A cement plant in Camden, N.J., shouldn’t be allowed to operate because it may be imposing an unfair pollution burden on a poor, minority neighborhood, a South Camden citizens group argued before a federal appeals court on Tuesday. A lawyer for the group told a three-judge panel of the 3rd U.S. Circuit Court of Appeals that the New Jersey Department of Environmental Protection was wrong to give the go-ahead to the plant before conducting a “disparate-impact” analysis to determine if the facility would affect minorities more than whites. The environmental-justice community is watching the case closely. The 3rd Circuit sided with advocates in an earlier environmental-justice case, but since then, the U.S. Supreme Court has made it harder for citizen-filed, civil-rights lawsuits to proceed.