Arlington police, ending a six-month undercover investigation, said yesterday that they have arrested 30 persons from South Arlington’s Green Valley area on drug charges and are seeking 41 others on similar charges.

The arrests stemmed from a prolonged investigation of drug dealing in Green Valley, especially at the intersection of S. 24th Street and S. Shirlington Road, police said. Residents described the streets of the area, a few blocks from Shirley Highway, as a drug supermarket that draws its customers from throughout Northern Virginia.

Lt. Arthur Christiansen, head of the department’s vice squad, said that the people arrested and those sought on warrants do not constitute an “organized drug-selling group or ring.”

“It’s simply a number of individuals who sold drugs in the area,” he said.

Most of the arrests were for selling small amounts of cocaine, marijuana, PCP or heroin and came after undercover officers either bought drugs or observed sales being made, police said. None of those arrested are considered top-level dealers, but at least four face numerous charges and are considered to be major street-level dealers, police said.

Of the 71 persons arrested or sought, 52 were indicted on drug charges earlier this week, authorities said. Four of the 52 are juveniles.

Community leaders and businessmen in the area of apartment houses, single-family homes and small stores hailed the crackdown, but expressed doubt that it would permanently end drug traffic in the area.

“I commend the police department,” said John Robinson, director of the nearby Martin Luther King Jr. Community Center. “It’s the best thing that could have happened here. The drugs have gotten out of hand.”

He said the drug-users and dealers have been burglarizing houses in the area, robbing passersby and harassing customers at local stores.

Robinson added that police have asked his aid in locating some of the suspects being sought, and said he has urged several to surrender.

“I think this will put a dent in the drugs, but some of these guys will be right back on the street and take their place in days,” he predicted. Some of those arrested yesterday already had been released on bond, police said.

“The community’s been concerned abut this for years,” said Leonard Muse, who has owned the Green Valley Pharmacy at 2415 S. Shirlington Rd. for 32 years. “It’s always a good deal when the police run them off the corner. But they’ll come right back again.”

Muse said the drug traffic in the area started in the late 1960s and then grew.

Police officials also disclosed that a smaller undercover investigation in a Hispanic neighborhood in the vicinity of S. Eighth and S. Greenbrier streets has led to 11 persons being charged in the past few weeks with distributing cocaine.

Residents described the outdoor drug trade in their neighborhood as similar to the drug dealing in such D.C. neighborhoods as 14th and U streets NW and the H Street NE corridor, which continually are swept for drugs by District police.