New details about the federal government’s plan to convert an industrial warehouse in Merrimack, N.H., into a regional processing center with up to 600 beds for immigration detainees were released by Governor Kelly Ayotte’s office Thursday afternoon.
The plan is part of a $38 billion nationwide initiative to establish a “new detention model” for President Trump’s mass deportations agenda, according to newly released records from the US Department of Homeland Security. ICE plans to have all facilities online by Nov. 30.
The documents confirm key details about the Merrimack project, which has been the subject of intense speculation and scrutiny for months. Up to this point, the specifics about the plan to renovate the warehouse at 50 Robert Milligan Parkway have been sparse as federal officials have remained tight-lipped.
The DHS documents show the 324,000-square-foot Merrimack facility would have 400 to 600 beds. Detainees would stay in the facility for about three to seven days, and the facility would serve as a staging location for transfers or removals.
An economic impact analysis said DHS will spend $158 million retrofitting the Merrimack facility in 2026 and $146 million operating it in the first three years. It would directly employ 756 people during the retrofit and 162 people in each year of operation.
The government’s master plan calls for DHS to acquire and renovate eight large-scale detention centers and 16 smaller processing sites, including the warehouse in Merrimack. Those facilities, combined with 10 others already in operation, would expand US Immigration and Customs Enforcement’s detention capacity to 92,600 beds, according to the records released Thursday.
Ayotte, a Republican, obtained and released the records — which are labeled as being intended “for official use only” — after the acting ICE director, Todd M. Lyons, told a congressional committee on Thursday that she had already received them. Lyons told lawmakers that DHS officials had “worked with” the governor and given her “an economic impact summary” regarding the Merrimack warehouse, but Ayotte said that was “simply not true.”
In a statement, Ayotte said she immediately shared the DHS records with local officials in Merrimack, who have been raising alarms about ICE’s warehouse plans.
On Friday, Massachusetts Governor Maura Healey called on Ayotte to “do everything in her power to block a new ICE facility in Southern New Hampshire.”
“This is outrageous and absolutely the wrong move for New Hampshire, Massachusetts, and our entire region,” Healey said in a statement.
“ICE is shooting people dead on the street. Mothers have been ripped from cars and separated from children. U.S. Citizens have been stopped, detained and even killed. Peaceful protestors have been assaulted. Parents are afraid to send kids to school, to go to church, to seek health care and report crimes. None of this makes people safer — it makes us all less safe."
“We should be opposing ICE’s tactics, not allowing them to expand,” she added. “We certainly should not be allowing ICE to build new human warehouses when they can’t be trusted to keep people safe and protect due process.”
In addition to their concerns about the conditions in which ICE detainees would be held, Merrimack leaders warned that an ICE warehouse in their town of about 30,000 residents could place a heavy burden on emergency services and tarnish the community’s public image while reducing property tax revenues.
The warehouse that ICE has been looking to buy had an assessed value of about $23.6 million and generated $529,000 in property tax revenues for the town in 2025 alone, according to property tax records. Unlike the current owner, the federal government is generally exempt from local property taxes.
The records that Ayotte obtained from DHS on Thursday contend that the Merrimack warehouse project would constitute “a major economic investment” with far-reaching positive “ripple effects.”
The documents refer erroneously to benefits for “the Oklahoma economy,” which suggests DHS may have drafted similar documents for one or more other locations. The documents also refer to expected revenues from sales and income taxes, even though New Hampshire doesn’t collect either of those.
Ayotte has largely expressed approval of efforts to increase immigration enforcement activity. She signed legislation last year banning “sanctuary” policies and encouraged state and local police to sign agreements to help make arrests on ICE’s behalf. Her statements on Thursday marked perhaps her most pointed critique of the Trump administration on this topic, though she still didn’t express outright opposition to the Merrimack warehouse.
Gracie Willis, a Texas-based attorney with the National Immigration Project, said it’s “horrifying” to watch ICE pursue an agenda to detain even more people.
“Seeing this dehumanizing plan as a coordinated and considered strategy is eerie and demonstrates an overarching denial of immigrants’ humanity,” she said.
Willis said her team has been skeptical of DHS’s claims that it will “retrofit” industrial spaces and make them habitable.
“Even within its existing network of detention centers, there is a long history of inhumane treatment and disregard for the lives of people detained there,” she said, calling on the public to speak out against this “supersized detention initiative.”
The plans for an ICE warehouse in Merrimack were first reported in December by The Washington Post, which outlined the government’s broader effort to expand detention capacity with a nationwide network.
The total cost for the nationwide rollout is estimated to reach $38.3 billion, funded through the massive spending package that Trump signed into law last summer in the so-called “One Big Beautiful Bill Act,” which also enabled DHS to hire and unleash thousands of new ICE officers.
The facilities are intended to provide detention capacity both for a near-term surge in immigration enforcement activity and “sustained long-term operations,” according to the records.
“These facilities will ensure the safe and humane civil detention of aliens in ICE custody, while helping ICE effectuate mass deportations,” the records state.
There was no indication in local property records, as of Thursday evening, that DHS had completed its planned purchase of the Merrimack warehouse.
The federal government has successfully purchased warehouses to support ICE operations in some other states, from Maryland and Pennsylvania to Texas and Arizona. But the government has also encountered setbacks, as the owners of warehouses in Missouri and Virginia have reportedly refused to sell.
Spokespeople for the private businesses involved in building the Merrimack warehouse in 2023 and marketing it more recently — including the Trammel Crow Company, Diamond Realty Investments Inc., and Cushman & Wakefield — have not responded to the Globe’s inquiries about the property in recent weeks.
Republican US Senator Roger Wicker of Mississippi said DHS agreed to “look elsewhere” after he raised objections to plans for an ICE warehouse in his state. Democratic US Senator Maggie Hassan of New Hampshire told Lyons during Thursday’s hearing that DHS should heed her pleas, too, and refrain from establishing the ICE warehouse in Merrimack.
This article has been updated to include a statement from the Massachusetts governor.
Steven Porter can be reached at steven.porter@globe.com. Follow him @reporterporter. Amanda Gokee can be reached at amanda.gokee@globe.com. Follow her @amanda_gokee.