A December 2007 revision of Financial Accounting Statement No. 141 requires that a buyer recognize all assets and liabilities, including environmental liabilities, in a transaction at fair value. The new rules arose from the 2002 Sarbanes-Oxley Act, which established new or enhanced financial reporting standards in the wake of major corporate scandals including the collapse of Enron.

"The accounting standards board saw this as a way of getting around liability, making it much more difficult to get out of reporting liabilities," David Robinson, vice president of remedial services for The Whitman Co.--an East Brunswick, N.J.-based environmental engineering and management firm--says to GlobeSt.com. Robinson, with Edward Sullivan, a Whitman project manager, has written on the effect of these changes on the transaction process. Outside experts, they say, will need to provide detailed analyses regarding the need for environmental investigations or remediations, the technologies to achieve it, relationships with the regulators, range of potential outcomes, the "expected value" of the liability and even the possibility of natural resource damages.

Remediating brownfields are not the only cause for a greater reliance on consultants. As "green" building continues to take off, developers are looking for outside expert assistance even as they build internal staffs. "It's never been a bad time to be a consultant," said Jerry Yudelson, a principal of Tucson-based Yudelson Associates, a green building consultancy. "There is a huge interest in green and sustainable building."