Frequently Asked Questions

Common Questions About Wastewater Injection

Class II Injection Wells safely return fluids associated with the production of oil and natural gas to layers of the earth where they naturally occur.

You can read more about Class II Injection Wells here.

Brine (saltwater) is a naturally occurring by-product of oil and natural gas production.  During oil and natural gas production, brine is brought to the earth’s surface.  Brine is saltier than seawater, is not suitable for drinking, and is classified as ‘residual waste’. Class II Injection Wells safely return this saltwater back into earth.

As part of the drilling and construction of an injection well, concentric runs of steel pipe (called a casing) are cemented to various depths designed to protect fresh groundwater and to isolate the injection formation.

Tubing is placed into the well just above the injection zone and a packer is inserted to create a watertight seal against the casing.  The packer prevents water from entering the space between the tubing and casing when water is injected down the tubing.

Several tests are then done to make sure the well is operating properly and the injection zone is isolated. The annular space between the injection tubing and the well casing is pressure monitored in real-time to ensure there are no leaks or cross-contamination.

Read more about Injection Wells here.

Our injection zone is located deep in the earth, in a sandstone formation. Sandstone is a rock that is porous enough to accept injected fluids. We chose our particular injection zones because they’re covered by shale, an impenetrable rock that acts as a cap to confine injected water to the porous sandstone layer. The injection zone contains naturally occurring fluids containing high concentrations of various salts.  These zones are called 'wet formations'.

After oil and gas are separated from the produced water at our clients’ production well, the water is trucked to the injection site. There, the water is transferred to holding tanks, filtered, and pumped into the Class II injection well.

Penneco Environmental Solutions’ injection wells are monitored 24 hours a day, 7 days a week to ensure proper operation and to ensure mechanical integrity. Automated digital and redundant mechanical sensors monitor all essential parameters related to the well to ensure that operational characteristics remain within the permitted performance envelope. In addition, our wells are regularly inspected by the United States Environmental Protection Agency and state Departments of Environmental Protection.

Read more about the EPA’s Underground Injection Control (UIC) Program here.

Yes.  Depending on which state an injection well is located, either the US or state Environmental Protection Agency regulates the construction, operation, permitting, and closure of injection wells.

Depending on which state the injection well is located, either the US EPA or state department of Environmental Protection, or both issue a permit. 

Operators of Class II Injection Wells file for a permit with the EPA.  Before the permit is issued, the injection project is closely studied and reviewed by various oversight entities.

The EPA’s technical staff, including engineers, geologists, and hydrogeologists, evaluate the geologic and engineering information, obtain public comments, and hold a public hearing. Injection project permits include extensive conditions, such as site approval, injection well pressures, safe construction, and monitoring requirements.

Yes. Class II Injection Wells provide a safe and reliable way to dispose of fluids associated with oil and gas production operations. Not only are they are constructed using a multilayer protection system, but they also go through rigorous testing and regular monitoring to ensure that our sources of drinking water are protected.
According to regulators, injection wells are the preferred method of disposal for oil and gas brine that cannot be recycled.  You can read more about Injection Wells on the Pennsylvania DEP Injection Well Fact Sheet here.

While the water that is returned to the earth is not suitable for drinking or other uses, it is not what most of us refer to as toxic waste. The Department of Environmental Protection classifies it as ‘Residual Waste’, and it cannot be discharged into waterways, even with treatment. The wastewater that is injected back into the earth is the same water that was extracted during oil and gas well completion process and production operations.

No.  Nuclear waste results from nuclear power generation and other types of nuclear technology.  While the water that is injected back into the earth may contain metals and radioactive elements, they are naturally occurring radioactive materials, and not the result of nuclear activity performed by humans.

Numerous studies have been conducted to determine whether Class II Injection Wells are associated with earthquakes. Properly constructed and operated injection wells do not cause seismic activity.  There are areas of the country where injection activity has induced seismicity, and the science behind those events is well understood.  None of the conditions necessary for seismicity which are found at those locations are found geologically or operationally at our facilities. 
You can download a few of these studies here and here.

No. Hydraulic fracturing, also known as ‘fracking’, is the process of fracturing the earth (splitting the rock) to maximize the recovery of oil and natural gas. When a disposal well candidate is still in the testing phase, pressure and step rate tests are conducted to determine the characteristics required to fracture that specific formation. The results of those engineering tests become limiting factors on the disposal operation. Our US EPA and state DEP operating permits specifically prohibit us from fracking. Our permits are pressure limited and monitored by regulators to operate at pressures below that required to initiate fractures.

During oil and natural gas extraction, large amounts of brine (saltwater) are recovered from the earth’s deepest layers.  Brine is saltier than seawater and can damage the environment and public health if disposed into surface water.  Class II Injection Wells return brine to the layers of the earth where it naturally occurs.

During fracking, mineral laden, saltwater, known as brine, is extracted along with oil and natural gas.  Because this water is saltier than seawater and contains heavy metals, it is not safe to drink.  Class II Injection Wells put this saltwater back into the earth where it naturally comes from.

The earth’s deepest layers naturally contain a very salty water known as brine.  Brine is saltier than seawater, and would damage the environment and public health if it were on the earth’s surface water.  During oil and natural gas extraction, large amounts of this saltwater are recovered from the earth’s deepest layers.  Class II Injection Wells safely return this brine to the layers of the earth where it naturally occurs.

No.  Not only are injection wells constructed using a highly regulated multilayer protection system, they also undergo regular testing and pressure monitoring. Some of these include frequently checking the pressure, and volume as well as routinely surveying the structural integrity of the injection well. Regulators from the Environmental Protection Agency conduct audits of injection well operational procedures. The wells are constructed of concentric strings of casing with an open annulus (the void between a pipe inside a pipe).  Any leaks or loss of pressure within the injection string would be captured in the annulus and would also trip pressure monitoring alarms.  This occurs inside a steel casing which is isolated from freshwater aquifers by additional casing strings, confining layers in the earth, and hydrostatic pressure.

After decades of operation, an injection well can reach a volume where it can no longer accept injected water.  Once this occurs, a cement plug is placed in the well over the injection zone. An additional cement plug placed across the base of the lowest level of underground sources of drinking water, as well as near the injection well’s surface. While the cement mechanically isolates the zones, they are further isolated by the natural hydrostatic pressure of a fluid column.

The SEDAT #3A well was drilled in 1989 to a total depth of 4,320 feet below surface and produced natural gas for many years from Speechley, Balltown, and Bradford formations.  It was plugged back to the Murrysville formation several years ago.  It was originally cased through the Murrysville formation but never produced from the Murrysville formation because the Murrysville formation is ‘wet’ - it naturally contains brine in this area.  We are injecting brine into a formation that is already flooded with brine. The Murrysville formation in this area naturally holds billions upon billions of gallons of brine.    The Department of Environmental Protection changed the well ID suffix when it was converted from a producing well to a disposal well.  The groups stating that the well never produced are either referring to the new disposal well ID or did not review the legacy production records filed with DEP under the original well ID, 37-003-21223-00.

No. They are not factually correct according to the current well construction and actual permitted operational methods. The current SEDAT 3A injection well is designed for disposal operations and has been properly upgraded. The design has been reviewed by United States Environmental Protection Agency technical experts within the Underground Injection Control program and by Pennsylvania Department of Environmental Protection Oil and Gas Program geologists and water quality specialists. The well’s current construction for disposal operations has been inspected by the United States Environmental Protection Agency on multiple occasions. US EPA regulators have been physically present on site for various injection and pressure tests.
New casing has been installed and cemented inside of the original legacy well. The casing and cement are not pressurized by injection operations, as suggested by some groups. Because we do not pressurize the casing or cement, there is no cyclical loading. Regardless, the casing and cement were inspected via a modern cement bond log, run in anticipation of injection service, and reviewed by regulators. There is a newly installed string of pressure rated injection tubing inside of the new casing, which is all inside of, and isolated from, the legacy casing. It terminates at a recently installed injection packer which isolates the formation and injection brine from both the new and the legacy well casings. The injection packer mechanically seals in two directions preventing injectate from migrating up and preventing any other fluids from migrating down.
The outside of the new injection tubing is free in the new cemented casing from the surface to the packer. The ‘annular space’ between the outside of the injection tubing and the inside of the new casing is filled with a static fluid; the pressure and volume are continuously monitored to ensure that no injectate enters that space, assuring well integrity. The injection pressure and the annular pressure are monitored and recorded continuously by automation equipment. The injection fluids and injection pressures are constrained by the new tubing and are never in contact with either the legacy casing and cement or the new tubing and cement; therefore, it is incorrect to state the well casing experiences fatigue due to repeated cyclical pressurization – it does not. DEP and EPA have approved each of these construction, installation, and operational methods. Both regulatory entities have physically inspected the well both before and after authorization to inject was granted.

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