Nine men and women, including three employees of the already scandal-plagued Chicago (search) city water department, were arrested Wednesday as federal officials rolled up what they described as the Chicago branch of a Colombian heroin-trafficking operation.

Eight individuals were arrested Wednesday morning in Chicago and one in New York (search) on charges involving an alleged conspiracy to distribute sizable quantities of heroin on city streets.

Among those charged was Gerald A. Prado (search), a hoisting engineer for the city's water department and the leader of the distribution cell, according to federal prosecutors.

Also charged were Prado's brother-in-law, Anthony C. Ritacco, and Michael D. Hart, both identified by federal officials as low-level employees in the city water department.

Chicago's water department has been the focus of a scandal involving the $38 million Hired Truck Program (search), under which the city outsources hauling jobs to private trucking companies.

Donald Tomczak, the former deputy commissioner of the water department, is charged along with a number of aides and trucking company officials with a scheme under which bribes and campaign contributions were exchanged for work within the no-bids Hired Truck Program.

Tomczak, who was in day-to-day charge of the department, is not alleged to have had any involvement in the drug-trafficking ring.

Federal officials said an unnamed Individual A who was a water department employee had cooperated in the investigation and provided key information that led to the fresh charges.

Federal officials said that on March 10, about 100 grams of heroin were seized when Individual A tried to sell it to another cooperating witness who had first told them of the ring.

They said that on May 24, Vito J. Renteria, 45, of Chicago, described as a courier for the ring, was stopped by state police for lacking a valid driver's license and a kilogram of heroin was seized. They said Renteria later tried and failed to explain losing the drugs to Prado.

Prado allegedly then called two other ring members and discussed kidnapping, beating and possibly killing Renteria for failing to come up with the drugs.

If convicted, each individual faces a mandatory minimum sentence of 10 years in prison and a maximum of life as well as a $4 million fine, federal officials said.