The U.S. Supreme Court handed down the last decisions of its October 2012 term on June 26, issuing rulings in closely watched affirmative-action and same-sex-marriage cases. But perhaps more significant for the construction and engineering industry are the cases the court agreed to hear in its next term.

The first, National Labor Relations Board v. Noel Canning, could have significant ramifications in the way presidential recess appointments are made.

The second, Environmental Protection Agency v. EME Homer City Generation, will review a decision by the D.C. Circuit Court of Appeals that struck down EPA's cross-state air-pollution rule and left in place a clean-air interstate rule from the George W. Bush administration.

Court observers say both cases are important. A broad ruling by the court in the NLRB case could limit the president's ability to put his personal stamp on the board and other federal agencies as well as federal courts.

The air-pollution case will take a close look at a law that is intended to save thousands of lives each year, environmental advocates say.

The federal appeals court held in NLRB v. Noel Canning that the appointments of Sharon Block and Richard Griffin, both Democrats, and Terence Flynn, a Republican, to the nation's top labor panel were invalid because they were not made during the period after the Senate goes home for the year and before it starts the next session—the only time, the three-judge panel said, that presidential appointments can be made. Obama nominated Block, Griffin and Flynn to the board in January 2012 while the Senate was in a pro forma session, when only one or two senators were on the chamber's floor each day.

"These particular recess appointments cast a cloud of uncertainty over the board that needs to be resolved," said Rachel Brand, vice president and chief counsel for regulatory litigation, the U.S. Chamber of Commerce's National Litigation Center, at an end-of-term briefing for reporters. She said that since the D.C. Circuit Court of Appeals ruled, the board "has acted as though nothing happened and ruled on hundreds of cases."

Josh Goldstein, an AFL-CIO spokesman, says, "We hope the Supreme Court will reverse the D.C. Circuit's radical ruling. But workers can't wait for the Supreme Court—we need the Senate to confirm the bipartisan package of NLRB nominees now." The Senate's labor committee approved Obama's slate of five nominees in May.

In the EPA case, which will be consolidated with a similar case filed by the American Lung Association, the court agreed to consider the legality of the agency's rule seeking to reduce pollution that crosses state lines. A three-judge panel from the D.C. Circuit Court ruled 2-1 in August 2012 that the EPA had imposed "massive emissions-reduction requirements on upwind states without regard to the limits imposed by the statutory text" of the Clean Air Act (CAA). In her dissent, Judge Judith Ann Rogers wrote that the court disregarded "the plain text of the CAA and this court's settled precedent interpreting the same statutory provisions at issue" in the case.

A ruling in another environmental case, Koontz v. St. Johns River Water Management District, was issued on June 25. That case broadened the rights of property owners and developers to challenge decisions by governmental authorities to impose certain conditions on landowners requesting permits.