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The Facts about Fracking Waste Disposal
Edward Camp, II
ShaleNavigator Team Lead at Geospatial Corporation
Where does all the Wastewater Go?
The number of hydraulic fracturing shale oil and gas wells in the U.S. continues to increase. Pennsylvania, Ohio and West Virginia (Marcellus & Utica shale formations) wells total over 10,000, while the Bakken Shale formation, located in North Dakota and Montana, is home to upwards of 15,000 hydraulic fracturing wells .
Alongside the shale energy revolution is the ever-increasing volume of wastewater generated from these fracking wells, which requires capture, then disposal or recycling. Much of the water required during the fracking process is discharged back out of the well, and is known as flowback wastewater.
With record-breaking oil and gas production, and the waste products to go with it, how are companies handling frack waste? Let’s take a look at what makes up the fracking waste, and what can be done with it.
Wastewater = Flowback and Brine
Wastewater from shale drilling is a by-product of drilling and comprised primarily of two components. The first is “flowback”–the water, sand and chemical mixture used during the drilling and hydraulic fracturing process that returns to the surface. An average 20% of fracking fluid pumped into a borehole comes back to the surface.
The second component of wastewater is naturally occurring “brine,” also known as “produced water.” This mineral laden water is called brine because the water is very salty—far more salty than ocean water by comparison. The brine needs to be disposed of along with flowback water.
Produced water comes to the surface weeks, months, and in some cases years after a well is drilled. Produced water/brine does not contain the chemicals found in flowback—but the minerals and chemicals present in brine are potent nonetheless, and brine, along with flowback, must be properly recycled or disposed.
Many drillers now recycle part or even all of the flowback, as well as the produced water that comes from the wells they drill. Sometimes wastewater recycling is done right at the drill site, and sometimes it’s done at regional sites set up by the driller to service all of their well drilling activities in a given area.
However, some drillers are not prepared to handle the extra activity of flowback and brine recycling themselves (due to size of the company, geographic constraints, etc.). For those drillers who do not recycle on site or at their own regional facilities, there are several methods for disposing of flowback and brine.
The two primary methods are to ship it to a centralized recycling facility owned by a third party set up for that purpose or ship it to an underground injection well where it is permanently pumped deep into the earth. In some cases, flowback and brine can be stored until it is eventually disposed of either by recycling or injection well.
Some brine is processed to strip out the salts, leaving the water usable for spreading on roads in summertime as a dust suppressant. The salts in brine can be further processed to be used as ice treatments for roadways during winter.
Drill Cuttings and Solid Waste
In addition to wastewater (flowback and brine), as the drill bit cuts through the earth, all of the rock and soil and semi-liquid drilling mud pumped down the borehole comes out and must be disposed. As drillers cut through various rock layers, some of those rocks contain low levels of naturally occurring radioactivity.
Most of the time the radiation is so low, it’s undetectable. On occasion, drilling cuts (the mix of rock, dirt and drilling mud) trips a radiation alarm. In those cases, the drill cuttings must be disposed of in a specially permitted landfill—or treated before disposal to remove radioactive elements. The Marcellus & Utica Databook contains a list of landfills that accept drill cuttings.
West Virginia made a change in their landfill regulations in 2013 that allows most municipal landfills throughout the state to accept high volumes of drill cuttings without special permits. Therefore, the WV Department of Environmental Protection does not track shipments of drill cuttings.
Just about any WV landfill now accepts drill cuttings, so in addition to the landfills you see in the map below; many of the existing municipal landfills in WV are also likely candidates for accepting fracking by-product.
Both ShaleNavigator and the Marcellus & Utica Databook have identified and mapped these valuable waste facilities that are currently accepting fracking by-products, an important resource for the oil and gas industry.
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