Taking preparations for a disaster to new levels, the House today will conduct its first drill to practice evacuating the chamber as it would in the event of a catastrophe.

With the House in recess until Tuesday, leadership aides and other senior staffers will act as stand-ins for Members during the simulated evacuation, according to Office of Emergency Planning, Preparedness and Operations Director Curt Coughlin.

“This is just going to be one of multiple drills that we are doing in the coming year,” Coughlin said Friday. He emphasized that Members will go through the evacuation plans themselves at some point: “We’ll ramp up and make it more realistic eventually.”

In the meantime, staffers will serve as “actors [who] will simulate Members” in Monday’s exercise, according to an e-mail sent to the aides asked to participate. A source said the memo went out Friday to about 40 people, instructing them to arrive on the House floor between 1:45 and 2 p.m.

According to the source, the run-through will proceed until about 4:30 p.m. and end with a trip to a “briefing center” at an unspecified location.

Emergency planning officials in the Senate, who coordinate out of the Sergeant-at-Arms office, will be observing, Coughlin said, adding: “They have their own exercise schedule.”

Coughlin indicated that future drills, including those that would include Members, haven’t yet been scheduled. “We’re doing these as we can do them,” he added.

As for today’s drill, Coughlin described it as involving “normal evacuation procedures by the Capitol Police from the chamber.”

By going through the process with staff, officials will be able to fine-tune the procedures Members would be asked to carry out and look for “holes,” he said, “so then when you do use Members, you don’t waste their time.”

“It’s like a fire drill … a very important part of emergency planning,” Coughlin said.

Congressional officials charged with disaster preparedness have also focused on staff evacuations. House and Senate emergency planners have stressed to offices for more than a year that they need to have evacuation plans of their own. The Office of Compliance conducted spot checks last year to ensure offices had such plans in place.

Those efforts were quietly stepped up after the terror alert level was raised last month from “elevated” to “high.” The Homeland Security Department lowered the threat level back to elevated, or code yellow, last week.

The House and Senate Sergeant-at-Arms and the Capitol Police also renewed efforts to train staff and Members to use the Quick 2000 Escape Hoods in recent weeks. Thousands of staffers were taught to use the devices last year — which could provide up to an hour of safe air to breathe in an area contaminated with a chemical or biological agent — in the months after they were purchased, but classes were offered to Hill staff again recently.

Offices have been encouraged in the strongest possible terms to designate an emergency action coordinator, who should plan escape routes, determine meeting places outside of the Capitol office buildings and attend regular planning meetings. Those staffers also serve as point people for the distribution of emergency kits, large duffel bags that hold escape hoods and other supplies.

Additionally, House and Senate offices recently received networked communication devices, which could be used by the Capitol Police to communicate instructions to the entire campus in an emergency.

Today’s scheduled evacuation drill follows a Capitol security briefing held for House Members last month, during which they were told by Capitol Police Chief Terrance Gainer to lower their profiles. Along with House Sergeant-at-Arms Bill Livingood, Gainer recommended that Members remove state-

issued vanity license plates from their vehicles, avoid predictable routines and come up with emergency plans for their own families. Although they were told there have been no specific threats regarding kidnapping or assassination, Members were asked to take precautions, including using the underground tunnels when traveling to and from votes.

And every so often, preparedness procedures are tested without warning.

That happened Friday when emergency protocols became action plans after some House and Senate offices received suspicious letters containing white powder.

According to a memo put out by the Senate Sergeant-at-Arms, the Capitol Police were called to investigate and field tests were immediately performed by the hazardous materials team.

The substances all tested negative, but the news spread around the Hill in minutes and created panic in some offices.

“The Capitol Police have taken the letters and are investigating the incident further,” the letter read.

A final number of offices reporting such letters was not made available, but Officer Kimberly Bolinger, a Capitol Police spokeswoman, said that “numerous” offices had received them.

“The corners of both letters were clipped, indicating the letters had been irradiated by the United States Postal Service and subsequently tested by the Senate Post Office for biological contaminants,” said an e-mail the Sergeant-at-Arms sent to Senate offices Friday. “Irradiation is designed to kill biological contaminants and the Senate Post Office confirms the absence of a potentially harmful substance through its testing before any mail is delivered to Senate offices.

“The protocols designed to prevent the introduction of harmful biological contaminants in the Senate community were followed as prescribed and the U.S. Capitol Police responded appropriately,” the memo continued.

The offices of GOP freshman Sens. Norm Coleman (Minn.) and Saxby Chambliss (Ga.) were among those that received the letters, as was House Majority Leader Tom DeLay’s

(R-Texas) personal office.

A Chambliss aide said that when the staffer who regularly handles mail opened the letter Friday morning, a white powder fell in his lap. The aide said the Capitol Police responded to their call immediately and that the office was not evacuated while the police conducted field tests.

“The Capitol Police were great,” said the aide.

The staffer added that the powder was folded up in an 8 1/2-by-11 piece of white typing paper with no writing or threats of any kind.

The letters had no return address on them, though sources said they all bore the same Seattle postmark.

The Capitol Police sent out a voicemail message to every office Friday saying that “multiple” offices had received suspicious letters and emphasizing that all of the field tests were negative.

At least one office had a false alarm. After the initial warning was put out Friday, Senate Minority Leader Thomas Daschle’s (D-S.D.) office found a seemingly suspicious letter that appeared similar to the ones already found. The Capitol Police investigated and found that there was no powder in the letter.

The screening process that includes irradiation of the mail was implemented after a Daschle aide opened a letter containing anthrax in October 2001, prompting a massive shutdown on the Hill and a broad revision of Congressional security procedures.

Paul Kane contributed to this report.