BART is set to reopen two of the underground station bathrooms that officials closed at the urging of federal authorities after 9/11.

But the new bathrooms at the Powell Street Station in San Francisco and 19th Street in Oakland won’t be the same ones that riders used in the 1990s. Powell Street’s forthcoming all-gender facilities will have sinks and hand dryers outside, as well as an attendant to keep them clean and safe. The bathrooms at 19th will likely have a similar design, and may open first.

A larger station modernization project under way at Powell includes glass barriers to deter fare cheats, LED lighting on the platforms and new offices and break rooms, among other things. BART’s Board of Directors approved an $11 million contract on Thursday to start the improvements, funded with revenue from sales taxes, state infrastructure bonds and a significant contribution from San Francisco Municipal Transportation Agency, which runs Muni trains from the station.

Reopening restrooms aligns with BART’s efforts to make its stations secure and contemporary, said agency spokesman Jim Allison.

“We’re changing the lighting, moving the ticket vending machines, and we thought we might as well do something customers have been asking for — but do it in a way that doesn’t leave the restrooms vulnerable to behavior problems,” he said.

Officials set aside $20 million for the work at Powell, though the attendant would have to be funded in next year’s budget, Allison said. So far BART has no plans to open bathrooms in the other underground stations.

“I’ve never been more excited about bathrooms in my life,” Director Janice Li said. “And it’s because the sight and smell of urine or otherwise has become something we’ve forced our riders to put up with,” she added, referring to the transit system’s ongoing problem with people who relieve themselves on trains, escalators or stairways.

BART Assistant General Manager Carl Holmes anticipates the bathrooms will open in early 2021.

Though the board unanimously approved the contract, three directors weren’t satisfied, and asked that the anti-cheat barrier be raised to 6 feet, to prevent people from vaulting over it.

“Five feet will stop most people ... but 6 feet would pretty much stop everyone,” said Director Debora Allen, who plans to discuss the issue with the project’s architect.

About 54,000 people enter and exit Powell Street Station each day, according to ridership reports from BART. Officials expect that number to climb in the coming years, particularly with the opening of the Central Subway in 2021.

Rachel Swan is a San Francisco Chronicle staff writer. Email: rswan@sfchronicle.com Twitter: @rachelswan