Frequently Asked Questions

Common Questions About Wastewater Injection

What are Class II Injection Wells?

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.

Why Do We Need Injection Wells?

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.

What are Injection Wells Like?

After drilling occurs to construct an injection well, a steel pipe (called a casing) is cemented down the entire length of the hole. 

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.

What are Injection Zones Like?

Our injection zone is located deep into 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 further keep injected water in the porous sandstone bed. The injection zone contains naturally occurring fluids containing high concentrations of various salts.  These zones are called 'wet formations'.

How is Produced Water Handled?

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.

How Often are Injection Wells Checked?

Penneco Environmental Solutions’ injection wells are monitored 24 hours a day, 7 days a week to ensure proper operation and high levels of structural and mechanical integrity.  Monitoring includes reviewing operational data and running tests like temperature and pressure tests. 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.

Are Injection Wells and Wastewater Disposal Regulated?

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.

How are Injection Wells Permitted?

Depending on which state the injection well is located, either the US or state Environmental Protection Agency, 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 engineers 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 temperatures and pressures, safe construction, and monitoring requirements.

Are Injection Wells Safe?

Yes. Class II Injection Wells provide a safe and reliable way to safely dispose of fluids associated with oil and gas production operations. Not only are they are constructed using a multilayer protection system, they also go through rigorous testing and regular monitoring to ensure that our sources of drinking water are protected.

You can read more about Injection Wells here.

Is Wastewater 'Toxic Waste'?

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 the hydraulic fracturing process.

Is Wastewater 'Nuclear Waste'?

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.

Does Wastewater Disposal Cause Earthquakes?

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.

Is This the Same Thing As 'Fracking'?

No. Hydraulic fracturing, also known as ‘fracking’, is the process of fracturing the earth (splitting the rock)  to recover oil and natural gas.  Class II wastewater disposal returns the fluids. Produced as a result of frack flowback to the earth.  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.

Why Can’t This Water Just Be Dumped Into a River or Ocean?

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.

Why Can’t We Just Use This As Drinking Water?

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.

Where Does Wastewater Come 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.

Can Wastewater Leak Into Places It Shouldn’t?

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 air 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.

What Happens When Injection Wells Get Full?

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.

Still Have Questions?