H 2 O Where Did It Go?
By Mary Ellen Cassidy, Community Outreach Coordinator, FracTracker Alliance
A Water Use Series
Many of us do our best to stay current with the latest research related to water impacts from unconventional drilling activities, especially those related to hydraulic fracturing. However, after attending presentations and reading recent publications, I realized that I knew too little about questions like:
- How much water is used by hydraulic fracturing activities, in general?
- How much of that can eventually be used for drinking water again?
- How much is removed from the hydrologic cycle permanently?
To help answer these kinds of questions, FracTracker will be running a series of articles that look at the issue of drilling-related water consumption, the potential community impacts, and recommendations to protect community water resources.
Ceres Report
We have posted several articles on water use and scarcity in the past here, here, here and here. This article in the series will share information primarily from Monika Freyman’s recent Ceres report, Hydraulic Fracturing & Water Stress: Water Demand by the Numbers, February 2014. If you hunger for maps, graphs and stats, you will feast on this report. The study looks at oil and gas wells that were hydraulically fractured between January 2011 and May 2013 based on records from FracFocus.
Class 2 UI Wells
Water scarcity from unconventional drilling is a serious concern. According to Ceres analysis, horizontal gas production is far more water intensive than vertical drilling. Also, the liquids that return to the surface from unconventional drilling are often disposed of through deep well injection, which takes the water out of the water cycle permanently. By contrast, water uses are also high for other industries, such as agriculture and electrical generation. However, most of the water used in agriculture and for cooling in power plants eventually returns to the hydrological cycle. It makes its way back into local rivers and water sources.
In the timeframe of this study, Ceres reports that:
- 97 billion gallons of water were used, nearly half of it in Texas, followed by Pennsylvania, Oklahoma, Arkansas, Colorado and North Dakota, equivalent to the annual water need of 55 cities with populations of ~ 5000 each.
- Over 30 counties used at least one billion gallons of water.
- Nearly half of the wells hydraulically fractured since 2011 were in regions with high or extremely high water stress, and over 55% were in areas experiencing drought.
- Over 36% of the 39,294 hydraulically fractured wells in the study overlay regions experiencing groundwater depletion.
- The largest volume of hydraulic fracturing water, 25 billion gallons, was handled by service provider, Halliburton.
Water withdrawals required for hydraulic fracturing activities have several worrisome impacts. For high stress and drought-impacted regions, these withdrawals now compete with demands for drinking water supplies, as well as other industrial and agricultural needs in many communities. Often this demand falls upon already depleted and fragile aquifers and groundwater. Groundwater withdrawals can cause land subsidence and also reduce surface water supplies. (USGS considers ground and surface waters essentially a single source due to their interconnections). In some areas, rain and snowfall can recharge groundwater supplies in decades, but in other areas this could take centuries or longer. In other areas, aquifers are confined and considered nonrenewable. (We will look at these and additional impact in more detail in our next installments.)
Challenges of documenting water consumption and scarcity
Tracking water volumes and locations turns out to be a particularly difficult process. A combination of factors confuse the numbers, like conflicting data sets or no data, state records with varying criteria, definitions and categorization for waste, unclear or no records for water volumes used in refracturing wells or for well and pipeline maintenance.
Along with these impediments, “chain of custody” also presents its own obstacles for attempts at water bookkeeping. Unconventional drilling operations, from water sourcing to disposal, are often shared by many companies on many levels. There are the operators making exploration and production decisions who are ultimately liable for environmental impacts of production. There are the service providers, like Halliburton mentioned above, who oversee field operations and supply chains. (Currently, service providers are not required to report to FracFocus.) Then, these providers subcontract to specialists such as sand mining operations. For a full cradle-to-grave assessment of water consumption, you would face a tangle of custody try tracking water consumption through that.
To further complicate the tracking of this industry’s water, FracFocus itself has several limitations. It was launched in April 2011 as a voluntary chemical disclosure registry for companies developing unconventional oil and gas wells. Two years later, eleven states direct or allow well operators and service companies to report their chemical use to this online registry. Although it is primarily intended for chemical disclosure, many studies, like several of those cited in this article, use its database to also track water volumes, simply because it is one of the few centralized sources of drilling water information. A 2013 Harvard Law School study found serious limitations with FracFocus, citing incomplete and inaccurate disclosures, along with a truly cumbersome search format. The study states, “the registry does not allow searching across forms – readers are limited to opening one PDF at a time. This prevents site managers, states, and the public from catching many mistakes or failures to report. More broadly, the limited search function sharply limits the utility of having a centralized data cache.”
To further complicate water accounting, state regulations on water withdrawal permits vary widely. The 2011 study by Resources for the Future uses data from the Energy Information Agency to map permit categories. Out of 30 states surveyed, 25 required some form of permit, but only half of these require permits for all withdrawals. Regulations also differ in states based on whether the withdrawal is from surface or groundwater. (Groundwater is generally less regulated and thus at increased risk of depletion or contamination.) Some states like Kentucky exempt the oil and gas industry from requiring withdrawal permits for both surface and groundwater sources.
Can we treat and recycle oil and gas wastewater to provide potable water?
Will recycling unconventional drilling wastewater be the solution to fresh water withdrawal impacts? Currently, it is not the goal of the industry to recycle the wastewater to potable standards, but rather to treat it for future hydraulic fracturing purposes. If the fluid immediately flowing back from the fractured well (flowback) or rising back to the surface over time (produced water) meets a certain quantity and quality criteria, it can be recycled and reused in future operations. Recycled wastewater can also be used for certain industrial and agricultural purposes if treated properly and authorized by regulators. However, if the wastewater is too contaminated (with salts, metals, radioactive materials, etc.), the amount of energy required to treat it, even for future fracturing purposes, can be too costly both in finances and in additional resources consumed.
It is difficult to find any peer reviewed case studies on using recycled wastewater for public drinking purposes, but perhaps an effective technology that is not cost prohibitive for impacted communities is in the works. In an article in the Dallas Business Journal, Brent Halldorson, a Roanoke-based Water Management Company COO, was asked if the treated wastewater was safe to drink. He answered, “We don’t recommend drinking it. Pure distilled water is actually, if you drink it, it’s not good for you because it will actually absorb minerals out of your body.”
Can we use sources other than freshwater?
How about using municipal wastewater for hydraulic fracturing? The challenge here is that once the wastewater is used for hydraulic fracturing purposes, we’re back to square one. While return estimates vary widely, some of the injected fluids stay within the formation. The remaining water that returns to the surface then needs expensive treatment and most likely will be disposed in underground injection wells, thus taken out of the water cycle for community needs, whereas municipal wastewater would normally be treated and returned to rivers and streams.
Could brackish groundwater be the answer? The United States Geological Survey defines brackish groundwater as water that “has a greater dissolved-solids content than occurs in freshwater, but not as much as seawater (35,000 milligrams per liter*).” In some areas, this may be highly preferable to fresh water withdrawals. However, in high stress water regions, these brackish water reserves are now more likely to be used for drinking water after treatment. The National Research Council predicts these brackish sources could supplement or replace uses of freshwater. Also, remember the interconnectedness of ground to surface water, this is also true in some regions for aquifers. Therefore, pumping a brackish aquifer can put freshwater aquifers at risk in some geologies.
Contaminated coal mine water – maybe that’s the ticket? Why not treat and use water from coal mines? A study out of Duke University demonstrated in a lab setting that coal mine water may be useful in removing salts like barium and radioactive radium from wastewater produced by hydraulic fracturing. However, there are still a couple of impediments to its use. Mine water quality and constituents vary and may be too contaminated and acidic, rendering it still too expensive to treat for fracturing needs. Also, liability issues may bring financial risks to anyone handling the mine water. In Pennsylvania, it’s called the “perpetual treatment liability” and it’s been imposed multiple times by DEP under the Clean Streams Law. Drillers worry that this law sets them up somewhere down the road, so that courts could hold them liable for cleaning up a particular stream contaminated by acid mine water that they did not pollute.
More to come on hydraulic fracturing and water scarcity
Although this article touches upon some of the issues presented by unconventional drilling’s demands on water sources, most water impacts are understood and experienced most intensely on the local and regional level. The next installments will look at water use and loss in specific states, regions and watersheds and shine a light on areas already experiencing significant water demands from hydraulic fracturing. In addition, we will look at some of the recommendations and solutions focused on protecting our precious water resources.
I’m puzzled by the MIT study posted by Charles. The very last line of the article is “The scientists said that water and other fluids used to open wells through hydraulic fracturing, or fracking, are a different matter, requiring other kinds of treatment and disposal.” Meaning they really haven’t found a way to do it completely. Water returns from fracturing do contain chemicals associated with the process. If he could give some more details – I would greatly appreciate it.
According to the February 5, 2013 article in Science, “New Tech Said to Clean Up Fracking Water”, the HDH (Humidification Dehumidification) desalination technology developed by the MIT team is “not aimed at the large volumes of water that flow back just after a frack, but could work unattended by a human for months as it treats the really salty water to drinking-water quality, according to engineers working on the system”. (Flowback water is water that returns to the surface immediately after the fracking process and is a mixture of fracking fluid and formation water from the target shale. Once the chemistry of the water coming out of the well resembles the shale rock formation rather than the fracking fluid injected, it is known as produced water and can continue to flow as long as a well is in operation.)
“Lienhard (mechanical engineer, MIT) said he envisions the desalination plants at each individual well pad, processing hundreds to a few thousand liters of produced water per day at a cost of about “a couple of dollars” per barrel. The team has filed for patents on the technology and launched a company to commercialize it.”
In the January 20, 2014 Texas Water Desalination Report, Prakash Govindan describes a successful demonstration of Gradiant’s first commercial humidification-dehumidification (HDH) unit in Texas’ Permian Basin. “The system operated over six weeks while producing 500 barrels per day of distilled water from a produced water feed stream with a TDS (total dissolved solids) of 120,000- 140,000 mg/L.” (Seawater has an average TDS of 35,000 mg/L.)
“The company will begin ramping-up the facility’s production to 4,000 barrels a day by furnishing seven more modules. ( 4,000 barrels a day ~ 168,000 gallons/day. According the the EPA, American residents use about 100 gallons of water per day.) The facility will also produce 10-pound brine for well completions, while the fresh water will be used in new frac operations. According to Govindan, “Nothing goes down a disposal well.”
Technology already exists to turn waste water into drinking water and it will almost certainly get better and cheaper over time.
http://ens-newswire.com/2013/02/05/u-s-saudi-engineers-turn-gas-well-water-to-drinking-water/
“Researchers at the Massachusetts Institute of Technology, MIT, have filed for patents on a new water purification system that turns the produced water from natural gas wells into drinking water.”
I simply don’t understand why the argument that removing water from the water cycle is supposed to be bad thing keeps being repeated. Why is it supposed to be bad? Usually when I ask this question I get a reply that betrays a lack of understanding of how much water there is on Earth and how the hydrological cycle works.
You can’t just remove fresh water from the hydrological cycle. Water is water. Rivers flow to the sea and seawater evaporates to fall as rain. Whatever isn’t used by biological processes (and that eventually returns as well), or recharges groundwater, or evaporates (to fall as rain again), or is locked in ice and snow flows back to the sea. More importantly the oceans are rising! If we could possibly sequester enough water underground to actually lower sea levels the result would be a good thing not a bad thing. Taking fresh water out of the cycle doesn’t reduce the total amount available any more than the Mississippi River flowing into the Gulf for millions of years has. Abusing ground water resources does. Global warming’s melting of glaciers and ice caps does. But we could probably take the entire flow of the Mississippi and direct it straight underground for ten years without much affecting either the weather or the amount of fresh water available to us (ecological consequences to the Gulf aside). To the hydrological cycle water is just water. And the seas are rising.
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Comments posted by Charles Younger and responses for consideration –
Comment Post– “I simply don’t understand why the argument that removing water from the water cycle is supposed to be bad thing keeps being repeated. Why is it supposed to be bad?”
Response – Taking Water out of the natural hydrological cycle is a “bad thing” because in drought prone areas it can restrict the volume available to the public for potable water, threaten the water supply needed for industrial processes, limit agricultural productivity, impede commercial barge and river traffic and result in a contentious competition for precious water resources.
Comment Post – “Usually when I ask this question I get a reply that betrays a lack of understanding of how much water there is on Earth and how the hydrological cycle works”…” You can’t just remove fresh water from the hydrological cycle. Water is water. Rivers flow to the sea and seawater evaporates to fall as rain. Whatever isn’t used by biological processes (and that eventually returns as well), or recharges groundwater, or evaporates (to fall as rain again), or is locked in ice and snow flows back to the sea. Taking fresh water out of the cycle doesn’t reduce the total amount available any more than the Mississippi River flowing into the Gulf for millions of years has.”
Response: I agree there is often a misunderstanding of the hydrological cycle and how it works. It is well established that the water cycle is a closed system – All the water that ever was on earth will always be on earth.
Unfortunately, this is little comfort to communities whose water resources have been diminished or polluted. The concern is not that the total volume of water on earth is changing but rather that redistribution and/or contamination of a community water source makes it inaccessible or too expensive for communities to recover or purify.
Regarding underground injection of hydraulic fracturing wastewater and its potential return to the hydrological cycle – the hope of both industry and public is actually that it does not, in fact, migrate outside of the injection well back into the hydrological cycle where possible contamination of ground or surface waters could result.
Comment Post – “More importantly the oceans are rising! If we could possibly sequester enough water underground to actually lower sea levels the result would be a good thing not a bad thing”.
Response – Collecting and transporting enormous volumes of ice/snow melts and rainwater and then sequestering them underground to prevent sea level rise would be an expensive and mammoth engineering project. Finding underground injection sites for frackwaste water is already a challenge so locating underground sites that would secure and protect fresh water would be up against those same geological obstacles. Also, this plan would not address the major sea level rise due to thermal expansion.
Prevention or mitigation of catastrophic sea level rise by implementing a diverse energy system is an affordable and technologically available alternative to consider that has additional advantages along with water sustainability rewards.
Comment Post – “But we could probably take the entire flow of the Mississippi and direct it straight underground for ten years without much affecting either the weather or the amount of fresh water available to us (ecological consequences to the Gulf aside)”
Response – I am not certain which study or statistical analysis this statement is based upon, but based on impacts to communities where rivers actually have dried up or have been diverted, I would anticipate significant changes to the hydrological cycle and local microclimates were we to test this hypothesis.
It is typically not recommended to use recycled wastewater as drinking water but it can be used as a secondary water supply for other needs to conserve existing water supplies for drinking.
In PA – we have used recycled water for landscape irrigation, evaporator cooling, and with some polishing it would be a good source of water for hydraulic fracturing. The same could be said for stormwater runoff, acid mine drainage, production brines and other degraded water.
I would not recommend using recycled flowback for drinking water – but we should be using 100% recycling and using degraded waters as the source this would include AMD.