(Terri Castelaz/Daily News photo) The U.S. Postal Service announced Tuesday it will convert its facility in Kingsford into a local processing center.

IRON MOUNTAIN — A bipartisan group of U.S. senators Wednesday pressed U.S. Postal Service officials to put on hold planned changes to mail processing centers across the country, including its Kingsford facility.

In a letter to Postmaster General Louis DeJoy and U.S. Postal Service Board of Governors, U.S. Sen. Gary Peters, chair of the Homeland Security and Governmental Affairs Committee, and 25 other senators called on USPS to pause going forward with its Delivering for America plan. The changes should be put on hold “until the potential impacts are further studied by the Postal Regulatory Commission and addressed by the postal service,” Peters, D-Michigan, stated in a news release Wednesday.

The letter comes a day after USPS issued its final decision to switch the Kingsford facility to a local processing center that will send all outgoing mail — even if to a local address — to a regional processing and distribution center in Green Bay, Wis.

In a news release, USPS officials said the decision came after “a thorough business review and solicitation of public feedback on the facility’s future” that it concluded “supports transferring mail processing outgoing operations to the Green Bay” center.

“USPS is moving forward swiftly with plans to consolidate and alter its facilities across the country, making irrevocable changes to its processing and delivery network which links all communities,” the senators’ letter to DeJoy states. “This plan includes moving mail processing further away from local communities, by transferring operations out of local facilities (Local Processing Centers and Delivery Units) and into more distant hubs (Regional Processing and Distribution Centers and Sorting and Delivery Centers). The plan also includes local transportation optimization, an initiative that cuts the number of truck trips and mail collections at USPS facilities, causing mail to sit overnight in local offices. USPS has begun to implement this change without notifying the public, causing critical delays for mail that requires overnight delivery.”

The senators want the Postal Regulatory Commission to do a comprehensive advisory opinion — which commission Chair Michael Kubayanda called a “deeper dive” report during a Homeland Security and Governmental Affairs Committee hearing on the USPS plan April 16 — that “would provide a robust and public process to study the impacts of these changes.”

DeJoy at that April 16 hearing had indicated he would be open to requesting the advisory opinion and slowing down the postal changes, the letter notes, but “disappointingly, the Postmaster General did not commit to the scope of an Advisory Opinion, or to meaningfully stopping changes until further study is complete.”

The senators’ letter contends “In regions where USPS has implemented significant changes, on-time mail delivery has declined. In addition, it is not clear these changes will improve efficiency or costs. Despite these concerns, USPS has moved forward with announcing and approving additional facility changes across the country. The nature of these changes creates concerns that local and rural service could be degraded. For example, USPS proposals to remove all outbound mail operations from local processing facilities seem to particularly harm local mail, since mail sent to a nearby locality would first have to go through a far-away processing facility, often in another state.”

The letter was signed by U.S. Sens. Susan Collins, R-Maine; Jacky Rosen, D-Nevada; Cynthia Lummis, R-Wyoming; Michael Bennet, D-Colorado; Kevin Cramer, R-North Dakota; Jeanne Shaheen, D-New Hampshire; John Barrasso, R-Wyoming; Catherine Cortez Masto, D-Nevada; Steve Daines, R-Montana; Kyrsten Sinema, I-Arizona; Shelley Moore Capito, R-West Virginia; Angus King, I-Maine; John Hoeven, R-North Dakota; Jeff Merkley, D-Oregon; Deb Fischer, R-Nebraska; Jon Tester, D-Montana; Roger Wicker, R-Mississippi; Debbie Stabenow, D-Michigan; Mike Rounds, R-South Dakota; Joe Manchin, D-West Virginia; Marsha Blackburn, R-Tennessee; Cory Booker, D-New Jersey; Pete Ricketts, R-Nebraska; Maggie Hassan, D-New Hampshire; and John Cornyn, R-Texas.

“The Postal Service’s primary responsibility is to provide timely and reliable delivery to every community across the nation,” the letter concludes. “While USPS must continue adapting as an agency to remain stable and serve the public’s current needs, it must proceed with caution and understand the implications of its plans in order to protect mail delivery for all communities.”

USPS officials have pledged to invest up to $6.3 million in the Kingsford center as part of the conversion, including $2.4 million for modernization efforts and deferred maintenance and $3.9 million for a robotic “Flex Rover Sorter Quad” system in the facility.

According to Tuesday’s news release, the conversion should “result in expanded and streamlined package and mail processing and distribution capabilities for the facility.”

In earlier statements, USPS claimed the switch will save an estimated $1.1 million to $1.5 million annually at the Kingsford facility.

It is part of USPS’s $40 billion Delivering for America plan, which officials claim “will upgrade and improve the postal processing, transportation, and delivery networks.” The plan relies heavily on creating regional processing and distribution centers and converting a number of other existing PDCs into local processing centers.