The Marcellus shale gas exploration rush that has washed over Pennsylvania has created concerns over how hydraulic fracturing impacts local water supplies.

 

A single well hydrofracture in the Marcellus may require two million to five million gallons of fracturing fluid, of which 25 percent to 100 percent may be returned to the surface as "flowback" or "produced water." Historically, flowback and produced water has traditionally gone to metals-precipitation plants, where metals and items are removed. The fluid that leaves the plant is clean salt brine, which has gone to sewage treatment plants where the salt is not removed, but diluted with treated sewage and discharged to the rivers.

 

In the past, this was never an environmental concern as the salt levels were very low and did not harm the environment. However, the sharp rise in Marcellus shale drilling in recent years means that the amount of water from shale gas operations being released into state waters would grow from a trickle to a tidal wave.

 

Fountain Quail Water Management, a Fort Worth, Texas-based subsidiary of Calgary-based Aqua-Pure Ventures Inc., recently partnered with Eureka Resources of Williamsport, Pa., to offer wastewater recycling to shale gas drillers in Pennsylvania.

 

Last month, Eureka opened its expanded 60,000-square foot water treatment facility in Williamsport, which will be capable of recycling up to 200,000 gallons of wastewater every day.

 

Fountain Quail's technology, originally developed by Aqua-Pure for use in northern Alberta's oil sands, offers a cost-effective solution for recycling wastewater in the Marcellus.

 

"Our recycling technology is achieving results that many people in the industry thought were impossible," said Brent Halldorson, Fountain Quail's chief operating officer. "Our evaporators are capable of producing pure distilled water, regardless of the feed composition."

 

The great challenge with treating flowback wastewater from shale wells is the variability of chemicals in the water. Current methods for treating wastewater, including membranes and ion exchanges, work when treating water with consistent levels of specific contaminants. The variability requires machinery to be constantly cleaned, recalibrated or for treatment to fail altogether. Water in the early stage flowback is likely very contaminated, while later flowback will typically have more salt it picks up from the ground.

 

Halldorson said the long-term solution may be a mix of onsite recycling and centralized treatment of wastewater, but the economics and decision of regulators in each state will determine that mix. In Pennsylvania, the company is releasing treated water back into rivers but also offering it to producers for use in fracturing wells.