Drilling in the Chequamegon Forest
Drilling plans underway for gold deposits near Wausau and in Chequamegon National Forest
(Wausau, WI) If Toronto-Ontario, Canada based GreenLight Metals has its way, the winter of 2022-2023 will be a busy time for metallic sulfide mine development in Wisconsin. GreenLight has submitted plans to start exploration drilling at many of Wisconsin’s most loved natural features – The Chequamegon-Nicolet National Forest, The Ice Age National Scenic Trail, and The Dells of the Eau Claire State Natural Area, are all being targeted.
Project documents here: https://dnr.wisconsin.gov/topic/Mines/Projects.html
GreenLight has plans for a 450-foot deep open pit mine near the Dells of the Eau Claire SNA where the Ice Age Trail has a popular segment. The Wausau-Reef Gold Deposit is located between Birnamwood and Wausau. The DNR received GreenLight’s Notice of Intent for exploration drilling on October 7, 2022. The exploration drilling in wetlands includes 9 boreholes up to 650 feet deep. The wetlands form the headwaters of Mole Brook. Mole Brook is a Class 1 Trout Stream and tributary of the Eau Claire River that flows through nearby Weston Wisconsin. 1,000 to 2,000 gallons of water a day will be taken from these sources and mixed with chemicals to lubricate the drill tooling. Drillers are free to choose from over 200 approved chemical products on the DNR’s list. GreenLight’s plans indicate Halliburton’s EZ-MUD might be one of lubricants they select for use. The Safety Data Sheet for EZ MUD indicates it is toxic to fish and aquatic plant life. Many of the drilling products on the DNR’s list warn of extreme toxicity and potential harm to groundwater.
DNR Approved Drilling, Filling & Sealing Products: https://dnr.wisconsin.gov/topic/Wells/drillerPumpInstall.html
Roadways are planned to be bulldozed and trees cleared in the wetland to accommodate drill sites and heavy equipment. Plans call for 4-inch to 6-inch steel casing to be drilled through glacial overburden (sand, gravel, rocks) and into solid bedrock to prevent cross contamination between aquifers or introduction of contaminants to groundwater (drinking water). Smaller diameter diamond-impregnated drill bits (3-inch or 3-3/4-inch) are inserted into the steel casing and drilling continues through bedrock to retrieve solid rock cores for analysis.
Hazardous wastes (drilling fluids, sulfuric acid, and drill cuttings) will not be allowed to spill over and seep into wetlands. These wastes will be captured inside recirculation tanks located at each drill site and then disposed of in earthen dug pits at higher elevations on the property.
Before leaving the sites, GreenLight is required to fill the holes that penetrate groundwater with cement in seemingly reverse order. The holes must be filled from the bottom back up to the top by using a small diameter conductor pipe. The pipe is inserted into the steel casing and cement slurry is then pumped to the bottom of each hole. The casing and conductor pipe are then lifted and removed simultaneously so as to keep the ends submerged in cement the entire time. The intent is to keep groundwater from rushing in and further diluting the cement mix. Each 650-foot deep drillhole requires over 7,000-pounds of cement to fill. Heavy cement trucks will have to traverse the wetlands to deliver the cement. Mixing all the required cement on site by hand in winter is unrealistic. Drilling and filling is planned to take place round the clock.
GreenLight’s plans for mine development inside the National Forest in Taylor County at the Medford-Bend Copper-Gold Deposit are similar to the plans for Wausau-Reef. GreenLight also recently submitted plans to drill in wetlands on those public lands. The Taylor County drill site has groundwater that drains into the Yellow River. The Yellow River is part of the Lower Chippewa River Basin that reaches the Mississippi River near Eau Claire Wisconsin.
Lower Chippewa River Basin info: https://dnr.wisconsin.gov/topic/Watersheds/basins/lowerchip
For both projects it is unclear if threatened or endangered animals or plants will be affected. The reports supplied by GreenLight to the DNR specifying what species might be harmed are not part of the documents disclosed to the public.
The DNR only has 15-days to review GreenLight’s submitted plans. Mining development is off to a fast start after the repeal of Wisconsin’s Prove It First Law that required an example of a single mine that did not harm groundwater. Although an example of a non-polluting sulfide mine has never been found, the Wisconsin Legislature implemented Assembly Bill 499 and Act 134 in 2017 to make mining easier for companies like GreenLight to develop mines in Wisconsin.
Assembly Bill 499 history: https://docs.legis.wisconsin.gov/2017/proposals/ab499
Wausau-Reef Mitigation Standards: https://dnr.wisconsin.gov/sites/default/files/topic/Mines/Exhibit_A-Mitigation_Standards_Redacted.pdf
Wausau-Reef Wetland Delineation: https://dnr.wisconsin.gov/sites/default/files/topic/Mines/Attachment_2-Wetland_Delineation_Confirmation.pdf