Classification of Water
Most states draw legal distinctions between specific types of surface waters and specific types of ground waters. However, the recent trend has been towards regulating and managing surface and ground waters in conjunction.
Watercourses: A watercourse consists essentially of a definite natural stream, flowing in a definite natural channel, and originating from a definite source of supply.
Runoff: Waters that originate from rain and melting snow and that flow freely over the surface before becoming concentrated in watercourses or before sinking into the ground are runoff. Most regulation dealing with runoff is aimed at preventing erosion and pollution caused by runoff.
Tributary: Underneath a surface stream, there is usually an underflow or subflow. This consists of water in the sands, gravels, and other subsoil over which the surface stream flows, moving in the same direction and in intimate contact with the surface stream. The boundaries may extend laterally for considerable distances beyond the banks of the surface channel. From a legal as well as a physical standpoint, the surface stream and the underflow are not two separate rivers, but are component parts of a single watercourse. Watercourses that are partially, or entirely underground are also generally considered to be tributary waters. Depending on the location, the produced water from oil and gas operations may be tributary.
Non-Tributary: Underground water that neither draws from nor contributes to a natural surface stream in any measurable degree. These are also refered to as sedimentary or fossil waters. The aquifers containing these waters generally have no ability to recharge and will be depleted by ongoing use. Depending on the location, the produced water from oil and gas operations may be non-tributary.
- Water Withdrawals
Volume of freshwater that is taken from surface or groundwater resources.
- Water Consumption
Volume of freshwater that is taken from surface or groundwater resources and is not returned. There are concerns that hydraulic fracturing consumes a large amount of water. The water used in operations and pumped underground may remain in the well or be disposed elsewhere deep underground, making it unavailable for reuse. Water consumption metrics in most regions are poorly measured due to lack of consistent water sourcing disclosure and measurement statistics of water returning to the surface.
- Water Stress
Measures total annual water withdrawals (municipal, industrial and agricultural) expressed as a percentage of water available. This metric denotes the level of competition for water in a given region. The highest demand for water in most regions comes from agricultural or municipal uses followed by industrial uses. Water stress tends to be higher in regions of high population density or intense agricultural development. Water stress can be low even in arid regions such as North Dakota, where low population density and non water-intensive agricultural practices do not result in high water demand.
- Water Scarcity
Is the volumetric abundance, or lack thereof, of freshwater supply and increasingly accounts for water flow required to maintain the ecological health of rivers and streams.
- Water Risk
Refers to the ways in which water-related issues potentially undermine business viability.
- Brackish Water
Water that is generally saltier than freshwater, but not as salty as seawater.
"Oil and Gas Water Definitions"
- Flowback Water
Water returning to the surface directly after hydraulic fracturing. This water is often mixed with water found in the geological formation. The amount and quality (often poor) of plowback water returning to the surface varies depending on local geologic conditions and hydraulic fracturing fluids utilized.
- Produced Water
Water that returns to the surface along with the oil or gas that is being pumped from the well.
- Recycled Water
Water utilized a second time in hydraulic fracturing operations after undergoing treatment for contaminants.
- Reused Water
Water utilized a second time in hydraulic fracturing operations with minimal treatment requirements.
- Water Used for Enhanced Oil Recovery (EOR)
When water is pumped underground to increase pressure in a well to boost lagging oil production (generally after a reservoir has been depleted). EOR can require far larger volumes of water than the average well requirements for hydraulic fracturing operations.
- Drilling Water
Water that is used, often in conjunction with other chemicals, to cool and lubricate the drill bit and carry out drill cuttings during the drilling of the borehole.
In most states, water is legally owned by the State. To use water, it is therefore necessary to acquire a water right. In some states water rights will be acquired by co-operatives, municipalities, or other group entities, which then issue water shares for purchase by potential water users. Depending on the source of the water used in oil and gas development, different state water laws, agency regulation, and local authority will apply. Although, the laws governing ground and surface water use and production vary across the United States, all states in the Intermountain West region follow the Prior Appropriation Doctrine:
The Prior Appropriation Doctrine historically derives from water conflicts between mining operators. The doctrine generally follows the principle of "first come, first served." Under this doctrine the first person to develop a water resource in an area stakes first claim to the amount of water that is produced for beneficial purposes. Later users are entitled to any remaining resources in the order that they begin production.
Lifecycle of Water Use
Exploration & Site Construction
During this phase of development, water is used primarily for dust control on access roads and equipment cleaning. The amounts used are relatively small and this use is similar to other construction projects.
Drilling & Completion
The majority of water use in oil and gas development occurs during the drilling and completion phase. Well stimulation methods - hydraulic fracturing & water flooding - are the largest use. The second largest use is for drilling with water-based drilling muds. A relatively small amount of water is also used for equipment cleaning & when cementing well casing in the bore hole.
Reclamation & Abandonment
During the end a development's lifespan amounts of water used are minimal. Potential uses will be for cement plugging of the well and reclamation activities.
Water Recycling and Reuse
Reducing the amount of fresh water used in oil and gas development includes reusing and recycling water where possible. How much water can be reused on the well site, for new wells in the area or for other uses depends, in part, on water quality considerations [link to the water quality page]. For more information on this topic and a decision support tool, see:
"Produced Water Beneficial Use Dialogue: Opportunities and Challenges for Re-Use of Produced Water on Colorado's Western Slope", a 2014 report from the Colorado Energy Office and Colorado Mesa University Water Center on produced water re-use along Colorado's Western Slope indicates a growing interest in finding alternative ways to treat and use produced water from oil and gas development.
Water Treatment Technology and Decision Tool
This website provides a cost-effective tool that will allow operators to make fiscally and environmentally sound decisions on water management. It also promotes the identification of new sources of useable water for communities near unconventional gas resources by identifying potential end-uses for produced and flow-back water. The project website includes an overview of water treatment options, a catalog of treatments that characterizes and assesses existing and emerging technologies that are either being applied in shale gas arena, or have the capability for application, and regulatory information. The information provided is specific to the Barnett, Fayetteville, Haynesville, Marcellus, and Woodford shale plays, but provides information that would be generally applicable to other shale gas plays as well.
There are several processes employed to dispose of waste water from oil and gas development: evaporation, land application, surface water discharge, and injection. The process used depends on the regulatory regime, water quality, and developer practice. Injection is generally favored to dispose of brackish and otherwise contaminated waters unsuitable for surface water uses.
For a comprehensive analysis of current (2012) federal and state laws regulating oil and gas waste waters see the NRDC's In Fracking's Wake: New Rules are Needed to Protect Our Health and Environment from Contaminated Wastewater. The NDRC report finds that currently available storage, treatment, and disposal options are inadequate to fully protect human health and environment, but that stronger safeguards at state and federal levels could better protect against the risks associated with oil and gas wastewater.
Wastewater Injection -- Class II Injection Wells
The EPA Underground Injection Control (UIC) Program is responsible for regulating the construction, operation, permitting, and closure of injection wells that place fluids underground for storage or disposal in order to protect drinking water resources. Under this program, which is often delegated to the states for implementation, there are six classes of wells. Class II wells are used for injection of oil and gas related fluids. A small number of class II wells are used for storage of liquid hydrocarbons for the U.S. Strategic Petroleum Reserve. Most oil and gas related fluids are injected to enhance oil and gas development (secondary or tertiary recovery) or to dispose of waste fluids.
Based on an amendment to the Safe drinking Water Act added by the Energy Policy Act of 2005, however, the UIC Program does not regulate injection for hydraulic fracturing, unless diesel fuels are used in the fluids or propping agents. See the EPA webpage on Hydraulic Fracturing Under the Safe Drinking Water Act.
See the Induced Seismicity White Paper for an introduction to the issues.
One unintended consequence of wastewater injection is induced seismicity. While most earthquakes are naturally-occurring geologic phenomena, seismicity can be triggered by injection of fluids into the subsurface increasing the pore pressure in the rock that effectively reduces the natural friction on a fault. In Colorado, examples include induced seismicity from enhanced oil recovery in the Rangely Colorado oil field in the 1960-70s, brine disposal to control Colorado River salinity near Paradox, Colorado in the 1990s, and liquid waste disposal at the Rocky Mountain Arsenal in the 1960s. More recent earthquakes have been attributed to wastewater disposal wells in Greeley, Colorado and various other states including Oklahoma, Ohio, and Texas.
See the paper Regulating Our Way to Earthquake Free for legal and policy avenues to eliminate or minimize induced seismicity.
States are responding to both speculation and confirmation of wastewater injection induced seismicity with review and some revision of their regulations. For example, Colorado requires an operator to define, prior to permit approval, the seismicity potential and the proximity to faults through geologic and geophysical data if historical seismicity has been identified in the vicinity of a proposed wastewater injection well. The Texas Railroad Commission revised its wastewater injection regulations in August, 2014 to add various permit requirements and to clarify the authority of the agency to take action if a well is likely to be contributing to seismic activity. Oklahoma has responded with a “traffic light” system applied to both permitting decisions and active disposal wells. Oklahoma’s rules address various issues including permitting, monitoring, testing, and reporting requirements.
In addition to taking individual actions, states are also proactively discussing the possible association between earthquakes and injection of waste fluids with their peers. Under the auspices of the State Oil and Gas Regulatory Exchange of the States First initiative, states have initiated the Induced Seismicity by Injection Work Group.
Drought restrictions on water use are currently dealt with at the local level. In drought-stricken areas concern is particularly high over water used for well stimulation, for example, in 2011, the municipality of Grand Prairie, Texas banned the use of city water for hydraulic fracturing. However, the proportion of domestic water use in oil and gas development to total domestic water use is less than 0.1%.
In their 2014 report Hydraulic Fracturing & Water Stress, the non-profit organization Ceres reported that nearly half of the 39,294 reported hydraulically fractured wells drilled in the U.S. since 2011 (just over 18,000 wells) are in regions with high or extreme water stress. Over 28,000 wells, or 73 percent, are located in regions of at least medium water stress. In extreme water stress regions, municipal, industrial or agricultural users are already using over 80 percent of the annual available flows (from both surface water and shallow groundwater). In high stress regions, 40 to 80 percent is already allocated. Hydraulic fracturing in the U.S. is largely taking place in regions already experiencing high competition for water.
For a series of interactive maps presenting the competition for water, drought areas, and groundwater depletion overlaid by areas of shale energy development, click here: Ceres: Hydraulic Fracturing & Water Stress
Increasing recognition that regional economic reliance on groundwater in many regions may not be sustainable and that groundwater withdrawals by all users must be carefully balanced with declining groundwater levels and impacts on surface water flows. Another level of added complexity concerning oil and gas development in many western states is prolonged drought conditions, growing climate change impacts, and anticipated population growth. Texas, Colorado, Oklahoma, Wyoming, New Mexico, and California are all expected to experience 20 percent or higher population growth by the end of the decade. Texas is projected to experience an 80 percent growth in population by 2060. For the full report from Ceres, see: Ceres: Hydraulic Fracturing & Water Stress: Water Demand by the Numbers
For a global picture of water for oil and gas development, see Global Shale Gas Development: Water Availability and Business Risks.
Challenges of Tracking Water Consumption
In a series of articles focusing on the issue of drilling related water consumption, the organization FracTracker has identified a number of obstacles holding back accurate collection of water consumption data for unconventional drilling activities.
A combination of factors have made it increasingly difficult for a concerned landowner or citizen to attain a complete picture of water consumption statistics for oil and gas discovery and production on national, state, and local levels. Conflicting data sets, lack of data, and state records with varying criteria, definitions, and categorization of waste products all contribute to the difficulty of attaining accurate records. Additionally, unclear or absence of records for water volume used in refracturing wells and for well and pipeline maintenance leave a significant quantity of water unaccounted for.
Because oil and gas operations are often shared by many companies on multiple levels, chain of custody also becomes a vexing issue for tracking water consumption. Operators oversee exploration and production, service providers (such as Halliburton) oversee field operations and supply chains and often subcontract specific jobs to specialist companies. Thus it is often almost impossible to create a full cradle-to-grave assessment of water consumption for even a single discovery and production operation.
The organization FracFocus, launched in 2011, is intended to be a one stop shop for chemical and fluid disclosure of hydraulically fractured wells in the United States. However, a 2013 Harvard Law School study found a number of significant limitations to the site including incomplete and inaccurate disclosures and a cumbersome search format that, "...does not allow searching across forms..." which "...prevents site managers, states, and the public from catching many mistakes or failures to report."
Finally, state regulations on water withdrawal permits vary widely throughout the country. Regulations often differ based on whether withdrawal is from a surface or groundwater source, and different states employ different permitting and reporting standards. For a state by state comparison of water quantity regulations and standards, see the Law Atlas's Water Quantity Page.
State by State
Law Atlas Database - Water Quantity
The LawAtlas Water Quantity dataset captures laws and regulations addressing the amount of water used in oil and gas development, including water administration systems, reporting requirements and disposal methods — all of which provide a picture of the life cycle of water use in the hydraulic fracturing process. Laws and regulations compiled for 17 states, three federal agencies (Bureau of Land Management, Bureau of Indian Affairs, and U.S. Forest Service), and three local jurisdictions may require those drilling to identify the physical source of water used for development, submit a water plan, and to identify the amount of water used during completion of the well, the amount of water that flows to the surface after hydraulic fracturing, and the volume of disposed water. The laws and regulations also address how surface and groundwater rights are obtained and whether the state distinguishes types of surface water and groundwater.
A factsheet: Oil & Gas Operations: Creating Successful Water Policies in Colorado, State Laws Regulating the Life Cycle of Water in Oil and Gas Development gives a brief description of the types of state laws that regulate water monitoring and tracking in oil and gas operations. It also provides examples of policies that Colorado could adopt to improve life cycle analysis and suggests recommendations for drafting such policies based on best practices from other states.
Produced Nontributary Ground Water Rulemaking:
Ground water in the State of Colorado is legally presumed to be "tributary," or hydraulically connected to surface water in such a fashion so as to require administration within the prior appropriation system in conjunction with surface rights, unless it is demonstrated to be nontributary ground water in accordance with the law. This rulemaking defines specific locations of Nontributary Ground Water. 2 CCR 402-17
Colorado Oil and Gas Conservation Commission
Colorado Division of Water Resources
Colorado Department of Public Health and Environment
Montana Board of Oil and Gas Conservation
DNRC : Water Resources Division
New Mexico Oil Conservation Division
New Mexico Office of the State Engineer
Utah Division of Oil, Gas and Mining
Utah Division of Water Rights
Water Exports Restriction
Exports of water from Wyoming of over 1,000 acre-feet per year require regulatory permission and must follow a statutory process laid out in WS 41 -3-115. This statute would not effect smaller developers, however a number of developers in Weld County, Colorado would use enough water if they solely sourced from Wyoming exports.
Wyoming Oil and Gas Conservation Commission
Wyoming's State Engineer's Office
Beyond the Region
The Railroad Commission of Texas (RRC) is responsible for regulating all waste associated with oil.
Analysis of current oil and gas development practices in Texas, the growing conflict with water conservation, and potential resolutions for the oil and gas industry:
Texas's Oil & Water Tightrope