FOLLY BEACH - Beachgoers expecting cushy sand have been stepping gingerly lately to avoid the rocky path to the water from dunes to the high-tide mark near the pier.

"It's horrible. It's supposed to be soft," said Natalie Smith of Columbus, Ohio.

It's also bad luck, according to the Army Corps of Engineers: The chunks resembling limestone wound up on the beach because they were mixed-in with sand dredged from the ocean floor and pumped ashore for beach re-nourishment.

A contractor for the U.S. Army Corps of Engineers has hauled away truckloads of the rocks, said Mayor Tim Goodwin, but that is a short-term fix because more stones are redeposited when tides and wind shift the sands.

Goodwin said the beach rocks are a problem from 2nd Street East to 4th Street West. The chunks from the sea bed appear to be calcified remains of sea creatures or petrified wood or bone, he said.

The Army Corps offered to donate a $30,000 "rock-picker" to the city, but Goodwin said he nixed the deal because it would require Folly to buy a $100,000 tractor to pull the machinery.

"I didn't want to have to spend that much money to cover up their mistake," he said.

Getting beach-quality sand hinges on the results of samples obtained by drilling into the ocean floor at selected locations, said Corps Project Manager David Warren. "It's not an exact science," he said, explaining that an infinite number of samples to rule out any chance of "cemented sand" is impossible.

There was "no indication of that much cemented rock" in the dredged material, he said.

The sand was suctioned from the ocean floor and pumped to the beach from four miles offshore.

"Bad luck" played a role, Warren said.

"Occasionally you run into an area of cemented sand," he said.

The Corps is negotiating with the project contractor for one or two more rock clean-ups on the beach, but that is not likely a fix, he said.

"It's probably going to be a recurring problem," he said.

The beach on the rest of the island received "pretty good quality sand," he noted.

Overall, five miles of Folly Beach got a total of 1.5 million cubic yards of sand in a $30 million project. The federal government picked up 85 percent of the tab, and the city paid the rest, officials said.

Folly and the federal government have an agreement through 2043 for renourishment as needed, or about every eight years, to settle charges that island erosion was worsened by the Charleston Harbor jetties disrupting the flow of sand that would otherwise replenish the beach.

Goodwin said planning for the next beach renourishment is already underway.

Near the pier, beach worker Jesse Mattson said it is hard to drill down into the sand to place a beach umbrella.

"You just hit a ton of rock," he said.

Savannah, Tenn., resident Neal Smith said the rocks affect his tender feet.

"I'm not a fan of the rocks. It makes it a little tough," he said.

Reach Prentiss Findlay at 937-5711