Salt Water Disposal FAQs

What purpose do saltwater disposal wells serve?
Oil and gas reservoirs are found in porous rock formations that also usually contain significant amounts of saltwater. In Texas, the saltwater produced with oil and gas (sometimes referred to as produced water), as well as hydraulic fracturing flowback fluid (if a well undergoes hydraulic fracturing stimulation treatment), must be disposed of in a manner that will not cause or allow the potential for pollution of surface or subsurface waters.

There are three different categories of underground injection used to manage the disposal of oil and gas produced wastewater:
  1. Oil and gas produced wastewater may be returned to the reservoir where it originated by injection for secondary or enhanced oil recovery. These injection wells are referred to as “injection wells” or wells involved in “secondary recovery/injection wells” (permit applications are filed on Form H-1/H-1A);
  2. Oil and gas produced wastewater may be disposed of by injection into underground porous rock formations not productive of oil or gas that are isolated from useable quality groundwater and sealed above and below by unbroken and impermeable strata. Injection wells of this type are referred to as “disposal wells” or are wells involved in “disposal into a non-productive zone” (permit applications are filed on Form W-14); or
  3. Oil and gas produced wastewater may be disposed of by injection back into the productive zone where it originated with the associated oil or natural gas that it was produced with. This type of waste management is referred to as “disposal” because it occurs without the added benefit of “secondary recovery” as in the first category, and is also referred to as “disposal into a productive zone” (these permit applications are also filed on Form H-1/H-1A).
The vast majority of wells in Texas are injection wells, not disposal wells. As of calendar year 2013, Texas has more than 50,000 permitted oil and gas injection and disposal wells with approximately 35,000 currently active as of calendar year 2013. Of these 35,000 active injection and disposal wells, about 7,500 are wells that are disposal wells and the remainder are injection wells.

Operators are required to follow the Railroad Commission’s (RRC) disposal regulations administered by the agency’s Technical Permitting Section-Underground Injection Control (UIC) Program. Underground Injection Control is a program that is federally delegated by the U.S. Environmental Protection Agency (EPA) to Texas, and it follows national guidelines under the federal Safe Drinking Water Act for surface and groundwater protection. EPA awarded the Railroad Commission “primary enforcement responsibility” over oil and gas injection and disposal wells on April 23, 1982.
What is the difference between a disposal well and an injection well?
Disposal wells may inject fluid into an underground interval that is not productive of oil and gas and sealed above and below by unbroken, impermeable strata or dispose produced water back into a productive zone where the oil or natural gas is produced.

Injection wells re-inject fluids into the same reservoir from which the fluids originated for secondary or enhanced oil recovery from depleted reservoirs. The vast majority of wells in Texas are injection wells, not disposal wells. Operators use secondary recovery techniques to maintain an oil field’s pressure that gets depleted as oil is produced and also to displace or “sweep” more oil toward producing wells. Secondary recovery is sometimes known as waterflooding.
How many of these wells are in Texas?
Texas is the nation’s number one oil and gas producer with more than 295,000 active oil and gas wells statewide. Injection and saltwater disposal wells are also located throughout the state to improve oil and gas recovery and to safely dispose of the produced water and hydraulic fracturing flowback fluid from oil and gas wells. Texas has more than 50,000 permitted oil and gas injection and disposal wells with approximately 35,000 currently active as of calendar year 2013. Of these 35,000 active injection and disposal wells, about 7,500 are wells that are used for disposal, the remainder are injection wells.*

* SOURCE: Distribution of Wells Monitored by the Railroad Commission, updated April 27 2013: and online “Oil and Gas Data Query-Injection/ Disposal Permit Query.”
What chemicals are found in saltwater that goes into injection and disposal wells?
The overwhelming majority of injected fluid is oilfield brine, which is also sometimes referred to as “produced water.” Oilfield brine is the water, with varying levels of salinity, that is found in the same geologic formations that produce oil and gas. This produced water comes up simultaneously with the production of oil and gas. However, small quantities of substances used in the drilling, completion and production operations of a well may be mixed in this waste stream. Some of these materials that may enter into the oilfield brine waste stream are minor amounts of drilling mud, fracture fluids and well treatment fluids. Also, since the produced water is associated with crude oil and natural gas, small amounts of residual hydrocarbons can also be found in the produced water.
Can I be guaranteed that saltwater disposal wells will not contaminate my water well?
In Texas, the saltwater that is produced with oil and gas (known as produced water), as well as hydraulic fracturing flowback fluid, must be disposed of in a manner that will not cause or allow the potential for pollution of surface or subsurface waters.

The Commission’s Underground Injection Control (UIC) program is federally delegated to Texas by the U.S. Environmental Protection Agency (EPA) and follows national guidelines under the federal Safe Drinking Water Act regarding surface and groundwater protection. The UIC program features regulations specifically tailored to protect underground sources of drinking water from harm resulting from injection of oilfield waste into underground formations.

In addition to the UIC permitting process, proper well construction and completion, injection procedures and monitoring ensure that fresh water sources are not impacted by saltwater.

The Railroad Commission also regulates the surface management of oil and gas waste through other regulations (see 16 Texas Administrative Code §3.8 at the following link HERE).

In Texas, the Texas Groundwater Protection Committee (TGPC) tracks groundwater pollution. All water protection agencies are members, including the Railroad Commission. Each year, the TGPC publishes a Joint Groundwater Monitoring and Contamination Report, which can be found at:
What is involved in the Underground Injection Control (UIC) permitting process for injection/disposal wells?
The Commission grants injection and disposal wells permits for UIC Class II wells when they meet the requirements of the Commission’s Underground Injection Control (UIC) Program. The UIC permitting process features numerous requirements and safeguards including: notice to the public; hearing opportunities; a review of area geology; and required areas of review near the proposed wells to determine if there are other wells penetrating the same geologic horizon proposed for disposal.

When permitting commercial or non-commercial wells, the RRC must determine:
  • Whether an operator is eligible for a permit (has no past due franchise taxes, has the required financial assurance, and has no outstanding compliance problems applicable to the proposed injection or disposal operation.)
  • Whether all affected parties have been properly notified. For non-commercial wells, the surface owner and nearby oil and gas well operators are required by Commission rules to be notified. For commercial wells, adjacent surface owners also must be notified under Commission rules.
  • If a protest is filed, the RRC notifies the operator that the application cannot be approved administratively, and the operator is advised of their right to a hearing on the application.
  • That the proposed injection well is properly completed to protect groundwater with required surface casing to the base of usable quality water as determined by RRC’s Groundwater Advisory Unit with long string casing and cement to ensure that the injected fluid is confined to the proposed injection or disposal interval.
  • That there are no improperly completed, improperly plugged or unplugged and abandoned oil and gas wells of public record within ¼ mile of the proposed injection well. (This is known as the area of review, and may be expanded up to ½ mile or more in some circumstances.)
For a commercial disposal facility, there are more requirements in addition to those listed above, such as restricted access through a 24-hour security guard or a gated and locked facility, and leak and overflow protection requirements.

A permit may be administratively approved by the Railroad Commission’s technical staff if it is technically complete. However, if a permit is protested, a hearing is required to be held, and based on evidence presented during the hearing, a staff proposal for decision (PFD) recommending approval or denial of the permit will be issued. The staff PFD then goes to the three Railroad Commissioners for final consideration in an open meeting.
What are the construction standards for a disposal well?
Railroad Commission rules for the construction of all oil and gas related wells, including injection/disposal wells, are intended to protect groundwater and are specially designed to require multiple layers of cement and steel to ensure that shallow, usable quality water is not impacted. Disposal wells inject saltwater into underground formations, often over a mile in depth, into fields that are already full of naturally occurring saltwater. In contrast, wells that supply fresh water can vary in depth throughout the state, and generally can range from no deeper than a few hundred to a thousand feet.

Specifically, a disposal well’s construction standards require three layers of casing to ensure groundwater is protected. The first protection layer is surface casing, a steel pipe that is encased in cement that reaches from the ground surface to the base of the deepest usable quality groundwater level. Surface casing acts as a protective sleeve through which deeper drilling occurs. The second protection layer is the production casing—a pipe placed in the wellbore to the well’s total depth and permanently cemented in place. The third protection layer is the injection tubing string and packer that conducts the injected water down through the production casing to perforations at the bottom of the well to inject the water into an underground formation. The tubing/packer assembly creates an isolated annulus that is monitored to detect any pressure changes that may indicate a leak or other type of mechanical problem and allow the well to be shut down before any harm could occur. With this well construction, all three protection layers must fail at the same time to impact groundwater.
How are these wells monitored and inspected?
Operators are required to report to the Railroad Commission monthly average injection rates, total monthly volumes, and maximum wellhead injection pressures for wells, both to assure the injection rates and pressures are consistent with amounts specified in the Commission’s injection/disposal permit and to signal if a significant pressure change occurs. If there is a significant pressure change on the well or if other monitoring data indicates the presence of leaks, an operator is required to notify the RRC District Office within 24 hours. If there is a problem, the Commission requires wells to be shut in and repaired.

The Railroad Commission inspects commercial disposal wells (wells that take produced water from various operators for a fee) at least once per year.

There is no "schedule" for non-commercial disposal or injection well inspections. These wells are inspected based on several factors including their location (near sensitive environmental areas or public areas) and the operator’s compliance record.

In addition to inspections, each saltwater disposal well is required to be tested for mechanical integrity to show there are no leaks before the well begins to inject fluid. After this initial test, wells also must undergo mechanical integrity tests at least once every five years. The Railroad Commission’s standard mechanical integrity test (MIT) is designed to identify small leaks before they become catastrophic failures. Wells that fail MITs must be shut in immediately and repaired until they pass an MIT, or plugged within 60 to 90 days. Operators are required to notify the commission prior to conducting the test to allow the Commission’s staff the opportunity to witness the test. Commission inspectors randomly witness about one third of these tests to verify compliance. The commission often directs injection well operators to conduct an MIT to verify the mechanical integrity of a well when troubleshooting potential problems.
How are "affected parties" in a community notified of a proposed saltwater disposal well?
The notification of affected parties is required by rule and procedures. For non-commercial wells, the surface owner and nearby oil and gas well operators must be notified. For commercial wells, all surface owners adjoining the legal tract of the well’s location are affected parties and are required to be directly notified.

In the case of commercial disposal wells, affected parties also include local cities if the well is to be located within city limits, or local water conservation districts if the well is to be located within the district’s boundaries. Notification also is required to be published in a newspaper of general circulation in the county to allow anyone who is interested, to find out about the permit and the permitting process.
What is the protest procedure for a proposed well?
Any permit application that is protested by an affected party must go to hearing to evaluate protest issues. The Railroad Commission can accept a protest at any point during the permitting process. In addition, every application has a minimum 15-day holding period before a permit can be issued to allow time for protests to be received by the Railroad Commission.

For non-commercial wells, the surface owner and nearby oil and gas well operators are affected parties. For commercial wells, all surface owners adjoining the legal tract of the well’s location are affected parties. In the case of commercial disposal wells, affected parties also include local cities if the well is to be located within city limits, or local water conservation districts if the well is to be located within the district’s boundaries.

Applications may be protested by affected parties by contacting the Railroad Commission at:
Railroad Commission of Texas
Underground Injection Control Program
Wm B. Travis Building, 1701 N. Congress
Austin, Texas 78711
Does the Railroad Commission ever deny a permit or are they just "rubber-stamped?"
All injection and disposal well permits are carefully reviewed by the Railroad Commission’s technical staff to ensure they meet both state and federal standards.
How many gallons of fluid are disposed in the wells?
You can use RRC’s online H-10 report query to see the amount injected by Railroad Commission District or county. Be sure to use the reset button if you are doing more than one query. The link can be found at:
Is it possible to look up injection/disposal wells on the RRC website?
Yes, you can view currently permitted commercial injection/disposal wells on the RRC website.

Use this link to view Commercial Disposal Wells and Commercial Surface Disposal Facilities:

This link can be used to look up company phone numbers and addresses.
Is there a map that show where these wells are located?
All wells, including injection/disposal wells can be found on the Commission’s Public GIS Map Viewer for Oil & Gas Wells, Pipeline Data and LP Gas Sites. The map includes a legend designating the icon for an injection/disposal well. Please make sure your pop-ups are not blocked when using this map. Here is a link to the map:
Has the Railroad Commission found any relationship between saltwater disposal wells and earthquakes?
RRC staff welcomes more data and science about current theories that hypothesize a causation link between minor seismic events and injection wells. RRC staff is closely following various studies that are being conducted to determine possible man-made causes of recent seismic events. Commission staff has participated in industry workshops concerning this phenomenon and cooperates with the National Academy of Sciences and the U.S. Environmental Protection Agency whenever appropriate.

Seismic waves are continuously traversing the earth's crust due to both natural causes and human activity. Texas has a long history of safe injection, and staff has not identified a significant correlation between faulting and injection practices.

Commission regulations require injection be confined to a permitted interval, and if faults, stratigraphy, or any other geologic phenomena are identified as a concern, they are evaluated. In addition, Commission staff could suspend or terminate a permit if science and data indicated a problem.

As epicenters are reported, RRC staff evaluates the area to see if there are any Underground Injection Control (UIC) wells nearby. For some reported epicenters, there have been no UIC wells nearby. If there is a UIC well nearby, RRC staff conduct physical inspections of the area as well as a review of UIC well permit restrictions to ensure compliance with Commission Statewide Rules.
Does the RRC allow the discharge of produced water into inland and offshore waters?
Produced water that is already in the formation with oil or gas has varying degrees of quality. Commission discharge permits to inland waters and offshore waters (discharges in bays and estuaries are not allowed) involve produced water where the quality and volume is evaluated. Water quality standards for discharging into inland waters are set by the Texas Commission on Environmental Quality (TCEQ).

Permits of this type make up a very small percentage of the water that is disposed of in Texas. The vast majority of produced water and hydraulic fracture flowback water is disposed of in Commission-permitted disposal and injection wells.

Commission staff evaluates analysis of water to be discharged to inland waters to ensure TCEQ's water quality standards are met. Discharges into offshore waters in the Texas Gulf require whole effluent toxicity (WET) testing to ensure these discharges will not adversely affect marine organisms. These permits also require federal approval from the U.S. Environmental Protection Agency. Also, these discharge permits do not involve the discharge of hydraulic fracturing flowback water, and instead primarily involve the discharge of produced water from oil leases.
Why isn't this fluid being recycled instead of injected?
While some portion of hydraulic fracturing flow back fluid may be recycled or reused in subsequent hydraulic fracturing jobs, the majority of these fluids are disposed of by injection into geologically confined underground formations.

The primary reason cited by operators for injecting waste fluid is that it is less expensive than recycling. However, just as operators have used technology to bring about advances in oil production, they are also looking for technological advances to reduce fresh water use.

In March 2013, the Commission adopted new rules to encourage Texas operators to continue their efforts at conserving water used in the hydraulic fracturing process for oil and gas wells, even though hydraulic fracturing and total mining use accounts for less than 1 percent of statewide water use, with irrigation, municipalities and manufacturing making up state’s top three water consumers.

Major changes adopted to the Commission’s water recycling rules include eliminating the need for a Commission recycling permit if operators are recycling fluid on their own leases or transferring their fluids to another operator’s lease for recycling. The changes adopted by the Commission also clearly identify recycling permit application requirements and reflect existing standard field conditions for recycling permits.

The Commission hopes that by removing regulatory hurdles, these rule amendments will help foster recycling efforts by oil and gas operators who continue to examine ways to reduce freshwater use when hydraulically fracturing wells.

Learn more about hydraulic fracturing at: more about water use in association with oil and gas activities at:
What can be done about the increased truck traffic and potential road damage caused by traffic going to and from saltwater disposal wells?
The Railroad Commission does not have the authority to regulate truck traffic or potential road damage. The Texas Department of Transportation and local county or municipal governments have the authority and jurisdiction to address traffic and road damage issues.