Ch. 17 - Solid Waste Management and Disposal

Kinds of Solid Waste Solid waste is generally made of objects or

particles that accumulate on the site where they are produced. They are typically categorized by the sector of the economy responsible for producing them.• Mining wastes are generated in three ways• Industrial solid waste consists of solid waste other than

mining.• Agricultural waste • Municipal solid waste consists of all the materials

people in a region no longer want.

Municipal Solid Waste

In modern society, many products are discarded when they are broken or worn out, while others only have a temporary use.

Those that have only temporary uses make up the majority of solid waste.

Unites States produces about 210 million metric tons of municipal solid waste annually.• This equates to 2 kg (4.4 lbs) of trash per person per

day.– Per capita waste has increased 70% since 1960.

Municipal Solid Waste

Municipal solid waste generation rates

Municipal Solid Waste

Nations with a higher standard of living tend to produce more municipal solid waste per person than less-developed countries.

Large metropolitan areas have the greatest difficulty dealing with solid waste.

Waste generation and lifestyle

Methods of Waste Disposal

In the past, the favored means of waste disposal was to dump solid wastes outside of city or village limits.

To minimize the volume of waste, the dump was often burned.• This practice is still employed in remote or sparsely populated

areas in the world.

Five techniques are now used in waste disposal:• Landfills• Incineration• Source reduction• Composting• Recycling

Methods of Waste Disposal

A well-designed modern landfill

Methods of Waste Disposal Recycling is one of the best environmental success stories

of the late 20th century.• In the United States, recycling (including composting) diverted about

30% of solid waste stream from landfills and incinerators in 2001.

Container laws provide an economic incentive to recycle.• Case Study 17.2 – Beverage Container Deposit-Refund Programs

Mandatory recycling laws provide a statutory incentive to recycle.

Curbside recycling provides a convenient way for people to recycle.

There are many technical and economic problems associated with recycling.• Case Study 17.1 – Resins used in consumer packaging

What You Can Do to Reduce Waste and Save Money:• Buy things that last, keep them as long as possible, and have them

repaired, if possible.• Buy things that are reusable or recyclable, and be sure to reuse or

recycle them.• Buy beverages in refillable glass containers instead of cans or

throwaway bottles.• Use plastic or metal lunch boxes and metal or plastic garbage

containers without throwaway plastic liners.• Use rechargeable batteries.• Skip the bag when you buy anything you can carry with your hands.• Buy recycled goods, and recycle them.• Recycle all newspaper, glass, and aluminum, and any other items

accepted for recycling in your community.• Reduce the amount of junk mail you get.• Push for mandatory trash separation and recycling programs in your

community and schools.• Choose items that have the least packaging or no packaging at all.• Compost your yard and food wastes, and pressure local officials to

set up a community composting program.

Ch. 18 - Environmental Regulations:Hazardous Substances and Wastes

Case Study 18.3 – Computers – A Hazardous Waste

Hazardous and Toxic Materials in Our Environment

The life cycle of toxic substances

Hazardous and Toxic Substances—Some Definitions

Hazardous substances or hazardous materials are those that can cause harm to humans or the environment.

The EPA defines hazardous materials as having one or more of the following characteristics:• Ignitability (Fire hazard)• Corrosiveness (Corrodes material)• Reactivity (Explosiveness)• Toxicity (May release toxins)

Some hazardous materials, such as gasoline, fall into several categories.

Terms are incorrectly used interchangeably.• Toxic commonly refers to a narrow group of substances that cause

human injury or death.• Hazardous is a broader term; it refers to all dangerous materials

that create a human health or environmental problem.

Defining Hazardous Waste

Hazardous wastes are by-products of industrial, business, or household activities for which there is no immediate use.• They must be disposed of in an appropriate manner.• There are stringent regulations pertaining to production, storage,

and disposal. U.S. Resource Conservation and Recovery Act of 1976

(RCRA):• This act created the “cradle-to-grave” concept.

Under RCRA, substances are considered toxic or hazardous if they:• Cause or significantly contribute to an increase in mortality or an

increase in serious irreversible, or incapacitating reversible, illness; or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed.

Determining Regulations

The U.S. has attempted to deal with hazardous substances and wastes by using “command and control” methods of governmental regulations, beginning with the development of the EPA and OSHA in 1970.

Many states, as well as some countries, have tried to mirror these regulations by codifying their own statues specific to their needs.

State regulations can be equal or more stringent than federal regulations.

Determining Regulations

Acute vs. Chronic Toxicity• Effects of massive doses at once (acute toxicity) and

small doses over time (chronic toxicity) differ.– Chronic toxicity is much harder to detect as effects may not

surface for long periods of time. Synergism

• Assessing the effects of chemical mixtures is also problematic.

– Most toxicity studies focus on a single compound.– Synergism is the potential of relatively harmless individual

compounds to become highly toxic and do great damage when combined.

Hazardous-Waste Dumps— A Legacy of Abuse

Prior to RCRA in 1976, hazardous waste was essentially unregulated.

In the U.S., the federal government has become the principal participant in the cleanup of hazardous-waste sites.• The Comprehensive Environmental Response, Compensation,

and Liability Act (CERCLA) was enacted in 1980.• This program deals with financing the cleanup of large, uncontrolled

hazardous-waste sites and has become known as Superfund.• A National Priorities List was drawn up for Superfund action. Under

CERCLA, over 44,000 sites were evaluated, and about 11,000 were considered serious enough to warrant further investigation.

Hazardous-Waste Dumps— A Legacy of Abuse

Toxic Release Inventory (TRI) In 1987, any industrial plant that released at least

23,000 kg of toxic pollutants into the environment was required to file a report.

These were primarily manufacturing industries. The information collected allowed EPA to target

specific industries for enforcement action. About 2.0 billion kg of toxic chemicals were

reported released into the environment by industry in 2003.

Hazardous-Waste Management Choices

Pollution-prevention hierarchy

International Trade in Hazardous Wastes

There is particular concern about rich, industrialized countries exporting wastes to poorer, developing countries lacking administrative and technological resources to safely dispose of the waste.

Objectives of the Basel Convention (1989) are to minimize generation of hazardous wastes and control and reduce transboundary movements to protect human health and the environment.