SAN DIEGO -- A 19-year-old San Diego State fraternity member described as a major source for cocaine dealers on campus pleaded not guilty Thursday to four felony charges.

Kenneth Ciaccio was one of dozens of SDSU students arrested during the yearlong probe called "Operation Sudden Fall."

Ciaccio, a Theta Chi member, was ordered jailed in lieu of $150,000 bail.

A total of 125 people were arrested in the sweep, which netted cocaine, marijuana, methamphetamine and other drugs, according to the District Attorney's Office. Ninety-five of those arrested were SDSU students, according to prosecutors. On Wednesday, SDSU President Stephen Weber said only 33 SDSU students had been arrested and suspended.

On Thursday, prosecutor Shawn Tafreshi told Judge David Szumowski that Ciaccio sold eight ounces of cocaine to undercover agents last month. When asked if he could get a quarter-ounce, he said he could get a quarter-pound, the prosecutor said.

On another occasion, Ciaccio -- using a bodyguard or a lookout -- allegedly sold a half-ounce of cocaine to agents for $460, the prosecutor said.

When going out of town, Ciaccio sent text messages to his "faithful customers," saying he and his associates would be in Las Vegas for the weekend and unable to supply them, Tafreshi alleged.

Ciaccio sent other text messages, one announcing a "sale," complete with prices, the prosecutor said.

Upon his return from Las Vegas, Ciaccio sent a message, saying "We're back," and "I'm going to hook you guys up," prosecutors said.

Outside court, defense attorney Michael Messina said Ciaccio was an honor student who made some mistakes.

"My client is not a major player in this particular enterprise," Messina said, noting that Ciaccio faces up to 18 years in prison if convicted.

Six other young men -- Cory Barclay, 18; Chad Frazier, 22; James Dennis Schurr III, 21; Thomas Watanapun, 20; Clynton Parsons, 20; and Thomas George Brindley, 20, were arraigned Thursday at the downtown courthouse.

"Operation Sudden Fall" was the largest campus drug bust in San Diego County history, according to Ralph Partridge, special agent in charge of the Drug Enforcement Administration's San Diego Field Office.

The probe stemmed from the death last year of a college freshman found dead with cocaine and alcohol in her system the morning after attending a fraternity party.

Theta Chi is one of the six fraternities put on suspension due to the busts. The others are Lambda Chi Alpha, Phi Kappa Psi, Phi Kappa Theta, Sigma Alpha Epsilon and Sigma Alpha Mu. The fraternities were suspended pending a hearing into their involvement in the drug dealing, Weber said.