Environmental laws cover various subjects such as littering; solid and hazardous waste disposal; air, land, and water pollution control; natural resource conservation; and public lands regulation. These laws are categorized as no offense, administrative, or regulatory. Police have no role in enforcing no offense and administrative laws but do have an actual and potential enforcement role in regulatory environmental laws. The police mandate regarding environmental law enforcement is found in two sources, the law enforcement function and the order maintenance function. In Canada, environmental law enforcement is already a police responsibility to a certain degree. Police have traditionally enforced Criminal Code provisions in a context involving environmental hazards, and this role is expanding to such contexts as the transportation and disposal of hazardous waste. An expanded role for police in environmental law enforcement should not involve no offense or administrative laws, but should involve enforcing regulatory offenses when enforcement powers are clear and involve the coordination and exploitation of police and regulatory services. Sufficient training should be available to help police carry out their expanded role safely and effectively. 16 references