Overnight delivery of First Class mail could be a thing of the past in many parts of South Carolina.

The U.S. Postal Service announced Monday that it is moving forward with a proposal that could close 52 percent of mail processing facilities nationally, including the Florence Processing and Distribution Facility.

The good news is the changes should not affect delivery locally, said Michael R. Miles, communications manager for the Postal Service district that includes South Carolina.

On Sept. 15, the Postal Service announced it would begin studying 252 out of 487 mail processing facilities, including the Florence facility, for possible closure.

The Florence center would consolidate with the Columbia facility, Miles said. So far, such consolidations have not resulted in job loss. Some employees have been moved to different positions or facilities, he said.

Processing facilities are also in North Charleston and Greenville.

“In order to consolidate facilities, it will impact the time it takes to process and deliver mail from one place to another,” Miles said. “Right now, you can drop a letter with us today, and it gets to its destination tomorrow. When we do the consolidation, it could take two days.”

The change would take place in the spring, Miles said, but “it would not affect delivery times in Charleston because we are talking about consolidating Florence and Columbia.

“In Charleston, if you mail a letter today, it will probably still get there tomorrow.”

First Class mail is delivered in a one- to three-day window. The plan changes that to two to three days. Delivery time for periodicals also becomes at least two days. Express Mail and Priority Mail are not affected.

On Monday, the Postal Service announced it will request an advisory opinion on the changes from the Postal Regulatory Commission, which is required before implementing nationwide service changes. It will publish a notice in the Federal Register seeking public comment.

The changes are necessary because of financial problems caused by the drop in the amount of First Class mail. In October, the Postal Service said the cost of First Class stamps will rise 1 cent, to 45 cents, on Jan. 22. “The U.S. Postal Service must reduce its operating costs some $20 billion by 2015 in order to return to profitability,” said David Williams, vice president of network operations.

The proposed changes will generate a projected net annual savings of about $2.1 billion.

Mail volume has declined by more than 43 billion pieces in the last five years. First Class mail has dropped 25 percent, and single-piece First Class mail has declined 36 percent.

The Postal Service receives no tax dollars for operating expenses and relies on the sale of postage, products and services to fund its operations.

Reach Brenda Rindge at 937-5713.