401 Water Quality Certification
Under Section 401 of the Clean Water Act, DHEC certifies projects that require federal permits for the discharge of fill into wetlands and waters of the state. The purpose of the 401 Water Quality Certification is to ensure that the projects can meet water quality standards. During this review, DHEC staff will consider whether there are feasible alternatives to the project and all potential water quality impacts of the project.
Before any Section 404 permit from the US Army Corps of Engineers can be issued, Haile Gold Mine must receive a 401 Water Quality Certification from DHEC. On March 3, 2021, the Corps issued a Joint Public Notice soliciting comments on the proposed expansion of the gold mine. This public notice serves as an application to DHEC for a 401 Water Quality Certification. All comments submitted will be considered in DHEC’s Water Quality Certification process.
NPDES Permit #SC0040479
HGM is permitted to discharge treated wastewater and stormwater of a tributary to Haile Gold Mine Creek under a National Pollutant Discharge Elimination System (NPDES) permit issued by DHEC. This permit sets monitoring requirements and pollutant limits, as necessary, on the effluent from the wastewater treatment system. Duration of discharge, flow, pH, total suspended solids (TSS), total and free cyanide, sulfide, un-ionized hydrogen sulfide, hardness (as CaCO3), arsenic, cadmium, copper, lead, thallium, zinc, selenium, mercury, and whole effluent toxicity (WET) are all currently monitored by the NPDES permit.
Also, through the NPDES permitting process, groundwater in the vicinity of the wastewater treatment facility is monitored for copper, iron, sulfate (as SO4), field pH, total dissolved solids (TDS), filed specific conductance, depth to groundwater, and groundwater elevation.
The current NPDES permit for the Haile Gold Mine was issued on October 7, 2013. DHEC is currently reviewing a renewal application and two modifications to the permit.
- NPDES Permit & Rationale
- NPDES Permit Renewal Application (received 5/21/2018)
- NPDES Permit Modification (received 6/24/2019)
- NPDES Permit Modification (received 10/5/2020)
Wastewater Construction Permit
DHEC's Bureau of Water has also issued a wastewater construction permit to Haile Gold Mine, Inc. for an upgrade to the wastewater treatment system for the removal of thallium.
- Wastewater Construction Permit Application (received 10/5/2020)
- Wastewater Construction Permit (issued 3/17/2021)
- Letter of Approval - Summary of Pilot Study Results (March 5, 2021)
- Letter of Approval - Treatment Chemical Change (March 4, 2021)
Dam Safety Program
The Haile Gold Mine Duckwood Tailings Storage Facility (TSF), State ID # D4933, is a completely self-contained basin for storing mine tailings, which are the finely crushed rock and process water that has been through the milling and metal extraction process. The tailings are pumped from the mill to the TSF as a slurry. The tailings then settle out in the TSF and the water is evaporated off using natural evaporation and aided by floating evaporators when necessary or pumped back to the mill for processing operations. The water inside the TSF is considered “process water,” which means it has been in contact with the sodium cyanide solution and other chemicals used in extraction of gold, silver, and copper. There is no outflow to the environment. The soil embankment that surrounds the TSF is a complete perimeter berm that prevents inflow from streams or runoff. Rainfall is contained within the perimeter berm. The TSF is lined with 60-mil HDPE on the inside and up to the top of the embankment.
The resumption of operations at Haile Gold Mine in 2014 required creation of the Duckwood TSF. A permit application for construction of a new dam was initially received on September 7, 2012. The permit application called for a staged construction, with each stage increasing the height of the perimeter berm to expand the tailings storage capacity. The dam construction permit was issued on October 7, 2013. A NEPA review and Environmental Impact Statement (EIS) was required for Army Corps of Engineers permitting at that time.
The 2013 dam construction permit allows the TSF to be expanded in 4 stages (Stages I through IV), with each stage expanding the perimeter berm’s footprint outward as the height grows, to a top of dam elevation for Stage IV of 630’ AMSL (above mean sea level). The original EIS considered the final buildout of the TSF to Stage IV with accompanying footprint and impacts to Waters of the United States.
- Stage I – certified complete by DHEC on November 23, 2016.
- Stage II – certified complete by DHEC on October 7, 2020, bringing the top of the dam to elevation 585’ AMSL. The low point of the surrounding ground is on the south side of the TSF at elevation ~470’ AMSL, resulting in a maximum height of dam of 115’ for Stage II.
- At the completion of Stage IV, total height will be approximately 160’.
In July 2019, DHEC received a permit application for expansion of the TSF. The proposed design calls for the following modifications to the staging plan:
- Stages II and III are combined into a new Stage B with a top of dam elevation of 600’ AMSL
- a new Stage C with a top of dam elevation of 630’ AMSL
- a new Stage D with a top of dam elevation of 650’ AMSL (which will require the relocation of US 601 before construction begins), and
- a new Stage E with a top of dam elevation 670’ AMSL, corresponding to a final dam height of approximately 200 feet. The Draft Supplemental EIS considers buildout of the TSF to Stage E with accompanying footprint and impacts to Waters of the US.