Recycling

Botkin, Daniel B. Environmental Science: Earth as a Living Planet, 9th Edition. Wiley, 2013-12-23. VitalBook file.

CHAPTER 23

Materials Management

LEARNING

OBJECTIVES

The waste-management concept of “dilute and dis- perse” (for example, dumping waste into a river) is a holdover from our frontier days, when we mistak- enly believed that land and water were limitless re- sources. We next attempted to “concentrate and contain” waste in disposal sites—which also proved to pollute land, air, and water. We are now focusing on managing materials to reduce environmental deg- radation associated with resource use and eventually eliminate waste entirely. Finally, we are getting it right! After reading this chapter, you should be able to:

• Discuss why the standard of living in modern so- ciety is related in part to the availability of natural resources

• Summarize the importance of resources to society

• Discuss the social impacts of mineral exploitation and how wastes generated from the use of mineral resources affect the environment

• Discuss how sustainability may be linked to the way we use nonrenewable minerals

• Evaluate the emerging concept of materials man- agement and how to achieve it

• Synthesize the advantages and disadvantages of each of the major methods that constitute integrat- ed waste management

• Summarize the various methods of managing haz- ardous chemical waste

• Discuss the problems related to ocean dumping and why they will likely persist for some time

(Botkin 576)

Treasures of The Cell Phone

The number of cell phones in use in the United States rose from about 5 million in 1990 to about 350 million in 2012. More than 6 billion cell phones are in use world- wide. Some countries (for example, the United States and Russia) have more cell phones in use than people living in the country. India has more cell phones than flush toilets. We wonder if the explosive use of cell phones and mes- saging is a signal of a core value to communicate socially.

Today, we are connected across the planet by our cell phones—and this has enormous social and political im- plications. Text messaging, video, and cell phones have connected us as never before. For example, cell phone use was integral to the recent “Arab Spring.” People were constantly using them to communicate their desires for change and to organize political protests.

Cell phones are commonly replaced every two years as new features and services become available—witness the iPhone’s popularity. Each cell phone is small, but the mil- lions of phones retired each year in the United States col- lectively contain a treasure chest of valuable metals worth over $300 million, not counting the cost of recycling (Table 23.1). Worldwide, their value probably exceeds a billion dollars, but although the money potentially avail- able through recycling is attractive, less than 1% of dis- carded cell phones are recycled. Most end up stored in our closets or disposed of at municipal solid-waste facilities.

The life cycle of a cell phone is shown in Figure 23.1 and is typical of most electronic waste (e-waste).1 The primary reason more e- waste is not recycled is that we lack a simple, effective, small-scale, and inexpensive way to do it. We also need to bet- ter educate people about the environmental value of recy- cling and to offer more attrac- tive financial incentives to do it. Some states (California, for example) have laws that re- quire building recycling costs into the prices of products. (Botkin 577)

Our failure to manage cell phones and other e-waste reminds us that in the past 50 years we have proved un- able to move from a throwaway, waste-oriented society to a society that sustains natural resources through improved materials management. However, in some cases we are moving in that direction by producing less waste and re- cycling more discarded products. With this in mind, in this chapter we introduce concepts of waste management applied to urban waste, hazardous chemical waste, and waste in the marine environment.

23.1 The Importance of Resources to Society

Modern society depends on the availability of both re- newable resources (air, surface water, some groundwater, plants, animals, and some energy sources) and nonrenew- able resources (soil, some groundwater, oil, coal, and most minerals).2–4 What partially differentiates renewable from nonrenewable resources is their availability in a human time framework. Air and water, along with biological resources such as fish and crops, are regularly replenished as long as the processes that renew them continue to operate at an adequate rate. Nonrenewable resources, such as oil and minerals, even those that are being replenished by Earth processes today, are not being replenished in a time frame useful to people. Thus, strategies to use resources sustainably are linked to specific resources. We can sustain water resources by careful water management (see Chapter 18), but sustaining min- erals or oil requires strategies linked more to conservation, recycling, reuse, and substitution than to management of next year’s supply delivered by Earth processes.

Many products made from both renewable and non- renewable resources are found and consumed in a typical American home (see Figure 23.2 for nonrenewable miner- als used in a home office). Consider this morning’s break- fast (food is a renewable resource). You probably drank from a glass made primarily of sand; ate from dishes made of clay; flavored your food with salt mined from Earth; ate fruit grown with the aid of fertilizers, such as potassium

carbonate (potash) and phosphorus; and used utensils made of stainless steel, which comes from processing iron ore and other minerals. While eating your tasty renewable resources, you may have viewed the news on a television or computer screen, listened to music on your iPod, or made appointments using your cell phone. All these electronic items are made from metals and petroleum.

Resources are vital to people, and the standard of living increases with their availability in useful forms. Indeed, the availability of resources is one measure of a society’s wealth. Those who have been most successful in locating and extracting or importing and using resources have grown and prospered. Without resources to grow food, construct buildings and roads, and manufacture everything from computers to televisions to automobiles, modern technological civilization as we know it would not be possible. For example, to maintain our standard of living in the United States, each person requires about 10 tons of nonfuel minerals per year.5 We use other resources, such as food and water, in much greater amounts.

23.2 Materials Management: What It Is

Materials management has the visionary environmental goal of sustainably obtaining and using renewable and nonrenewable resources. This goal can be pursued in the following ways: 6

• Eliminate subsidies for extracting virgin materials such as minerals, oil, and timber.

• Establish “green building” incentives that encourage the use of recycled content materials and products in new construction.

• Assess financial penalties for production that uses poor materials management practices.

• Provide financial incentives for industrial practices and products that benefit the environment by enhancing sustainability (for example, by reducing waste produc- tion and using recycled materials).

• Provide more incentives for people, industry, and agri- culture to develop materials management programs that eliminate or reduce waste by using it as raw material for other products.

Materials management in the United States today is beginning to influence where industries are located. For example, because approximately 50% of the steel pro- duced in the nation now comes from scrap, new steel mills are no longer located near resources such as coal and iron ore. New steel mills are now found in a variety of places, from California to North Carolina and Nebraska; their resource is the local supply of scrap steel. Because they are starting with scrap metal, the new industrial facilities use far less energy and cause much less pollution7 than older steel mills that must start with virgin iron ore.

Similarly, the recycling of paper is changing where new paper mills are constructed. In the past, mills were built near forested areas where the timber for paper pro- duction was being logged. Today, they are being built near cities that have large supplies of recycled paper. New Jer- sey, for example, has 13 paper mills using recycled paper and 8 steel “mini mills” producing steel from scrap metal. Remarkably, New Jersey has little forested land and no iron mines; resources for the paper and steel mills come from materials already in use, exemplifying the power of materials management.7

We have focused on renewable resources in previous parts of this book (Chapter 11, agriculture; Chapter 12, forests; Chapter 13, wildlife; Chapter 18, water; and Chapter 21, air). We discussed nonrenewable resources with respect to fossil fuels in Chapter 15. The remainder of this chapter will discuss other nonrenewable mineral resources and how to sustain them as long as possible by intelligent waste management.

23.3 Mineral Resources

Minerals can be considered a very valuable, nonrenewable heritage from the geologic past. Although new deposits are still forming from Earth processes, these processes are producing new deposits too slowly to be of use to us today or anytime soon. Also, because mineral deposits are generally in small, hidden areas, they must be discovered, and unfortunately most of the easily found deposits have already been discovered and exploited. Thus, if modern civilization were to vanish, our descendants would have a harder time finding rich mineral deposits than we did. It is interesting to speculate that they might mine landfills for metals thrown away by our civilization. Unlike bio- logical resources, minerals cannot be easily managed to produce a sustained yield; the supply is finite. Recycling and conservation will help, but, eventually, the supply will be exhausted.

How Mineral Deposits Are Formed

Metals in mineral form are generally extracted from natu- rally occurring, unusually high concentrations of Earth materials. When metals are concentrated in such large amounts by geologic processes, ore deposits are formed. The discovery of natural ore deposits allowed early peoples to exploit copper, tin, gold, silver, and other metals while slowly developing skills in working with metals.

The origin and distribution of mineral resources is intimately related to the history of the biosphere and to the entire geologic cycle (see Chapter 7). Nearly all aspects and processes of the geologic cycle are involved to some ex- tent in producing local concentrations of useful materials. Earth’s outer layer, or crust, is silica-rich, made up mostly of rock-forming minerals containing silica, oxygen, and a few other elements. The elements are not evenly distrib- uted in the crust: Nine elements account for about 99% of the crust by weight (oxygen, 45.2%; silicon, 27.2%; aluminum, 8.0%; iron, 5.8%; calcium, 5.1%; magnesium, 2.8%; sodium, 2.3%; potassium, 1.7%; and titanium, 0.9%). In general, the remaining elements are found in trace concentrations.

The ocean, covering nearly 71% of Earth, is anoth- er reservoir for many chemicals other than water. Most elements in the ocean have been weathered from crustal rocks on the land and transported to the oceans by rivers. Others are transported to the ocean by wind or glaciers. Ocean water contains about 3.5% dissolved solids, mostly chlorine (55.1% of the dissolved solids by weight). Each cubic kilometer of ocean water contains about 2.0 metric tons of zinc, 2.0 metric tons of copper, 0.8 metric ton of tin, 0.3 metric ton of silver, and 0.01 metric ton of gold. These concentrations are low compared with those in the crust, where corresponding values (in metric tons/km3) are zinc, 170,000; copper, 86,000; tin, 5,700; silver, 160; and gold, 5. After rich crustal ore deposits are depleted, we will be more likely to extract metals from lower grade deposits or even from common rock than from ocean wa- ter, unless mineral extraction technology becomes more efficient.

Why do the minerals we mine occur in deposits with anomalously high local concentrations? Planetary scien- tists now believe that all the planets in our solar system were formed by the gravitational attraction of the forming sun, which brought together the matter dispersed around it. As the mass of the proto-Earth increased, the mate- rial condensed and was heated by the process. The heat was sufficient to produce a molten liquid core, consisting primarily of iron and other heavy metals, which sank to- ward the center of the planet. When molten rock material known as magma cools, heavier minerals that crystallize (solidify) early may slowly sink toward the bottom of the magma, whereas lighter minerals that crystallize later are left at the top. Deposits of an ore of chromium, called chromite, are thought to be formed in this way. When magma containing small amounts of carbon is deeply bur- ied and subjected to very high pressure during slow cool- ing (crystallization), diamonds (which are pure carbon) may be produced (Figure 23.3).8,9

Earth’s crust formed from generally lighter elements and is a mixture of many different kinds. The elements in the crust are not uniformly distributed because geologic processes (such as volcanic activity, plate tectonics, and sedimentary processes), as well as some biological pro- cesses, selectively dissolve, transport, and deposit elements and minerals.

Sedimentary processes related to the transport of sedi- ments by wind, water, and glaciers often concentrate ma- terials in amounts sufficient for extraction. As sediments are transported, running water and wind help segregate them by size, shape, and density. This sorting is useful topeople. The best sand or sand and gravel deposits for con- struction, for example, are those in which the finer ma- terials have been removed by water or wind. Sand dunes, beach deposits, and deposits in stream channels are good examples. The sand and gravel industry amounts to several billion dollars annually and, in terms of the total volume of materials mined, is one of the largest nonfuel mineral industries in the United States.5

Rivers and streams that empty into oceans and lakes carry tremendous quantities of dissolved material from the weathering of rocks. Over geologic time, a shallow marine basin may be isolated by tectonic activity that uplifts its boundaries; or climate variations, such as the ice ages, may produce large inland lakes with no outlets. As these basins and lakes eventually dry up, the dissolved materials drop out of solution and form a wide variety of compounds, minerals, and rocks that have important commercial value.9

Biological processes form some mineral deposits, such as phosphates and iron ore deposits. The major iron ore deposits exist in sedimentary rocks that were formed more than 2 billion years ago.10 Although the processes are not fully understood, it appears that major deposits of iron stopped forming when the atmospheric concentration of oxygen reached its present level.11

Organisms, too, form many kinds of minerals, such as the calcium minerals in shells and bones. Some of these minerals cannot be formed inorganically in the biosphere. Thirty-one biologically produced minerals have been identified.12

Weathering, the chemical and mechanical decomposi- tion of rock, concentrates some minerals in the soil, such as native gold and oxides of aluminum and iron. (The more soluble elements, such as silica, calcium, and sodium, are selectively removed by soil and biological processes.) If sufficiently concentrated, residual aluminum oxide forms an ore of aluminum known as bauxite. Important nickel and cobalt deposits are also found in soils developed from iron and magnesium-rich igneous rocks.

23.4 Figuring Out how Much Is Left

Estimating how much is left of our valuable and nonrenewable mineral resources will help us estimate how long they are likely to last at our present rate of use and motivate us to do everything we can to sustain them as long as possible for future generations. We can begin by looking at the classification of minerals as resources and reserves.

Mineral Resources and Reserves

Mineral resources are broadly defined as known concentrations of elements, chemical compounds, minerals, or rocks. Mineral reserves are concentrations that at the time of evaluation can be legally and economically extracted as a commodity that can be sold at a profit (Figure 23.4).

The main point here is that resources are not reserves. An analogy from a student’s personal finances may help clarify this point. A student’s reserves are liquid assets, such as money in the bank, whereas the student’s resources include the total income the student can expect to earn dur- ing his or her lifetime. This distinction is often critical to the student in school because resources that may become available in the future cannot be used to pay this month’s bills.13 For planning purposes, it is important to continually reassess all components of a total resource, considering new technology, the probability of geologic discovery, and shifts in economic and political conditions.

Availability and Use of Our Mineral Resources

Earth’s mineral resources can be divided into broad cat- egories according to their use: elements for metal production and technology, building materials, minerals for the chemical industry, and minerals for agriculture. Metallic minerals can be further classified by their abundance. Abundant metals include iron, aluminum, chromium, manganese, titanium, and magnesium. Scarce metals include copper, lead, zinc, tin, gold, silver, platinum, ura- nium, mercury, and molybdenum.

Some minerals, such as salt (sodium chloride), are necessary for life. Primitive peoples traveled long distances to obtain salt when it was not locally available. Other minerals are desired or considered necessary to maintain a particular level of technology.

When we think about minerals, we usually think of metals; but with the exception of iron, the predominant minerals are not metallic. Consider the annual world con- sumption of a few selected elements. Sodium and iron are used at a rate of approximately 100–1,000 million metric tons per year; and nitrogen, sulfur, potassium, and cal- cium at a rate of approximately 10–100 million metric tons per year, primarily as soil conditioners or fertilizers. Elements such as zinc, copper, aluminum, and lead have annual world consumption rates of about 3–10 million metric tons, and gold and silver are consumed at annual rates of 10,000 metric tons or less. Of the metallic miner- als, iron makes up 95% of all the metals consumed; and nickel, chromium, cobalt, and manganese are used mainly in alloys of iron (as in stainless steel).

The basic issue associated with mineral resources is not actual exhaustion or extinction but the cost of main- taining an adequate stock by mining and recycling. At some point, the costs of mining exceed the worth of mate- rial. When the availability of a particular mineral becomes limited, there are four possible solutions:

• Find more sources.

• Recycle and reuse what has already been obtained.

• Reduce consumption.

• Find a substitute.

Which choice or combination of choices is made depends on social, economic, and environmental factors.

U.S. Supply of Mineral Resources

Domestic supplies of many mineral resources in the Unit- ed States are insufficient for current use and must be sup- plemented by imports from other nations. For example, the United States imports many of the minerals needed for its complex military and industrial system, called strategic minerals (such as bauxite, manganese, graphite, cobalt, strontium, and asbestos). Of particular concern is the possibility that the supply of a much-desired or much- needed mineral will be interrupted by political, economic, or military instability in the supplying nation.

That the United States—along with many other countries—depends on a steady supply of imports to meet its domestic demand does not necessarily mean that suf- ficient kinds and amounts can’t be mined domestically. Rather, it suggests economic, political, or environmental reasons that make it easier, more practical, or more desir- able to import the material. This has resulted in politi- cal alliances that otherwise would be unlikely. Industrial countries often need minerals from countries whose poli- cies they don’t necessarily agree with; as a result, they make political concessions on human rights and other is- sues that they would not otherwise make.3

Moreover, the fact remains that mineral resources are limited, and this raises important questions. How long will a particular resource last? How much short-term or long- term environmental deterioration are we willing to accept to ensure that resources are developed in a particular area? How can we make the best use of available resources?

23.5 Impacts of Mineral Development

The impact of mineral exploitation depends on ore qual- ity, mining procedures, local hydrologic conditions, cli- mate, rock types, size of operation, topography, and many more interrelated factors. In addition, our use of mineral resources has a significant social impact.

Environmental Impacts

Exploration for mineral deposits generally has a minimal impact on the environment if care is taken in sensitive areas, such as arid lands, marshes, and areas underlain by permafrost. Mineral mining and processing, however, generally have a considerable impact on land, water, air, and living things. Furthermore, as it becomes necessary to use ores of lower and lower grades, the environmental effects tend to worsen. One example is the asbestos fibers in the drinking water of Duluth, Minnesota, from the disposal of waste from mining low-grade iron ore.

A major practical issue is whether open pit or under- ground mines should be developed in an area. As you saw in our earlier discussion of coal mining in Chapter 15, there are important differences between the two kinds of mining.2 The trend in recent years has been away from sub- surface mining and toward large, open pit mines, such as the Bingham Canyon copper mine in Utah (Figure 23.5). The Bingham Canyon mine is one of the world’s largesthuman-made excavations, covering nearly 8 km2 (3 mi2) to a maximum depth of nearly 800 m (2,600 ft).

Surface mines and quarries today cover less than 0.5% of the total area of the United States, but even though their impacts are local, numerous local occurrences will eventu- ally constitute a larger problem. Environmental degrada- tion tends to extend beyond the immediate vicinity of a mine. Large mining operations remove material in some areas and dump waste in others, changing topography. At the very least, severe aesthetic degradation is the result. In addition, dust may affect the air quality, even though care is taken to reduce it by sprinkling water on roads and on other sites that generate dust.

A potential problem with mineral resource develop- ment is the possible release of harmful trace elements into the environment. Water resources are particularly vulnerable even if drainage is controlled and sediment pollution is reduced (see Chapter 15 for more about this issue, including a discussion of acid mine drainage). The white streaks in Figure 23.6 are mineral deposits appar- ently leached from tailings from a zinc mine in Colorado. Similar-looking deposits may cover rocks in rivers for many kilometers downstream from some mining areas.

Mining-related physical changes in the land, soil, wa- ter, and air indirectly affect the biological environment. Plants and animals killed by mining activity or by contact with toxic soil or water are some of the direct impacts. Indirect impacts include changes in nutrient cycling, total biomass, species diversity, and ecosystem stability. Periodic or accidental discharge of low-grade pollutants through failure of barriers, ponds, or water diversions, or through the breaching of barriers during floods, earthquakes, or volcanic eruptions, also may damage local ecological sys- tems to some extent.

Social Impacts

The social impacts of large-scale mining result from the rapid influx of workers into areas unprepared for growth. This population influx places stress on local services, such as water supplies, sewage and solid-waste disposal systems, as well as on schools, housing, and nearby recreation and wilderness areas. Land use shifts from open range, for- est, and agriculture to urban patterns. Construction and urbanization affect local streams through sediment pollution, reduced water quality, and increased runoff. Air quality suffers as a result of more vehicles, construction dust, and power generation.

Perversely, closing down mines also has negative so- cial impacts. Nearby towns that have come to depend on the income of employed miners can come to resemble the well-known “ghost towns” of the old American West. The price of coal and other minerals also directly affects the livelihood of many small towns. This is especially evident in the Appalachian Mountain region of the United States, where coal mines have closed partly because of lower prices for coal and partly because of rising mining costs. One of the reasons mining costs are rising is the increased level of environmental regulation of the mining indus- try. Of course, regulations have also helped make mining safer and have facilitated land reclamation. Some miners, however, believe the regulations are not flexible enough, and there is some truth to their arguments. For example, some mined areas might be reclaimed for use as farmland now that the original hills have been leveled. Regulations, however, may require that the land be restored to its origi- nal hilly state, even though hills make inferior farmland.

Minimizing the Environmental Impact of Mineral Development

Minimizing the environmental impacts of mineral development requires consideration of the entire cycle of min- eral resources shown in Figure 23.7. This diagram reveals that waste is produced by many components of the cycle.

In fact, the major environmental impacts of mineral use are related to waste products. Waste produces pollution that may be toxic to people, may harm natural ecosystems and the biosphere, and may be aesthetically displeasing. Waste may attack and degrade air, water, soil, and living things. Waste also depletes nonrenewable mineral resources and, when simply disposed of, provides no offsetting benefits for human society.

Environmental regulations at the federal, state, and local levels address pollution of air and water by all aspects of the mineral cycle, and may also address reclamation of land used for mining minerals. Today, in the United States, approximately 50% of the land used by the mining industry has been reclaimed.

Minimizing the environmental effects of mining takes several interrelated paths:3

• Reclaiming areas disturbed by mining (see A Closer Look 23.1).

• Stabilizing soils that contain metals to minimize their release into the environment. Often this requires plac- ing contaminated soils in a waste facility.

• Controlling air emissions of metals and other materials from mining areas.

• Treating contaminated water before it can leave a mining site or treating contaminated water that has left a mining site.

• Treating waste onsite and offsite. Minimizing onsite and offsite problems by controlling sediment, water, and air pollution through good engineering and conservation practices is an important goal. Of particular interest is the development of biotechnological processes such as biooxidation, bioleaching, and biosorption, the bonding of waste to microbes, as well as genetic engineering of microbes. These practices have enormous potential for both extracting metals and minimizing environmental degradation. At several sites, for example, constructed wetlands use acid-tolerant plants to remove metals from mine wastewaters and neutralize acids by biological ac- tivity.14 The Homestake Gold Mine in South Dakota uses biooxidation to convert contaminated water from the mining operation into substances that are environ- mentally safe; the process uses bacteria that have a natu- ral ability to oxidize cyanide to harmless nitrates.15

• Practicing the three R’s of waste management. That is, Reduce the amount of waste produced, Reuse waste as much as possible, and maximize Recycling opportuni- ties. Wastes from some parts of the mineral cycle, for example, may themselves be considered ores because they contain materials that might be recycled to provide energy or other products.16–18

We will look at the three R’s in greater detail in Section 23.7, Integrated Waste Management.

23.6 Materials Management and Our Waste

History of Waste Disposal

During the first century of the Industrial Revolution, the volume of waste produced in the United States was rela- tively small and could be managed using the concept of “dilute and disperse.” Factories were located near rivers because the water provided a number of benefits, includ- ing easy transport of materials by boat, enough water for processing and cooling, and easy disposal of waste into the river. With few factories and a sparse population, dilute and disperse was sufficient to remove the waste from the immediate environment.19

As industrial and urban areas expanded, the concept of dilute and disperse became inadequate, and a new concept, “concentrate and contain,” came into use. It has become ap- parent, however, that containment was, and is, not always achieved. Containers, whether simple trenches excavated in the ground or metal drums and tanks, may leak or break and allow waste to escape. Health hazards resulting from past waste-disposal practices have led to the present situa- tion, in which many people have little confidence in gov- ernment or industry to preserve and protect public health.20

In the United States and many other parts of the world, people are facing a serious solid-waste disposal problem. Basically, we are producing a great deal of waste and don’t have enough acceptable space for disposing of it. It has been estimated that within the next few years approximately half the cities in the United States may run out of landfill space. Philadelphia, for example, is es- sentially out of landfill space now and is bargaining with other states on a monthly or yearly basis to dispose of its trash. The Los Angeles area has landfill space for only about ten more years.

To say we are actually running out of space for landfills isn’t altogether accurate—land used for landfills is minute compared to the land area of the United States. Rather, existing sites are being filled, and it is difficult to site new landfills. After all, no one wants to live near a waste-dis- posal site, be it a sanitary landfill for municipal waste, an incinerator that burns urban waste, or a hazardous waste- disposal operation for chemical materials. This attitude is widely known as NIMBY (“not in my backyard”).

The environmentally correct concept with respect to waste management is to consider wastes as resources out of place. Although we may not soon be able to reuse and recycle all waste, it seems apparent that the increas- ing cost of raw materials, energy, transportation, and land will make it financially feasible to reuse and recycle more resources and products. Moving toward this objective is moving toward an environmental view that there is no such thing as waste. Under this concept, waste would not exist because it would not be produced—or, if produced, it would be a resource to be used again. This is referred to as the “zero waste” movement.

Zero waste is the essence of what is known as indus- trial ecology, the study of relationships among industrial systems and their links to natural systems. Under the prin- ciples of industrial ecology, our industrial society would function much as a natural ecosystem functions. Waste from one part of the system would be a resource for an- other part.21

Until recently, zero waste production was considered unreasonable in the waste-management arena. However, it is catching on. The city of Canberra, Australia, may be the first community to propose a zero waste plan. Thou- sands of kilometers away, in the Netherlands, a national waste reduction goal of 70 to 90% has been set. How this goal is to be met is not entirely clear, but a large part of the planning involves taxing waste in all its various forms, from smokestack emissions to solids delivered to landfills. Already, in the Netherlands, pollution taxes have nearly eliminated discharges of heavy metals into waterways. At the household level, the government is considering programs—known as “pay as you throw”—that would charge people by the volume of waste they produce. Tax- ing waste, including household waste, motivates people to produce less of it.22

Of particular importance to waste management is the growing awareness that many of our waste-management programs involve moving waste from one site to another, and not really managing it. For example, waste from ur- ban areas may be placed in landfills; but eventually these landfills may cause new problems by producing methane gas or noxious liquids that leak from the site and contami- nate the surrounding areas. Managed properly, however, methane produced from landfills is a resource that can be burned as a fuel (an example of industrial ecology).

In sum, previous notions of waste disposal are no longer acceptable, and we are rethinking how we deal with materi- als, with the objective of eliminating the concept of waste entirely. In this way, we can reduce the consumption of min- erals and other virgin materials, which depletes our environ- ment, and live within our environment more sustainably.21

23.7 Integrated Waste Management

The dominant concept today in managing waste is known as integrated waste management (IWM), which is best defined as a set of management alternatives that includes reuse, source reduction, recycling, composting, landfill, and incineration.

Reduce, Reuse, Recycle

The ultimate objective of the three R’s of IWM is to re- duce the amount of urban (municipal solid waste) and other waste that must be disposed of in landfills, incin- erators, and other waste-management facilities. Study of the waste stream (the waste produced) in areas that use IWM technology suggests that the amount (by weight) of urban refuse disposed of in landfills or incinerated can be reduced by at least 50% and perhaps as much as 70%. A 50% reduction by weight could be achieved by (1) source reduction, such as packaging better designed to reduce waste (10%reduction); (2) large-scale composting pro- grams (10% reduction); and (3) recycling programs (30% reduction).20

As this list indicates, recycling is a major player in reducing the urban waste stream. Metals such as iron, aluminum, copper, and lead have been recycled for many years and are still being recycled today. The metal from al- most all of the millions of automobiles discarded annually in the United States is recycled.16,17 The total value of re- cycled metals is about $50 billion. Iron and steel account for approximately 90% by weight and 40% by total value of recycled metals. Iron and steel are recycled in such large volumes for two reasons. First, the market for iron and steel is huge, and as a result there is a large scrap collec- tion and scrap processing industry. Second, an enormous economic and environmental burden would result from failure to recycle because over 50 million tons of scrap iron and steel would have to be disposed of annually.17,18

Today in the United States we recycle over 30% of our total municipal solid waste, up more than 10% from 25 years ago. This amounts to 99% of automobile bat- teries, 63% of steel cans, 71% office type papers, 63% of aluminum cans, 35% of tires, 28% of glass contain- ers, and about 30% of various plastic containers (Table 23.2).23 This is encouraging news. Can recycling actu- ally reduce the waste stream by 50%? Recent work sug- gests that the 50% goal is reasonable. In fact, it has been reached in some parts of the United States, and the po- tential upper limit for recycling is considerably higher. It is estimated that as much as 80 to 90% of the U.S. waste stream might be recovered through what is known as in- tensive recycling.24 A pilot study involving 100 families inEast Hampton, New York, achieved a level of 84%. More realistic for many communities is partial recycling, which targets specific materials such as glass, aluminum cans, plastic, organic material, and newsprint. Partial recycling can provide a significant reduction, and in many places it is approaching or even exceeding 50%.25,26

Recycling is simplified with single-stream recycling, in which paper, plastic, glass, and metals are not sepa- rated before collection; the waste is commingled in one container and separated later at recycling centers. This is more convenient for homeowners, reduces the cost of col- lection, and increases the rate of recycling. Thus, single- stream recycling is growing rapidly.

Public Support for Recycling

There is enthusiastic public support for recycling in the United States today. Many people understand that managing our waste has many advantages to society as a whole and the environment in particular. People like the notion of recycling because they correctly assume they are helping to conserve resources, such as forests, that make up much of the nonurban environment of the planet.

An encouraging sign of public support for the environ- ment is the increased willingness of industry and business to support recycling on a variety of scales. For example, fast-food restaurants are using less packaging and provid- ing onsite bins for recycling paper and plastic. Groceries and supermarkets are encouraging the recycling of plastic and paper bags by providing bins for their collection, and some offer inexpensive reusable canvas shopping bags in- stead of disposables. Companies are redesigning products so that they can be more easily disassembled after use and the various parts recycled. As this idea catches on, small appliances such as electric frying pans and toasters may be recycled rather than ending up in landfills. The automo- bile industry is also responding by designing automobiles with coded parts so that they can be more easily disassem- bled (by professional recyclers) and recycled, rather than left to become rusting eyesores in junkyards.

On the consumer front, people are more likely to purchase products that can be recycled or that come in containers that are more easily recycled or composted. Many consumers have purchased small home appliances that crush bottles and aluminum cans, reducing their volume and facilitating recycling. The entire arena is rapidly changing, and innovations and opportunities will undoubtedly continue.

Large cities from New York to Los Angeles have initi- ated recycling programs, but many people are concerned that recycling is not yet “cost-effective.” As with many other environmental solutions, implementing the IWM concept successfully can be a complex undertaking. In some communities where recycling has been successful, it has resulted in glutted markets for recycled products, which has sometimes required temporarily stockpiling or suspending the recycling of some items. It is apparent that if recycling is to be successful, markets and processing facilities will also have to be developed to ensure that recy- cling is a sound financial venture as well as an important part of IWM.

To be sure, there are success stories, such as a large urban paper mill on New York’s Staten Island that recycles more than 1,000 tons of paper per day. It is claimed that this paper mill saves more than 10,000 trees a day and uses only about 10% of the electricity required to make paper from virgin wood processing. On the West Coast, San Francisco has an innovative and ambitious recycling program that diverts nearly 50% of the urban waste from landfills to recycling programs. City officials are even talk- ing about the concept of zero waste, hoping to achieve to- tal recycling of waste by 2020. In part, this goal is being achieved by instigating a “pay-as-you-throw” approach; businesses and individuals are charged for disposal of gar- bage but not for materials that are recycled. Materials from the waste of the San Francisco urban area are shipped as far away as China and the Philippines to be recycled into usable products; organic waste is sent to agricultural areas; and metals, such as aluminum, are sent around California and to other states where they are recycled.

To understand some of the issues concerning recy- cling and its cost, consider the following points:

• The average cost of disposal at a landfill is about $40/ ton in the United States, and even at a higher price of about $80/ton may be cheaper than recycling.

• Landfill fees in Europe range from $200 to $300/ton.

• Europe has been more successful in recycling, in part because countries such as Germany hold manufacturers responsible for disposing of the industrial goods they produce, as well as the packaging.

• In the United States, packaging accounts for approxi- mately one-third of all waste generated by manufacturing.

• The cost to cities such as New York, which must export its waste out of state, is steadily rising and is expected to exceed the cost of recycling within about ten years.

• Placing a 10-cent refundable deposit on all beverage containers except milk would greatly increase the num- ber recycled. For example, states with a deposit sys- tem have an average recycling rate of about 70–95% of bottles and cans, whereas states that do not have a refundable-deposit system average less than 30%.

• When people have to pay for trash disposal at a landfill, but are not charged for materials that are recycled— such as paper, plastic, glass, and metals—the success of recycling is greatly enhanced.

• Beverage companies do not particularly favor requir- ing a refundable deposit for containers. They claim that the additional costs to do this would be several billion dollars, but they do agree that recovery rates would be higher, providing a steadier supply of recycled metal, such as aluminum, as well as plastic.

• Education is a big issue with recycling. Many people still don’t know which items are recyclable and which are not.

• Global markets for recyclable materials, such as paper and metals, have potential for expansion, particularly for large urban areas on the seacoast, where shipping materi- als is economically viable. Recycling in the United States today is a $14 billion industry; if done right, it generates new jobs and revenue for participating communities.

There are a number of good reasons to recycle mu- nicipal solid waste:27

• Saving money by recycling: For many years we have known that it is less expensive to make products us- ing materials that have been recycled. Using recycled aluminum has been mentioned more than many other materials, probably because about 90% more energy is expended to extract and use new aluminum resources from the planet than to recycle and reuse that aluminum. Products made from recycled metals and other materi- als are generally less expensive than those manufactured from materials mined for the first time from Earth.

• Recycling increases employment: As we recycle more, new businesses are generated in transporting, processing, and selling recycled materials to be used in manufactur- ing new goods. On the one hand, for every 100,000 tons of waste that enters the waste stream and ends up in a landfill, six new jobs are created. On the other hand, if that same 100,000 tons of waste is recycled, six times as many jobs may be created. The number of jobs required at landfills is less than the number created through recycling because, as materials are reused, more employment results, including jobs for people who sort, transport, and sell the material, as well as for engineers and chemists who work to create better uses for those recycled materials. Furthermore, these jobs are often created in urban environments where more people live and work. Today, more than one million people are em- ployed in the recycling industry, and over 55,000 recy- cling and reuse facilities have been built.

• Recycling politics: Becoming energy self-sufficient has been a longtime U.S. objective. Recent oil and gas dis- coveries are heading us in that direction, but recycling of materials can also play a role. Today, the United States recycles just over 30% of municipal solid waste, and this recycling results in a savings of about 5 billion gallons of gasoline. Thus, it is argued that through greater use of recycling, the United States and other countries that recycle may be more self-reliant and independent.

• Recycling and values: One of the fundamental prin- ciples of this book centers on values and science. It is argued that recycling is the right thing to do because it provides for better management of the Earth’s resources. Value judgments include the fact that it is far better to reuse and recycle than to simply discard materials and products we have used. Extraction of raw materials from the planet poses serious environmental concerns, and reusing those products reduces our impact. An example often cited is the use of recycled paper so that fewer trees need to be harvested for paper production, thereby reducing the impact of deforestation. Another example is the use of plastics that, when recycled and reprocessed, can produce a number of products we rou- tinely use (see A Closer Look 23.2). The ethical and moral argument is that by recycling and reusing more we can help minimize potential damages resulting from resource exploitation.

Recycling of Human Waste

The use of human waste, or “night soil,” on croplands is an ancient practice. In Asia, recycling of human waste has a long history. Chinese agriculture was sustained for thousands of years through collection of human waste, which was spread over agricultural fields. The practice grew, and by the early 20th century the land application of sewage was a primary disposal method in many met- ropolitan areas in countries, including Mexico, Austra- lia, and the United States.28 Early uses of human waste for agriculture occasionally spread infectious diseases through bacteria, viruses, and parasites in waste applied to crops. Today, with the globalization of agriculture, we still see occasional warnings and outbreaks of disease from contaminated vegetables (see Chapter 19).

A major problem associated with recycling human waste is that, along with human waste, thousands of chemicals and metals flow through our modern waste stream. Even garden waste that is composted may contain harmful chemicals, such as pesticides.28

23.8 Municipal Solid-Waste Management

Municipal solid-waste management continues to be a problem in the United States and other parts of the world. In many areas, particularly in developing countries, waste- management practices are inadequate. These practices, which include poorly controlled open dumps and illegal roadside dumping, can spoil scenic resources, pollute soil and water, and pose health hazards.

Illegal dumping is as much a social as a physical problem because many people are simply disposing of waste as inexpensively and as quickly as possible, perhaps not see- ing their garbage as an environmental problem. If nothing else, this is a tremendous waste of resources, since much of what is dumped could be recycled or reused. In areas where illegal dumping has been reduced, the keys have been awareness, education, and alternatives. Education programs teach people about the environmental problems of unsafe, unsanitary dumping of waste, and funds are provided for cleanup and for inexpensive collection and recycling of trash at sites of origin.

Next, we look at the composition of solid waste in the United States, and then we describe specific disposal methods: onsite disposal, composting, incineration, open dumps, and sanitary landfills.

Composition of Solid Waste

The average content of solid waste that is not recycled and is likely to end up at a disposal site in the United States is shown in Figure 23.10. It is no surprise that paper is by far the most abundant component. However, considerable variation can be expected, based on factors such as land use, economic base, industrial activity, climate, and time of year.

People have many misconceptions about our waste stream.29 With all the negative publicity about fast-food packaging, polystyrene foam, and disposable diapers, many people assume that these make up a large percentage of the waste stream and are responsible for the rapid filling of landfills. However, excavations into modern landfills using archaeological tools have cleared up some misconceptions. We now know that fast-food packaging accounts for only about 0.25% of the average landfill; disposable diapers, ap- proximately 0.8%; and polystyrene products about 0.9%.29 Paper is a major constituent in landfills, perhaps as much as 50% by volume and 40% by weight. The largest single item is newsprint, which accounts for as much as 18% by volume.30 Newsprint is one of the major items targeted for recycling because big environmental dividends can be expected. However, (and this is a value judgment), the need to deal with the major waste products doesn’t mean that we need not cut down on our use of disposable diapers, poly- styrene, and other paper products. In addition to creating a need for disposal, these products are made from resources that might be better managed.

Onsite Disposal

A common onsite disposal method in urban areas is the garbage disposal device installed in the wastewater pipe under the kitchen sink to grind garbage and flush it into the sewer system. This effectively reduces the amount of handling and quickly removes food waste. What’s left of it is transferred to sewage treatment plants, where solids remaining as sewage sludge still must be disposed of.31,32

Composting

Composting is a biochemical process in which organic materials, such as lawn clippings and kitchen scraps, de- compose to a rich, soil-like material. The process involves rapid partial decomposition of moist solid organic waste by aerobic organisms. Although simple backyard com- post piles may come to mind, large-scale composting as a waste-management option is generally carried out in the controlled environment of mechanical digesters. This technique is popular in Europe and Asia, where intense farming creates a demand for compost. However, a major drawback of composting is the necessity of separating organic material from other waste. Therefore, it is probably economically advantageous only where organic material is collected separately from other waste. Another negative is that composting plant debris previously treated with herbicides may produce a compost toxic to some plants. Nevertheless, composting is an important component of IWM, and its contribution continues to grow.31,32

Incineration

Incineration burns combustible waste at temperatures high enough (900°–1,000°C, or 1,650°–1,830°F) to consume all combustible material, leaving only ash and noncombustibles to dispose of in a landfill. Under ideal conditions, incineration may reduce the volume of waste by 75–95%.32 In practice, however, the actual decrease in volume is closer to 50% because of maintenance problems, as well as waste supply problems. Besides reducing a large volume of combustible waste to a much smaller volume of ash, incineration has another advantage: It can be used to supplement other fuels and generate electrical power.

Incineration of urban waste is not necessarily a clean process; it may produce air pollution and toxic ash. In the United States, for example, incineration is apparently a significant source of environmental dioxin, a carcinogenic toxin (see Chapter 8).33 Smokestacks from incinerators also may emit oxides of nitrogen and sulfur, which lead to acid rain; heavy metals, such as lead, cadmium, and mercury; and carbon dioxide, which is related to global warming.

In modern incineration facilities, smokestacks fitted with special devices trap pollutants, but the process of pol- lutant abatement is expensive. The plants themselves are expensive, and government subsidization may be needed to aid in their establishment. Evaluation of the urban waste stream suggests that an investment of $8 billion could build enough incinerators in the United States to burn approximately 25% of the solid waste that is generated. However, a similar investment in source reduction, recycling, and composting could divert as much as 75% of the nation’s urban waste stream away from landfills.24

The economic viability of incinerators depends on revenue from the sale of the energy produced by burning the waste. As recycling and composting increase, they will compete with incineration for their portion of the waste stream, and sufficient waste (fuel) to generate a profit from incineration may not be available. The main conclu- sion that can be drawn based on IWM principles is that a combination of reusing, recycling, and composting could reduce the volume of waste requiring disposal at a landfill by at least as much as incineration.24

Open Dumps (Poorly Controlled Landfills)

In the past, solid waste was often disposed of in open dumps (now called landfills), where refuse was piled up and left uncovered. Thousands of open dumps have been closed in recent years, and new open dumps are banned in the United States and many other countries. Nevertheless, many are still being used worldwide (Figure 23.11)

Sanitary Landfills

A sanitary landfill (also called a municipal solid-waste landfill) is designed to concentrate and contain refuse without creating a nuisance or hazard to public health or safety. The idea is to confine the waste to the smallest prac- tical area, reduce it to the smallest practical volume, and cover it with a layer of compacted soil at the end of each day of operation, or more frequently if necessary. Cover- ing the waste is what makes the landfill sanitary. The com- pacted layer restricts (but does not eliminate) continued access to the waste by insects, rodents, and other animals, such as seagulls. It also isolates the refuse, minimizing the amount of surface water seeping into it and the amount of 34 gas escaping from it.

Leachate

The most significant hazard from a sanitary landfill is pollution of groundwater or surface water. If waste buried in a landfill comes into contact with water percolating down from the surface or with groundwater moving later- ally through the refuse, leachate—a noxious, mineralized liquid capable of transporting bacterial pollutants—is produced.35 For example, two landfills dating from the 1930s and 1940s on Long Island, New York, have pro- duced subsurface leachate trails (plumes) several hundred meters wide that have migrated kilometers from the dis- posal site. The nature and strength of the leachate pro- duced at a disposal site depend on the composition of the waste, the amount of water that infiltrates or moves through the waste, and the length of time that infiltrated water is in contact with the refuse.32

Site Selection

The siting of a sanitary landfill is very important and must take into consideration a number of factors, includ- ing topography, location of the groundwater table, amount of precipitation, type of soil and rock, and location of the disposal zone in the surface water and groundwater flow system. A favorable combination of climatic, hydrologic, and geologic conditions helps to ensure reasonable safety in containing the waste and its leachate.36 The best sites are in arid regions, where disposal conditions are relatively safe be- cause little leachate is produced. In a humid environment, some leachate is always produced; therefore, an acceptable level of leachate production must be established to deter- mine the most favorable sites in such environments. What is acceptable varies with local water use, regulations, and the ability of the natural hydrologic system to disperse, di- lute, and otherwise degrade the leachate to harmless levels.

Elements of the most desirable site in a humid cli- mate with moderate to abundant precipitation are shown in Figure 23.12. The waste is buried above the water table in relatively impermeable clay and silt that water cannot easily move through. Any leachate therefore remains in the vicinity of the site and degrades by natural filtering ac- tion and chemical reactions between clay and leachate.37,38

Siting waste-disposal facilities also involves important social considerations. Often, planners choose sites where they expect minimal local resistance or where they perceive land to have little value. Waste-disposal facilities are frequently located in areas where residents tend to have low socioeconomic status or belong to a particular racial or ethnic group. The study of social issues in siting waste facilities, chemical plants and other such facilities is an emerging field known as environmental justice. Monitoring Pollution in Sanitary Landfills

Once a site is chosen for a sanitary landfill and before filling starts, monitoring the movement of groundwater should begin. Monitoring involves periodically taking samples of water and gas from specially designed moni- toring wells. Monitoring the movement of leachate and gases should continue as long as there is any possibility of pollution, and it is particularly important after the site is completely filled and permanently covered. Continued monitoring is necessary because a certain amount of set- tling always occurs after a landfill is completed; if small depressions form, surface water may collect, infiltrate, and produce leachate. Monitoring and proper maintenance of an abandoned landfill reduce its pollution potential.34

How Pollutants Can Enter the Environment from Sanitary Landfills Pollutants from a solid-waste disposal site can enter the environment through as many aseight paths (Figure 23.13):41

1. Methane, ammonia, hydrogen sulfide, and nitrogen gases can be produced from compounds in the waste and the soil and can enter the atmosphere.

2. Heavy metals, such as lead, chromium, and iron, can be retained in the soil.

3. Soluble materials, such as chloride, nitrate, and sul- fate, can readily pass through the waste and soil to the groundwater system.

4. Overland runoff can pick up leachate and transport it into streams and rivers.

5. Some plants (including crops) growing in the disposal area can selectively take up heavy metals and other toxic materials. These materials are then passed up the food chain as people and animals eat the plants.

6. If plant residue from crops left in fields contains toxic substances, these substances return to the soil.

7. Streams and rivers may become contaminated by waste from groundwater seeping into the channel (3) or by surface runoff (4).

8. Wind can transport toxic materials to other areas. Modern sanitary landfills are engineered to include multiple barriers: clay and plastic liners to limit the movement of leachate; surface and subsurface drainage to collect leachate; systems to collect methane gas from decomposing waste; and groundwater monitoring to de- tect leaks of leachate below and adjacent to the landfill. A thorough monitoring program considers all eight possible paths by which pollutants enter the environment. In prac- tice, however, monitoring seldom includes all pathways. It is particularly important to monitor the zone above the water table to identify potential pollution before it reaches and contaminates groundwater, where correction would be very expensive. Figure 23.14 shows (a) an idealized dia- gram of a landfill that uses the multiple barrier approach and (b) a photograph of a landfill site under construction.

Federal Legislation for Sanitary Landfills

New landfills that opened in the United States after 1993 must comply with stricter requirements under the Resource Conservation and Recovery Act of 1980. The legislation, as its title states, is intended to strengthen and standardize the design, operation, and monitoring of sani- tary landfills. Landfills that cannot comply with regulations face closure. However, states may choose between two options: (1) comply with federal standards or (2) seek EPA approval of solid-waste management plans. The federal standards include the following:

• Landfills may not be sited on floodplains, wetlands, earthquake zones, unstable land, or near airports (birds drawn to landfill sites are a hazard to aircraft).

• Landfills must have liners.

• Landfills must have a leachate collection system.

• Landfill operators must monitor groundwater for many specified toxic chemicals.

• Landfill operators must meet financial assurance criteria to ensure that monitoring continues for 30 years after the landfill is closed.

EPA approval of a state’s landfill program allows greater flexibility:

• Groundwater monitoring may be suspended if the landfill operator can demonstrate that hazardous con- stituents are not migrating from the landfill.

• Alternative types of daily cover over the waste may be used.

• Alternative groundwater protection standards are al- lowed.

• Alternative schedules for documentation of groundwa- ter monitoring are allowed.

• Under certain circumstances, landfills in wetlands and fault zones are allowed.

• Alternative financial assurance mechanisms are allowed.

Given the added flexibility, it appears advantageous for states to develop EPA-approved waste-management plans.

Reducing the Waste that Ends Up in a Landfill

Most of the municipal solid waste we generate is from our homes, and over 50% of it could be diverted from the landfill by the 3 R’s of waste management: reduce, reuse, and recycle. Diversion may eventually be increased to as much as 85% through improved waste management. In other words, the life of the landfill can be extended by keeping more waste out of the landfill through conserva- tion and recycling, or through turning waste, even waste that is presently buried, into a source of clean energy. The latter involves first removing materials that can be recy- cled, then linking noncombustion thermal or biochemical processes with the remaining solid waste to produce elec- tricity and alternative fuels (for example, biodiesel). The less waste in the landfill, the less potential for pollution of ground and surface water, along with the important fringe benefit of green energy.

The average waste per person in the United States in- creased from about 1 kg (2.2 lb) per day in 1960 to 2 kg (4.5 lb) per day in 2008. This is an annual growth rate of about 1.5% per year and is not sustainable because the doubling time for waste production is only a few decades. The 236 million tons we produced in 2003 would be close to 500 million tons by 2050, and we are already having big waste-management problems today. Table 23.3 lists some of the many ways you could reduce the waste you generate. What other ways can you think of?

23.9 hazardous Waste

Creation of new chemical compounds has proliferated in recent years. In the United States, approximately 1,000 new chemicals are marketed each year, and about 70,000 chemicals are currently on the market. Although many of these chemicals have been beneficial to people, approxi- mately 35,000 chemicals used in the United States are classified as definitely or potentially hazardous to people or ecosystems if they are released into the environment as waste—and unfortunately, a lot of it is.

The United States currently produces about 700 million metric tons of hazardous chemical waste per year, referred to more commonly as hazardous waste. About 70% of it is generated east of the Mississippi River, and about half of the total by weight is generated by chemical products in- dustries. The electronics industry (see A Closer Look 23.3 for a discussion of e-waste) and petroleum and coal prod- ucts industries each contribute about 10%.42–44 Hazard- ous waste may also enter the environment when buildings are destroyed by events such as fires and hurricanes, releas- ing paints, solvents, pesticides, and other chemicals that were stored in them, or when debris from damaged build- ings is later burned or buried. As a result, collection of such chemicals after natural disasters is an important goal in managing hazardous materials.

In the mid-20th century, as much as half the to- tal volume of hazardous waste produced in the United States was indiscriminately dumped.43 Some was illegal- ly dumped on public or private lands, a practice called midnight dumping. Buried drums of illegally dumped hazardous waste have been discovered at hundreds of sites by contractors while in the process of constructing buildings and roads. Cleanup has been costly and has delayed projects.42

The case of Love Canal is a well-known hazardous waste horror story. In 1976, in a residential area near Niagara Falls, New York, trees and gardens began to die. Rubber on tennis shoes and bicycle tires disintegrated. Puddles of toxic substances began to ooze through the soil. A swimming pool popped from its foundation and floated in a bath of chemicals.

The story of Love Canal started in 1892 when Wil- liam Love excavated a canal 8 km (5 mi) long as part of the development of an industrial park. The development didn’t need the canal when inexpensive electricity arrived, so the uncompleted canal remained unused for decades and became a dump for wastes. From 1920 to 1952, some 20,000 tons of more than 80 chemicals were dumped into the canal. In 1953 the Hooker Chemical Company— which produced the insecticide DDT as well as an herbi- cide and chlorinated solvents, and had dumped chemicals into the canal—was pressured to donate the land to the city of Niagara Falls for $1.00. The city knew that chemi- cal wastes were buried there, but no one expected any problems. Eventually, several hundred homes and an el- ementary school were built on and near the site, and for years everything seemed fine. Then, in 1976–1977, heavy rains and snows triggered a number of events, making Love Canal a household word.42

A study of the site identified many substances sus- pected of being carcinogens, including benzene, dioxin, dichlorethylene, and chloroform. Although officials ad- mitted that little was known about the impact of these chemicals, grave concern was voiced for people living in the area. Eventually, concern centered on alleged high rates of miscarriages, blood and liver abnormalities, birth defects, and chromosome damage. The government had to destroy about 200 homes and a school, and about 800 families were relocated and reimbursed. After about $400 million was spent on cleaning up the site, the EPA eventually declared the area clean, and about 280 remain- ing homes were sold.45 Today, the community around the canal is known as Black Creek Village, and many people live there.

Uncontrolled or poorly controlled dumping of chemi- cal waste has polluted soil and groundwater in several ways:

• In some places, chemical waste is still stored in barrels, either stacked on the ground or buried. The barrels may eventually corrode and leak, polluting surface water, soil, and groundwater.

• When liquid chemical waste is dumped into an unlined lagoon, contaminated water may percolate through soil and rock to the groundwater table.

• Liquid chemical waste may be illegally dumped in de- serted fields or even along roads.

Some sites pose particular dangers. The floodplain of a river, for example, is not an acceptable site for storing hazardous waste. Yet, that is exactly what occurred at a site on the floodplain of the River Severn near a village in one of the most scenic areas of England. Several fires at the site in 1999 were followed by a large fire of unknown origin on October 30, 2000. Approximately 200 tons of chemicals, including industrial solvents (xylene and toluene), clean- ing solvents (methylene chloride), and various insecticides and pesticides, produced a fireball that rose into the night sky. Wind gusts of hurricane strength spread toxic smoke and ash to nearby farmlands and villages, which had to be evacuated. People exposed to the smoke complained of a variety of symptoms, including headaches, stomach- aches and vomiting, sore throats, coughs, and difficulty breathing.

A few days later, on November 3, the site flooded. The floodwaters interfered with cleanup after the fire and increased the risk of downstream contamination by waterborne hazardous wastes. In one small village, contaminated floodwaters apparently inundated farm fields, gardens, and even homes.46 Of course, the solution to this problem is to clean up the site and move waste storage to a safer location.

23.10 hazardous Waste Legislation

Recognition in the 1970s that hazardous waste was a dan- ger to people and the environment and that the waste was not being properly managed led to important federal leg- islation in the United States.

Resource Conservation and Recovery Act

Management of hazardous waste in the United States began in 1976 with passage of the Resource Conserva- tion and Recovery Act (RCRA). At the heart of the act is identification of hazardous wastes and their life cycles. The idea was to issue guidelines and assign responsibilities to those who manufacture, transport, and dispose of haz- ardous waste. This is known as “cradle-to-grave” manage- ment. Regulations require stringent record keeping and reporting to verify that the wastes are not a public nui- sance or a health problem.

RCRA applies to solid, semisolid, liquid, and gaseous hazardous wastes. It considers a waste hazardous if its con- centration, volume, or infectious nature may contribute to serious disease or death or if it poses a significant hazard to people and the environment as a result of improper management (storage, transport, or disposal).42 The act classifies hazardous wastes in several categories: materi- als highly toxic to people and other living things; wastes that may ignite when exposed to air; extremely corrosive wastes; and reactive unstable wastes that are explosive or generate toxic gases or fumes when mixed with water.

Comprehensive Environmental Response, Compensation, and Liability Act

In 1980, Congress passed the Comprehensive Envi- ronmental Response, Compensation, and Liability Act (CERCLA). It defined policies and procedures for release of hazardous substances into the environment (for exam- ple, landfill regulations). It also mandated development of a list of sites where hazardous substances were likely to produce or already had produced the most serious environmental problems and established a revolving fund (Superfund) to clean up the worst abandoned hazardous waste sites. In 1984 and 1986, CERCLA was strength- ened by amendments that made the following changes:

• Improved and tightened standards for disposal and cleanup of hazardous waste (for example, requiring double liners, monitoring landfills).

• Banned land disposal of certain hazardous chemicals, including dioxins, polychlorinated biphenyls (PCBs), and most solvents.

• Initiated a timetable for phasing out disposal of all un- treated liquid hazardous waste in landfills or surface im- poundments.

• Increased the Superfund. The fund was allocated about $8.5 billion in 1986; Congress approved $5.1 billion for fiscal year 1998, which almost doubled the Super- fund budget.47 Today (2010 to 2014) the EPA cost for Superfund sites is about $500 million per year and ris- ing. The EPA does not include cost of cleanup at sites that are early in the process.

The Superfund has had management problems, and cleanup efforts are far behind schedule. Unfortunately, the funds available are not sufficient to pay for decontami- nating all targeted sites. Furthermore, present technology may not be sufficient to treat all abandoned waste-disposal sites; it may be necessary to simply try to confine waste at those sites until better disposal methods are developed. It seems apparent that abandoned disposal sites are likely to remain problems for some time to come.

Federal legislation has also changed the ways in which real estate business is conducted. For example, there are provisions by which property owners may be held liable for costly cleanup of hazardous waste on their property, even if they did not directly cause the problem. As a result, banks and other lending institutions might be held liable for re- lease of hazardous materials by their tenants.

The Superfund Amendment and Reauthorization Act (SARA) of 1986 permits a possible defense against such liability if the property owner completed an environmen- tal audit before purchasing the property. Such an audit involves studying past land use at the site, usually deter- mined by analyzing old maps, aerial photographs, and reports. It may also involve drilling and sampling ground- water and soil to determine whether hazardous materi- als are present. Environmental audits are now completed routinely before purchasing property for development.47

In 1990 the U.S. Congress reauthorized hazardous waste control legislation. Priorities include:

• Establishing who is responsible (liable) for existing haz- ardous waste problems.

• When necessary, assisting in or providing funding for cleanup at sites identified as having a hazardous waste problem.

• Providing measures whereby people who suffer damages from the release of hazardous materials are compensated.

• Improving the required standards for disposal and cleanup of hazardous waste.

23.11 hazardous Waste Management: Land Disposal

Management of hazardous chemical waste involves sev- eral options, including recycling; onsite processing to re- cover by-products that have commercial value; microbial breakdown; chemical stabilization; high temperature de- composition; incineration; and disposal by secure landfill (Figure 23.16) or deep well injection. A number of tech- nological advances have been made in toxic waste man- agement; as land disposal becomes more expensive, the recent trend toward onsite treatment is likely to continue. However, onsite treatment will not eliminate all hazard- ous chemical waste; disposal of some waste will remain necessary.

Table 23.4 compares hazardous “waste” reduction technologies for treatment and disposal. Notice that all available technologies cause some environmental disrup- tion. There is no simple solution for all waste-management issues.

Direct land disposal of hazardous waste is often not the best initial alternative. The consensus is that even with extensive safeguards and state-of-the-art designs, land disposal alternatives cannot guarantee that the waste will be contained and that it will not cause environmental disruption in the future. This concern holds true for all land disposal facilities, including landfills, surface impoundments, land application, and injection wells. Pollution of air, land, surface water, and ground- water may result if a land disposal site fails to contain hazardous waste. Pollution of groundwater is perhaps the most significant risk because groundwater provides a convenient route for pollutants to reach people and other living things.

Some of the paths that pollutants may take from land disposal sites to contaminate the environment include leakage and runoff to surface water or groundwater from improperly designed or maintained landfills; seepage, runoff, or air emissions from unlined lagoons; percolation and seepage from failure of surface land application of waste to soils; leaks in pipes or other equipment associated with deep well injection; and leaks from buried drums, tanks, or other containers.48–51

23.12 Alternatives to Land Disposal of hazardous Waste

Our handling of hazardous chemical waste should be multifaceted. In addition to the disposal methods just dis- cussed, chemical waste management should include such processes as source reduction, recycling and resource re- covery, treatment, and incineration. Recently, it has been argued that these alternatives to land disposal are not be- ing used to their full potential—that is, the volume of waste could be reduced, and the remaining waste could be recycled or treated in some form prior to land disposal of the treatment residues.52 The advantages of source reduc- tion, recycling, treatment, and incineration include the following

• Useful chemicals can be reclaimed and reused. • Treatment may make waste less toxic and therefore less likely to cause problems in landfills.

• The volume of waste that must eventually be disposed of is reduced.

• Because a reduced volume of waste is finally disposed of, there is less stress on the dwindling capacity of waste disposal sites.

Although some of the following techniques have been discussed as part of integrated waste management, they have special implications and complications in regard to hazardous wastes.

Source Reduction

The object of source reduction in hazardous waste man- agement is to reduce the amount of hazardous waste gen- erated by manufacturing or other processes. For example, changes in the chemical processes involved, equipment and raw materials used, or maintenance measures may successfully reduce the amount or toxicity of hazardous waste produced.52

Recycling and Resource Recovery

Hazardous chemical waste may contain materials that can be recovered for future use. For example, acids and solvents collect contaminants when they are used in manufacturing processes. These acids and solvents can be processed to remove the contaminants and then be reused in the same or different manufacturing processes.52

Hazardous waste resulting from industrial processes can be recycled effectively and safely. The Environmental Protection Agency (EPA) reported that in 2011, approxi- mately 39 million tons of hazardous waste was managed, and of that, approximately 4% was recycled and another 4% was recovered. The EPA distinguishes between those wastes that are used or reused without reclamation and those that require reclamation before they may be used again. A particular material is said to be reclaimed if it is processed to recover usable products.53 For example, haz- ardous waste reclamation includes the recovery of solvents such as acetone from industrial processes or recovery of metals such as lead.

The EPA keeps track of how much hazardous waste is generated, how it is managed, and the final disposition of those wastes as mandated by the Resource and Conserva- tion and Recovery Act of 1976 discussed earlier. While the total percentage of hazardous waste that is recycled is low at 4%, it is encouraging that all hazardous waste is now managed. Hopefully, with continued improvements in technology and industrial processes, more hazardous waste will be reused and recycled.53

Treatment

Hazardous chemical waste can be treated by a variety of processes to change its physical or chemical composition and reduce its toxicity or other hazardous characteristics. For example, acids can be neutralized, heavy metals can be separated from liquid waste, and hazardous chemical compounds can be broken up through oxidation.52

Incineration

High-temperature incineration can destroy hazardous chemical waste. However, incineration is considered a waste treatment, not a disposal method, because the pro- cess produces an ash residue that must itself be disposed of in a landfill. Hazardous waste has also been inciner- ated offshore on ships, creating potential air pollution and ash—disposal problems in the marine environment—an environment we consider next.

23.13 Ocean Dumping

Oceans cover more than 70% of Earth. They play a part in maintaining our global environment and are of major importance in the cycling of carbon dioxide, which helps regulate the global climate. Oceans are also important in cycling many chemical elements important to life, such as nitrogen and phosphorus, and are a valuable resource because they provide us with such necessities as food and minerals.

It seems reasonable that such an important resource would receive preferential treatment, and yet oceans have long been dumping grounds for many types of waste, including industrial waste, construction debris, urban sewage, and plastics (see A Closer Look 23.4). Ocean dumping contributes to the larger problem of ocean pollution, which has seriously damaged the marine environment and caused a health hazard. Figure 23.17 shows locations in the oceans of the world that are accumulating pollution continuously; have intermittent pollution problems; or have potential for pollution from ships in the major shipping lanes. Notice that the areas with continual or intermittent pollution are near the shore.

Unfortunately, these are also areas of high productivity and valuable fisheries. Shellfish today often contain organisms that cause diseases such as polio and hepatitis. In the United States, at least 20% of the nation’s commercial shellfish beds have been closed (mostly temporarily) because of pollution. Beaches and bays have been closed (again, mostly temporarily) to recreational uses. Life- less zones in the marine environment have been created. Heavy kills of fish and other organisms have occurred, and profound changes in marine ecosystems have taken place (see Chapter 19).54,55

Marine pollution has a variety of specific effects on oceanic life, including the following:

• Death or retarded growth, vitality, and reproductivity of marine organisms.

• Reduction of dissolved oxygen necessary for marine life, due to increased biochemical oxygen demand.

• Eutrophication caused by nutrient-rich waste in shal- low estuaries, bays, and parts of the continental shelf, resulting in oxygen depletion and subsequent killing of algae, which may wash up and pollute coastal areas. (See Chapter 19 for a discussion of eutrophication in the Gulf of Mexico.)

• Habitat change caused by waste-disposal practices that subtly or drastically change entire marine ecosystems.54

Marine waters of Europe are in particular trouble, in part because urban and agricultural pollutants have raised concentrations of nutrients in seawater. Blooms (heavy, sudden growth) of toxic algae are becoming more com- mon. For example, in 1988 a bloom was responsible for killing nearly all marine life to a depth of about 15 m (50 ft), in the waterway connecting the North Sea to the Baltic Sea. It is believed that urban waste and agricultural runoff contributed to the toxic bloom.

Although oceans are vast, they are basically giant sinks for materials from continents, and parts of the marine environment are extremely fragile.55 One area of concern is he microlayer, the upper 3 mm of ocean water. The base of the marine food chain consists of planktonic life abun- dant in the microlayer, and the young of certain fish and shellfish also reside there in the early stages of their life. Unfortunately, these upper few millimeters of the ocean also tend to concentrate pollutants, such as toxic chemicals and heavy metals. One study reported that concentrations of heavy metals—including zinc, lead, and copper—in the microlayer are from 10 to 1,000 times higher than in the deeper waters. It is feared that disproportionate pollution of the microlayer will have especially serious effects on marine organisms.55 There is also concern that ocean pollution is a threat to some marine ecosystems, such as coral reefs, estuaries, salt marshes, and mangrove swamps.

Marine pollution can also have major impacts on people and society. Contaminated marine organisms, as we mentioned, may transmit toxic elements or diseases to people who eat them. In addition, beaches and har- bors polluted by solid waste, oil, and other materials may not only damage marine life but also lose their visual appeal and other amenities. Economic loss is also con- siderable. Loss of shellfish from pollution in the United States, for example, amounts to many millions of dol- lars per year. In addition, a great deal of money is spent cleaning up solid waste, liquid waste, and other pollut- ants in coastal areas.52

23.14 pollution prevention

Approaches to waste management are changing. During the first several decades of environmental concern and management (the 1970s and 1980s), the United States approached the problem through government regulations and waste-control measures: chemical, physical, or bio- logical treatment and collection (for eventual disposal), or transformation or destruction of pollutants after they had been generated. This was considered the most cost- effective approach to waste management.

With the 1990s came a growing emphasis on pollution prevention—ways to stop generating so much waste, rather than ways to dispose of it or manage it. This ap- proach, which is part of materials management, includes the following:56

• Purchasing the proper amount of raw materials so that no excess remains to be disposed of.

• Exercising better control of materials used in manufac- turing processes so that less waste is produced.

• Substituting nontoxic chemicals for hazardous or toxic materials currently used.

• Improving engineering and design of manufacturing processes so that less waste is produced.

These approaches are often called P-2 approaches, for “pollution prevention.” Probably the best way to illustrate the P-2 process is through a case history.56

A Wisconsin firm that produced cheese was faced with the disposal of about 2,000 gallons a day of a salty solu- tion generated during the cheese-making process. Initially, the firm spread the salty solution on nearby agricultural lands—then a common practice for firms that could not discharge wastewater into publicly owned treatment plants. This method of waste disposal, when done incorrectly, caused the level of salts in the soil to rise so much that it damaged crops. As a result, the Department of Natural Resources in Wisconsin placed limitations on this practice.

The cheese firm decided to modify its cheese-making processes to recover salt from the solution and reuse it in production. This involved developing a recovery process that used an evaporator. The recovery process reduced the salty waste by about 75% and at the same time reduced the amount of the salt the company had to purchase by 50%. The operating and maintenance costs for recovery were approximately 3 cents per pound of salt recovered, and the extra cost of the new equipment was recovered in only two months. The firm saved thousands of dollars a year by recycling its salt.

The case history of the cheese firm suggests that rather minor changes can often result in large reductions of waste produced. And this case history is not an isolated example. Thousands of similar cases exist today as we move from the era of recognizing environmental problems, and regulating them at a national level, to providing economic incentives and new technology to better manage materials.56

23.15 Sustainable Resource Management

Sustaining renewable resources, such as water, wildlife, crops, and forests, though complex and sometimes diffi- cult to achieve, is fairly easy to understand. Management of the environment must include development of goals and procedures to ensure that what makes a particular resource renewable persists over the long term (numerous genera- tions). We have devoted several chapters in this book to sustainability with respect to renewable resources (water, air, energy, crops, forests, fish, and wildlife). However, simultaneously considering sustainable development and mineral exploitation and use is problematic. This is because, even with the most careful use, nonrenewable mineral resources will eventually be used up, and sustainability is a long-term concept that requires finding ways to assure future genera- tions a fair share of Earth’s resources. Recently, it has been argued that, given human ingenuity and sufficient lead time, we can find solutions for sustainable development that incorporate nonrenewable mineral resources.

Human ingenuity is important because often it is not the mineral we need so much as what we use the mineral for. For example, we mine copper and use it to transmit electricity in wires or electronic pulses in telephone wires. It is not the copper itself we desire but the properties of copper that allow these transmissions. We can use fiber- glass cables in telephone wires, eliminating the need for copper. Digital cameras have eliminated the need for film development that uses silver. The message is that it is possible to compensate for a nonrenewable mineral by finding new ways to do things. We are also learning that we can use raw mineral materials more efficiently. For ex- ample, in the late 1800s when the Eiffel Tower was con- structed, 8,000 metric tons of steel were used. Today the tower could be built with only a quarter of that amount.57

Finding substitutes or more efficient ways to use nonrenewable resources generally requires several decades of research and development. A measure of how much time we have for finding solutions to the depletion of nonrenewable reserves is the R-to-C ratio, where R is the known reserves (for example, hundreds of thousands of tons of a metal) and C is the rate of consumption (for example, thousands of tons per year used by people). The R-to-C ratio is often misinterpreted as the time a reserve will last at the present rate of consumption. During the past 50 years, the R-to-C ratios for metals, such as zinc and copper, have fluctuated around 30 years. During that time, consumption of the metals roughly tripled, but we discovered new deposits. Although the R-to-C ratio is a present analysis of a dynamic system in which both the amount of reserves and consumption may change over time, it does provide a view of how scarce a particular mineral resource may be. Metals with relatively small ra- tios can be viewed as being in short supply, and it is those resources for which we should find substitutes through technological innovation.57

In sum, we may approach sustainable development and use of nonrenewable mineral resources by developing more efficient ways of mining resources and finding ways to more efficiently use available resources, recycling more and applying human ingenuity to find substitutes for a nonrenewable mineral.

SUMMARY

• Mineral resources are usually extracted from naturally occurring, anomalously high concentrations of Earth materials. Such natural deposits allowed early peoples to exploit minerals while slowly developing technological skills.

• Mineral resources are not mineral reserves. Unless dis- covered and developed, resources cannot be used to ease present shortages.

• The availability of mineral resources is one measure of the wealth of a society. Modern technological civilization would not be possible without the exploitation of mineral resources. However, it is important to recognize that min- eral deposits are not infinite and that we cannot maintain exponential population growth on a finite resource base.

• The United States and many other affluent nations rely on imports for their supplies of many minerals. As other nations industrialize and develop, such imports may be more difficult to obtain, and affluent countries may have to find substitutes for some minerals or use a smaller portion of the world’s annual production.

• The mining and processing of minerals greatly affect the land, water, air, and biological resources and have social impacts as well, including increased demand for hous- ing and services in mining areas.

• Sustainable development and use of nonrenewable resources are not necessarily incompatible. Reducing consumption, reusing, recycling, and finding substi- tutes are environmentally preferable ways to delay or alleviate possible crises caused by the convergence of a rapidly rising population and a limited resource base.

• The history of waste-disposal practices since the In- dustrial Revolution has progressed from dilution and dispersion to the concept of integrated waste manage- ment (IWM), which emphasizes the three R’s: reducing waste, reusing materials, and recycling.

• One goal of the emerging concept of industrial ecology is to develop a system in which the concept of waste doesn’t exist because waste from one part of the system would be a resource for another part.

• The most common way to dispose of solid waste is the sanitary landfill. However, around many large cities, space for landfills is hard to find, partly because few people wish to live near a waste-disposal site.

• Hazardous chemical waste is one of the most serious environmental problems in the United States. Hundreds or even thousands of abandoned, uncontrolled disposal sites could be time bombs that will eventually cause serious public health problems. We know that we will continue to produce some hazardous chemical waste. Therefore, it is imperative that we develop and use safe ways to dispose of it.

• Ocean dumping is a significant source of marine pol- lution. The most seriously affected areas are near shore, where valuable fisheries often exist.

• Pollution prevention (P-2)—identifying and using ways to prevent the generation of waste—is an important emerging area of materials management.

Botkin, Daniel B. Environmental Science: Earth as a Living Planet, 9th Edition. Wiley, 2013-12-23. VitalBook file.

REExAMining ThEMES AnD iSSUES

Materials management strategies are inextricably linked to the human population. As the population increases, so does the waste generated. In developing countries where population increase is the most dramatic, in- creases in industrial output, when linked to poor environmental control, produce, or aggravate waste-management problems.

Assuring a quality environment for future generations is closely linked to materials management. Of particular importance here are the concepts of integrated waste management, materials management, and industrial ecol- ogy. Carried to their natural conclusion, the ideas behind these concepts would lead to a system in which the issue would no longer be waste man- agement but instead resource management. Pollution prevention (P-2) is a step in this direction.

Materials management is becoming a global problem. Improper manage- ment of materials contributes to air and water pollution and can cause environmental disruption on a regional or global scale. For example, waste generated by large inland cities and disposed of in river systems may eventually enter the oceans and be dispersed by the global circula- tion patterns of ocean currents. Similarly, soils polluted by hazardous materials may erode, and the particles may enter the atmosphere or water system, to be dispersed widely.

Because so much of our waste is generated in the urban environment, cities are a focus of special attention for materials management. Where population densities are high, it is easier to implement the principles behind “reduce, reuse, and recycle.” There are greater financial incentives for materials management where waste is more concentrated.

Production of waste is a basic process of life. In nature, waste from one organism is a resource for another. Waste is recycled in ecosystems as energy flows and chemicals cycle. As a result, the concept of waste in nature is much different than that in the human waste stream. In the human system, waste may be stored in facilities such as landfills, where it may remain for long periods, far from natural cycling. Our activities to recycle waste or burn it for energy move us closer to transforming waste into resources. Converting waste into resources brings us closer to nature by causing urban systems to operate in parallel with natural ecosystems.

People today value a quality, pollution-free environment. The way ma- terials have been managed continues to affect health and other envi- ronmental problems. An understanding of these problems has resulted in a considerable amount of work and research aimed at reducing or eliminating the impact of resource use. How a society manages its waste is a sign of its maturity and its ethical framework. Accordingly, we have become more conscious of environmental justice issues related to materials management.

Botkin, Daniel B. Environmental Science: Earth as a Living Planet, 9th Edition. Wiley, 2013-12-23. VitalBook file.