Spent lead pellets that accumulated at an old skeet range and are now scattered on Kaimalino Beach — posing a public health risk — will be removed using a vacuum cleaner and a concept from old gold mining days.

Crews will be on scene starting Monday to clear lead material from a pathway to the beach and along fossilized coral in front of 23 homes.

By the time they're finished in one to two weeks, they will have scoured more than 10,000 square feet of fossilized coral shoreline and removed hundreds of pounds of lead that could pose a threat, particularly to children.

"At this point, I anticipate that the operation will net a few hundred pounds of pellets and significantly reduce the risk of unintended ingestion exposure for small children," Fenix Grange, a supervisor in the state Department of Health office that deals with hazards, said in an e-mail.

Cost of the project is $50,000.

The area outside Marine Corps Base Hawaii's Mokapu gate was a skeet-shooting range for about 40 years, and thousands of pounds of lead pellets were shot into the ocean and at beachside targets before the range closed in the 1970s. In the mid-1990s, the state health department concluded that the lead posed little danger unless it was ingested.

A recent area survey found an increase in the number of pellets in an area that is eroding at Kapoho Point. That situation is a concern, said Cal Miyahara, state project manager for the health department's Hazard Evaluation and Emergency Response Office.

"Based on our testing ... if a child were to consume one pellet, it could be a potential problem," Miyahara said, adding that there have not been any reports of lead poisoning from the area since the department began monitoring it. "So we want to try to help reduce the risk."

The project isn't expected to collect 100 percent of the lead there because lead breaks up into smaller pieces and even dust, he said. But the contractor should be able to collect the larger pieces and even some of the smaller ones using techniques that could be considered low-tech.

VACUUMING CORAL

A modern version of an old sluice box used by gold miners will remove the sand from the pellets, and an outdoor shop vacuum will suck up pieces in the coral rocks along the shoreline, Miyahara said.

After researching the possibilities, Miyahara said he found two ways to collect the particles, by size or by weight. Since the sand and pellets are of similar size, they decided to use the weight method and the sluice box.

Sand, lead and debris will be hand-fed into the box and seawater will be pumped over the material, he said. Water, sand and debris will flow out into a sock filter, with the water being returned to the ocean.

"The heavier lead pellets will sink toward the bottom of the sluice box and get stuck in the riffle (slats) on the bottom," Miyahara said. "The sand, water and other debris will just flow over the top."

The project should be completed by Feb. 24, he said. The reclaimed lead will be sent to the Mainland for reuse.

The state isn't sure how many pellets are out there, but this pilot project will focus on the pathway, which has relatively thin sand deposits, Grange said.

"These are the areas where pellets pose potential risk."

According to the federal Agency for Toxic Substances and Disease Registry, lead can affect almost every organ and system in the body. The main target for lead toxicity is the nervous system, both in adults and children, though children are more vulnerable to lead poisoning.

Miyahara said subdivisions were built atop the skeet range but the area was covered with fill, and the eventual topsoil and grass in yards act as a cap to any lead below the surface, guarding against exposure.

MORE TO DO?

John Stestow, who lives in the area but not near the cleanup sites, said he believes any lead on his property is buried under several feet of fill. The cleanup is good, he said, though he wondered about lead in the water.

"I kind of wonder if it's in fish," Stestow said. "A lot of people come here to fish out on the point."

Knud Lindgard, a Kailua Neighborhood Board member who has been after the state for decades to clean up the mess, was glad it is getting done but thought the federal government should pay under a special program that cleans old hazardous sites.

Lindgard predicted that once the project gets under way, the contractor will find bigger problems.

"They've completely disregarded that at one time or other there was a total of six ranges involved," he said. "They're only doing half of it."

The pilot project is being paid for by the state with the understanding that it could seek federal funds later, Miyahara said. The pathway is about 700 square feet and the coral rocks that are being vacuumed cover about 10,000 square feet, he said.

"We can elect to ask EPA (the U.S. Environmental Protection Agency) to pay, but not at the moment," he said. "We're going to do post monitoring to see if the problem recurs."