Sitting high atop one of the many mountains in the beautiful Black Hills is Sanford Underground Research Facility (SURF). The former Homestake Gold Mine closed in 2002 and was the largest, deepest gold mine in North America. In the 126 years it was open, it produced nearly 41 million ounces of gold. At the surface, SURF takes up about 223 acres of space. But deep below the earth’s surface, the mine spans 7,700 acres in size, the equivalent of over 5,800 football fields.
Today, it is producing something that to many, is worth much more than gold. SURF houses world-leading science experiments that hope to give a better understanding of the universe. At 4,850 feet deep, the facility provides a near-perfect environment, free of cosmic radiation, allowing scientists to conduct experiments in biology, geology, and engineering. It is also bringing millions of dollars annually into the state.
SURF AND THE AFFECTS IT HAS ON THE ECONOMY
Although all the scientific aspects of this is fascinating to some, the economic impact that SURF has had on South Dakota is hard to deny. With 185 jobs at SURF and another 160 annually at LBNF, SD’s workforce has been dramatically affected. Since 2004, SD has seen a $165 million investment through the state and another $253 million in the last nine years federally.
Constance Walter, Communications Director for SURF said, “The economic impact is amazing. The closure of the mine created an economic crisis in Lead. But through its resiliency and all the activity surrounding SURF and other projects, Lead is thriving.”
SURF’s net economic impact through 2029 is projected to be $1.6 billion while household earnings will top $572 million. The project is also projected to create over 1,000 jobs statewide.
“Sanford Underground Research Facility has provided the community of Lead the opportunity to be recognized as a premier scientific and technology hub not only in SD, but the world. The economic impact of their presence will be felt for years to come,” said Lori Frederick, Senior Business Development Representative for the South Dakota Governor’s Office of Economic Development.
SURF AND WHAT IT’S DOING TODAY
In 2006, SURF received a $70 million donation from T. Denny Sanford to revive the facility. Barrick Gold Corporation, who owned the property, donated the land, and the State of SD formed the SD Science and Technology Authority (SDTSA), and the legislature committed over $40 million. After an extensive dewatering process, SURF was dedicated in 2009.
Scientists hoped to be able to solve many mysteries once they began working underground. Everything on earth, including people, planets, stars, and even the galaxies make up a fraction of the matter in this universe. The missing matter is called dark matter, and it can not be seen or touched. But, scientists know it exists because of its gravitational effects on the solar system. However, it interacts so rarely, it is difficult to detect. Scientists call the particles Weakly Interacting Massive Particles (WIMPs) and want to learn more about them to better understand the universe.
The second mystery that scientists were hoping to unravel revolves around neutrinos. Neutrinos, also called ghost particles, pass through matter like it isn’t even there. Scientists don’t know much about them, except that they have mass and change between types as they travel.
And so, once up and running, two major experiments located almost a mile below the earth’s surface, the LUX-ZEPLIIN (LZ) and the Deep Underground Neutrino Experiment (DUNE), could discover the mysteries surrounding dark matter and neutrinos.
The LZ uses super dense liquid xenon that if bumped by a WIMP, it will cause a tiny spark of light. LZ’s predecessor, LUX, showed results in 2013. After an initial run of 80 days, LUX was determined to be the most sensitive dark matter detector in the world. Further analysis confirmed this in 2016, before the experiment was decommissioned. Today, they are working on a second-generation dark matter detector, LUX-ZEPLIN (LZ). The detector will be 30 times larger and 100 times more sensitive than the original dark matter detector.
Hundreds of scientists from around the world are interested in neutrinos and that is where the collaboration on the next project came from. DUNE is managed by the Department of Energy’s Fermilab and is planned at both the Sanford Mine and at the Fermi National Accelerator Lab in Illinois. The project is an international neutrino experiment that is being hosted by the United States. Scientists and engineers from more than 30 countries are developing technologies for this mega-science project. South Dakota’s facility, called the Far Site, will be housing part of the Long-Baseline Neutrino Facility (LBNF) which will power the DUNE experiment. Fermilab will host the Near Site and produce the world’s most intense neutrino and then send it 800 miles through the earth to the DUNE detectors at the Sanford Lab. DUNE could unlock the mysteries of neutrinos, the particles that could be the key to explaining why matter and the universe exist.