Mayor Michael Nutter of Philadelphia speaks at a press conference in New York City in September. (Jemal Countess/Getty Images)

Philadelphia Mayor Michael Nutter (D) signed an ordinance Wednesday decriminalizing the possession and use of up to 30 grams of marijuana.

“I do not condone marijuana use, it is illegal,” Nutter said in a statement. “But the punishment needs to be proportionate to the crime, and these are common sense changes that will have a positive impact on many Philadelphians.”

Under the measure, non-violent offenders will no longer be arrested, and fines will be set at $25 for possession and $100 or up to nine hours of public service for public use, effective Oct. 20.

Individuals can still be arrested, however, for possessing more than 30 grams, distributing, driving under the influence, or failing to provide accurate information if stopped by an officer. The city also noted that under state and federal law, other law enforcement agencies could still arrest residents for marijuana possession and use.

The city will also begin a public service campaign about the new penalties and addiction treatment services, “to educate residents about the impact and consequences of marijuana use and how they can get help to overcome the habit,” Nutter said.