Deep Injection Wells - Beaver County Marcellus Awareness Community

What Are Deep Injection Wells?

Deep injection wells are very deep holes in the ground that are used to get rid of liquid waste, often from oil and gas drilling.

They pump the waste between about 1,700 and 12,000 feet underground, depending on where in the U.S. the well is located. The waste is pushed into certain types of rock, usually sandstone or limestone. These rocks have tiny spaces inside them (like pores in a sponge) that normally hold water, gas, or both.

The idea is to carefully pump waste into those spaces without cracking the rock. To do this, the pressure is kept just strong enough to move out the natural fluids already there but not so strong that the rock breaks.

The Environmental Protection Agency (EPA) Underground Injection Program (UIC) program divides injection wells into five categories:

Class I wells are technologically sophisticated and inject hazardous and non-hazardous wastes below the lowermost underground source of drinking water (USDW). Injection occurs into deep, isolated rock formations that are separated from the lowermost USDW by layers of impermeable clay and rock.

Class II wells are oil and gas production brine disposal and other related wells. Operators of these wells inject fluids associated with oil and natural gas production. Most of the injected fluid is brine that is produced when oil and gas are extracted from the earth (about 10 barrels of brine for every barrel of oil).

Class III wells are wells that inject superheated steam, water, or other fluids into formations in order to extract minerals. The injected fluids are then pumped to the surface and the minerals in solution are extracted. Generally, the fluid is treated and re-injected into the same formation. More than 50 percent of the salt and 80 percent of the uranium extraction in the U.S. is produced this way.

Class IV wells inject hazardous or radioactive wastes into or above underground sources of drinking water. These wells are banned under the UIC program because they directly threaten public health.

Class V wells are injection wells that don’t fit into the other categories. Some are advanced waste water disposal systems used by industry, but most are “low-tech” wells like septic systems and cesspools. Generally, they are shallow and rely on gravity to drain or “inject” liquid waste into the ground above or into underground sources of drinking water. Because they are simply built, they provide little or no protection against groundwater contamination. That’s why it’s important to control what goes into them.

Are Deep Injection Wells Dangerous?

Injection wells pose many threats. The fluids that are used in oil and gas extraction contain toxic metals and radioactive chemicals. Radium-226 and Radium-228, chemicals found in fracking waste, are known carcinogens and can cause bone, liver, and breast cancer at high concentrations. Once fluids are injected into geologic formations, it is difficult to track where these fluids can migrate. Injection wells are designed to inject in layers of permeable rock that are capped by impermeable rock, however fluid can move laterally. When this happens, toxic fluid can seep into cracks from other wells or cracks in rock layers. Injected fluids can also migrate up abandoned wells under pressure. In many of the older unregulated abandoned wells, cracks in well casings can allow toxic fluids to seep into different layers. This lets toxic fluid seep into places it shouldn't be. Leaking injection wells can contaminate aquifers, rivers, and lakes with radioactive toxins, endangering communities’ drinking water supplies and posing serious threats to human health.

What is Radium-226 & Radium-228?

Radium is a radioactive metal found in nature. Radium forms when uranium and thorium break down in rocks and soil. Radium undergoes radioactive decay which releases alpha, beta, and gamma ray particles. Beta particles can penetrate the skin, while gamma radiation can go through the body.

Radium is present at low levels in rocks and soil. It can also be found in air. High levels of radium are found in water, in some parts of the U.S. radium in the soil may be taken in by plants and can also build up in fish life found in water.

You can be exposed to it by breathing the air: when burning coal or other fuels, radium can enter the air and people can be exposed to it, drinking it in water: radium in drinking water is usually low. Higher levels can be found in contaminated water sources, and by touching it at worksites: high exposure is present at radioactive waste disposal sites, rock and uranium mining sites.

After breathing radium will slowly enter the blood and be taken to all parts of the body. If ingested, some will enter the blood and be taken to all parts of the body, mostly to the bones. After exposure, very small amounts will leave the body every day through urine and waste matter.

Exposure to higher levels of radium over a long period can lead to death and other severe health problems. High levels of radium can cause cancer (bone, liver and breast cancer), anemia, fractured teeth and cavities, and cataracts.

Do Deep Injection Wells Cause Earthquakes?

The underground injection of wastewater has long been documented to induce earthquakes. Wastewater injected into rock formations can build up significant pressure depending on the volume of wastewater, rate of injection, and the permeability of the rock. This pressure build-up can induce an earthquake if the pressure is relayed to a fault that is already stressed and close to failure. The pressure can reduce the natural friction on the fault enough to cause it to slip and trigger an earthquake. The larger the fault, the larger the magnitude of earthquakes it can host.

As early as the 1960s, scientists began documenting seismic activity from the injection of large volumes of fluids underground. One of the first recorded cases of human-induced earthquakes due to underground fluid injection occurred in 1961, when the U.S. Army began disposing of millions of gallons of liquid hazardous waste 12,000 feet below the surface at the Rocky Mountain Arsenal near Denver, Colorado. This injection spurred more than 1,500 earthquakes over a five-year period in an area not known for active seismicity. It culminated in three earthquakes of magnitudes 5.0 to 5.5 more than a year after injection ceased, the largest of which caused more than $500,000 in damages. Geologists discovered that the Army well had been drilled into an unknown fault. This example, as well as two other well-studied fluid injection projects — at Rangely, Colorado, in the 1970s and Paradox Valley, Colorado, in the 1990s — established that wastewater injection wells could induce earthquakes large enough to cause significant damage.

What Can I Do?

Beaver County has (9) Deep Injection Wells, and the U.S. EPA is currently accepting public comments on the draft permit for a UIC Class IID disposal injection well in Beaver Falls. All comments must be received by Monday, October 6, 2025.

Public Notice: Underground Injection Control (UIC) Program Notice of Draft Permit Columbia Gas of Pennsylvania, Inc., PAS2D041BBEA (U.S. EPA)