by Bill Schlesinger
In the South of Georgia, the land of Pogo, lies Okefenokee Swamp, its waters held back from drainage to the sea by the presence of a ridge of sandy deposits known as Trail Ridge that extends from South Georgia into Florida. The Swamp harbors dense cypress forest and open water habitats with submerged aquatic vegetation. It is a popular recreation area for fishing, canoeing, and bird watching, which contribute much to the economy of the region.
Okefenokee is known as a black-water swamp, inasmuch as its waters have a rich brown color derived from dissolved organic acids. The shallow waters of the Swamp, varying seasonally from one to five feet in depth, are underlain by peat deposits, with radiocarbon ages extending to 6500 years ago. Trail Ridge appears integral to the presence of the Swamp, which would otherwise drain away to the Atlantic Ocean.
Now recently, an Alabama Company, Twin Pines LLC., has proposed to mine titanium from beneath Trail Ridge, in 8000 acres adjacent to Okefenokee National Wildlife Refuge. Titanium is used as a whitener for toothpaste, white paints, and cosmetics and as an alloy to produce strong, lightweight metals for a variety of specialized purposes.
One should question whether the mining activity, which will disrupt the normal flow of groundwater in this region, will be a danger to Okefenokee Swamp. First, the integrity of the Trail Ridge deposits will be altered, which could change their drainage characteristics, even if they are reconfigured. Second, the mining activity will use groundwater, which is predicted to drop the level of the regional water table and increase the hydraulic “head” between the Swamp and the underlying groundwater, promoting downward drainage. If the Swamp should drain, it will lose most of its value for recreational activities and leave the region vulnerable to forest fires.
An iconic landmark of the region, and the largest swamp in North America, is now vulnerable to these impacts owing to the Trump Administration’s vacating portions of the Clean Water Rule, which protected upland watersheds that are a source of downstream waters. Even though the Refuge is a Federal property, the provision of permits to mine in the area now rests solely with the Georgia Environmental Protection Division—an odd twist for the fate of a national treasure.
References:
Cohen, A.D. 1973. Possible influences of subpeat topography and sediment type upon the development of the Okefenokee swamp-marsh complex of Georgia. Southeastern Geology 15: 141-151.
Clark, J.F. and 4 others. 1997. A tracer study of the Floridan aquifer in southeastern Georgia: Implications for groundwater flow and paleoclimate. Water Resources Research 33: 281-289
Creveling, J.R., J. Austermann, and A. Dutton. 2019. Uplift of Trail Ridge, Florida by karst dissolution, glacial isostatic adjustment, and dynamic topography. Journal of Geophysical Research, Solid Earth. 123: 13354-13366
Schlesinger, W.H. 1978. Community structure, dynamics and nutrient cycling in the Okefenokee cypress swamp forest. Ecological Monographs 48: 43-65.
