WASHINGTON - A plan to check fingerprints of foreigners leaving the United States is popular in Congress - but not at the Department of Homeland Security, where officials say the technology would do little to halt illegal immigration.

But thanks in part to lobbying by security contractors, the Senate immigration bill that goes to the Republican-led House this week includes a computerized "biometric" exit system that could cost more than $7 billion.

The plan is part of the bill's $46 billion "border surge" of security measures, a 10-year spending gusher that would produce a financial bonanza for some of America's largest aerospace, technology and security companies, as well as some border states.

The legislation would force the Homeland Security Department - which has a total proposed budget of $39 billion in fiscal year 2014 - to absorb a staggering increase in funding, equipment and staffing at a time when most federal agencies and departments are struggling with budget cutbacks, furloughs and reduced services.

After months of wrangling, a bipartisan group of eight senators initially had proposed spending $4.5 billion for border security as part of an overhaul of immigration law. However, that sum jumped tenfold in the final days of debate last month in a bid to win over Republicans who demanded stronger measures before they would consider a path to citizenship for the estimated 11 million people in the country illegally.

If the law is enacted, the Treasury Department would set aside $46.3 billion in a special trust fund account to protect it from lawmakers who might seek to draw on or reduce the money in future budget battles.

The border crackdown includes more than $50 million to increase prosecutions of border crossers in Arizona, and another $50 million to reimburse other border states.

Most immigration violators are sent to jails and detention facilities owned or run by private companies under contracts with Immigrations and Customs Enforcement, and the Marshals Service. Their role is likely to grow substantially.

In Arizona, the immigration-detention business is dominated by Corrections Corp. of America. The Tennessee-based company was paid $750 million under federal contracts last year, and spent more than $1 million to lobby officials in Washington, records show.

Steve Owen, a spokesman for CCA, said the company doesn't lobby Congress for policies to increase the number of prisoners. "We certainly advocate for full funding of our contracts," Owen said.

Critics, even those who support reform, say the bill is laden with pork and that politics has trumped policy.

Among other problems, the Department of Homeland Security, which was created after the terrorist attacks of Sept. 11, 2001, has a reputation of poor management and wasteful spending.

The Government Accountability Office, the investigative arm of Congress, considers Homeland Security acquisitions programs to be at "high risk" for abuse. A GAO report in February concluded that major acquisitions "continue to cost more than expected, take longer to deploy than planned, or deliver less capability than promised."

"There could be abuses," said Stewart Baker, former head of policy at Homeland Security, warning it would take "gut-straining effort" to complete the surge in 10 years.

The spending surge already has generated opposition in the House.

The bill is "throwing $46 billion at a problem without any plan, without any strategy, without any definition of operational control," Rep. Michael McCaul, R-Texas, chairman of the Homeland Security Committee, said Sunday on CBS' "Face the Nation."

The immigration bill is unusual in its specificity. It sets aside $7.5 billion to build a 700-mile, high-tech fence, giving the secretary of Homeland Security the authority to "waive all legal requirements" to get the project built quickly.

It would spend $30 billion to add nearly 20,000 agents to the Border Patrol, doubling the size of the force and making it the nation's biggest law enforcement agency. Nearly all would be posted along the Southwest border.

Janet Napolitano, the secretary of Homeland Security, supports the bill but has said that more border agents are not necessary.

The bill specifies what the agents will get and where: 4,595 ground sensors, 507 radiation detectors, 917 camera towers, 820 pairs of night vision goggles and more.

U.S. Customs and Border Protection, which includes the Border Patrol, flies 10 unarmed Predator drones along the border, but the bill requires nonstop airborne surveillance: Internal documents show that would require enlarging the fleet to 24 drones.

The bill also requires the purchase of 15 Black Hawk helicopters from Connecticut-based Sikorsky Aircraft, along with a drone-mounted radar system developed by Virginia-based Northrop Grumman.