This tutorial will cover the topic of hazardous waste. We will define hazardous waste and discuss how it is managed. We will also cover its negative impacts on the environment and human health, and address efforts to reduce its impacts, including U.S. law surrounding hazardous waste.
Our discussion breaks down as follows:
- Hazardous Waste
- Storage of Hazardous Waste
- Impacts of Hazardous Waste
- Hazardous Waste Management
1. Hazardous Waste
Hazardous waste is basically solid waste with a nature of one or more of the following characteristics:
Hazardous Waste Characteristics
It is harmful to human or ecological health if ingested or absorbed.
It is acidic or basic enough to corrode metal.
It is unstable enough to cause explosions, and to create toxic fumes, gases, or vapors when it's heated, compressed, or combined with water and other substances.
It can catch on fire.
Hazardous waste includes radioactive, medical, and industrial waste, as well as some paints and solvents.
Hazardous waste that can be found at home include paint that you might use to touch up the bathroom, lawn chemicals used to keep it green, and even batteries.
Household cleaning products, such as ones that contain ammonia or bleach, can also be considered hazardous waste.
2. Storage of Hazardous Waste
Hazardous waste can be stored in a variety of locations, such as tanks, containment buildings, waste piles, containers, and holding ponds.
It can be intentionally or accidentally released from these locations in many different ways:
- Underground and above tanks for storing petroleum products both above and below ground can leak and/or catch on fire. A gas station is a good example of this, because it is common for leakages from tanks to contaminate local drinking water supplies.
- Hazardous waste reservoirs, holding ponds, and pipelines can have leaks as well, which release chemicals into the environment, causing all sorts of problems.
- In the event that trains or trucks carrying hazardous waste crash, their contents can leak out.
- It is not uncommon for hazardous waste to be illegally dumped into water systems and sewer systems, ditches, and abandoned buildings so that individuals and companies don't have to pay for disposal.
Despite their impacts, agricultural chemicals used normally on fields are not considered hazardous waste by law.
3. Impacts of Hazardous Waste
Hazardous waste has the potential to contaminate and pollute air, water, and land resources. Without proper management and disposal, it can have negative effects on human and environmental health.
A coal-fired plant like the one shown below is a good example. Sludge is a hazardous waste created from normal processes of a coal plant. Sludge can contain arsenic, mercury, chromium, and cadmium, which, if leaked from a containment pond, can contaminate water, damage human organs, and even cause cancer.
Hazardous waste can become dangerous to humans, plants, and animals if it is ingested, inhaled, or experienced through dermal exposure, meaning if it touches skin.
Impacts to human and ecological health are determined by three factors:
- Amount of waste released at first, as well as over time
- Concentration of the waste's harmful components
- Toxicity of the waste
4. Hazardous Waste Management
Efforts to reduce hazardous waste and its impacts include:
- Reducing the amount of waste at its source
- Recycling hazardous waste for other uses
- Monitoring waste's life cycle from harvesting to disposal to prevent unwanted leakages or illegal disposal
- Treating the waste chemically, thermally, or biologically to render it less dangerous and mitigate impacts
- Storing it in landfills specially built for hazardous waste containment
The U.S. government has developed a permitting system for hazardous waste landfills, and this system tracks the waste in its management and disposal facilities.
The 1980 Comprehensive Environmental Response Compensation & Liability Act, which is also known as Superfund, taxes certain chemicals and then uses funds to address environmental impacts of hazardous waste.
Finally, it is important to note that unless the following types of waste contain hazardous substances or by-products, they are not considered hazardous waste themselves:
- Animal waste
- Septic waste
- Petroleum, which includes automotive, heating, cooking fuels, natural gas, and crude oil
None of these three are, by themselves, considered hazardous waste by law.
Today we learned about hazardous waste, which is essentially solid waste that is one or more of the following: toxic, corrosive, reactive, or ignitable. We discussed how it can be intentionally or unintentionally released into the environment, and the negative impacts that this can have. We also learned about the ways those impacts can be addressed, and U.S. law related to hazardous waste.