(CBS)-- After years of intense public criticism, Congress has seriously curbed its earmark habit of spending tax dollars for pet projects outside the normal public review. The new "Pig Book" -- which has tracked Washington pork since 1991 -- says the amount of tax dollars destined for earmarks in 2012 is way down: $3.3 billion.
The high was $29 billion in 2006.
Tom Schatz's watchdog group, Citizens Against Government Waste, publishes the Pig Book. He says the decline in earmarks is due to the House banning them in 2010 and the Senate following suit in 2011, after several years of anger from taxpayers.
"The good news is it's the smallest amount of money since 1992, and the lowest number of earmarks since we issued the first Pig Book in 1991," Schatz told CBS News.
If there's a "ban" on earmarks, why are there any at all? Schatz says Congress has figured out ways to stuff earmarks into spending by calling them different names. The result, he says, is less transparency. Since they're technically not called "earmarks" under Congress' definition, Congress doesn't have to disclose details -- including who requested the money to be spent.
"The transparency is much more difficult and it will be hard to see where, exactly, the money is being spent as it goes out the door," says Schatz.
So Citizens Against Government Waste did some detective work to identify what it considers earmarks, even if Congress doesn't call them earmarks. They are projects that meet any of the following criteria:
Requested by only one chamber of Congress
Not specifically authorized
Not competitively awarded
Not requested by the president
Greatly exceeds the president's budget request or the previous year's funding
Not the subject of congressional hearings
Serves only a local or special interest
The Pig Book found $120 million tax dollars going to the military to research alternative energy. Sen. John McCain, R-Ariz., says that's a bad idea. He cites a Navy project that recently spent $400 per gallon for algae-based biofuel.
"That kind of experimentation should be done by private industry and then adopted by the military, not experimentation on the part of the military," McCain told CBS News. "It's not their job. And by the way, they don't do it very well."
Another Pig Book pick: the Army's M1 Abrams tank. The Pentagon wants to halt production to save money. But Congress stuffed in $255 million tax dollars to upgrade the tanks anyway, saying it'll preserve thousands of jobs.
"The Pentagon is in a budget crunch," says Schatz. "They're facing massive cuts over the next ten years. They have said clearly they don't want to spend the money on the M1 upgrade. Yet Congress added $255 million dollars, and part of that money was spearheaded by members in whose districts the parts will be made."
The Pig Book also flagged $5.8 million for the East-West Center in Hawaii meant to improve relations among Pacific nations. The center's recent projects include an endowment to honor President Obama's mother.