FAQ

A deepwell allows for the secure injection of nonhazardous wastewater into deep geologic formations with impermeable confining structures. These confining structures prevent the movement of the wastewater. This process is highly protective of drinking water aquifers used for human consumption or other purposes.

More information on deepwells can be found at: https://www.epa.gov/uic/general-information-about-injection-wells.

The Carleton Farms Deepwell will consist of two Class 1, non-hazardous wells that will inject treated wastewater into locations at depths between 3,000-3,800 feet. These wells will only be used for treated wastewater – also known as leachate – which is a byproduct of waste decomposition and landfill operations.

The Carleton Farms Deepwell operates under permits issued by the U.S. EPA. The wells are permitted and regulated through its Underground Injection Controls (UIC) program.

U.S. EPA has the right to inspect the facility to ensure compliance with all the regulations and permits and receives operations and compliance reports.

Carleton Farms Deepwell Partners, a subsidiary of Republic Services.

Safety is the top priority for the Carleton Farms Deepwell project team, and implementing safeguards begins long before the facility is constructed, or wells are drilled. Working with U.S. EPA, the Carleton Farms Deepwell project team undertook a detailed geological study, including modeling, testing and verification, to ensure the injection zone is safe to accept and confine the wastewater, consistent with U.S. EPA’s guidelines.

Once construction begins, the Carleton Farms Deepwell project team will conduct additional extensive performance testing by injecting clean water into the wells to ensure geological conditions are consistent with design expectations. This testing ensures that the wells will be capable of performing as designed when wastewater is injected.

As part of a highly engineered design, the wells will offer strong environmental protections, including:

• Multiple barriers of concrete and steel casing;
• Well casings set in concrete over 1,400 feet below ground level, nearly three times the depth of the nearest groundwater table;
• Additional steel casing and concrete set in the well bores 3,000 feet below ground level;
• Pressurized seals in-between the casing and the injection tubing to ensure the wastewater is injected into the designated formation;
• Pressure sensors within the well to ensure that seals are secure and automatically shut off in the event of a pressure variation;
• Regularly scheduled mechanical integrity testing; and
• Regular inspections by U.S. EPA regulators.

In addition to the above safeguards, the facility will:

• Verify that wastewater passes multiple tests and sampling checkpoints in an onsite lab before disposal;
• Properly store, process, and treat wastewater in a closed system of surface tanks before injection;
• Establish and maintain detailed safety, emergency preparedness and spill containment plans;
• Employ remote monitoring and technical redundancies to allow for automatic shut-down, if necessary; and
• Require extensive employee training to ensure compliance with all permits, statutes and regulations, as well as our own industry-leading safety program.

The facility is requesting the approval to inject 80 gallons per minute of liquid wastewater.

The wells will inject treated liquids from Carleton Farms Landfill. Any precipitation or liquids that are the byproduct of waste decomposition must be properly disposed. Today, landfill liquids are treated at a highly engineered onsite facility before being loaded onto semi-truck tankers for transport to various offsite wastewater treatment facilities. The Carleton Farms Deepwell will be entirely dedicated to disposing of these liquids.

All liquid waste disposed of at the Carleton Farms Deepwell is injected more than 3,000-3,800 feet below the surface into a thick layer of a confined Mt. Simon formation. The injection zone is well defined through extensive testing and the well is constructed to ensure that the waste only goes into the defined, permitted injection zone. The injection zone is capped by the Utica-Cincinnatian formation, which is 400 feet of shale that has little vertical permeability – meaning it won’t allow the injected material to move up from the injection interval. Constant monitoring of the wells different pressures and operating conditions makes sure that the well is operating properly, or it is shut down.

U.S. EPA issues 10-year permits for deepwells. Permits may be renewed.

Once the facility ceases operation, it is closed in accordance with its approved closure plan, which is part of the facility’s permit. All waste is removed from the facility and disposed of through the deep wells or off-site facilities. All tanks, pipes and equipment would be decontaminated, disassembled, and properly disposed, or recycled. The entire site would then be decontaminated to the requirements of federal and state regulation.