Illinois Gov. Bruce Rauner signed legislation Friday making marijuana possession in small amounts punishable by fines but not jail time.
The Republican's signature means the new law takes immediate effect, making Illinois the third largest state to decriminalize the possession of small amounts of marijuana.
Rauner had been expected to sign the bill because it included language he requested after vetoing similar legislation last year. He has said that existing penalties for petty marijuana offenses were too severe and that "criminal prosecution of cannabis possession is also a drain on public resources."
The Associated Press was first to report the bill signing. A state official with knowledge of the governor's decision told the AP about the signing but spoke on the condition of anonymity because a formal announcement had not yet been made.
The new law means possessing 10 grams or less of marijuana will be a civil offense, punishable with a fine of up to $200. The governor's signature makes Illinois the 17th state — and the third largest — to decriminalize the possession of small amounts of marijuana.
The new law also sets a standard for what's considered too impaired to drive. Currently, any trace of marijuana is enough to be considered impaired, but marijuana advocates have long criticized zero-tolerance states' approach because marijuana can stay in a person's system for several weeks.
The new law makes the standard 5 nanograms of THC, marijuana's intoxicating chemical, in a driver's blood within two hours of consumption.
Last year, Rauner vetoed an attempt to reduce penalties for possessing small amounts of marijuana. But he told lawmakers he supported the concept and made recommendations.
In the bill he vetoed last year, lawmakers wanted possession of up to 15 grams of marijuana to be a civil offense punishable with a fine between $55 and $125. Rauner wanted the threshold to be lower, at 10 grams or less, and fines between $100 and $200.
Rauner also recommended that the driving while intoxicated standard for marijuana be 5 nanograms of THC. Lawmakers initially proposed that the standard be 15 nanograms.