Cobb County stepped up its efforts to curb underage drinking by passing an ordinance holding adults more accountable for their roles in the illegal act.

Last week, the county became the second jurisdiction in the area to approve a social host ordinance that includes penalties for hosting parties where alcohol is available to minors. The county's ordinance complements the state's existing law prohibiting furnishing alcohol to minors. The local rules set the minimum penalty for an initial offense at $150; second and subsequent offenses begin at $500, with a judge's discretion to enforce heavier penalties. The offense is a misdemeanor.

Austell passed a similar ordinance last year, possibly the first in the state to do so, said Cathy Finck, executive director of the Cobb Alcohol Taskforce. Austell Mayor Joe Jerkins said he doesn't think the city has charged anyone with the offense yet.

Cobb now joins hundreds of communities in 24 other states with social host ordinances on its books.

Georgia health surveys of middle and high students found that, of the students surveyed who had used alcohol, the average age of first use was 13. At least 30 percent of Cobb tenth through twelfth-grade students surveyed in the state's 2010 report strongly agreed that alcohol was easy to get.

"Their parents are providing it for them, drinking with them or having parties where alcohol is there. The adults take their keys, but that's not good enough, because it's still illegal," said Elizabeth Osmond, 16, a sophomore at Walton High School and a member of the Taskforce's Youth Council.

Osmond doesn't attend parties where drinking occurs, but says the problem is prevalent among teenagers. She said open events with drugs and alcohol are sometimes publicized on social media sites, including Facebook.

"This is important for Cobb to make adults more responsible, to instill morals in kids so I don't lose any more peers," she said.

Two years ago in Marietta, part-time magistrate judge Diane Busch was cited for multiple violations, including furnishing alcohol to persons under 21, after a Christmas party at her Marietta home. Busch accepted a prosecutor's deal of community service and a diversion program. She resigned her court posts in Marietta and Woodstock.

The social host ordinance follows a move last year by the county to require those minors who are caught in possession of alcohol and want to enter a diversion program for first-time offenders to report the names of those who furnished the booze.