Georgia Conservancy’s Public Comments Regarding Twin Pines, LLC Permit Application SAS-2018-00554

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August 29, 2019

Ms. Holly Ross
U.S. Army Corps of Engineers
1104 North Westover Boulevard, Suite 9
Albany, Georgia, 31707

RE: Comment Letter, Georgia Conservancy
Permit Application No. SAS-2018-00554
Twin Pines Site, Charlton County, Georgia

Dear Ms. Ross,

The Georgia Conservancy is pleased to provide this letter of comment to the U.S. Army Corps of Engineers (USACE) for Twin Pines Minerals, LLC heavy minerals, mine permit application number SAS-2018-00554, located on Trail Ridge in Charlton County, Georgia.

The Georgia Conservancy is a statewide conservation organization that works to develop solutions to protect Georgia’s natural resources through advocacy, engagement, and collaboration on conservation issues. The conservation, protection, and enjoyment of the Okefenokee National Wildlife Refuge for the people of Georgia and beyond has been a top priority for the Georgia Conservancy throughout its entire 52-year history.

The concerns and issues expressed in this letter center on three vital landscape features that are susceptible to project impacts:

  • Okefenokee National Wildlife Refuge: One-third of the mining site drains to streams that discharge to the Okefenokee, one of Georgia’s most precious ecological sites and an internationally-recognized treasure. The Okefenokee’s 438,000-acre biodiverse ecosystem is home to the headwaters of two notable rivers, the Suwannee and the St. Marys, and contains nearly 353,981 acres of federally-designated wilderness. Stephen C. Foster State Park, located within the Okefenokee National Wildlife Refuge, was recently designated a Gold-tier International Dark Sky Park.

  • St. Marys River: Much of the site drains to this southernmost river on Georgia’s coast. This river is a blackwater stream ecosystem home to several threatened and endangered species that could be impacted by changes in surface water brought by mining, including alterations to the pH and turbidity.

  • Trail Ridge: Trail Ridge plays a significant role in the hydrogeology of this area of Georgia; this saturated, low sand ridge acts as a sill for the eastern side of the vast Okefenokee Swamp. Trail Ridge is also a critical element of Georgia’s State Wildlife Action Plan (SWAP), as it provides a vital ecological link northward from Florida to the Altamaha River.

The mining plan shows the stream and wetland impacts are aggressive and on a scale not seen in this section of Georgia. On the project site, 1,201 acres of 2,414 acres are wetlands (Figure 4.1a). Impacts affect roughly half the site, including temporary impacts to 522 acres of wetlands and 2,454 linear feet of tributaries, and permanent impacts of 65 acres of wetlands and 4,658 linear feet of tributaries.

The Georgia Conservancy seeks to have the following issues addressed in the USACE wetland impact permitting (and forthcoming Georgia Environmental Protection Division’s Open Pit Mining Permit) process for this first phase of a proposed multi-stage mine.

Stream and Wetland Impacts: the permit application is for the first phase, comprising of 2,414 acres, on an overall tract of 12,000 acres. The applicant has made it clear that this permit area is part of a larger project. How will the cumulative effects of the mining in the remaining tract be included in the environmental assessment (EA)?

The limited detail provided in the mining plan shows the draglines moving back and forth (east-west) in the active mining area, requiring reconstruction of impacted streams and wetlands. The permit application lacks the stream and wetlands reconstruction details which explain the means and methods employed for streams and wetlands reconstruction (biotic and abiotic). Will credits be purchased to offset the temporary impacts of reconstruction on the reclaimed land?

Groundwater Issues: Georgia Conservancy has reviewed the application to discern the probable impacts on-site and in the adjoining landscape. The application outlines a plan to excavate an average of 50 feet below the land surface, sort the material with a wet mill, and backfill in a 24-hour per day operation. The process exposes approximately 25-40 acres per month of ground. The site has shallow groundwater with much of the area having groundwater within two feet of the ground surface.

It is vital to understand if there are potential impacts that mining operations and soil homogenization on the water level of the Okefenokee. Changes in groundwater flow from mining operations, which lower the area water table, could also have an impact on the adjacent (Trail Ridge) isolated wetlands.

Page 559 of the USACE application indicates a series of four reports are forthcoming. These reports provide critical information needed to analyze the merits of the project. Without this information available during the comment period we have limited ability to review two of the most critical aspects of the project; 1) the hydrogeology of the area and 2) the methodology and feasibility for stream and wetland construction after mining. The four anticipated reports focus on the following:

  • “Pumping Tests Conducted in the Twin Pines Project Area” – The activities associated with and interpretation of two pumping tests conducted in the study area are the subject of this report.

  • “Subsurface Hydrogeology of the Twin Pines Project Area, Trail Ridge, Georgia” – This report will summarize the regional geology and hydrology of the Trail Ridge area, document drilling efforts (including boring logs), identify subsurface hydrogeologic units, present cross-sections and subsurface maps of hydrogeologic units, define the potentiometric surface of the surficial aquifer system, and develop a conceptual hydrogeological model of the study area.

  • “Hydraulic Properties of Subsurface Soils in the Twin Pines Project Area, Trail Ridge, Georgia” – Measured hydraulic and other properties of the subsurface soils are the subject of this report.

  • “Groundwater Models of the Twin Pines Project Area, Trail Ridge, Georgia” – This report will document the groundwater models produced to evaluate the pre-mining conditions, the impact of mining activities on groundwater flow, and the post-mining groundwater conditions.

Many of the above comments relate to habitat reduction and fragmentation on the unique Trail Ridge sands. The Georgia Conservancy is concerned that the proposed mining operations along Trail Ridge may adversely impact wildlife habitat within and nearby the site.

These potential impacts include:

  • The cumulative loss of habitat for the gopher tortoise, a keystone species and one listed as threatened by the State, along with other notable species that depend on the tortoise (Gopherus polyphemus), including the eastern indigo snake (Drymarchon couperi) and gopher frog (Lithobates capito).

  • Changes in fire frequency and intensity as a result of groundwater alternations. During the last ten years, there have been two major fires in the area of this site. Thus, there is significant concern related to fire management in and around the Okefenokee.

  • Diminishing of water quality and quantity necessary to sustain fish populations in the St. Marys River. Both the Shortnose sturgeon (Acipenser brevirostrum) and Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) are present in the St. Marys River. Sturgeon use freshwater rivers such as the St. Marys to spawn and as juvenile habitat. Under the Endangered Species Act, both species are “Endangered throughout its range.” The St. Marys River is designated a Critical Habitat for the Atlantic Sturgeon. The SWAP has also identified the St. Marys as a high priority watershed.

More than 600,000 visitors per year visit the Okefenokee National Wildlife Refuge and its surrounding State and local parks. The combination of noise, light, and other impacts for wildlife and visitors to the area from mining on this site is of significant concern. The Okefenokee is essential to the economy of Charlton and nearby counties. The citizens of the area should have a chance to learn more and discuss the impacts.

Thank you for extending the comment period for this application. However, the application still lacks essential information from the applicant. The Okefenokee Swamp is a unique ecosystem, and Trail Ridge is an integral element. Given that nearby mining could impose significant impacts on this ecological treasure, the Georgia Conservancy respectfully requests the development of a full Environmental Impact Statement for cumulative impacts over the entire Twin Pines tract (12,000 acres).

Please let me know if you have any questions or need any information.


Charles H. McMillan, III

Natural Resource Director
The Georgia Conservancy, Inc.

Cc: Bart Gobeil, President, The Georgia Conservancy, Inc.

For more information on the proposed mining along Trail Ridge, please visit: