The looming closure of the United States Postal Service’s distribution center in Petaluma will slow down service and could affect not just letters but medication delivery and voting by mail, according to local Congressional representatives and North Bay residents.

The closure is part of the newest phase of a nationwide consolidation of postal service distribution centers, a plan the U.S.P.S. calls “network rationalization.” (The shift also entails the closure of a Eureka plant that serves northern California; service there will switch to an outpost in Medford, Ore.) The postal service says the move—which will shutter 82 centers—is needed to save money at a time when the amount of mail has dropped sharply in the past decade. Opponents of the move say the agency has not been transparent and that the resulting degraded service will only exacerbate the service’s problems. 

In West Marin, the chamber of commerce this month started circulating an online petition, which has garnered close to 200 signatures.

The postal service argues that there is not enough mail to justify the expense of operating centers in places like Petaluma. “We have a network that was designed to process and deliver 300 billion pieces of mail. We are now down to 155 billion pieces. Network rationalization is a ‘right sizing’ of the network,” said James Widgel, a spokesperson for U.S.P.S. (He did note, however, that last Monday was “the day that people will be statistically mailing the most mail: 640 million pieces.”)

The postal service expects to save $750 million a year nationally with the 82 closures, which are predicted to affect only about four percent of mail. Mr. Widgel said the nationwide consolidation will be completed by the fall of 2015; he did not know when the Petaluma facility would close.

Earlier this month, 30 members of the United States Senate—including Sens. Dianne Feinstein and Barbara Boxer—sent a letter to Postmaster General Patrick Donahue, requesting that the 

postal service delay the proposed closures until it completes studies on service impacts. The letter cited a report from the Inspector General of the postal service that was critical of the proposed consolidation.

As part of those service standard changes, a “large portion” of first-class mail would no longer be eligible for overnight delivery, the report said, and some mail now receiving two-day shipping would switch to three-day shipping. 

Mr. Widgel said he did not believe that medication deliveries would be affected by the new plans because they are not typically overnight deliveries.

But the Inspector General report, released in October, said the postal service “has not analyzed the impact of planned service standard changes or informed stakeholders of the changes related to [the second phase of] consolidations.”

 The service hadn’t finished studies on the impacts of the new mail standards because those proposed changes weren’t final when it was undertaking feasibility studies on the consolidation. But instead of delaying the plans, a postal service official told the Inspector General that the agency would publish final studies in January, at the same time consolidation would begin.

The Inspector General concluded that the U.S.P.S. should “evaluate the impacts that revised standards will have on each affected community before implementing the consolidations.”

In some ways, that consolidation is already happening. Area codes beginning with 954 and 949—all of West Marin—have been through San Francisco since last spring. Valerie Schropp, the executive vice president of the postal workers union that covers Marin, Sonoma, Lake and Mendocino Counties, called that shift a failure, and said a portion of that mail is being sent up to Petaluma for distribution. “We are working more overtime in the Petaluma building because the mail is coming back to us, because they can’t handle it in San Francisco, so that’s where we are right now,” she said.

The postal service’s original plan was to route mail through Oakland, which happened temporarily. “It was just a business decision that was made,” said Mr. Widgel of the switch to San Francisco. “It’s more efficient. We have the capacity.”

Ms. Schropp said the union is requesting more information from the postal service, including how much mail is getting routed from San Francisco to Petaluma, why it’s being sent to Petaluma and how the switch to San Francisco affects estimates of cost savings made a few years ago.

Rep. Jared Huffman has been particularly vocal with his frustration over the closure and what he has called the lack of transparency with the plans. He said the postal service told him about six months ago that the plans weren’t finalized, but that since then he has heard that it’s a “done deal.”

“I think it speaks to the arrogance of the Postmaster General and the agenda that they’ve been driving, that I think threatens to run the postal service into the ground,” Rep. Huffman told the Light. His constituents, he went on, are worried they won’t receive their medication or have their votes counted when they send in their ballots by mail. “Those seemingly small impacts to bureaucrats in the postal service are a big deal… I would never trivialize that,” he said.

Rep. Huffman, who held two town hall meetings in the North Bay this fall about the proposed closure, is still hoping to find a way to keep the Petaluma center open. “I’ll work with other members of Congress who may be in a similar situation [to try to find a way to] freeze some of these decisions,” he said.

Postal workers are also concerned about their future. According to Mr. Widgel, the U.S.P.S. has been able to find new jobs for those whose positions were cut in the previous phase of the consolidation. Ms. Schropp said the employment contracts for clerks, maintenance and vehicle repair personnel—which expire next year—stipulate that the postal service would find them other jobs in the organization within a 50-mile radius. But since Oakland and San Francisco offices are considered overstaffed, Ms. Schropp went on, she was unsure where those employees might go.