The drop boxes are coming.

In the next few weeks, hundreds of election drop boxes will be installed in the District and surrounding suburbs, providing a new voting option for residents wary of casting their ballots in person because of the coronavirus pandemic or worried about the reliability of mail-in voting.

In D.C. and Montgomery and Prince George’s counties, voters can expect to see 400-pound, six-foot tall structures made of heavy-duty steel placed outside public high schools, libraries and community centers. Starting at the end of this month, the boxes will be available 24 hours a day and guarded by surveillance cameras, in-person security or a mix of both.

In the suburbs of Virginia, where state lawmakers approved the use of drop boxes just two weeks ago, voters are likely to see smaller, foldable boxes placed inside early-voting sites and Election Day polling places. These will be available only during the day, guarded by an attendant at all times.

President Trump in August questioned the use of drop boxes, claiming they are “a voter security disaster” in a tweet that has since been flagged by Twitter for violating rules on election integrity. Trump suggested that drop boxes allow voters to cast their ballot multiple times, adding, “Also, who controls them, are they placed in Republican or Democrat areas? They are not Covid sanitized. A big fraud!”

Local election officials and outside experts roundly rejected the president’s characterization of the voting tool.

“There should be no concern about security,” said Jim Shalleck, a Republican appointed by Maryland Gov. Larry Hogan (R) to chair of the Montgomery County Board of Elections. “We know who votes, and we can detect if someone tries to vote twice — that’s our job.”

In Maryland, 13 percent of voters used drop boxes in the June primary election, when officials deployed 75 of them. The state ordered 200 more boxes for the general election, at $1,400 apiece. That cost does not include transportation or surveillance.

Nikki Charlson, deputy administrator for the Maryland State Board of Elections, said voter demand for drop boxes has surged in light of ongoing public concerns over whether the U.S. Postal Service will be able deliver ballots on time.

“If voters are at all worried about returning their ballot, we’re telling them to find drop boxes,” Charlson said.

Armstead Jones, who has served as election director for Baltimore City since 2007, said he has not witnessed as much anxiety over the voting process before. “A lot of people right now . . . they’re not trusting any part of the process,” Jones said.

In recent weeks, he added, many residents — including Baltimore Mayor Bernard Young (D) — dropped off their applications for an absentee ballot directly at the elections office to avoid any mail delays.

The outdoor drop boxes that will be used in Maryland and D.C. are designed by a North Carolina manufacturing company called Recyclingbin.com. Each one is made of thick, weatherproof steel that has been smoothed to prevent tampering and has an access door sealed by a high-security padlock. It has an open slot that fits a ballot, but not much else.

“It’s 400 pounds and can be mounted to the ground,” said Scott Gardner, the company’s chief executive. “It’s not like you can just huff and puff and blow them down.”

In Prince George’s County, each of the 40 or so drop boxes will be monitored by a 24/7 security camera as well as a person from the sheriff’s office, police department or Department of Parks and Recreation, said Daneen Banks, deputy administrator of the Board of Elections. In Baltimore City, officials plan to hire a private security company to guard the boxes overnight, Jones said.

In Montgomery County, once a ballot is slipped into a drop box, it will be transported to the county’s elections’ office within 24 hours, said Gilberto Zelaya, a spokesman for the elections board. At least twice a day, bipartisan teams of election workers will open the drop boxes, inspect “tamper” tapes and seals to ensure that the box was not prematurely opened, collect the ballots and place new seals for the next collection cycle. Voters can track the status of their ballot on the Maryland State Board of Elections website, Zelaya said.

There will be 55 drop boxes in the District placed outside libraries, recreation centers and other public locations. They’ll be monitored by surveillance cameras but not necessarily by guards on-site, local elections officials said. Police may also add the drop box locations to their patrol detail.

Voters in D.C. and Maryland will be able to drive or walk to these outdoor drop boxes starting in about three weeks. In Maryland, ballots will be mailed to the people who requested them starting Sept. 24; in D.C., ballots will be mailed to every registered voter in the first week of October.

But in Fairfax County, Virginia’s most populous jurisdiction, voters in most cases will have to wait till mid-October and enter a building to drop off their ballots. Mail-in ballots will be available in Virginia starting Sept. 18 and distributed on a first-come-first-serve basis.

Fairfax will distribute about 260 drop boxes for the general election — one at each of its 14 satellite voting locations and 243 Election Day polling places.

The boxes — 3½ -foot tall foldable containers made out of plastic — will be available only during the hours that the sites are open. They’ll be secured by a steel lock, guarded by an attendant and emptied daily, said Gary Scott, general registrar of elections in Fairfax County.

Virginia’s General Assembly voted Aug. 28 to allow drop boxes, which left local and state elections officials scrambling to procure them. It wasn’t possible for Fairfax to order heavy-duty outdoor drop boxes that would arrive in time, Scott said.

The state legislation to expand absentee voting was specific to this year’s general election and does not appear to permanently change the laws in Virginia barring drop boxes. So unlike in Montgomery or Prince George’s, where officials expect to use drop boxes for all future elections, officials in Fairfax see it as a “single-use” voting option for this year, Scott said.

For these reasons, the boxes the county bought — also supplied by Recyclingbin.com — cost $116 apiece, less than one-tenth the price of the ones in the Maryland suburbs.

Other Virginia jurisdictions are still in the process of figuring what type of drop boxes they want and how to get them. In Loudoun County, officials have ordered 14 lightweight drop boxes to be placed at early voting sites. In Arlington and Alexandria, officials were still seeking out appropriate vendors as of last week.

“It’s not something you can just go to Walmart and buy,” said Gretchen Reinemeyer, Arlington County’s director of elections. Only a few vendors are still taking requests, she said, and some say they can only deliver the boxes a week before the November election.

That would be far too late for officials to legally notify the public where the drop boxes will be located, Reinemeyer added.

Patricia Sullivan and Michael Brice-Saddler contributed to this report.