Horizontal drilling and hydraulic fracturing have revolutionized natural gas production in the U.S., projected to rise 44 percent from 2011 to 2040 largely due to these technologies.
And yet water—arguably the most important ingredient in the fracking process—represents a weak spot in this growth. One well uses anywhere from 3 to 7 million gallons of water which, when mixed with sand and chemicals, allows drillers to blast apart shale at depth to release natural gas.
Adding to questions over whether local water supplies can support such high demands, many in the public are fired up over the volumes of contaminated wastewater fracking produces, worried they could threaten water supplies.
“We have to calm these fears,” says Laura St. Pierre of YSI, based in Yellow Springs, Ohio. St. Pierre is one of a handful of speakers who focused on fracking at the National Ground Water Association’s (NGWA) annual conference, held in December in Nashville, Tenn.
Water quality and supply issues have the potential to severely restrict the use of fracking in natural gas production. Take, for instance, the state of New York, which in March placed a moratorium on fracking until 2015.
Fortunately, there are technical and strategic tools available to address public concerns and expand shale gas production, several of which were highlighted at the recent NGWA conference.
Preventing Water Quality Problems
Fears over fracking-related contamination include whether methane released during the process migrates through fractured bedrock to local wells, as well as whether wastewater in injection wells can affect public water supplies.
“Proper well development makes the risk of contamination very low,” says St. Pierre, pointing out that modern well design is actually quite robust. In reality, handling flowback or produced water poses the greatest risk. Produced water can be recycled, but the vast majority of it must be treated and disposed of appropriately.
To minimize threats to public water supplies, some states are expanding water quality monitoring requirements for fracking operations. For example, next year Michigan is expected to adopt new rules requiring monitoring in and around frack sites. But the benefits of implementing a monitoring strategy go beyond regulatory compliance.
“A comprehensive monitoring program can be low-cost in respect to the entire operation, while also easing public fears and proving the fracking process is not affecting drinking water supplies or aquatic life,” says St. Pierre.
In particular, she says that baseline data—including hydrologic surveys and sampling of nearby residential wells—are key to reducing a company’s liability.
“Let’s make sure you don’t get blamed for what’s already there,” she says.
Other critical elements include portable monitoring stations at drill sites equipped with spill response kits, as well as real-time monitoring upstream and downstream of water treatment facilities handling produced water.
In the Susquehanna River Basin, for example, a 75-station monitoring network delivers 144,000 readings daily on surface water temperature, total dissolved solids, pH, turbidity and dissolved oxygen.
This real-time monitoring immediately detects any unexpected changes, alerting operators to potential contamination issues. Sharing the data through a public portal, as St. Pierre recommends, can also go a long way toward easing fears.
“Let the data speak for itself,” she says, emphasizing that this type of monitoring program is the only way to validate the safety of groundwater and surface water supplies.
Randy Curtis, PG, of Gresham Smith & Partners in Nashville, also urges drillers to do their homework before starting operations, not just in terms of baseline monitoring but also in terms of understanding local geology.
He points specifically to Tennessee’s abundance of high-angle faults, which can cause problems for drillers—including spills—due to incomplete data in remote areas.
“All kinds of structures nobody knows about aren’t even mapped,” he says, adding that it’s up to drillers to determine whether to proceed if they encounter unexpected subsurface conditions.
Like St. Pierre, Curtis also recommends baseline monitoring of nearby wells prior to drilling. He also says monthly operating reports (MORs) kept by water treatment plants can provide useful information.
“This raw data is gold,” says Curtis, pointing specifically to information on sulfide and chloride ion concentrations. Elevated sulfur levels in residential wells could be blamed on drilling, but Curtis says the key is to understand baseline ratios of sulfide to chloride.
“If the sulfur was coming from fracking, the ratio to chloride would change,” he says.
Baseline sampling and ongoing monitoring are important tools for improving both the real and perceived safety of fracking, but these alone won’t solve the industry’s water problems. Drillers and energy companies must also tackle questions of water supply.
Meeting Water Demands
The staggering volume of water consumed in the fracking process is problematic in terms of supply and logistics, particularly in arid locations where drought is an ongoing issue.
Water transfer via truck delivery strains local infrastructure, and long-distance piping systems create other problems. For instance, while aluminum pipe is inexpensive and fast to set up, it can leak where pipes join together. A common alternative is fused HDPE piping, which takes longer to install.
Tanner Tryon of Hose Solutions was on hand at the NGWA conference to discuss a method that’s quickly becoming a new industry standard: lay flat hoses.
This technology offers several advantages over traditional water transfer methods. Since it’s carried on spools, it can be moved to a drill site very quickly. Hose Solutions' lay-flat product, Mineflex, is abrasion-resistant and works in temperatures from minus 40 to 160 degrees Fahrenheit. Tryon notes that miles of hose can be laid without leaking a single drop of water.
Tryon’s company also manufactures flexible drop pipe for accessing water wells. Made of polyurethane and high-tenacity fibers, flexible drop pipe isn’t susceptible to corrosion, internal growth or degradation the way steel piping is.
“It’s like a firehose on steroids,” Tryon says of the flexible drop pipe, adding that 750 feet of 3-inch pipe can be installed in a matter of minutes
The portability of lay flat hose and flexible drop pipe makes them ideal for remote locations and confined spaces, minimizing damage to the environment and local infrastructure. Not surprisingly, the use of lay flat hose has exploded over the past two years, with some exploration and production companies even mandating its use for transfer projects on their leases.
Tryon says nearly all sales calls at water transfer companies these days revolve around lay flat hose. Everyone wants to know if water transfer companies offer it.
Despite advances in water transfer efficiency, the sheer amount of water used in the fracking process is still cause for concern. Carrie Blankenship, PG, of Draper Aden Associates in Blacksburg, Va., discussed how local governments are using regional water supply plans to address the issue, with implications for what industry can expect in the future.
“We really need to get comfortable with understanding and managing water demands,” notes Blankenship.
There are several key elements in an effective water supply plan. First, it requires a detailed account of current resources and users, including timing of withdrawals. Planners include not just public utilities, but also private systems, agricultural users, and high-volume users like drillers and exploration companies.
“It’s important to take a multidisciplinary approach to get input from all stakeholders,” says Blankenship, adding, “Local governments aren’t dictating what individuals can do. They’re trying to get information back from them to get a better overall picture of area needs.”
Once planners understand existing resources and uses, they can then project demand up to 50 years into the future. With new shale plays discovered every year, many local governments are already planning for future high-volume users.
Blankenship highlights Virginia’s Danville Basin, a target for future shale gas production that represents an important economic development opportunity for the area. Local planners there developed a regional water supply plan for the area as early as 2011.
“They’re ahead of the game, so if it were to happen, they will be ready for it,” says Blankenship.
Another crucial element is drought contingency planning, including trigger points for implementing a drought watch, warning or emergency. Blankenship uses the example of the 2012 Midwestern drought, which led several Texas cities to revoke water permits for fracking operations across the board.
“This is a case where a water supply plan would have been a great tool to manage competing demands,” says Blankenship, adding that implementation isn’t always easy. “The results may not be popular, but it’s important to stick to the plan.”
Shale gas has the potential to add to U.S. energy resources for decades to come. But if environmental and public health concerns are not addressed, the fracking industry may see continuing restrictions on its growth. The future belongs to those who actively develop and adopt new solutions, from technologies like lay flat hoses to strategic tools like proactive water quality monitoring programs.
Note: This story was updated after publication to make a clear distinction between Hose Solutions' lay flat hose and its flexible drop pipe. Parts of the story confused the two products. National Driller regrets the error.