A niche wall in a columbarium is part of a new expanded section of Arlington National Cemetery. The project, 17 years in the making, extends the life of the cemetery. (Dayna Smith for The Washington Post)

The 6,000 pre-dug graves, with their concrete crypts inches apart just under the surface, are ready. The 16,000 spaces in the new niche wall and columbaria are waiting. And the area has been decorated with new redbud, locust and magnolia trees.

In a few weeks, Arlington National Cemetery will host the first of an expected 27,000 funerals in its elegantly landscaped expansion, built into a hillside and designed to extend the cemetery’s life for more than 30 years.

The $81.7 million Millennium Project is the first geographic expansion of the cemetery in four decades.

And it was badly needed. Facing dwindling space and heavy use, the 154-year-old cemetery is desperately working to extend its life before the day when there is no room left.

Without the expansion, “we’d be planning to close in the mid-2020s,” said Renea Yates, deputy superintendent for cemetery administration. “So this takes us out to the 2040s.”

Still, under current rules and conditions, the cemetery’s life span appears limited. “Most veterans from the recent wars in Iraq, Afghanistan and the war on terror will not have the option to be buried” at Arlington, the cemetery wrote in a report last year.

Arlington is trying to address that.

The new expansion involved the movement of huge amounts of earth, 1,200 feet of a historic sandstone wall, and the construction of extensive granite and concrete committal shelters and walkways.

There are cedar ceilings in the shelters, stainless-steel step railings and decorative stone gardens.

The 27 new acres in the northwestern part of the cemetery were carved out of a recreation spot for an adjacent military base, a construction staging area for the cemetery and National Park Service woodland.

“You’re talking about hundreds of thousands of cubic yards removed from the site,” Army Col. Mike Peloquin, the cemetery’s director of engineering, said in a recent interview.

Some trees were taken down. New ones were planted. Shrubs were added.

New numbered sections were created. And a new grave digging procedure was inaugurated.

“This is the first location at Arlington National Cemetery where we used a technique . . . where you have what’s essentially a concrete box, double-stacked, with a lid to get to the lower one that you get to from the inside of the upper one,” Peloquin said.

The crypts were then placed close together and covered with about two feet of gravel, fill and topsoil, said David H. Petrie, construction control representative for the U.S. Army Corps of Engineers at the site.

The process greatly eases grave opening and makes for greater efficiency.

The new section also has room for traditional in-ground burials and in-ground burial of cremated remains.

Growing pains

The country’s most famous cemetery was established by the War Department in 1864 on the Arlington plantation of Confederate Gen. Robert E. Lee’s deceased father-in-law.

The site was vacated by Lee’s family after he joined the rebel forces in the Civil War, and it was taken over by the Union army.

The first person buried there was William Christman, 20, a Union soldier from Pennsylvania who had died of disease in a Washington hospital. He was buried May 13, 1864. By the end of the war, 5,000 more had joined him.

Since then, over 400,000 people have been buried there. President John F. Kennedy, his wife, Jacqueline Kennedy Onassis, and his brothers, U.S. Senators Robert F. Kennedy and Edward M. Kennedy, rest there.

Abraham Lincoln’s son Robert and grandson, Abraham, are buried there.

With the new expansion, Arlington has about 100,000 spaces left, Yates said.

The cemetery is planning for an additional 37-acre addition called the “Southern Expansion,” where the old Navy Annex building was before it was demolished in 2013. Peloquin said the cemetery would like to have that $274 million project completed by 2025.

That would extend the cemetery’s life out to the mid-2050s, Yates said. But there is not much more room to grow. “We can’t expand out of our challenge,” she said. “We are surrounded” by the local community

The cemetery has been seeking public comment on whether eligibility should be made more restrictive to lengthen its life span.

High demand

The always-sensitive eligibility rules have been changed 14 times in the last 150 years, the cemetery report said.

“The life of the cemetery’s got two factors,” Yates said. “Space available, and individuals . . . eligible for interment: What I have to use. And who’s going to use it. [We’re] trying to shape what that eligibility is right now. Wait times are significant . . . Demand is very high.”

With certain exceptions, most active-duty or retired members of military service are eligible to be interred at Arlington, the cemetery’s website says.

Many recipients of military medals, as well as most former prisoners of war, are also eligible for interment.

Among others, active-duty and former members of the armed forces honorably discharged, except those who were on active duty for training, are eligible for aboveground inurnment, along with their spouses, minor children and adult dependent children.

Yates said that the new space will also allow for proper “dispersion” of the 30 burial services a day. The cemetery often must balance five services an hour, without undue noise or space overlap.

“We pride ourselves to make sure each family that comes feels like they’re the only service going on,” she said in a recent interview at the cemetery.

The on-again, off-again expansion project has been in the works for more than 20 years and was redesigned about seven years ago. Construction got underway about five years ago.

Yates said the first burials in the expansion will probably be take place in mid- to late summer, in conjunction with a dedication ceremony. First use of the niches will probably be in midsummer, “like a soft launch,” she said.

“We strive to make sure everything’s the best it can be before we start bringing families into the area,” she said.

There will be a new choreography of vehicles, families and honor guards in the area that must be worked out.

One day recently, Petrie, of the Corps of Engineers, and cemetery horticulturist Kelly Wilson, showed off elements of the new section.

Wilson indicated wispy bald cypress trees, the drooping white blossoms of itea plants and a giant swath of ornamental grasses, which will turn red in the fall.

In the distance, the Washington Monument was visible over the tree tops. And waiting beneath one of the shelters were seven movable signs, black with silver lettering.

“Arlington National Cemetery,” they said. “Silence and Respect.”