Montgomery County police have broken up what they described as a major PCP ring with the arrests of 20 persons, who were charged with conspiracy to distribute the drug.

Nineteen of the arrests Tuesday night were made in dozens of raids in Montgomery County and one other man was arrested in Frederick, Md.

Montgomery Sgt. James A. Taylor said undercover officers had been investigating PCP sales for four months, making frequent purchases of the drug in the Gaithersburg, Rockville and Poolesville areas.

The man considered the leader of the ring had been placed under surveillance, Taylor said.

Taylor said detectives believe that the PCP may have originated on the West Coast and was purchased in liquid form from dealers in the District.

The substance was sprayed on marijuana and parsley, the officers said, and distributed to sellers in the county.

Young said a PCP-laced marijauna cigarette typically sold on the street for $5 to $10 and an ounce of PCP-laced marijuana sold for $250 to $400.

Film canisters and aluminum foil "lids," or packets, containing the drug were also sold, he said.

Police said the arrests were the first to result since an antidrug task force, composed of police and prosecutors, was set up in the county in November.

The man arrested in Frederick was identified by police as Arthur Hebron, 26, who was staying at the Red Horse Motel there.

Hebron was charged in Montgomery County with conspiracy to distribute PCP, and charged in Frederick with possession with intent to distribute PCP and marijuana, possession of PCP and cocaine, and being a common nuisance.

He was being held in Frederick yesterday without bond.

Young described Hebron as "the major dealer in the upper Montgomery County," and said police believe that Hebron was supplying PCP to "over 100 people on a daily basis."

Young added that he anticipates that more arrests will be made as the investigation continues.

Those arrested in Montgomery County were charged with conspiracy to distribute PCP, and some were also charged with less serious crimes.

Seven remained in custody yesterday, with bonds set between $500 and $75,000.

The persons arrested in Montgomery County were:

Ray Ritchie, 29, of 17060 King James Way, Gaithersburg; Carlton Thomas Savage, 38, of 20901 Westerley Rd., Poolesville; Dalvin Hebron, 30, of 17841 Laytonsville Rd., Gaithersburg; Billy Chapman, 27, of Dalamar Street, Gaithersburg; Sherman Perry, 24, no home address given, and Charles Carter, 25, of 7 Chestnut St., Gaithersburg.

Also: Tammy Combs, 21 and Scotty Neal Combs, 24, both of 18 North Summit Ave., Gaithersburg; John Earp, 31, of 17120 Queen Victoria Ct., Gaithersburg; Sheryl Bynum, 26, of 8310 Fairhaven Dr., Gaithersburg; Gary Moyer, 27, of Whetstone Dr., Gaithersburg, and Robert Reed, 29, of 17014 King James Way, Gaithersburg.

Also: Cathy Bisnett, 27, and Richard Emmett Bisnett, 24, both of 807 Maple Ave., Rockville; James Arnold, 28, of 6716 Muncaster Mill Rd., Gaithersburg; Robert Graham, 25, of 17022 King James Way, Gaithersburg; Terry Taylor, 26, of 19001 Shannon Way, Poolesville; and Bobbie King, 27, of 17014 King James Way, Gaithersburg.