Pressing Onward: A Dewatering Blog

Frac Sand Creation and Flowback Water Cleanup in the Fracking Industry

By Michael Stock

Cleaning Water In The Hydraulic Fracturing Industry

Whether or not you are a fan of sand fracking, it's been around for about 50 years. The process involves large amounts of water that must be treated - that's where Evoqua comes in! Evoqua creates different types of filter presses for different types of applications even though they're still in the same industry...fracking.

Making Frac Sand 

Sand fracking involves lots of sand and water. When the drilling begins water and sand are pumped into the ground at a high rate. The sand "props" open cracks in the shale, where oil and natural gas reside. The sand is called a "proppant." Who knew?


When we think of sand, we naturally think of the beach. But sand for fracking must be different. It must be about the same size, so it must be screened, and it also needs to be clean, so it must be washed. The demand for sand for this process is so great that it may take thousands of tons of clean, uniform sand (proppant). Washing and screening the sand must happen quickly and be a continual process.

After the clays, minerals and other materials are washed from the sand, before it's pumped into the ground, the water is then filtered through a filter press at a very high flow rate. It takes many huge filter presses, running automatically to handle this type of material at this high flow rate.

That's why we make 3 different models of the MC Press for mining. They're huge, super sturdy and work automatically in 'lights-out' mode - in other words you don't need a person to monitor them. They just work. They are used in the beginning of the fracking process, where the frac sand is made.

Evoqua-MC_Press_D_Model.jpeg Evoqua_MCPress_H-style_.jpeg Evoqua_MCPress_S Model-.jpeg
Evoqua's MC Press D Model Evoqua's MC Press H Model Evoqua's MC Press S Model


Flowback Water

The sand and water are then pumped into the ground at a high rate. This goes on for some time and the drilling hole is filled with sand and water. After the drilling portion of the process is complete the drill is removed and the water and sand are forced by pressure to come back up.

Think of filling a balloon with water, then holding onto the end. When you let go, the water comes whooshing back out. The material in the ground stays under pressure, but as soon as the pressure is released, the material comes back up. That's called "Flowback Water" or backflow water. There is also water already present underground. That's called "produced water". All the water that comes back up may contain heavy metals, sodium, calcium, magnesium, barium and even naturally occurring radioactive material and hydrocarbons. It all must be cleaned and often reused.

Evoqua makes filter presses to clean Flowback Water, too! We have an entire line of industry-leading J-PressĀ® filter presses that have served the mining industry for over 30 years. Flowback water is pumped through an Evoqua J-Press - typically an 800 - 1200 mm press - and the material and chemicals are separated - dewatered - from the water. The water can be reused or repurposed.

The solid waste is generally non-hazardous and easily disposed of.   




Most industries have a place for a filter press to separate solids from a liquid, and mining is no different. Sand fracking uses Evoqua's filter presses twice - once at the beginning of the process, and once again at the end! Evoqua enriches life by taking some of the world's dirtiest water and transforming it back into a clean, reusable state.

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