Parts of the lower southern portion of North Charleston are polluted.

City leaders want to inventory these ground sites with an eye toward cleaning them up, either for development that could boost the tax rolls or as parks in "gateway" locations leading into the city.

North Charleston recently received a $400,000 Environmental Protection Agency grant to assess buried pollutants, ranging from trash to hazardous materials and petroleum tanks.

The grant comes under what the government has labeled its "Brownfields" program, which covers areas thought to have been exposed to pollutants. The opposite of a brownfield would be a "greenfield" -- undeveloped lands judged to be relatively free of pollutants.

The target area is the southern half of North Charleston, where decades of Navy and industrial operations meant many residues were left behind. So far, about 40 properties have been mapped with a goal of prioritizing the ones where efforts could be the most productive.

Officials admit the cleanup will be a long-term effort aimed at revitalizing areas where blight dominates and fear of unknown pollutants will keep developers away.

"We're simply trying to create redevelopment opportunities," said Tom Hutto, a professional geologist with GEL Engineering LLC, who said the target area includes properties south of Interstate 526.

Cleanup neighborhoods, such as Chicora-Cherokee, represent a potential gold mine of opportunity, Hutto said. The area offers rail and highway access and is close to downtown Charleston. "It has so much potential," he said.

Cleaning up the land -- or at least identifying costs associated with properties that can be recovered -- can go a long way toward helping developers decide to move into North Charleston, Hutto said. For example, if a prime but vacant property has a $200,000 cleanup bill, but is potentially worth $2 million in investment returns, the study will help identify the best targets, he said.

City Councilman Michael Brown, whose district includes the city's southern tip, said efforts like grants may be the best step toward "restoring those properties back to use."