Two years after Montgomery County Police swept through area schools and made nearly 400 drug-related arrests, a group of students, police and school and county officials have come up with a plan to combat drug and alcohol abuse among the county's youth.

The plan calls for a family resource center to teach the public about the problem, a series of community seminars and workshops and trained drug-and-alcohol counselors to handle student offenders.

"Our overriding objective was to coordinate among the agencies, recognizing that this is not just a school problem, but a community problem," said Roy Stern, co-chairman of the Inter-agency Planning Committee on Drug and Alcohol Abuse.

Last year, 338 Montgomery County youths under the age of 18 were arrested for drug abuse violations, according to police. In 1978, police concentrated enforcement efforts on school grounds and made a total of 725 arrests, up from 332 in 1977.

"I don't think the problem has gone away. The arrests highlighted the problem. Kids became a little more careful and the political climate changed," said Lt. Paul Whitling of the Youth Division. "People thought it best to have a more low-key approach to enforcement. The problem is still there and extensive.

"I think that full participation by the schools will have some effect. I don't see the return to massive drug arrests, but enforcement has continued."

The 29-member committee submitted its report last week to County Executive Charles W. Gilchrist, the county council and Superintendent of Schools Edward Andrews.

"Drugs aren't a school-system problem, but we are in a key place to deal with it and we're willing to do this to help the community," said Andrews.

"I think the recommendations are good ones. I've reviewed the report and sent it to my key staff. I'm inclined to be willing to go along with those recommendations," he said.

Andrews said that every week one or more county high schools have had to call police and turn a student over to them because of a drug offense.

The committee says the entire package of recommendations can be implemented within the current school and county budgets by reallocating existing funds and asking for private sector support.

They are also applying for a $150,000 grant from the Govenor's Commission on Law Enforcement and the Adminstration of Justice to operate a referral service for students with drug abuse problems.

The resource center would cost about $82,000 to operate, using the school system's space and equipment.

Other recommendations are already in progress. All secondary- school employees spent half a day learning about drugs last spring. Eighty school counselors will be trained by health and police department officials at the end of November on how to deal with drug and alcohol abusers and their families.

The report asks for a countywide inventory on programs and services available to drug offenders and for a juvenile justice commission to coordinate services among juvenile justice agencies.