The tap water in a House office building has elevated lead levels and may be unsafe to drink, congressional officials told staff.

William Weidemeyer, superintendent for the House office buildings in Washington, sent staff a “dear colleagues” letter late Tuesday warning about the high lead in the Cannon House Office Building.

ADVERTISEMENT

“This week, the AOC received results within the Cannon House Office Building that indicate lead levels in drinking water sources are slightly above the [Environmental Protection Agency] standard,” Weidemeyer wrote in the letter, first reported by Politico.

He said the Architect of the Capitol is investigating the cause of the increase and said, in the meantime, drinking water sources would be shut off as a precaution.

The building is providing bottled water to staff while the water sources are shut off.

Cannon is the oldest of the congressional office buildings, built in 1908, when lead pipes were common for drinking water. The building is undergoing a decadelong renovation.

The EPA sets 15 parts per billion as its lead “action level” — the point at which warnings and enforcement action can begin.

But the Centers for Disease Control and Prevention says that no level of lead is safe for human consumption. At high exposure levels, it can cause nervous system problems, developmental issues and brain and kidney damage.

The warning comes amid high national attention toward lead in drinking water, spurred by Flint, Mich.’s contamination crisis, elevated lead levels in the public schools in Newark, N.J., and other instances.