By Tennille Tracy Of DOW JONES NEWSWIRES WASHINGTON (Dow Jones)--U.S. lawmakers are taking increased interest in the way BP PLC's $20 billion oil-spill fund is being administered, highlighting the scrutiny likely to follow the fund's process of paying claims to workers and businesses affected by the oil spill. In a hearing Wednesday before the U.S. House Judiciary Committee, fund administrator Kenneth Feinberg attempted to clarify the process he'll use to deploy the fund, while acknowledging sticky situations that are likely to pose a problem. In particular, Feinberg said he'll face challenges when attempting to determine just who qualifies for compensation under the fund, given the number of ripple effects the oil spill has on businesses around the country. In what has become a routine part of his recent speeches, Feinberg raises the question of a hypothetical restaurant that loses money because the oil spill has forced it to remove a popular seafood dish from its menu. Feinberg said he'll also struggle to determine whether workers or businesses are losing money because of the oil spill or because of the Obama administration's moratorium on deepwater drilling. "That is going to be tough for me, evidentiary wise, to distinguish," Feinberg said. Feinberg gained experience in overseeing large compensation funds while administering the fund to help victims of the Sept. 11 attacks. BP agreed to set aside $20 billion for its oil-spill fund in June, hoping to streamline the process of paying workers and businesses affected by the spill. The fund will start writing checks in August, taking over a claims process that BP is overseeing. BP has already paid $200 million in claims. It remains to be seen whether $20 billion will be enough to cover the full value of claims, Feinberg said. - "I hope it's enough, and I take some comfort in the fact that if it isn't enough, BP has promised ... to honor its supplementary financial obligations," Feinberg said to reporters. "So $20 billion is not the be-all, end-all if needed." In the hearing Wednesday, one lawmaker asked Feinberg to change the claims process to account for workers who suffer health problems or financial damages after they have accepted payment from the fund. These situations would pose a problem, said Rep. Jerrold Nadler (D.,-N.Y.), because workers who receive payment from the fund waive their right to sue BP in the future. Another lawmaker, Rep. Loretta Sanchez (D., Calif.), urged Feinberg to determine whether undocumented workers could receive compensation. -By Tennille Tracy, Dow Jones Newswires; 202-862-6619; tennille.tracy@dowjones.com (END) Dow Jones Newswires July 21, 2010 13:28 ET (17:28 GMT)