FAQ about mining in La Salle County

Does mining pollute the air?

Answer: Due to its close proximity to the earth’s surface, construction sand, gravel, stone (aggregates) and industrial sand (silica sand) extracted in La Salle County normally has a natural moisture content between 2% and 4% which, according to United States Environmental Protection Agency (USEPA) research data, provides adequate pollution control to convey raw materials on site.1  Dust emissions from processing operations are easily controlled and the dust typically does not travel beyond the plant area.

Most silica sand in La Salle County is hydraulically mined.  Under high pressure, water is sprayed into the disaggregated sandstone, creating a sand-water slurry. The slurry is pumped to the processing plant where it is washed again to remove silts and clays.  In addition, construction sand and gravel mined in La Salle County are washed at the plant and therefore, produce minimal dust at the plant because the products become saturated during processing.

Dust may be generated by vehicles entering and exiting the plant site and is potentially visible to passing motorists.  Mine operators use “best management practices” to reduce the amount of dust that leaves the site.  Observing posted speed limits and ensuring trucks are not overloaded, thus reducing spilled product, as well as paved entrances, on-site water trucks, street sweepers, wheel wash systems, vegetation, etc. are employed to reduce or eliminate dust that can be tracked off site.

Sand and stone mining in La Salle County is regulated in part by the Illinois Environmental Protection Agency (IEPA).  The IEPA, Bureau of Air is in charge of enforcing Federal and State air pollution regulations.  Mine operators are required to obtain a construction and/or operating permit from the Bureau of Air for the regulation of Particulate Matter (PM) emissions in order to convey and process aggregates.

Mine operators are also required to complete an Annual Emission Report to disclose PM, PM10 and PM2.5 emissions for each calendar year, based on recorded production levels and emission rate factors generated by USEPA research data. In addition, when new equipment is introduced into the production process, operators are required to notify the IEPA, test the equipment to ensure compliance with opacity limits and submit the test results within a specified period of time.

La Salle County is located in an air quality attainment area, and in compliance with the Federal Clean Air Act.2 There are a number of known and monitored sources of Particulate Matter (PM) at the PM2.5 and PM10 levels in the County including agriculture, dust, fires, fuel consumption, industrial processes, mobile, solvent and miscellaneous. PM2.5 and PM10 are considered inhalable particles.3   
According to the US EPA, using the most recent National Emission Inventory Data from 2011, all sources (agriculture, dust, fires, fuel consumption, industrial processes, mobile, solvent and miscellaneous) within La Salle County produced 3,703 Tons of PM2.5. All Industrial Processes, of which mining is a subcategory, in La Salle County produced 453 Tons, or 12.2% of all PM2.5 produced. However, mining produced zero (0) Tons of PM2.5, according to the US EPA.4
National Emission Inventory Data from 2011 (most recent) indicate all sources (agriculture, dust, fires, fuel consumption, industrial processes, mobile, solvent and miscellaneous) within La Salle County produced 16,149 tons of Particulate Matter at the PM10 level.  Industrial Processes (of which Mining is a subcategory) accounted for just 799 tons or 4.9% of all PM10 produced.  Of this amount less than one (1) ton is attributed to mining processes.5

1. (AP 42, Fifth Edition, Volume I, Chapter 11: Mineral Products Industry, 11.19.1 Sand And Gravel Processing; Accessed 10/17/2014)
2. (US EPA. Green Book. http://www.epa.gov/airquality/greenbook/. Accessed 10/24/2014)
3. (US EPA. Particle Matter: Basic Information. http://www.epa.gov/pm/basic.html. Accessed 10/24/2014)
4. (US EPA. Air Emission Sources: Particulate Matter. http://www.epa.gov/cgi-bin/broker?polchoice=PM&_debug=0&_service=data&_program=dataprog.national_1.sas#pmloc. Accessed 10/24/2014)
5. (US EPA. Air Emission Sources: Particulate Matter. http://www.epa.gov/cgi-bin/broker?polchoice=PM&_debug=0&_service=data&_program=dataprog.national_1.sas#pmloc. Accessed 10/24/2014).

Crystalline silica is in the air.  Where does it come from?

Answer: Crystalline silica in the form of quartz (which we will refer to as “crystalline silica” or “silica”) is the second most common material in the earth’s crust, making up 12% of the earth’s surface. Because silica is so common, it is found everywhere - in dirt, sand, gravel and rocks. It is a common part of most building products and it is in the air at low levels nearly everywhere. 

In 1996, the U.S. EPA published a review of the data concerning “ambient” crystalline silica levels. Ambient crystalline silica levels are those outside of a work place; that is, the levels of crystalline silica in the air outside of the property of a plant, quarry or any other work site. The U.S. EPA reported that ambient crystalline silica levels in the United States are up to 8 µg/m3 (micrograms per cubic meter), and estimated an average ambient silica level (measured as PM10) in urban areas of 1.9 µg/m3, with a range of 0.8 to 5.0 µg/m3. Based on the available particulate matter data, the U.S. EPA concluded that: (1) about 90% of ambient crystalline silica comes from fugitive dust sources, and (2) the largest fugitive dust sources are unpaved roads, paved roads, construction and agricultural tillage. The U.S. EPA concluded that mining and quarrying contribute only 1% of the ambient dust, roughly 15 times less than agriculture.1

1. (U.S. EPA. Health Effects of Inhaled Crystalline and Amorphous Silica. U.S. Environmental Protection Agency, Office of Research and Development, National Center For Environmental Assessment, Research Triangle Park Office, Research Triangle Park, NC, EPA/600/R-95/115, 1996)

Is crystalline silica dangerous to health?

There is no evidence that the low levels of crystalline silica found in the ambient air in the United States or around industrial sand mines cause illness or disease.1

While there is no evidence that ambient exposures to crystalline silica at levels present in the U.S. cause illness or disease, it is well established that occupational exposure to crystalline silica can cause the occupational disease silicosis and other diseases. Silicosis can occur after prolonged exposure to respirable crystalline silica at levels above the permissible exposure limits set by the US Occupational Safety and Health Administration (OSHA), which regulates general industry and construction, and the US Mine Safety Health Administration (MSHA), which regulates mining. The permissible exposure level established by OSHA and MSHA is a formula (10 ÷ %silica+2), which approximately equals 100 µg/m3.1

Mine operators in La Salle County are committed to working with OSHA and MSHA to ensure their employees are not exposed to dust and silica that exceed the Permissible Expose Level (PEL).

1. (Wisconsin Industrial Sand Association. Crystalline Silica May 2013. http://www.wisconsinsand.org/assets/Crystalline-Silica-Final-May-2013.pdf. Accessed 10/21/2014).

Does mining pollute the water?

Answer: In La Salle County, most mines do not discharge water as it is recycled during mining and processing operations. Typically, water from on-site surface water sources (including the capture of storm runoff) is used to wash the silts and clays out of the construction sand, gravel and silica sand, so the finished products are clean for market applications.  The wash waters containing silts and clays are pumped into a sedimentation pond, allowing the fines particles to settle out on-site.  “Clean” wash water is then recycled back to the processing plant for continued use in the washing process.  In addition, some of the water retained by on-site surface water sources is lost to evaporation or infiltrates into subsurface flows.

The IEPA, Bureau of Water is in charge of enforcing Federal and State water pollution regulations.  Mine operators are required to obtain a construction and/or operating permit from the Bureau of Water for the regulation of storm and process waters within a mining site.  Depending on the type of the mine configuration, the State will require a permit to retain or a permit to discharge all waters associated with the mining activities.

If a discharge permit is required, the mine operator must submit monthly monitoring reports to the IEPA, with calculations indicating the quantity and quality of water being discharged.  The water that is discharged from a site is usually a mixture of stormwater, groundwater seepage, and surplus process wash water, and must meet the effluent limitations of the permit.  Along with this important permitting function, the Bureau of Water is empowered to perform unannounced, random inspections. Operators who violate Federal and State water quality laws are subject to fines and criminal prosecution.

Does mining consume a lot of water?

Answer: Initially, water may be required to establish washing and slurry systems at the mine site if no onsite source of water is available.  Once established these systems recycle water on the mine site; however, reduced amounts of make-up water may be needed during extended periods of hot, dry weather.

Are mining operations safe?

Answer: Federal law mandates that two thorough health and safety inspections are conducted each year by trained inspectors from the Mine Safety and Health Administration (MSHA) at every surface non-metallic mineral mine, which includes aggregate and silica sand mines; underground mines are inspected four times each year.  However, inspectors from MSHA can inspect a mine more often and at any time.

MSHA standards (30 CFR 56/57.5002) require mine operators to conduct surveys for harmful airborne contaminants, including surveys of respirable dust containing crystalline silica, gas, mist, and fumes using the proper dust pump and filter collection system attached to each worker (or representative sample of workers) in order to determine the adequacy of control measures. An inspector from MSHA may conduct these tests as well to ensure compliance with permissible exposure limits (PEL). Survey samples are processed by a trained technician at a certified lab.

The mineral mining industry has significantly lower accident and fatality incidence rates than other major industries such as agriculture, forestry, fishing, construction, manufacturing and transportation. Within the overall mining industry, the non-metallic mineral mining category consistently has lower accident and fatality incidence rates compared to mining for coal, metals, oil, and gas.  There have been no aggregate mining deaths in Illinois for eleven years in a row, from 2004 to 2014.

Do mining operations create traffic issues?

Answer: Ninety-three percent of aggregate is transported by truck. Trucks can move throughout most areas of an aggregate operation. They can be loaded quickly at points of origin and can dump or drop their loads unassisted at the destination. Trucks can deliver practically anywhere there is a road. From small pickups to rigs that carry 28 tons (25 metric tons), trucks can be matched to requirements and, thus, make cost effective deliveries.

Generally, truck traffic is concentrated near an aggregate operation, and many trucks may enter or leave an aggregate operation every day the plant is operating. In rural areas, the trucks may have to navigate narrow, twisting roads to the construction site. Ultimately, truck traffic must intermingle with automobile traffic. Large trucks of any type, including those transporting aggregate, create the nuisances of noise and diesel exhaust as they pass suburban dwellings. Also, large trucks create a potential danger to motorists on local streets and highways. The environmental impacts and hazards of trucks can be minimized when the trucks are well-maintained and operated, and when automobile drivers yield reasonable space so that truck drivers can maneuver and stop safely. Trucks that haul aggregate are typically equipped with mud flaps and load covers to prevent loose material from being thrown from wheels and off of loads. Loads can be wetted to reduce dust. Paving quarry access roads, limiting the number of quarry entrances and exits, and wheel-washing procedures can minimize the amount of material tracked onto adjacent roads. Acceleration and deceleration lanes can be constructed at the entrance of the pit or quarry to improve the ability of trucks to enter and exit civilian traffic more smoothly, and delivery routes can be designed to minimize interference with neighborhood traffic.1

1. (American Geological Institute, Aggregate and the Environment, http://www.americangeosciences.org/sites/default/files/aggregate.pdf​, accessed 12/11/2014)

Does mining generate an excessive amount of noise?

Answer: Noise pollution is regulated by the IEPA and noise levels are required to be in compliance with State law.  Mining operations are typically screened from the public view by earth berms, trees, shrubs, etc. that provide more than adequate noise attenuation at the property boundaries.  In addition, the Mine Safety and Health Administration requires mining companies to ensure miners are not exposed to excessive levels of noise beyond the permissible expose level established by Federal rule. 

Are mining companies good stewards of the land?

Answer: The Illinois Department of Natural Resources (IDNR) requires a Surface Mining Permit for all operations that affect over 10 acres per year by mining or remove more than 10 feet of overburden (soil on top of the rock or mineral being extracted). A Surface Mining Permit application requires the operator to submit an operating plan that illustrates how the land will be affected by mining operations as well as a reclamation plan that describes how the mined land will be restored for future use.

In order to receive a Surface Mining Permit, the operator must post a bond with the State of Illinois that obligates the company to perform the activities specified in the reclamation plan. Mine inspections are performed annually by IDNR representatives; progress is mapped via aerial photography. 

Reclamation bonds can only be released if the IDNR inspector finds that enough work has been completed to allow the property to be returned to a productive use, as set forth in the operator’s reclamation plan.  If the operator fails to comply with the approved reclamation plan, the State may file a claim against the amount of the bond.  The State then uses the bond proceeds to complete the reclamation of the mined land. 

The State’s aggregate mine regulatory program was enacted more than 40 years ago.   To date, only one aggregate mine in Illinois has failed to comply with its reclamation plan, thereby triggering bond forfeiture.  The reason for this excellent industry track record is apparent – the residual value of reclaimed land is simply too valuable for a mine operator to walk away from.

The majority of land on which Rotary Park in La Salle will be built was once a quarry owned and mined by Illinois Cement.  The company donated the reclaimed land to the City and construction on the park site has already begun.1 Additional information about the park's design can be found here: http://lasallepark.pbworks.com/w/page/14989362/FrontPage

1. (City of LaSalle City Engineer Blog, LaSalle's Rotary Parkhttp://lasallecityengineer.blogspot.com/2008/11/lasalles-rotary-park.html; La Salle Rotary Park foundation, http://lasallerotarypark.com/, both sites accessed 12/11/2014).

Are mining companies good neighbors?

Answer:  Commercial aggregate and industrial sand mining has taken place in La Salle County for many decades.  In the past 20 years, the rural nature of La Salle County has changed significantly due to economic growth.  Most mining companies in the County are now surrounded by this growth, and are changing with the urban landscape. 

La Salle County aggregate and industrial sand producing companies and their employees are heavily involved in the day-to-day lives of their neighbors and work hard to be good corporate citizens.  For example [more specific examples will be added]:
  • They participate in a variety of educational activities including fieldtrips, tours and open house events
  • They support local commerce initiatives and generate tax revenues
  • They provide materials and volunteer labor for special projects (schools, park districts, non-profit organizations, etc.)
  • They participate in neighborhood committees adjacent to their operations
  • They support many jobs at the local level, including the trucking industry
  • They supply the region with high quality materials at competitive prices