Some of the top golfers in the world have been unable to distinguish between sand bunkers and waste areas, also known as waste bunkers. In 2010, Dustin Johnson played a shot out of a sandy area outside the ropes on the 72nd hole of the PGA Championship at Whistling Straits in Kohler, Wisconsin. Assuming he was in a waste bunker, he grounded his club behind the ball in an area that had been defined by the PGA of America as a sand bunker. The two-stroke penalty for grounding his club in a sand bunker knocked him out of a playoff. Usually, however, it's pretty easy to tell the difference between bunkers and waste areas.
A bunker is defined by the USGA Rules of Golf as a "prepared area of ground, often a hollow, from which turf or soil has been removed and replaced with sand or the like." The key word is "prepared." Usually it is obvious when a course designer has built a bunker, because it is well-maintained, raked and smooth. When you are in a bunker, you are not allowed to ground your club in the sand or hit the sand on a practice swing.
The USGA says the term "waste bunker" is one of the "Top 10 Misused Terms in Golf." The Rules of Golf do not even mention waste bunkers or waste areas. When golfers refer to waste areas or waste bunkers, they are describing areas that don't fit the definition of either hazards or bunkers. They might best be described as unmaintained areas on the course that are natural to the surroundings. If you are in one of these areas, you may ground your club behind the ball and pick up loose impediments around the ball, such as rocks or sticks, and hit the ground on your practice swings.
Because a waste area or waste bunker is not a hazard, there is no penalty if your ball winds up in one. It is treated as an area that the USGA defines as "through the green," which includes the fairway, rough and all other areas on the course that are not bunkers or hazards. The penalty for grounding your club in a sand bunker, or hitting the sand on a practice swing, is two strokes.
The PGA of America decided to define all of the sandy areas on the Whistling Straits course in 2010 as sand bunkers instead of waste bunkers. Since the course has numerous bunkers and patches of sand -- close to 1,000 -- the intent of the PGA of America was to eliminate confusion.
Some said Johnson should have asked for a ruling. As the Orlando Sentinel reported, however, Johnson told CBS, "I looked at it a lot, and it never once crossed my mind that I was in a bunker." He added that he thought the surface on which his ball sat was "a piece of dirt" trampled down by the crowd.