Concerns about exploration drilling at the Wausau-Reef gold deposit in Marathon County
The long known gold deposit 10-miles east of Wausau is being considered for a 450-foot deep open-pit gold mine. Although gold is in abundance and already stored in vast quantities in bank vaults and jewelry collections around the world, advocates for the project are claiming that the world needs more for the new “green economy”. This is an unsupported claim as the manufacturers of smart phones and computers confirm there are only trace amounts of gold in their products and they are moving away from the mineral. However, even the small amount of gold contained in a smart phone is vastly more worthwhile recycling rather than digging a new gold mine. In fact, one ton of smart phones contain 300 times more gold than one ton of gold ore. This confirms that the notion that constructing a new gold mine is an unwise and unneeded enterprise.
If more gold is needed, manufactures can simply recycle old devices or go to the vaults and get some of the already excavated gold for their uses. Jeopardizing the health of the residents in water saturated Marathon County with a 45-story deep open-pit mine is not worth the environmental risk. But some want to start drilling hundreds of exploration holes as soon as possible.
If the gold isn’t needed – then the drilling isn’t needed!
The Depth of Groundwater at Wausau-Reef site is a mere zero to 20-feet – meaning the groundwater aquifer that people get their drinking water from is at the earth’s surface. As the drill tooling advances downward it emits toxic drilling fluids through ports in the drill-bit’s leading edge. Chemicals injected into shallow groundwater increases the likelihood of widespread groundwater contamination. The exploration company plans on drilling 100 to 125 boreholes in the first phase of a project that would last three to five years. The Wausau-Reef site is situated in the middle of an area of Exceptional & Outstanding Waters and Classified Trout Streams. A multitude of sensitive features make it clear that this area will be negatively impacted should the first phase of drilling go forward.
This comes at a time when PFAS contamination is emerging as a statewide problem.
Evidence confirms that drilling for minerals is a major source of PFAS contamination. The DNR has a list of 210 chemicals approved for use to drill holes into groundwater aquifers on a statewide basis. These products have never been tested to determine if they contain PFAS forever chemicals. Reading the Safety-Data-Sheets (SDS’s) for the products reveals their toxicity. Warnings indicate they should never come in contact with groundwater, they are toxic to animals & plants, and that they may cause cancer. Chemical list here: https://dnr.wi.gov/topic/
The planned exploration drilling projects near Wausau and in the Chequamegon-Nicolet National Forest near Medford will utilize these products. The Wausau-Reef project is between Wausau and Birnamwood at the intersection of Thornapple Creek Road and Gold Dust Road (formerly Partridge Rd). See the project location map on page 17 of the plan documents for the Wausau-Reef project.
Plans to begin drilling can be found here: https://www.greenlightmetals.
The problems of drilling with toxic chemicals are made much worse because the targeted gold deposit is bound up in sulfuric acid bearing rock. In fact, the ratio of gold to sulfuric acid waste rock is as low as one gram of gold to as much as 3-tons of acid waste rock. That is less than the weight of a paperclip of gold for every 6,000-pounds of waste rock. When disturbed, the acid bearing rock formulates sulfuric acid that migrates through the water aquifer. The sulfuric acid loosens up (called mobilizing) heavy metal toxins like lead, mercury and arsenic, that then poison groundwater that people drink every day.
A DNR meeting, at which the NSF confirmed no one is testing drilling fluids for PFAS content, revealed the DNR does not know what is actually in the chemicals on their approved list. Most importantly, the DNR does not know if there are PFAS in these products. Any claim to the contrary is not supported by factual evidence.
Another DNR meeting, at which the public called for action to stop further PFAS contamination from drilling fluids, suggested the DNR not approve any future exploration drilling projects until the products are first tested to confirm they do not contain PFAS. It is irresponsible to approve projects that use untested chemicals that likely exacerbate the PFAS contamination crisis.
As recently as 2020 the DNR allowed the use of a drilling fluid called “EZ MUD” manufactured by oil industry giant Halliburton. Although the Safety-Data-Sheet (SDS) for EZ MUD indicates it is highly toxic and should never come in contact with groundwater (drinking water), it was used in the headwaters region of the Wolf River at the Schoepke Site. Any company wanting to drill exploration holes is free to choose EZ MUD or any of the over 200 other untested chemicals on the list of DNR Drilling Fluids.
In an effort to try minimize contamination brought on by drilling into sulfuric acid rock formations while using drilling lubricants that likely contain PFAS, the Wisconsin State Statutes have a chapter on how the process must be done. Wisconsin Chapter NR 130 has four pages of specific requirements for drilling and filling exploration drillholes. An exploration driller must follow the procedures in NR 130. Questions about the process must be answered prior to drilling so that contamination is avoided.
The first process – placing the casing and drilling:
1) A steel casing (a hollow round steel tube that has an outside diameter, and inside diameter, and a wall thickness that define its size) needs to be drilled or pounded into and through the unconsolidated formation (water, soil, rocks, sand and gravel) that extends from the surface of the earth down to the solid bedrock. The casing must also penetrate into the solid bedrock by approximately five feet. The purpose of the casing is to isolate the groundwater from the drilling process that takes place later. The casing also holds the unconsolidated sand, gravel and rocks from caving into the drillhole and binding against the rotating drill tooling. No use of any toxic chemical is allowed when initially placing the casing because any chemicals used will contaminate the groundwater. The casing must be in-place before any drill-bit tooling or drill-rod (drill stem) is used to start the actual drilling process. How steel casing (with no cutting edge) is advanced through the rocks, sand and gravel and into solid bedrock needs to be explained.
2) With the casing in-place and sticking out and upward from the earth by one or two feet, the drill tooling is inserted into the casing. The drill tooling must be small enough to fit inside the casing. The outside diameters of the drill-bit and drill-rod must be smaller than the inside diameter of the casing. There must also be enough clearance between the drill tooling and the casing to allow for drill cuttings (chips of rock and drilling fluids) to pass upward and out of the exposed top end of the casing. Clearance in the range of ¼-inch to ½-inch is necessary. If the drilling company cannot explain a compatible relationship of sizes it would be an indication that hazardous wastes will not be contained.
3) When the drilling starts there is immense friction and heat. The driller needs to lubricate and cool the rotating diamond-head drill-bit. This is accomplished with the use of chemicals listed on the DNR Drilling Fluids approved list of products. The drill-bit’s leading edge has hollow ports through which drilling fluids are emitted. Drilling into solid bedrock requires that drilling fluids be present at the interface between the drill-bit and the rock. The DNR knows that these products are toxic and must not come in contact with groundwater. That is why NR 130 requires the drilling process be fully confined inside a steel casing. The objective of the drilling is to retrieve solid rock cores from the sulfuric acid bearing mineralized bedrock for laboratory analysis. If the drilling company omits a detailed description of the placement methodology and use of steel casing to confine the toxic drilling process it is forewarning that environmental contamination is imminent.
4) Since the drilling is confined inside a casing, the only supposed opportunity for toxic drilling fluids to contact the ground or water is when drilling fluids and cuttings come out the top of the casing. NR 130 requires a plan to isolate drilling fluids, drill cuttings, any pollutant-bearing minerals or materials, drilling additives, and waste materials, from leaching into the environment. Because groundwater is at the surface at Wausau-Reef, there is no option in NR 130 to dispose of waste on-site. It is forbidden to excavate a pit in the mud to capture these liquid and solid wastes and just bury them. These toxic wastes can’t simply overflow out from the top of the casing and flood the surrounding area. These wastes must be removed and disposed of in an environmentally sound manner. If the waste was left on the surface of the saturated wetland it would leach into groundwater forever. Since the expectation is that the drilling project will encounter sulfuric acid bearing rock, the waste must be disposed of at a lined and licensed, engineered solid waste facility. The location of an approved facility is unknown and needs to be specified prior to the start of drilling.
The next process – filling and abandoning each drillhole:
1) All drillholes shall be filled from the bottom of the hole upward to the ground surface with cement. Because the filling will take place underwater, the cement must be applied through a conductor pipe that is long enough to reach the bottom of each drillhole. Holes could be hundreds of feet deep. Conductor pipes are usually 1-inch in outside diameter so that they are small enough to fit inside the casing. Since each drillhole requires the use of a casing because of the unconsolidated soil characteristics at Wausau-Reef, the casing and the conductor pipe must be removed concurrently – keeping both the casing and conductor pipe submerged in the liquid cement throughout the filling process. The concept being that as the casing is removed; the drillhole is immediately filled with cement so as to isolate groundwater from flowing into an open cavity that has toxic drilling fluids and sulfuric acid in it. Because the mix ratio of the cement is so heavily diluted with 6-gallons of water to 94-pounds of aggregate-lacking cement, and the cement is being placed in additional underground water, the effectiveness of this procedure is highly questionable. Since the drillhole is confined fully underground there is no way to inspect the process to confirm any level of success.
2) If any drillhole encounters flowing water or penetrates an aquifer under artesian pressure such that groundwater flows at the ground surface, approval of containment of such flow and the method of eventual abandonment of the drillhole must be obtained from the DNR prior to abandonment. The drilling company needs to explain how they will comply with NR 130 filling requirements prior to the start of drilling.
The drilling fluids need to be tested to confirm they do not contain PFAS.
The drilling and filling of exploration holes in the groundwater saturated region of the Wausau-Reef deposit pose significant environmental risks to all living things in the region. The chemicals used as drilling fluids that enter the environment are approved for use although they have never been tested to confirm they will not be emitting PFAS into groundwater. Further PFAS contamination needs to be prevented with the common sense requirement to pre-test all chemical products prior to use.
The drilling and filling procedure required in Chapter NR 130 requires the use of a steel casing to confine the contamination and fully isolate toxic emissions from entry into groundwater and the environment. The drillhole abandonment requirements include filling the holes from the bottom upward with a questionable slurry of cement. However, all of this would be made a moot point if the entire region was subsequently excavated to form a 450-foot deep open-pit mine. Since the area has so much water, numerous dewatering pumps would have to operate non-stop for years to keep the incessant rush of water from flooding the deep pit. This would create a major outflow of water from nearby aquifers. This is known as a “cone of depression”. There would be far and wide reaching consequences of draining the water aquifers that will negatively affect life as people in the region now know it. There is too much environmental and human health risk for scraping up a small amount of gold that isn’t really needed.
If the gold isn’t needed – then the drilling isn’t needed!