HAMPDEN, Maine — The U.S. Postal Service plans to study the feasibility of folding operations now handled at its Eastern Maine Processing and Distribution Facility into the Southern Maine Processing and Distribution Center in Scarborough.

The study, announced Thursday, is a first step in the Postal Service’s nationwide effort to downsize its processing and transportation capabilities to reflect dropping annual mail volumes, according to Tom Rizzo, spokesman for the Postal Service in Northern New England.

“Mail volume is no longer growing,” Rizzo said Thursday. At the same time, state-of-the-art automated mail-processing equipment has allowed for more efficient processing than ever before, he said.

These factors have created considerable excess processing capacity at many postal facilities where mail is canceled and sorted, which is why the Postal Service is looking at opportunities to increase efficiency by consolidating mail processing operations, he said.

“The network that was designed to handle the high volume of mail processed in past years is too big and costly to support today’s lower volume,” he said.

“Long term, our financial problems are not going to go away. We’ve got to do more and we have to do it faster,” he said.

The Hampden facility, which opened in 1994, is one of only two in Maine, Rizzo said. It employs 183 people, nine of whom are managers, 172 full-time workers and two part-timers, he said.

Rizzo said that nationwide, annual mail volume has declined by more than 43 billion pieces in the past five years and continues to decrease. Total first-class mail has dropped 25 percent, while single piece first-class mail — letters bearing postage stamps — has declined 36 percent over that period.

As a result, the Postal Service is gearing up to reduce the number of mail processing and distribution facilities from 500 to less than 200 — a move USPS officials say would save $3 billion a year, Rizzo said.

A complete list of the targeted facilities can be seen on the American Postal Workers Union website.

Nationwide, the facility closures also would reduce mail processing equipment by as much as 50 percent, dramatically decrease the nationwide transportation network, slash the work force by as many as 35,000 positions and revise service standards for first-class mail.

Rizzo said that if the feasibility study reveals an opportunity to consolidate Maine’s two mail processing operations in Scarborough, the USPS will hold a public meeting to explain the proposed operational changes and potential impacts on service and to gather public feedback, which will be considered before a final decision is made.

Rizzo said processing consolidation changes would not occur until at least March 2012.

In a telephone interview from her office Thursday evening, Hampden Town Manager Susan Lessard said that if it occurred, the closure of the Hampden plant would hit the region hard, both economically and in terms of quality of life.

While the Hampden facility, located on Meadow Drive, is assessed at more than $12 million, it is tax-exempt, Lessard said.

“The real impact would be in terms of payroll,” she said, estimating the annual payroll for the Hampden facility’s 183 employees in the $7 million range.

“I would hope that the assessment [of mail processing and distribution facilities] is part of a comprehensive view of the Postal Service in its entirety and that this is really a bigger bang for its buck in making itself more efficient and more effective,” she said.

“If it comes down to this, I would hope that the [decision-making process] will not be a quick deal and that decisions are not made in a vacuum, without considering the local and regional impacts, and not solely based on the number of people in an area,” she said.

“The idea may be that one facility is enough to serve X number of people but given the size of our state, it’s a geography issue. A one-size-fits-all model won’t work at all,” she said, adding, “Every time we pull services away from the more rural areas, it makes the livability and the likelihood of people staying a little bit less. It makes it more difficult for rural areas to sustain themselves.”

Word of the processing and distribution feasibility study comes less than two months after the USPS announced plans to conduct a similar study of post offices, with the goal of closing about 3,700 branches throughout the country, including 34 in Maine.

The Maine post offices targeted for closure are mostly rural, from St. David and Grand Isle in the north to Paris and North Waterford in the south and in coastal locations, including Matinicus and Cliff Island, according to a Bangor Daily News article published in late July.

Lessard noted that the Hampden plant already has seen some of its workload move south.

In August 2008, the processing of what is known as “standard class flat mail” for ZIP codes that begin with 044, 045, 047 and 049, which had been handled in Hampden for at least a decade, was shifted to the Scarborough site.

At that time, the Hampden facility employed about 200 people, according to published reports.