The Architect of the Capitol will begin removing materials containing asbestos from two Senate office buildings on Saturday, with some of the work expected to continue through April.

Workers on Saturday will be removing waterproofing that contains asbestos from the northwest terrace of the Russell Building at the corner of Delaware Avenue and C Street NE and floor tiles in the Dirksen Building, according to the Senate Superintendent’s office.

The project’s start is scheduled to align with the President’s Day recess.

Later this month, the Architect’s office will begin work on another portion of Russell, where asbestos-containing ductwork above the basement ceiling will be the target. The work, set to begin Feb. 25, will affect the east wing of Russell, near SR-B90 to SR-B96.

The asbestos abatement will be conducted overnight, not during the typical workday hours.

“Areas where the asbestos abatement is occurring will be fully enclosed with a sealed containment and property identified to avoid unauthorized access,” according to a memo from the superintendent’s office.

The memo says there will be constant air monitoring inside and outside the containment area, done by a licensed industrial hygienist. The work will be overseen by an EPA-accredited asbestos supervisor.

“All necessary precautions will be taken to ensure Senate staff and public safety,” the memo says.

Asbestos remediation problems have nagged the Capitol complex for years, with many areas of the historic buildings packed with the material.

There have been asbestos scares in the recent past on Capitol Hill:

• Rumors flew in 2016 when a duct in the attic of the Capitol separated, prompting the air to be shut off. Air samples were collected and analyzed by an independent hygienist, who determined they were below the regulatory limit.
• In 2015, the Cannon Building was evacuated for a potential asbestos leak, related to construction that was part of a major ongoing renovation of the oldest House office building.
• In July 2014, an asbestos spill that occurred during abatement work temporarily closed the House side of the Capitol. After that, unions representing AOC workers and the Capitol Police expressed concern about workers’ exposure to the carcinogen.
• In 2012, 10 AOC employees working in tunnels in the Capitol complex settled a major lawsuit against their employer for multiyear exposure to asbestos that caused lifelong debilitating health conditions.

Bridget Bowman contributed to this report.