WASHINGTON -- Construction of the new Danbury federal prison for women will begin this summer, U.S. Attorney General Loretta Lynch told a Senate panel Thursday under questioning by U.S. Sen. Chris Murphy, D-Conn.

"I regret to say I'm hesitant to offer (a completion estimate), having seen several federal construction projects in my day," Lynch said during her first appearance on Capitol Hill since being sworn-in as attorney general on April 27.

Speaking at a hearing of the Senate Appropriations subcommittee that oversees the Justice Department and its Bureau of Prisons, Lynch said an environmental impact statement that had been a hang-up in the process of restoring women prisoners to Danbury was "completed quite recently."

Murphy had asked Lynch for a construction timetable "so we can transition these women who are now in places like Brooklyn and Philadelphia back to a more long-term suitable facility."

The exchange between Murphy and Lynch was the latest chapter in an on-going discussion between lawmakers and the Bureau of Prisons over the fate of women at the Federal Correctional Institution, Danbury.

The prison, known as FCI Danbury, has hosted an array of famous convicts -- male and female -- since it opened in 1940, including the Rev. Sun Myung Moon and Watergate conspirator G. Gordon Liddy. As a women's prison starting in 1993, it was home to Piper Kerman. Her memoir of her 11-month stay at Danbury, "Orange is the New Black,'' became a Netflix television series.

Fairfield County's most famous female celebrity inmate, Martha Stewart, served her sentence in 2004 and 2005 at the federal prison in Alderson, W.Va.

The debate over the prison dates back to 2013 when the Bureau of Prisons announced it would turn Danbury, which had housed women prisoners for 20 years, into a mostly male facility. The initial plan was to send the 1,140 women prisoners to a new prison in Alabama, more than 1,000 miles away.

Murphy and a group of other Northeastern senators including U.S. Sen. Richard Blumenthal, D-Conn., wrote to the prison bureau charging that the move would "dramatically disrupt the lives of these female inmates, many of whom are from the Northeast, and place them out of reach of their families and loved ones."

The Bureau of Prisons said the main facility would be all-male, but pledged to build a new low-security prison housing 412 women on the Danbury site. The bureau estimated it would take 18 months, projecting a completion date of May 2015.

But the need for an environmental impact statement and confusion over when the 18-month clock began ticking led the BOP to push the date back to May 2016.

In the interim, the women prisoners who otherwise would be in Danbury are housed in federal prisons in Brooklyn and Philadelphia that normally house inmates facing trial, not those serving long-term post-conviction sentences. The facilities lack drug treatment and other programming designed to rehabilitate prisoners.