With nearly $30 billion set aside for reconstruction projects in Iraq, it is the largest U.S. foreign aid project since the Marshall Plan.

One office is tasked with assessing how the money is being spent.

"Our job in simplest terms is to provide reporting on what the U.S. taxpayer is getting for their investment in reconstruction of Iraq," said Stuart Bowen, the special inspector general for Iraq reconstruction.

Click into the video tab to the right to watch a report by FOX News' Reena Ninan.

Bowen was viewed by some as a loyal Bush ally, but in the 18 months since he's been on the job, Bowen has become a prominent critic of some of the reconstruction efforts.

"We don't want to play an 'I gotcha' game with the managers here. What we want to do is identify issues that need review," Bowen said.

In a January report, Bowen concluded that the American-run leadership in Iraq, known as the Coalition Provisional Authority, or CPA, headed by Paul Bremer, failed to track nearly $9 billion during the 2003-2004 term.

"CPA should have had more than the controls they implemented to account for how that money was being used by the Iraqis. It was an enormous sum of money," he said.

Bowen is also reviewing ongoing projects in Iraq, including the progress of a $178 million water treatment plant in Erbil along the Great Zab River. The facility is supposed to provide clean drinking water for almost half the population in Erbil. In May, it will be handed over to the Iraqis who will learn how to operate and maintain the plant.

With water one of the critical resources that groups are fighting over inside and outside the country, efforts are being made to crack down on corruption. Just last week, an American was charged with paying hundreds of thousands of dollars in bribes and kickbacks to CPA officials. More criminal charges are expected.

"Fighting corruption is an everyday battle here that needs to be addressed because it means that it will save dollars that can be used to restore Iraq's infrastructure and promote its fledgling democracy," Bowen said.

Since Iraq's reconstruction takes place in a hazardous environment, more than a quarter of reconstruction money goes toward security. Despite the difficulties, Bowen said the special inspector general's office is going to continue to monitor where the American dollars are being spent.

Click into the video tab above to watch a report by FOX News' Reena Ninan.