Every water treatment company, mine included, has a basic selling example: a jar of dirty water sits next to a jar of clear water that has gone through the company’s cleaning process. It is the cost of entry for water treatment, but is does not tell the whole story. In some cases what appears to be clear water is actually not clean, and therein lies the challenge for the fracking industry. You may wonder, how clear does not always equate with clean – a fair question that requires a serious answer.
Fracking requires 4.5-8 million gallons of water per well and concerns have been raised about the depletion of underground aquifers. The current practice of treating the flowback portion of the frac water has been to treat it as garbage and simply discharge it into disposal wells to never be seen again or be part of the eco-system. This practice has not only been a source of concern for earthquakes but, more important, many have voiced the opinion that water reuse regulation must be enacted in order to preserve our aquifer resources for agriculture and commercial applications. I agree that the industry needs a complete water management program in order to preserve our water resources and protect our future.
To date, the largest barrier for water reuse has been the variable nature of the flowback water produced at each frac site. Drillers are harvesting many different types of hydrocarbons (tight gas, coal-bed methane, natural gas, crude oil) by drilling into a diverse array of subterranean formations. The water that flows back from these sites ranges from thick black to very light brown, including every shade in-between.
Thousands of wells dot the landscape of our country and each one represents millions of gallons of flowback and produced water that require treatment. The sheer volume of water places yet another obstacle on water treatment companies operating in the industry. Treatment systems need to have the ability to process high volumes of water in a timely manner to produce a supply that remains at least as cost-effective an alternative as fresh water.
Many water treatment processes have been devised for frac water treatment, but few, if any, have been able to successfully address the whole array of complexities, inhibiting the industry’s full-scale adoption of water reuse practices.
One treatment approach is to evaporate the flow back water, resulting in two streams, distilled water and reject water that include solids and salt. The problem is that evaporators are expensive to build and to operate. Additionally, believe it or not, distilled water is actually harmful to the environment because it is void of oxygen and minerals. It is also bad to reuse for fracking operations because the absence of salt creates osmotic imbalance that would cause the clay formation to swell, resulting in up to 40% lower well productivity.