The U.S. shale boom has generated a boom in a related industry: “frac sand.” Sand has become an integral component of hydraulic fracturing. Oil companies use sand as a “proppant”: after shale formations are injected with water and chemicals, the proppant keeps the newly formed cracks open to allow natural gas or crude oil to escape more easily.

Hydraulic fracturing requires a special kind of sand, which is most commonly found in Wisconsin. This so-called “frac sand” is high quality quartz, which is highly resilient and has spherical grains. It is crush-resistant, and can withstand pressures between 6,000 and 14,000 pounds per square inch. A spike in the demand for frac sand has motivated other states to start producing sand. According to most experts, the best rock units to produce frac sand are the St. Peter Sandstone, Jordan Sandstone, Oil Creek Sandstone and Hickory Sandstone. Wisconsin and Minnesota are the biggest players currently, and have a total of 164 active frac sand facilities, and another 20 that have been proposed. 

Over the past year or so, drillers have determined that using larger amounts of sand in hydraulic fracturing can lead to significantly better energy production. In fact, just a year ago, hydraulic fracturing operations used around 2,500 tons of sand per well; today, new hydraulic fracturing techniques call for as much as 8,000 tons to be pumped into one well. To illustrate, 8,000 tons of sand would fill 75-100 railcars. Oil and gas companies are expected to use nearly 95 billion pounds of sand this year, according to the latest report from energy-consulting firm PacWest Consulting Partners. That is up nearly 30% from 2013 and a 50% increase from forecasts made by the firm a year ago.

As the frac sand industry has grown, so too has public concern about its environmental and health effects. An environmental group issued a report last week calling for action by state and local governments to address potential health and environmental risks from frac sand mining. The report noted that currently, “none of the states at the center of the current frac sand mining boom have adopted air quality standards for silica that will adequately protect the tens of thousands of people living or working near the scores of recently opened or proposed mining sites.” In 2012, the National Institute for Occupational Safety and Health identified exposure to airborne silica as a health hazard to some workers conducting some hydraulic fracturing operations. The Occupational Safety and Health Administration (OSHA) has identified a risk of silicosis when workers are exposed to dust with high levels of respirable crystalline silica during hydraulic fracturing. Silica sand mining operations are also subject to OSHA regulations. North America Shale Blog contributor Patricia Poole wrote a post about the OSHA crystalline silica rule in August of last year.

Frac sand-specific air quality standards and other regulations could have a significant impact on the growing frac sand mining industry and the oil and gas industry it services.

More information can be found here and here.