This year will go down as a busy year for the thousands of federal employees who manage federal facilities, fleets and energy sources.

From the massive spending provided to agencies in February's Recovery Act to October's landmark executive order that sets ambitious new requirements to cut the government's carbon footprint, 2009 ushered in a series of new requirements, challenges and opportunities that will continue to reverberate for years to come.

Here's a snapshot:

• President Barack Obama in October issued a new executive order that requires federal managers for the first time to begin measuring agencies' greenhouse gas emissions and set targets for reducing them. The order also set new goals or extended existing mandates for agencies to purchase green products and services, cut fuel and water consumption, and develop plans to make operations environmentally sustainable.

• Congress in February approved a massive stimulus bill that provided more than $20 billion for construction, maintenance and energy efficiency projects at federal facilities. Much of the money is being spent on either deferred maintenance projects or investments to make federal buildings more energy efficient.

• The Homeland Security Department in January won approval from federal planners to locate its new $3 billion headquarters on a historic site in Southeast Washington. The sprawling campus will house senior department leaders, a 24-7 intelligence operations center, and headquarters offices for the department's biggest bureaus: the Coast Guard, Transportation Security Administration, Customs and Border Protection, and Immigration and Customs Enforcement. Roughly 14,000 employees will be moved there once construction is complete around 2013.

• The General Services Administration spent $300 million purchasing fuel-efficient vehicles for federal agencies as part of the Recovery Act. Of the 17,205 total vehicles that were to be purchased by GSA for federal agencies, more than 5,100 were compact sedans and 3,100 were hybrid vehicles. For each vehicle purchased, an existing lower-mileage federal vehicle was traded out. Two-thirds of the total vehicles had been delivered to agencies by the end of October, resulting in an astounding 40 percent increase in fuel efficiency compared with the vehicles traded in.

• The much-criticized agency responsible for protecting employees and visitors at nearly 9,000 federal buildings nationwide was repositioned within the Homeland Security Department in October in hopes the move would make it more effective. The Federal Protective Service's transfer from Immigration and Customs Enforcement to the National Protection and Programs Directorate was included in the fiscal 2010 Homeland Security appropriations bill. The move occurred after congressional auditors discovered troubling lapses in the agency's performance.

• Obama in February ordered agencies to consider requiring construction firms for large federal projects to enter into project labor agreements with their workers. The agreements establish work rights such as wages and benefits for all employees working on the projects, even if they don't belong to a union themselves, and also lay out labor dispute procedures that ensure problems are settled quickly without strikes. Construction firms have railed against the new rules, saying they hurt competition and drive up costs.