(a) A person commits an offense if the person disposes litter, a dead animal, sewage, or any chemical in a cave.
(b) An offense under this section is a Class C misdemeanor unless:
(1) it is shown on the trial of the defendant that the defendant previously has been convicted once of an offense under this section, in which event the offense is a Class A misdemeanor; or
(2) it is shown on the trial of the defendant that the defendant previously has been convicted two or more times of an offense under this section, in which event the offense is a felony of the third degree.
(c) On conviction of an offense under this section, the court shall require the defendant, in addition to any fine or other penalty, to perform community service as provided by Article 42A.304(e), Code of Criminal Procedure.