MAYOR Nutter yesterday, during a news conference in City Hall, signed a bill decriminalizing possession of small amounts of marijuana in Philadelphia.

Starting Oct. 20, nonviolent offenders caught with 30 grams or less of pot will receive a citation and a $25 fine. Those caught smoking pot in public will be cited and given a $100 fine or up to nine hours of community service.

"It is our hope that by decriminalizing marijuana in the City of Philadelphia, we can begin to eliminate this great penalty to many who are otherwise law-abiding citizens trying to lead good, healthy lives," Nutter said.

Nutter and Councilman James Kenney, who introduced the bill, stressed that pot, in any amount, is still illegal under state law and that they don't condone its usage.

This means that situations, including driving under the influence, possessing more than 30 grams of pot or selling or distributing pot are still subject to punishment to the fullest extent.

"In this particular instance, punishment needs to be proportionate to the crime," Nutter said. "These are commonsense changes that will have a positive impact on many Philadelphians."

Nutter said that in Philadelphia, about 4,000 people are arrested yearly for having or using small amounts of pot.

A "mistake" like this made by a young person could negatively impact the rest of his life and could affect financial aid for schooling, military service, secured housing and employment, Nutter said.

"This type of action will keep kids out of the criminal-justice system, will keep people's records clean so they can get a job," Kenney said.

Along with the bill, Nutter launched a public-awareness campaign to explain the new law.

Jay Lassiter, who serves on the board of PhillyNORML, which works to reform marijuana laws, said the new law is a step in the right direction.

"We're here to see . . . this great step forward," he said. "Today we see Council getting stuff done, and I think people find that refreshing."