gas, or geothermal resources, or any other activity regulated by the Railroad Commission of Texas pursuant to the Natural Resources Code, §91.101;(8) transformers or other electrical equipment that contains a regulated substance and that is used in the transmission of electricity, to the extent that such a transformer or equipment is exempted by the United States Environmental Protection Agency under