Tex. Water Code § 29.045: USE OF UNMARKED VEHICLES.

No person who is required to have a permit under this chapter may haul oil and gas waste in a vehicle that does not bear the owner's name and the hauler's permit number. This information shall appear on both sides and the rear of the vehicle in characters not less than three inches high.

Amended by Acts 1977, 65th Leg., p. 2207, ch. 870, Sec. 1, eff. Sept. 1, 1977; Acts 1991, 72nd Leg., ch. 603, Sec. 31, eff. Jan. 1, 1992.