May 18, 2023

Environmental, Natural Resources, & Energy Law Blog

Mining for Real Earth Elements in Missouri – Is It Worth It? - Caryn Haddix


Caryn Haddix LLM

Emerging Topics Blog Post

April 18, 2023


Mining for Real Earth Elements in Missouri – Is It Worth It?


Missouri is one of only 10 states in the United States to have potentially economically viable rare earth element (“REE”) deposits. These elements are critical components in various modern technologies, including smartphones, wind turbines, electric vehicles and military equipment. However, REEs are also associated with significant negative health effects such as lung cancer and liver damage, as well as negative environmental impacts including wastewater discharge that contains heavy metals and radioactive elements. While there is economic benefit to mining REEs, and environmental benefit from their use in green technologies, the mining process must be done in a responsible, sustainable manner to protect the health and safety of miners, protect the surrounding communities from harmful pollutants and protect against the degradation of natural resources.


REEs are a group of 17 metallic elements that are not actually “rare.”[1] These elements are commonly found in the Earth’s crust and have been classified by the Secretary of the Interior as critical to the U.S. economy and national security.[2] Finnish chemist Johan Gadolin first discovered REEs in 1792 when he identified a mix of elements in Ytterby, Sweden that he named “ytterbia”. In 1803, the first individual REE, cerium, was identified and the remaining elements continued to be discovered until 1907.[3]

Prior to 1965, there was little demand for REEs, with much of the global supply originating in India, Brazil and South Africa. Demand for europium, the essential material needed for producing color images, skyrocketed with the invention of the color television, and the Mountain Pass Mine in California[4] began extracting it, making the United States the leading global producer.[5] China entered the market in the 1980’s and began selling REEs at low prices, vaulting them to the lead global supplier. By 2011, China accounted for 97% of the world’s production of REEs.[6]

In Missouri, REE deposits have been identified at Pea Ridge[7], a former iron mine located in Sullivan, Missouri approximately one hour southwest of St. Louis. Prior to its closure for economic reasons in 2001, Pea Ridge was one of the deepest underground ore mines in the world. It was sold in 2012 and its new owners hope to capitalize on REE mining at the location[8], which the USGS has described as a “principal REE deposit in the United States.”[9] The Pea Ridge mine contains “heavy” REEs, specifically yttrium, which is used in making televisions and computer screens.[10] Currently, there is no REE mining in Missouri, but that could change.


Rare earth mining can have hazardous impacts on the environment, including air pollution caused by the release of dust and gases into the atmosphere, water pollution from discharges that contain heavy metals and other pollutants, land degradation and soil erosion which leads to contaminated soil and habitat destruction. REEs also contain radioactive elements. Yttrium, the REE found in Pea Ridge, can cause lung cancer or embolisms, especially with long-term exposure, as well as cause damage to the liver.[11] The National Institute for Occupational Safety and Health (NIOSH) has recommended an exposure level for yttrium of 1mg/m3.[12]

Given the potential hazards, proposed mining operations at Pea Ridge and throughout Missouri stir up controversy, and for good reason. The Mountain Pass Mine in California, which was noted above as being instrumental in vaulting the U.S. to global leadership in REE production in the 1960’s, sustained a ruptured pipeline in 1996 resulting in the release of wastewater that contained heavy metals and radioactive elements. Some of the spillage occurred within the Mojave National Preserve placing residents and visitors at risk of exposure to radioactive materials. Molycorp, the company that owned the mine, was sued and fined $410,000 for failing to report hazardous and radioactive waste spills and incurred cleanup costs of $3.6 million. The wastewater pipeline was ultimately closed, and operations suspended at the site. In all, researchers estimate Molycorp allowed over 1 million gallons of wastewater to be released from the Mountain Pass Mine.[13]

China, too, has suffered the impacts of REE mining. Illegal and unregulated mining operations have resulted in catastrophic environmental damage that could take 100 years and billions of dollars to repair. In the city of Baotou, unlined wastewater ponds allow toxic chemicals to seep into the groundwater and flow into the Yellow River, a source of drinking water for much of northern China.[14] One nearby farmer spoke of destroyed crops, dead livestock, neighbors who died of cancer and impacts to his own health.[15] In the Jiangxi province, the mountainside is eroded and scarred by mining activity with wastewater ponds sometimes sitting abandoned and open to the elements.[16] And although the Chinese government introduced tougher regulations in 2016 that require technology and process improvements to mining practices that are costly, yet more environmentally friendly, the damage has been done.[17]

Extraction of REEs typically occurs in one of two ways – both of which result in the release of toxic chemicals into the environment. The first method removes layers of topsoil which are then transported to a leaching pond where chemicals are added to extract the rare earth elements from the surrounding soil.[18] As shown in the scenario from Baotou, this can result in contaminated wastewater leaching into groundwater and drinking water. The second method involves drilling holes into the ground, inserting PVC pipe and rubber hoses and then flushing the area with a mix of water and chemicals. This also creates a leaching pond and can result in similar environmental hazards.[19] For every ton of REE produced, the process yields 13 kg of dust, up to 12,000 m3 of gas, 75 m3 of wastewater and one ton of radioactive residue. [20]


There is an indisputable need for REEs in modern society. Today’s technology demands it. REE mining can also provide significant economic benefit to the local, state and even national, economies. REE mining can create jobs in the mining and manufacturing industries, supporting economic growth and improved standards of living for the communities where the mines are located. The sale and production of REEs can generate substantial revenue for mining companies and the broader economy via export opportunities. The market for technologies that utilize REEs is anticipated to reach $2.5 trillion by 2030. In addition, REEs support “green” technologies such as wind turbines, electric vehicles and LED lightbulbs. Currently, the United States imports 80% of its REEs from China.[21] China also controls the manufacturing needed to transform the REEs into products.[22]

However, the basic principles of supply and demand illustrate why allowing one country to dominate global supply is not a good idea.From a national security perspective, reliance on a foreign country for materials critical to the production of military equipment such as night-vision goggles, communications and GPS equipment, targeting and weapons systems, and even the alloys used in armored vehicles, creates a weakness in the country’s defenses. Recognizing this vulnerability, President Biden signed an Executive Order in 2021 requiring a review of the nation’s critical supply chains, including the supply of rare earth elements.[23]

Given the known health and environmental hazards, REE mining requires careful planning, strict regulation and oversight. The environmental and social impacts of REE mining can be reduced through sustainable mining practices that integrate conservation efforts and public health considerations. West Virginia University was recently awarded an $8M grant from the Department of Energy to develop a facility to extract and separate REEs and other critical elements from mining waste.[24] Purdue University and Harvard University have also researched clean extraction methods for REEs using new technologies[25] and chemical processes.[26] Millions of tons of e-waste are generated each year, much of it containing REEs and precious metals. However, only 25% of that e-waste gets recycled, presenting an opportunity for REE extraction.[27]

Agromining is yet another viable option for sustainable REE production. Agromining, also known as phytomining, employs plant species that accumulate high amounts of REEs (hyperaccumulators) from growing on REE-rich soils, for example. Once REEs are concentrated within the plant, the elements can be extracted. A demonstration “metal farm” in Malaysia yields between 200 to 300 kg of nickel per hectare, per year. While agromining offers an environmentally friendly, low-cost approach to REE mining, it requires significant tracts of land and is not yet close to being commercialized.[28]


While REE mining is not without its problems, Missouri should allow it, within reason, due to the benefits. A key challenge for Missouri will be balancing economic and environmental interests. Allowing REE mining at Pea Ridge or other Missouri mines requires strict regulation and oversight to mitigate risks to public health and the environment, and the State should also be selective on where mining takes place to ensure preservation of natural resources and sensitive sites. Missouri must enforce permitting requirements that address operations, waste management and disposal, air and water quality monitoring, potential health impacts, as well as any negative impact to other economic interests such as agriculture and tourism. Missouri can (and should) differentiate itself by being at the forefront of sustainable practices such as e-waste recycling, agromining and other clean extraction processes. Finally, public engagement is crucial. The communities most impacted by these operations should have opportunities to meaningfully engage in the determination of best practices, site selection and effective mitigation measures before any mining activity begins and throughout the lifecycle of the mining process.


[1] See, Periodic Table of Elements - PubChem (; REEs include elements 57-71, plus Yttrium (element 39) and Scandium (element 21).

[3] Rare Earth Elements - PUB2911, Missouri Department of Natural Resources, October 29, 2020.

[8] See, e.g., Three Consulting, describing owner James Kennedy and his involvement and interest in rare earth minerals; and Mr. Kennedy’s interview with CEOCFO Magazine ThREE Consulting LLC | Jim Kennedy | Green Steel Companies, Lynn Fosse, Sr. Editor, July 12, 2021.

[9] Rare Earth Elements - PUB2911, Missouri Department of Natural Resources, October 29, 2020.

[10] BBC News, What are ‘rare earths’ used for?, March 13, 2012.

[12] Centers for Disease Control and Prevention, NIOSH Pocket Guide to Chemical Hazards - Yttrium, October 30, 2019.

[13] Grand Canyon Trust, Mountain Pass Mine.

[15] Id.

[16] Michael Standaert, China Wrestles with the Toxic Aftermath of Rare Earth Mining, Yale Environment 360, July 2, 2019.

[17] Id.

[18] Jaya Nayar, Not So “Green” Technology: The Complicated Legacy of Rare Earth Mining, Harvard International Review, August 12, 2021.

[19] Id.

[20] Id.

[26] Leah Burrows, A clean way to extract rare earth metals, Harvard John A. Paulson School of Engineering and Applied Sciences, June 17, 2016.