Frac Sand Mining

Sandstone formations in Wisconsin contain some of the best sands available for use in the hydraulic fracturing process, a method for extracting hard-to-reach oil and natural gas. This “frac sand” is currently in high demand, as the drilling industry expands its extraction efforts into more challenging regions.

The high demand for frac sand has resulted in a sudden increase in mining and processing facilities in Wisconsin. This increase has taken place without specific regulations in place to prevent negative environmental or public health impacts, or impacts on local and regional infrastructure.

A primary concern around frac sand mining is that particulate matter released into the air from mines and processing sites can contain high amounts of crystalline silica, a known carcinogen. There is also the potential for chemical leakage or runoff contaminating local ground and drinking water. Additionally, the large quantities of water needed to operate these mines can have a huge impact on the local environment, which often overlaps with the limited range of the endangered Karner Blue butterfly.

Key Points

  • Wisconsin has no in-state natural gas resources; only the sand for hydraulic fracturing (frac sand) is mined in Wisconsin, and then it is shipped to other states.
  • Frac sand is made primarily of silica: a known carcinogen in certain forms, it can be released into the air during the mining process.[1]
  • Frac sand mines have the potential to result in toxins and harmful sediment running into Wisconsin’s lakes, rivers and streams.[2]
  • Frac sand mining is not well regulated in Wisconsin, and current laws may not be sufficient to protect human health and the environment.
  •  As of June 2014, the Wisconsin DNR has issued notices of violation to 23 different frac sand operations for environmental permit violations.[3]
Clean Wisconsin's Work

Frac sand mining has the potential to impact to our health, air, water and land in Wisconsin, as well as the endangered Karner Blue butterfly. As a result, Clean Wisconsin is paying close attention to the rapid increase in mine sites and processing facilities in the state. You can read a primer on the frac sand mining in the Spring 2012 issue of our quarterly newsletter, Defender.

Clean Wisconsin Media and Materials

Questions and Answers
What is frac sand? 
Frac sand is a highly rounded silica (i.e. quartz) sand used in hydraulic fracturing and other various industries. Frac sand is mixed with water and chemicals and injected into oil and natural gas wells creating fractures in the rock layer. The sand holds the cracks open, allowing the trapped oil and natural gas to be extracted. Characteristics of ideal frac sand include: spherical shape, high silica content, hardness (ability to withstand pressure), and uniform particle shape and size.[2]

What steps are involved in the mining process? 
There are several steps involved in the mining process, each with their own environmental, land and health impacts. The first step is the removal of excess soil and debris from the area of the mine. Next, the sand is excavated, sometimes using explosives or blasting when the formation is particularly tight. The debris is then crushed into a uniform size and sent to processing where it is washed, dried, sorted and eventually stored. Some sands then receive a resin coating to help increase the strength of the sand used in the fracking mixture.[2]

What are the environmental concerns from frac sand mining?
Frac sand mines can use millions of gallons of water a day and there is concern over toxic chemicals entering into the groundwater via runoff or spills from the mining process. Mines also involve massive amounts of raw land movement, which can impact the local landscape, especially wetlands, and cause erosion and soil runoff. This is especially important since the areas where frac sand mining takes place often overlaps with the limited habitat range of the endangered Karner Blue butterfly. Air pollution is also a big concern, with crystalline silica (the carcinogenic particulate matter released from blasting, crushing and transporting the frac sand) being released into the air in localized large quantities.[2]

What are the health concerns from frac sand mining?
The main health concerns result directly from potential air and water quality issues. Respirable crystalline silica is classified as a carcinogen and has a documented history of causing lung cancer in miners.[4] It also causes the lung disease silicosis, a disease that is irreversible and has no known cure. Air pollution can also lead to a number of other respiratory and health issues, ultimately reducing quality of life and potential increasing death rates. In addition to this air pollution, frac sand operations can result in water pollution. This includes the potential for hazardous chemicals to be leaked or spilled into groundwater, which can then cause drinking water contamination causing illness in humans and animals.

Is the frac sand mining industry regulated? 
The frac sand mining industry remains largely unregulated and uncontrolled by governmental and oversight parties. The regulations that can be applicable include routine air, storm water, high-capacity well and wetland permits from the DNR, as well as county-approved reclamation plans. These regulations aim to require mines to follow certain general environmental policies. However, they were not designed to take into account the special circumstances involved with frac sand mining, such the impacts from extensive surface mining and water use in concentrated regions, or the emissions of significant amounts of silica dust into the environment. Additionally, some mines receive special consideration based on their output and are excluded from some of the regulations.[5]

What research is being done to better understand the environmental and health impacts of frac sand mining?

     Air Quality:

  • Under state law, industrial sand mines are required to monitor particulate matter levels unless they are granted a variance.[6] However, only 11 (<10%) of operations are currently monitoring PM levels,[7] and even those are only monitoring PM10, rather than PM2.5 or PM4, which is the size of greatest concern (e.g., silicates).
  • All PM10 monitoring records reported by facilities to WDNR are below the state’s 150 µg/m3 24 hour standard. The maximum recorded 24 hour level was 105.7 µg/m3, and average levels are around 15 µg/m3.[8]
  • One facility monitored PM4 crystalline silica levels at four of its operations in Chippewa and Barron counties.[9] Average 24 hour levels from over 1,000 days of samples were 0.24 µg/m3. One station measured a maximum 24 hour level of 8.06 µg/m3. Wisconsin does not have a health standard for silica, but California’s chronic reference exposure limit is 3 µg/m3.
  • Dr. Crispin Pierce at UW-Eau Claire has been studying particulate emissions from frac sand operations and has found fenceline PM2.5 levels ranging from 5.82-50.8 µg/m3 in six 24-hour samples around sand mines and processing sites.[10] US EPA annual PM2.5 standard is 12 µg/m3.

Water Quantity:

  • A collaborative study between Chippewa County, the DNR, the USGS, and the Wisconsin Geologic Natural History Survey is underway that is studying the impact of groundwater pumping by both mining and irrigation in Chippewa County.[11] The five year study began in 2012, and aims to build a groundwater dynamics model in the area.

Water Quality:

  • No studies that Clean Wisconsin is aware of.

Mine Reclamation:

  • A study led by Dr. Holly Dolliver, a soil scientist at UW-River Falls is underway that seeks to compare physical, chemical, and biological characteristics of soil before it is removed to expose the sandstone to when it is put back over the site in the reclamation process.[12] The study is also looking to see if the “fines” (i.e., the clay and silt waste from the mining process) can be used to improve water retention in the reclaimed soils as an example of beneficial reuse.


  • In January 2015, the DNR’s Natural Resource Board unanimously approved undertaking a comprehensive study of the frac sand mine industry in response to a citizen petition. The last time DNR examined the industry was a 2012 report in which impacts of intensive sand mining were speculative.[2] The number of mining operations has since doubled and this comprehensive analysis of the actual human health and environmental impacts of the industry is urgently needed.
Quick Facts
  • In 2010, U.S. silica sand production was 33.3 million tons, with 25% used in the fracking industry. By 2013, production had increased to 75 million tons, with 72% used in the fracking industry.[13]
  • According to the U.S. Geological Survey, nearly 80% of the nation’s silica is produced in 8 states (listed in order of production): Wisconsin, Illinois, Texas, Minnesota, Arkansas, Oklahoma, Missouri, and Iowa.[14]
  • About 250 people in the U.S. will die this year due to workplace exposure to silica.[15]
  • Wisconsin’s silica sand is considered ideal frac sand because its shape, hardness, and silica content allow it to withstand serious heat and pressure underground.  It is also found at a relatively shallow depth, making it easier to mine.[16]
  • Although a 2011 report to the DNR suggested that silica meets Wisconsin’s standard definition of a hazardous air pollutant, silica is not currently regulated as a hazardous air pollutant by the Wisconsin DNR due to inadequate information on public exposure to silica particulate matter.[2]
  • As of November 2014, 10 facilities have been fined by the Wisconsin DNR for permit violations. Fines average $60,000 and range from $464 to $200,000.[16]
Wisconsin Data, Trends, and Legislation

Silica sand has been produced in Wisconsin for over 40 years, but only recently has the industry expanded dramatically due to high demand for sand for use in hydraulic fracturing by mining companies.[17] Oversight of this industry has not kept pace with the rapid expansion of frac sand mining.

  • According to DNR figures, Wisconsin had only five frac sand mines and five processing facilities in 2010.[2] As of May 2014, it had over 63 active mines and 45 active processing facilities, and counting.[18]
  • Wisconsin frac sand production doubled between 2012 and 2014 from 13 million tons per year to 26 million tons per year.[19]
  • Wisconsin leads the nation in frac sand production.[14]
  • Frac sand mines in Wisconsin are located primarily in western and northwestern Wisconsin in the Jordan, Wonewoc, Mt. Simon and St. Peter formations.[2]

Current Law

  • Wisconsin Statutes 66.1002: Limits the authority of cities, villages and municipalities to enact a moratorium. The municipality must obtain a written report from an engineer, physician or registered nurse justifying the need for a moratorium in the case of a significant threat to public health or safety.
  • NR 135: Requires all counties in the state of Wisconsin to implement a nonmetallic mining reclamation permit program, including adoption of an ordinance and administration of a mining reclamation program.[2]
  • A patchwork of local and state-level regulations may require various permits including but not limited to wetlands permits, navigable waterways permits, WPDES discharge permits, air permits, and reclamation permits. For a comprehensive list of applicable statutes and regulations, please reference “Silica Sand Mining in Wisconsin,” a 2012 report issued by the Wisconsin Department of Natural Resources.

Proposed Legislation

The following bills attempting to better regulate and monitor frac sand mining were proposed (and all ultimately failed to pass) in the 2013/14 legislative session:

  • 2013 Senate Bill 138 – (LRB 1342; Vinehout)  Public Notice. “This bill requires the governing body that considers frac sand mine applications to publish at least two separate newspaper notices (a class 2 notice) at least 30 days prior to taking action on an application. The bill also requires a written notice be sent, via first class mail, to property owners or occupants situated within one mile of the proposed mine.”
  • 2013 Senate Bill 139 – (LRB 1550; Vinehout) Property Disclosure. “LRB 1550 requires an owner to disclose on the applicable report whether the owner has notice or knowledge of a contract, or an option to contract, that allows a person to mine frac sand on a neighboring property.”
  • 2013 Senate Bill 140 – (LRB 1268; Vinehout) Prospector/Exploration Registration. “LRB 1268 authorizes counties to issue licenses for frac sand exploration…. a person who applies to a county for a frac sand exploration license must submit a bond to ensure that drill holes will be properly filled and proof that the person has liability insurance covering personal injury and property damage. The bill requires a licensee to notify the county before beginning drilling and before filling a drill hole. The bill also requires the Department of Natural Resources to provide technical assistance related to frac sand exploration to a county upon request.”
  • 2013 Senate Bill 141 – (LRB 1341; Vinehout) Public Meetings and Zoning. “LRB 1341 requires frac sand mining to be listed as a conditional use in areas zoned for agricultural use…. This bill also makes frac sand mining a prohibited use in residentially zoned areas.”
  • 2013 Senate Bill 142 – (LRB 1344; Vinehout) Setbacks and Buffer Space. “LRB 1344 prohibits a frac sand mine, a frac sand processing facility, or a frac sand loading facility from being located within 2,500 feet of a single-family or two-family residence or within 2,500 feet of a single-family or two-family residential zoning district.”
  • 2013 Senate Bill 411 – Proposed to create and fund 8 DNR positions for monitoring industrial sand mining and processing.
Cited Resources
  1. Wisconsin Department of Natural Resources. “Report to the Natural Resources Board: Silica Study.” (August, 2011).
  2. Wisconsin Department of Natural Resources. “Silica Sand Mining in Wisconsin.” (January 2012).
  3. Taylor Chase. “Wisconsin frac sand facility operates wells without permit, faces $52,500 in fines.” (July 17, 2014).
  4. U.S. Dept. of Labor, Occupational Safety and Health Administration. “Silica, Crystalline.” Web. Retrieved 2012 from
  5. University of Wisconsin-Extension, Cooperative Extension – Monroe County. “Understanding Sand Mining.” Web. Retrieved 2012 from
  6. Wis. Admin. Code s. NR 415.075(4).
  7. Rich Kremer. “Fewer than 10 percent of frac sand operations monitor air particulate levels.” Wisconsin Public Radio (November 13, 2014).
  8. Data available from DNR here.
  9. University of Wisconsin Stevens Point. 2014. “Frac sand mining environmental research webinar: current status of research findings.” Powerpoint available here.
  10. Crispin Pierce et al. 2015. PM2.5 airborne particulates near frac sand operations. In press at Journal of Environmental Health. More information about Dr. Pierce’s work available here.
  11. Chippewa County. 2014. Chippewa County Groundwater Study.
  12. Rich Kremer “First-of-its-kind study examines how frac sand mining affects soil.” Wisconsin Public Radio (April 22, 2014).
  13. Alison Sider. “Demand for Sand Takes Off Thanks to Fracking.” Wall Street Journal (August 4, 2014).
  14. U.S. Geological Survey. “Mineral Commodity Summaries, SAND AND GRAVEL (INDUSTRIAL).” (February 2015).
  15. Georgia Tech Safety and Health Consultation Program. “Silicosis Prevention.”
  16. Stephanie Porter. “Breaking the rules for profit: an analysis of the frac sand industry’s violations of state regulations and manipulation of local governments in Wisconsin.” The Land Stewardship Project (November 26, 2014).
  17. Wisconsin Legislative Reference Bureau. “2011 Senate Bill 504.” LRB-2389/1.
  18. Wisconsin Department of Natural Resources. “Locations of industrial sand mines and processing plants in Wisconsin.”
  19. Taylor Chase. “As rail moves frac sand across Wisconsin landscape, new conflicts emerge.” (July 13, 2014).


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Please cite this resource as: Clean Wisconsin, Inc. “Frac Sand Mining.” Clean Wisconsin Enviropedia. Retrieved from

Last updated: 2/18/2015