In a lightly populated area of northern Charleston County, developers are planning two major projects that could bring hundreds of new homes to the doorstep of the Cape Romain National Wildlife Refuge.

But unlike many development projects, the new communities will rely on septic tanks to dispose of sewage, a potentially risky process in the marshy, low-lying ground of South Carolina’s Lowcountry.

It’s a major concern because of the threat septic tanks present to creeks, groundwater and public health — and because the state’s environmental protection agency isn’t looking carefully enough at whether they will fail.

That’s the assessment of three environmental organizations, which have filed a lawsuit seeking to tighten South Carolina’s oversight of new septic tanks in vulnerable coastal areas. The Nov. 10 suit against the S.C. Department of Health and Environmental Control, filed in state court, is an effort to force DHEC to use the state’s coastal management law to review requests for septic tanks. The state doesn’t apply the coastal law now, the lawsuit says.

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