Hazardous waste disposal began to grip public consciousness in the US in the mid-1900s for four key reasons:
- More waste was being produced
- Hazardous material disposal was becoming costlier
- Disposal capacity was dropping
- New disposal facilities were sparking protests.
These growing concerns eventually led to the Resource Conservation and Recovery Act (RCRA) passage of 1976. The RCRA outlined a model of environmentally sound and cost-effective approaches for managing and disposal of hazardous materials.
Due to the health and environmental risks posed by this waste, the RCRA framework was comprehensive. Based on its mandates, the EPA created a “cradle-to-grave” regulatory program that managed its full lifecycle:
- Production
- Transport
- Treatment
- Storage
- Disposal.
This article focuses on the final stage: disposal. There are a few different standard hazardous waste disposal methods. Another increasingly popular way to handle it is to recycle it. While recycling is preferable to other methods, it is not always viable. Treatment is another way to approach waste rather than simply disposing of it. Below, we explore treatment options and the three top disposal methods (along with assessing sustainability), closing out with the recycling. By exploring these options, you can figure out which form of hazardous waste disposal is best for your business.
Table of Contents
8 Ways to Dispose of Hazardous Waste
Incineration or other treatment
There are a variety of ways to treat hazardous waste:
- Chemical treatment – e.g., neutralization, precipitation, ion exchange, reduction, or oxidation;
- Thermal treatment – e.g., incineration;
- Biological treatment – e.g., landfarming; and
- Physical treatment – e.g., solidification, flotation, sedimentation, evaporation, or filtration.
The first three categories transform waste at the molecular level, while the fourth results in waste solidification, concentration, or volume decrease.
To destroy some organic wastes, in addition to detoxifying them, you can use high-temperature incineration. Equipment used for this purpose includes:
- liquid-injection incinerators,
- multiple-hearth furnaces,
- fluidized-bed incinerators, and
- rotary kilns
Landfarming can be used to treat organic wastes from the petroleum industry or elsewhere. An area of land is designated, and the surface soil is conscientiously blended with the waste. Nutrients and waste-metabolizing microbes can be added to enhance treatment.
A common way to approach solidification is by utilizing asphalt, plastic, or concrete to encapsulate the waste. This approach creates a leach-resistant, solid material mass.
Regarding sustainability, air pollution is a concern with incineration.
#1: Underground disposal
The only way this method is compliant is when the hazardous waste is brought to mines that are either inactive or partially active (along with meeting additional geological and technical specifications). Many companies need to dispose of radioactive waste, whether from medical treatments, laboratory experiments, nuclear fuel production, or radioactive ore mining. For those cases, this method is considered a strong, cost-effective option.
According to the EPA, these hazardous material disposal facilities will vary in their sustainability. The agency is responsible for protecting people and the natural world by verifying that these units’ design, operation, and maintenance adhere to its standards.
In 2022, approximately 2.32 million cubic feet of radioactive waste was disposed of. Proper disposal in deep geological repositories, like the Waste Isolation Pilot Plant (WIPP) in New Mexico, ensures long-term containment of hazardous substances.
#2: Landfill disposal
Dumpsites and landfills are the most commonly used and oldest methods of hazardous waste disposal. Hazardous waste landfills are specially built and are NOT intended for liquid wastes. They are engineered and excavated so that they are within the ground rather than piling upward.
These landfills are lined with clay, HDPE, or other non-porous materials to prevent the waste from leaching into the ground. Wind dispersal controls, leak protection systems, and a double liner are additional protections so that humans and the environment come into contact with as little waste as possible.
Modern hazardous waste landfills are equipped with sophisticated systems for leachate collection and treatment, gas monitoring, and environmental protection. They can cost upwards of $1 million per acre to construct, reflecting the high level of engineering and safeguards required.
Human health is generally not impacted by hazardous waste landfills. However, it is possible for people near the landfill to be harmed if there is a leak.
#3: Ocean dumping
To avoid groundwater contamination, deep-sea depositing is sometimes used. It is necessary to treat hazardous waste before the disposal of hazardous materials, as ocean dumping has a major impact on marine life. This treatment is important to human health, too, since the waste can make its way to humans when they consume seafood. Some environmental agencies ban this practice, but it is allowed by the EPA if you have a permit and strictly follow its guidelines. (The US Army Corps of Engineers handles all dredged material permits while the EPA processes the remainder.)
Regarding sustainability, treatment is critically important. Radioactive waste, industrial waste, and sludge all cause considerable ocean pollution. Mercury and cadmium, toxic heavy metals, are within about 10 percent of dredged material.
Ocean dumping of hazardous waste is highly controversial due to its potential to devastate marine ecosystems. The London Convention, an international treaty, restricts ocean disposal practices, emphasizing the need for stringent regulation and oversight.
#4: Deep-well injection
A commonly used hazardous waste disposal method is deep-well injection. Deep-well injection involves pumping liquid hazardous waste deep into the earth, below the groundwater level, into porous rock formations. These wells are regulated to ensure the waste does not contaminate drinking water sources or surface ecosystems. This method is particularly useful for liquid waste and can be cost-effective. However, there are concerns about the potential for leaks or seismic activity.
The United States has approximately 800 Class I deep-well injection sites capable of handling millions of gallons of hazardous waste annually. These sites undergo rigorous testing and monitoring to detect and prevent leaks, with sensors placed at multiple depths to ensure safety.
#5: Surface impoundments
Surface impoundments are natural or man-made depressions, such as ponds, pits, or lagoons, used to treat, store, or dispose of hazardous waste. These are typically used for liquid waste and can provide a cost-effective solution. However, they require proper lining and monitoring to prevent leakage into the soil and groundwater. Long-term environmental impact and maintenance are critical factors in their sustainability.
Surface impoundments must be lined with impermeable materials like clay or synthetic liners to prevent leachate from contaminating groundwater. Regular inspections and maintenance are essential to ensure the integrity of these containment systems and to address any potential breaches.
#6: Incineration
A popular hazardous waste disposal method is incineration. Incineration involves burning hazardous waste at high temperatures to convert it into ash, flue gas, and heat. This method is effective for reducing the volume of waste and destroying toxic organic compounds. However, extensive air pollution control systems are required to capture harmful emissions such as dioxins and furans.
High-temperature incineration, reaching up to 1,200°C (2,192°F), can break down complex hazardous substances. The resulting ash, which still contains hazardous components, must be disposed of in secure landfills. Modern incinerators are equipped with scrubbers, filters, and electrostatic precipitators to minimize environmental impact.
#7: Encapsulation
Encapsulation involves enclosing hazardous waste in a solid material such as concrete or plastic to prevent the release of contaminants into the environment. This method is particularly useful for solid and semi-solid wastes, including contaminated soil, sludge, and asbestos.
The process typically involves mixing the hazardous waste with a binding agent and then pouring it into molds to harden. Encapsulation can significantly reduce the mobility of hazardous components, making it easier and safer to handle and store. This method is often used for long-term storage of radioactive waste and other materials that require stable containment.
#8: Macroencapsulation
Another hazardous waste disposal method is macroencapsulation, which involves enclosing large volumes of hazardous waste in a durable, impermeable barrier such as steel or concrete containers. This method is used for bulky waste materials, including contaminated debris, large equipment, and other industrial waste.
The containers are designed to withstand physical and chemical degradation, ensuring long-term containment of hazardous materials. Macroencapsulation is particularly useful for managing waste that cannot be easily treated or reduced in volume, providing a secure solution for disposal and storage.
Hazardous Waste Disposal Alternative: Recycling
A federal analysis revealed that 1.5 tons of hazardous waste were managed through recycling in 2017. Recycling is preferable to hazardous material disposal for numerous reasons. It results in economic benefits, decreases our raw material reliance nationally, conserves natural resources, prevents pollution, and cuts energy use.
Any of the following are ways that disposal of hazardous materials can be achieved:
- Reclaiming – Regeneration or processing to recover a useful product
- Reuse/use – Substituting it for another product or using it as an industrial ingredient
- Burning to recover energy – Burning for fuel
- Disposal through use – Placement of waste on the land.
FAQs on Hazardous Waste Disposal Methods
Can hazardous waste be recycled?
Yes, recycling hazardous waste is often preferable as it can lead to economic benefits, reduce reliance on raw materials, conserve natural resources, prevent pollution, and cut energy use. Methods include reclaiming, reuse, burning for energy recovery, and disposal through use.
What is the “cradle-to-grave” system for hazardous waste?
The “cradle-to-grave” system, mandated by the Resource Conservation and Recovery Act (RCRA), tracks hazardous waste from its point of origin (cradle) through its transportation, treatment, and storage until its final disposal (grave). This system ensures that hazardous waste is managed responsibly at every stage to protect human health and the environment.
Systematic & Thorough Industrial Waste Management
Are you considering your options for hazardous waste disposal? At AOTC, we design our industrial waste management services to control your costs and minimize your long-term liability. We even tailor our programs to meet your specific needs. Contact us today to discover how we can help your business with one of these hazardous waste disposal methods. We offer environmental remediation services as well.