R.I. Gen. Laws § 37-15.1-4: Prohibitions.

No person shall throw, drop, deposit, discard, or otherwise dispose of hard-to-dispose material upon any public property in the state or in the waters of this state or upon private property in this state owned by him or her except:

(1) When the property is designated by the state or by any of its agencies or political subdivisions for the disposal of hard-to-dispose material, and that person is authorized to use the property for that purpose; or

(2) Into a receptacle which has been provided by or authorized by the department.