Folly Beach and other area communities are anxiously awaiting the completion of a $12 million project aimed at improving Charleston County's problem-plagued digital radio system.

County officials said the work is on schedule. Barring a major hurricane or other problems, the upgraded system should be ready to roll by December, said Bill Tunick, county director of radio operations and telecommunications.

All of the necessary approvals are in place, though negotiations are still under way with Wild Dunes for some land needed to replace the Isle of Palms tower, Tunick said. Work on other tower upgrades already has begun, he said.

The current system, which cost $17.5 million, has been called unreliable, substandard and unacceptably dangerous since it went on line in 2007. The eight-tower system has been riddled with lost transmissions, strange noises, volume issues and gaps in service that have frustrated police, firefighters and other emergency workers. Some 53 public agencies with 5,500 radios depend on the system.

The upgrade, approved by County Council in November, will add six radio towers to try to bridge communication gaps that have been particularly nettlesome on Folly, in East Cooper and along other areas of the coast.

Public safety workers will have to make do with the current system through the summer months, when warmer weather tends to exacerbate transmission problems. But Tunick said county workers are tweaking the system and making adjustments to minimize problems as much as possible.

Though the upgraded system will come on line in late fall, the county will continue testing the network through next summer before signing off on the work, Tunick said.