Air Quality

Covia understands that healthy employees, customers, and communities need clean air to thrive. We monitor fugitive dust and particulate and hazardous air emissions related to the mining, processing, and transportation of our products, especially respirable crystalline silica (RCS) dust. We protect air quality by establishing advanced control mechanisms, following safe handling practices, and monitoring air quality around select operations to keep Safety First for all stakeholders.


Covia manages potential fugitive silica sand dust and other air emissions through a hierarchy of control mechanisms. First, we prioritize identifying and controlling particulate emissions at the source through engineering controls such as wet scrubbers, dust collectors, dust suppression hoppers, and sealed transport (e.g., pneumatic trucks). Next, we look to administrative and process controls to limit emissions and exposures. Finally, we use personal protective equipment (PPE) as a last safeguard to keep our employees safe. We also administer a medical surveillance program for all plant employees to help protect and prevent occupational disease like silicosis. This program includes biennial chest x-rays, pulmonary function tests, and medical fitness exams.

Our engineering and operations departments collaborate to evaluate control technologies for regulated air pollutants. For example, our sand coating operations generate volatile organic compounds (VOCs), which we control by using high temperature oxidation or other controls; and our lime operation uses selective non-catalytic reduction to reduce nitrogen oxide (NOx) emissions. In addition, a multi-disciplinary working group meets quarterly to discuss progress on shared air quality goals.

During the permitting process for new facilities or the expansion of existing facilities, we assess our potential to emit regulated air pollutants. We design and install appropriate equipment for emissions that require control. Once in operation, we monitor equipment and when necessary, submit data for permit compliance.


In 2016, the Occupational Safety and Health Administration (OSHA) released a new occupational exposure limit to respirable crystalline silica (RCS) dust, with different aspects of the rule becoming effective for different industries over time. The new rule reduces the allowable personal exposure by 50 percent over an eight-hour, time-weighted average (TWA), taking it from approximately 100 to 50 ug/m3 for our OSHA-regulated facilities. The Mine Safety and Health Administration’s (MSHA) occupational exposure limit to RCS remains at approximately 100 ug/m3 TWA. As industry leaders in this area, we will continue to maintain our occupational exposure limit of 50 ug/m3 at all our sites.

We also developed a new industrial hygiene module within our enterprise-wide Site Action Management (SAM) system that will track all exposure data in addition to air quality, environmental, and safety-related data. 

Dust Control Improves Air Quality and Bottom Line

Our Tuscaloosa, Alabama, facility recently replaced the multi-cyclone dust control system on its sand dryer as part of a larger effort to maximize the overall efficiency of the dryer circuit. The multi-cyclone was replaced with a high-efficiency wet scrubber that resulted in an estimated overall particulate reduction of 90 tons per year. In addition to dust reduction, the new system runs more efficiently, thereby reducing the facility’s energy costs and overall greenhouse gas (GHG) emissions.

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We regularly collaborate on research projects with the National Institute for Occupational Safety and Health (NIOSH), and because of our work on analyzing airborne dust generation during loadout, we installed a dust suppression hopper at multiple facilities. The hopper limits fugitive dust while loading trucks and railcars, and we hope to install this equipment at more of our facilities in 2019.  

In addition to controlling fugitive emissions within our operations, we monitor the air quality surrounding our operations to ensure the health and safety of our neighbors. In 2018, Covia continued to systematically collect physical monitoring data around nearby communities to detect fugitive emissions that may originate from our operations. This data also feeds analytical models that can help us predict how changes in various factors (e.g., weather patterns, operational activities) may affect air quality in the future. 

Our DST™ dust suppression technology coats sand with an additive to help customers comply with the new OSHA respirable crystalline silica (RCS) rule. This engineering control can reduce worker exposure to RCS (when used properly) at customer locations, as well as our plant and terminal locations. DST™ also provides a lower cost alternative to engineered solutions (such as boxes). We are also collaborating with several Industrial customers on replacing silica with nepheline syenite in paint fillers, which benefits consumers by reducing the risk of respirable silica exposure and improving the paint’s durability and ultraviolet (UV) protection. 


We will continue to advance dust mitigation within our own operations and surrounding our operations. We will also continue to innovate our value-added products that control dust across our value chain.

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