Frac sand mining

In 2010 the MPCA began receiving public inquiries about projects to mine silica sand for use in hydraulic fracturing, or “fracking,” a drilling method used for natural gas and oil wells. Southeastern and south central Minnesota and southwestern Wisconsin have extensive deposits of sand that meets the specifications required for fracking. Mining of certain types of these deposits has been occurring in the region for many years; however, there are new issues based on the quantity, type and depth of mining.

Residents near frac sand projects have recently contacted state and local governmental agencies with concerns about potential health risks associated with silica, for example, silicosis. The MPCA is sensitive to residents’ desires to know more about health or environmental risks of projects proposed for their communities.

Who has jurisdiction?

Local governments generally have the greatest opportunity for approving and supervising sand and gravel mining operations. Local units may have specific regulations for development, operation or reclamation of a pit. The MPCA and DNR do not have regulatory authority over the end use of mined silica sand.

MPCA and DNR permits may also be needed (e.g. water quality, discharge and appropriation; wetlands and air emissions). The Environmental Assessment Worksheet (EAW) threshold is operations that will exceed 40 acres to a mean depth of 10 feet. The local unit of government is generally the Responsible Governing Unit for environmental review.

Are MPCA permits required?

Generally, yes. The MPCA issues air and water permits for many sand and gravel mining operations. However, these permits typically do not have requirements specific to frac sand mining. Under certain circumstances, the MPCA may issue permits for sand storage sites.

Air permitting

MPCA air permits are issued to sand and gravel mining facilities to control air emissions from combustion sources such as dryers or particulate matter such as blowing sand.

The MPCA will continue to work with stakeholders and adjust permitting requirements as information becomes available.

For more information on air quality permits, check these publications on the MPCA website:

• Facts About Types of Air Quality Permits (aq2-02)
• Air Quality Permit Rules (aq4-03)
• Air Emission Registration Permits (aq3-01)

Water permitting

MPCA water permits are issued to facilities that conduct a variety of mining activities such as sand and gravel mining. Typical pollutants regulated in sand and gravel mining discharges are total suspended solids, iron and pH. Based on our current understanding of frac sand mining operations, we do not anticipate specific or unique environmental or health risks that are not already addressed though the current water permitting processes.

Currently permitted sand and gravel mining facilities will likely be able to also mine frac sand without modification of the existing permit.  New facilities will be required to apply for permit coverage.  For links to more information on MPCA wastewater permitting, visit the Water Permits and Rules page.

Are there health risks?

The potential air pollutants of most concern from frac sand mining are airborne particles, including particles less than 10 microns in size (PM₁₀), particles less than 2.5 microns in size (typically called “fine particles” or PM_2.5), and crystalline silica, which ranges across both size categories.

The crystalline silica particle size of most concern is smaller than 4 microns; no generally accepted ambient monitoring method exists for this size. There are known health risks associated with airborne crystalline silica. However, the available information on health effects comes almost exclusively from occupational settings, where exposures are more concentrated. There are no federal or state standards for silica in ambient air.

There also are health risks associated with other airborne particles, especially PM_2.5. There are state standards for airborne particles (called Total Suspended Particles or TSP), and state and federal air quality standards for PM₁₀ and for PM_2.5. However, no information is currently available that would help regulators assess if air concentrations of TSP, PM₁₀ or PM_2.5 near frac mining facilities are above state or federal standards.

What is the MPCA doing to address concerns?

We continue to work with the state of Wisconsin and our own Departments of Natural Resources and Health to find out what information is available and assess whether current science indicates any regulatory changes should be made. The Wisconsin Department of Natural Resources has extensively examined these issues, and recently concluded, “Very little conclusive information exists regarding sources, controls or levels of silica in ambient air; this means it is not possible at this time to determine conclusively whether or to what extent the quantity, duration or types of silica emissions in Wisconsin may be a public health concern.”

The Wisconsin DNR recently released a study summarizing current information on silica sand mining, its possible environmental impacts, and local, state and federal regulations that address sand mining and processing. The study is available on the Wisconsin DNR web site.

The MPCA will continue to investigate specific complaints related to frac sand mining and storage sites and take action, when appropriate, to minimize health risks and environmental impacts. The MPCA also can provide technical assistance to local units of government regarding air monitoring at or near frac sand mining operations in Minnesota.

Dust, traffic, etc. may be concerns for nearby residents. Local governments usually are the first point of contact for these issues. The MPCA has guidance for local units and residents in the fact sheet titled, Odors, Noise and Dust for Local Governments (aq2-05).

A number of sand mining proposals are going through environmental review at the local level in Minnesota. The environmental review process provides opportunities for community engagement on issues of concern.

For more information

• To file a specific complaint with the MPCA, visit the Citizen Complaint page.
• For more information on frac sand mining and handling, contact Ralph Pribble in the MPCA Public Information Office, ralph.pribble@state.mn.us . Call the MPCA at 651-296-6300 or toll-free at 1-800-657-3864.
• For more information on sand and gravel mining in Minnesota, contact the Department of Natural Resources. 
• For answers to health questions about silica sand exposure, contact Hillary Carpenter at the Department of Health, 651-201-4895 or hillary.carpenter@state.mn.us
• Contact local county offices to find out more about local frac sand mining or handling projects. Goodhue County has information on frac sand projects in the county on its Web site.

Connect with us