Cost estimates for various methods of wastewater disposal and recycling vary, depending on both the reservoir in question, and the information source.

A seven-well recycling and reuse program using electrocoagulation in Eddy County, New Mexico, substituted over 8 million gallons of produced water for fresh water, and saved $70,000-$100,000 per well in water management costs, according to a Society of Petroleum Engineers paper authored by employees of oilfield services giant Halliburton and ExxonMobil subsidiary XTO Energy. The paper noted that costs for reinjection into disposal wells averaged 75 cents to $1/bbl in 2011.

Electrocoagulation services are offered by several providers, including Halliburton. “Electrocoagulation as a category is probably the answer to doing large-scale, high-speed water recovery,” said OriginOil Chief Executive Riggs Eckleberry.

Eckleberry said that while treating water for reuse has traditionally been more costly than disposal in deep injection wells or trucking to a water treatment site – 11 cents per gallon for deep injection and 7.5 cents per gallon for hauling to a treatment plant, compared to more than 20 cents for chemical treatment – “for the newer generation of electrocoagulation, Halliburton’s running around 4-4.5 cents per gallon, and we’re running 1.25 cents per gallon for our process, and if you add the further downstream process that Pace is doing, it gets up to about 2.5 cents”.

“It’s a whole new ballpark of lower price,” Eckleberry said.

Ecosphere Energy Services Chief Executive Robbie Cathey said that Ecosphere’s treatment, including transportation of the mobile treatment unit to the site, can range from 30 to 50 cents per bbl, which translates into 0.70-1.20 cents per gallon at 42 gallons per bbl. “And of course in today’s market it’s much more attractive at those lower price points,” he said.

“The going rate for disposal is in that 50 cent [per barrel, or 1.20 cents per gallon] range, so we are very competitive when you talk about the alternative of using deep well injections from a price point,” Cathey said. He added that Ecosphere’s all-in cost estimates for trucking water to a disposal site are in the $1/bbl range.

Ecologix Chief Executive Eli Gruber preferred not to disclose cost estimates for the company’s Integrated Treatment System – which also uses mobile treatment units – saying that cost can depend on various factors, such as location. “In Canada, they will pay a lot more than in Texas – it has to do with the cost of materials and transportation, logistics, cost of living, and requirements to move one or another substance,” he said. Removing hydrogen sulfide from sour water, for example, may require another step in the treatment process, he said.

And there is plenty of opportunity for competitive technologies to capture market share. Information provided by OriginOil suggests that market research firm Lux Research expects the frac water clean-up market to grow nine-fold, to $9 billion, in 2020, while water market analysts at Global Water Intelligence predict that the market for produced water treatment will rise to $2.9 billion in 2025 from $693 million now.

Additional Issues

It remains to be seen which technology will prove most effective, both in performance and cost terms. And despite the potential environmental benefits of recycling, some concerns remain. Environmental group Natural Resources Defense Council (NRDC) raised the question of disposal of toxic waste produced from the cleanup process.

“The recycling of fracking waste is conceptually a good thing, but we’re concerned about the residual waste coming out of that process that could be toxic, but is not governed under waste rules,” NRDC Senior Policy Analyst Amy Mall told Breaking Energy. “The waste should be managed under federal hazardous waste laws, but the industry is exempt from the federal law that governs hazardous waste.”

An NRDC issue brief, In Fracking’s Wake: New Rules are Needed to Protect Our Health and Environment from Contaminated Wastewater, lays out disposal methods for wastewater, and health and environmental risks posed by the waste stream (you can access the full report here).  

Eckleberry concurred that the waste issue remains a concern. “There needs to be work to beef up legislation around this, I don’t think it’s at all adequately addressed,” he said. “But at the same time, there’s potential to use natural absorbents like algae.”

Though OriginOil is not currently involved in using algae as an additional clean-up stage, “algae does absorb heavy metals and radioactive isotopes”, Eckleberry said. “No one’s done it yet, but it could be very interesting to combine the two.”

The first two parts of this series, on benefits and technologies, are here and here.