In the term that begins on Oct. 6, the Supreme Court faces two cases that could have a major impact on construction firms, industry officials say.

KBR v. U.S. focuses on a whistle-blower's claims that KBR fraudulently billed the government for 2005 work at a water purification plant in Iraq earlier than work occurred. A lower court ruled in the whistle-blower's favor in 2013. The case's key question is whether a federal contractor can claim the same sovereign-immunity protections as the government.

Mike Kennedy, Associated General Contractors of America general counsel, says that if the justices uphold the lower-court decision, it could discourage firms from entering public-private partnerships (P3s). Kennedy contends that when contractors take on a traditionally governmental role, they should enjoy the same liability protections as the government. A ruling against KBR may have an "enormous impact on the [risks] contractors have to contemplate when they get into P3 programs," he says.

Perez v. Mortgage Bankers Association centers on whether federal agencies must seek public comments before issuing an interpretation of an earlier regulation. Maury Baskin, Associated Builders and Contractors general counsel, says the case could have a big effect on how agencies interpret and change rules without a notice-and-comment period. Noting many rule changes from federal labor agencies, Baskin says, "The ability of the business community to challenge executive overreach may hinge, in part, on the outcome of this case."

States and industry groups have asked the high court to hear their appeal of an April 2014 lower-court decision upholding the Environmental Protection Agency's 2012 mercury and air toxin rule. Sean Donahue, a Donahue & Goldberg LLP partner who represents the Environmental Defense Fund and other groups in the litigation, says he can't predict whether the Supreme Court will take the case. But he thinks the EPA is on solid legal ground in regulating powerplant emissions of mercury and other pollutants under the Clean Air Act.