HomeNews State reclamation works to stop flow of contaminants into Redwell Basin
State reclamation works to stop flow of contaminants into Redwell Basin
Written by Aimee Eaton
Wednesday, 31 July 2013
Water from borehole not conducive to most life
There was a time when I believed that if water flowed cold and clear and straight from the ground that it was pure. Untainted by man or machine. I don’t believe that anymore.
This is what happened. In the late 1960s or maybe the 1970s a mining company drilled an exploratory hole more than 6,000 feet deep into the northwest flank of Mt. Emmons. Shooting through millions of years of geologic history made notable by the presence of the granite that had been forced through layers of surrounding igneous rock like toothpaste mashed through the head of a toothbrush, the hole terminated in a large deposit of hard silvery-white rock. This rock, molybdenum or Mo, was, and is, used as an alloy in steel, cast iron and superalloys throughout the world to enhance hardness, strength, toughness and corrosion resistance. According to the United States Geologic Survey (USGS), there are few comparable replacements for its use, and it plays a critical role in industrial technology. Despite this, and for reasons unknown, the mining company that drilled the hole opted not to mine the deposit, and instead removed its equipment and abandoned the site. In its wake the company left the hole as it was, uncapped and open to the air. Weeks passed, maybe months. There is no record. However, what is known is that the hole transformed from a narrow dark tunnel leading toward the mountain’s inner workings to an artesian well that at a rate of more than 20 gallons per minute spewed water across the surface of the high alpine ecosystem. The water itself was highly acidic, falling somewhere between vinegar and lemon juice, and in the water were concentrations of dissolved metals that grossly surpassed federal recommendations for the safety of plants, aquatic organisms and drinking water. Yet, it ran clear as gin. For 40 years this water flowed down from midreaches of Redwell Basin, to Redwell Creek then into Oh Be Joyful Creek before entering the Slate River. Along the way the acidic well water and the contaminants it carried became diluted, but it never really went away and according to the Coal Creek Watershed Coalition the discharge from Redwell Basin “would probably be the highest source of metals loading into the Upper Slate River.” In the early 2000s as the United States Environmental Protection Agency (EPA) began to uncover and attempt to mitigate the disaster of the Standard Mine (a heavy metals mine that operated in the Ruby Mining District of Gunnison County from 1874 to 1966 and left behind a range of contaminants that regularly found their way to area water sources) the well in Redwell Basin was officially placed on the radar of environmental and reclamation agencies. “The geology and hydrology of the Redwell Basin is incredibly complicated,” said Tara Tafi, a reclamation specialist with the Colorado Division of Reclamation, Mining and Safety (CDRMS). “The old Daisy Mine is also in the basin, and before we jumped into reclamation for the sake of reclamation we needed to determine what projects would positively impact the area. The well was low-hanging fruit.” Last year, Tafi began a project to stop the flow of water from the well. She threaded a one-inch stainless steel pipe down the borehole and proceeded to pump roughly 3,300 pounds of grout through the pipe and into the darkness, creating a plug at a depth of about 100 feet. “It wasn’t effective,” said Tafi. “The hole was deeper than we had expected and the pressure greater.” Tafi left the well, now with a pipe sticking up several feet above ground, and its flowing waters for the winter. She returned last week to take some water quality measurements: pH, specific conductivity, temperature, nutrient load, etc.; and to place a valve on the end of the pipe that, if effective, will stop the flow of water until October when the CDRMS has plans to permanently fill the well using either a pressurized cement grouting method, or a chemical grouting method that is water-reactive. “Regardless of whatever option we need to use, that hole will be plugged and that water will no longer be entering Redwell Basin,” said Tafi. “Potentially we will see improvements in water quality down lower in the watershed in Oh Be Joyful and in the Slate River.” The USGS has conducted numerous studies in Redwell Basin to determine the extent water from the well has on local ecology. In 2010, Briant Kimball, a scientist with the USGS, based in Salt Lake City, Utah, led a study to determine what the chemical make-up of the basin’s water would have been had mining not occurred. Kimball found that if the input of water from the artesian well and the Daisy Mine were taken out of the equation, the water in Redwell Creek would have had a pH value of 5.1, up from the measured 3.8 (a value almost 100 times less acidic). In addition, levels of zinc and copper would have been about 2.5 times less and five times less, respectively. Yet, according to Kimball, “the pre-mining conditions would [even then] not have met aquatic life standards.” When Tafi measured the pH of the water flowing from the well, she recorded a reading of 2.45. That’s a level of acidity not conducive to the majority of all aquatic and vegetative life. Further, it’s a level that, according to the USGS, creates an environment in which heavy metals become more soluble and therefore more toxic to all life. “We do see some plants adapting to these conditions,” said Tafi, just before fitting the pipe with a shutoff valve and stopping the flow of water. “But these levels are outside the norm. When we come back in a few weeks we’ll see if the valve is holding and what the impact has been on the lower water sources.” If the valve holds, and the October project succeeds, the watershed could see a decrease in contaminants relatively quickly. However, after more than four decades it’s probably still not a good idea to drink the water.