What is Hazardous Waste Management?
Modern life produces literal tons of waste products that are hazardous to human life and the environment. Improper disposal of this waste can have disastrous consequences, which is why EPA regulations require the management of hazardous waste “from cradle to grave.”
Hazardous waste management is the systematic approach to handling, transporting, treating, and disposing of such waste to minimize its adverse effects on public health and the environment. In this blog, we will explore what hazardous waste management entails, its importance, and key principles for effective implementation.
What Is Considered Hazardous Waste?
In general terms, hazardous waste could be any discarded material with properties that make it dangerous to human health or the environment.
It sounds simple, but environmental regulations make it considerably more complicated. From a regulatory standpoint, hazardous waste is not a general label for dangerous garbage. It refers to substances that are subject to specific hazardous waste regulations.
In the U.S., the key regulation is the Resource Conservation and Recovery Act (RCRA). Under RCRA waste management guidelines, only certain types of solid waste are technically classified as hazardous waste. Identifying hazardous waste is a complicated and technical process full of exclusions and exceptions.
There are four questions for identifying hazardous waste, which we’ve covered in the past.
What Categories of Hazardous Waste Are There?
If you’re not actually subject to compliance with environmental protection laws, then the technical process for identifying hazardous waste doesn’t matter very much. It’s enough to know the types of waste that are typically considered hazardous.
There are four broad categories and a few subcategories that are worth understanding.
The first category of hazardous waste is “listed wastes.” These are specific substances named in Section 261 of the Code of Federal Regulations. Listed wastes are presumed to possess dangerous properties, but individual generators can get their waste delisted if they can prove that it doesn’t pose a risk.
The second category is “characteristic wastes.” These are wastes that possess one of four dangerous properties, including reactivity, ignitability, corrosiveness, and toxicity. Characteristic wastes have inherently dangerous characteristics, so they can’t be exempted.
“Mixed wastes” contain components that are both hazardous and radioactive. As a result, they’re subject to two waste management regulations: the RCRA and the Atomic Energy Act.
Finally, there are “universal wastes,” which aren’t subject to RCRA Subtitle C requirements but are considered hazardous waste. They’re handled by an alternate management standard called the universal waste program because they’re commonly generated by a wide variety of sources. Examples include batteries, pesticides, mercury-containing equipment, lamps, and aerosol cans.
How Is Hazardous Waste Managed?
The Environmental Protection Agency (EPA) requires a cradle-to-grave waste management system for anything classified as hazardous waste under the RCRA. According to RCRA Subtitle C, whoever generates hazardous waste is ultimately the one responsible for properly disposing of it.
Tracking Hazardous Waste with the Manifest System
Hazardous waste subject to RCRA Subtitle C must be described and tracked using a document known as the Uniform Hazardous Waste Manifest.
Waste generators are required to create the manifest document (which is now typically electronic), including a description of the waste as well as the proper way to handle it.
The manifest then travels with the waste en route to disposal. Each time it changes hands, the manifest must be signed as a proof of record.
While being transported, these substances are subject to the Department of Transportation’s Hazardous Materials Regulations, which regulates the details of packaging, labeling, and shipping standards.
How Is Hazardous Waste Disposed Of?
Recycling and reduction methods are available for some hazardous waste, but there will almost always be some waste left that will need to be treated or stored.
Once hazardous waste reaches its final destination, there are a few approved waste management practices for disposal.
Hazardous Waste Treatment
Waste treatment is the most widely used of all hazardous waste management strategies. It involves using chemical, physical, thermal, and/or biological processes to either destroy the waste completely or detoxify and remove the dangerous aspect of it.
Physical treatment methods focus on concentrating, solidifying, or reducing the volume of hazardous waste through evaporation, sedimentation, flotation, filtration, and/or solidification.
Thermal, chemical, and biological treatment methods focus on transforming the waste at the molecular level to render it harmless. Thermal treatment is better known as high-temperature incineration. Chemical treatment can take the form of ion exchange, precipitation, oxidation and reduction, and neutralization. The most common method of biological treatment is called landfarming, which involves mixing organic waste – often from the petroleum industry – with microbes designed to stabilize it.
In most cases, treating hazardous waste leaves behind residue or a remaining volume that needs to be appropriately stored.
Surface Storage
Surface or land storage is a popular solution for residual waste because it's the most affordable and accessible. Even in cases where surface storage isn’t considered a permanent solution, it’s often used as a temporary measure for collecting hazardous waste before treatment and disposal.
Examples of surface storage solutions include waste piles, ponds, and lagoons.
As you can imagine, surface storage runs the risk of contaminating the environment, with groundwater being a particular concern. In the past, unregulated surface storage resulted in waste escaping into the environment and causing havoc.
This led to a slew of environmental protection laws, including environmental safety standards for surface storage aimed at preventing leakage or erosion and environmental regulations mandating the cleanup and remediation of older waste sites.
Unfortunately, even with all of these regulations in play, surface or land storage can still negatively impact the environment.
Secure Landfills
Secure landfills are a safer option for long-term storage because hazardous waste regulations require multiple precautions to prevent escape.
First, the landfill needs to be at least 10 feet above underlying bedrock or groundwater tables, as well as two impermeable liners and a leachate collection system. On top of all these other precautions, there is a groundwater monitoring system installed to raise an alarm if there’s any leakage.
These environmental safety standards make secure landfills the best waste management practice for hazardous waste that hasn't been treated. However, it’s not considered an adequate solution for liquid waste.
Deep-Well Injection
Deep-well injection is considered to be a safe and inexpensive disposal method for hazardous waste that remains in liquid form.
This method involves injecting liquid waste through steel casings placed in limestone or sandstone. A high-pressure injection is used to ensure the waste is forced into the rock where it is permanently stored. The injection zone needs to be below an impenetrable layer of clay or rock, but it shouldn't be more than half a mile underground.
While multiple layers of protective casing make injection wells safer than surface storage, it can still pose a risk to the water supply.
How is Hazardous Waste Managed?
Once hazardous waste reaches its final destination, there are four main approved methods to dispose of it. Although there are recycling and reduction methods available, there will almost always be some waste leftover that will need to be treated or stored. The four main methods for treating hazardous waste include treatment, surface storage, landfill storage, and deep-well injection.
Method 1: Hazardous Waste Treatment
The most widely-used hazardous waste disposal method isn't really a type of disposal at all. As the name suggests, waste treatment involves using chemical, physical, thermal, and biological processes to detoxify and remove the dangerous part of the waste or destroy the waste in total. Chemical treatment methods include ion exchange, precipitation, oxidation and reduction, and neutralization. On the other hand, the most common type of thermal treatment method is incineration. There are special tools used to incinerate hazardous waste and turn it into smaller amounts of solid, liquid, or sludge. Biological hazardous waste treatment is typically used on waste from the oil and gas industry. And landfarming is the most common biological treatment method. Landfarming involves the use of genetically engineered microbes to stabilize the waste. Of course, even after the waste has been stabilized, crops cannot be safely grown on that land.
Method 2: Surface Storage
Even after waste has been treated, there will most likely be residue or remaining waste that will still need to be appropriately stored. Surface, or land storage, is the most popular storage solution for residual waste because it's the most affordable and accessible. Unfortunately, even with all the government regulations and precautions, this method can still negatively impact the environment. Conventional surface storage solutions include waste piles, ponds, and lagoons that are carefully constructed to eliminate the chance of leakage or erosion. Precautions are now used to protect groundwater, but historically these precautions weren't in place, so many older sites are scheduled for cleanup and remediation.
Method 3: Secure Landfills
Secure landfills are mostly used for hazardous waste that hasn't been treated, so there are additional regulations than those for surface storage facilities. Secure landfills are named such because the landfill needs to be at least 10 feet above underlying bedrock or groundwater tables. In addition, secure landfills also need two impermeable liners and a leachate collection system. On top of all these other precautions, secure landfills need a groundwater monitoring system installed to ensure all other precautionary methods are working. The monitoring system works by regularly sampling and testing the area to catch any leakage.
Method 4: Deep-Well Injection
The fourth method of waste disposal is deep-well injections, which involves injecting liquid waste through steel casings placed in limestone or sandstone. A high-pressure injection is used to ensure the waste is forced into the rock where it is permanently stored. The injection zone needs to be below an impenetrable layer of clay or rock, but it shouldn't be more than half a mile underground. While deep-well injection is relatively inexpensive, because the waste is stored underground, it can pose a risk to the water supply.
Get Hazardous Waste Training
While we hope this blog post has introduced you to how hazardous waste is disposed, workers involved in hazardous waste handling need to know so much more, including how to keep themselves safe and protect public health.
That’s why OSHA requires four specific job profiles, including workers involved in site cleanup and employed by Treatment, Storage, and Disposal Facilities (TSDFs), to complete extensive coursework and hands-on training to help them understand and comply with the HAZWOPER safety standard.
The amount of initial training required depends on how much contact you’ll have with hazardous substances. Employees who will have minimal contact need HAZWOPER 24, while employees who will regularly handle hazardous substances need HAZWOPER 40.
After initial training, all HAZWOPER employees need an annual 8-hour refresher.
We’re an experienced and OSHA-authorized provider, and we offer online and self-paced HAZWOPER courses to help you complete the required training in the most comfortable and convenient manner possible.
We also carry DOT HazMat courses required for anyone involved in the packaging, shipping, and transportation of hazardous materials.
