Zero (Discharge) Emissions

Photo courtesy of SiemensOpens in new window Water is essential for human life and development. A broad understanding of the hydrologic cycle allows a prediction of the consequences of man’s activities to water supplies. In any circumstance, to preserve our water courses, a rational water use is mandatory. In this literature, we emphasize the role of water as a major solvent and carrier of contaminants, guidelines for water quality, wastewater reclamation and reuse, water use in mining operations, recycling and zero discharge. Some technologies to preserve water supplies are discussed.

The concept of Zero Discharge or Zero Emissions gives the idea of no pollution. In the purest sense of the word, emissions are substances which are transmitted into the environment as a result of anthropogenic activity. According to this definition, any gas naturally emanating from the sub-soil would not be considered an emission. In this purest definition, gases, liquds, solids and radiation which are the wastes associated with human acitivity would all be considered emissions. In addition, it is possible to extend the definition of emissions to include other forces which degrade the environment including sound, aesthetic (visual) and thermal pollution. Finally, the definition can be broadened to include land use changes such as the conversion of natural habitat to other land uses. Another characteristic which must be present for the transmission of a substance into the environment to be considered an emission is that the substance must have an impact, either directly on humans, or indirectly through an impact on the natural or social environment. For example, if the environment has a natural ability to assimilate a harmful substance, the substance would not be considered an emission until that assimilative capacity has been exceeded.

It can be concluded, therefore, that for modern environmental law the Zero Emission is every kind of emission of substance, including toxic, that is below or up to the limit determined by the parameter or technical/legal standard.

Since the introduction of the “zero emission” concept, the often repeated question is: Is zero emission a feasible quest to achieve or Is it possible to achieve zero emission? The answer to this question depends on how the concept is defined and where the system boundary is drawn. If the boundary is defined too narrowly, it is always possible to prove that zero emissions have been achieved. One of the typical examples for this to “electric car.” Emissions from the car itself are zero; however, if the system boundary is drawn so to include the electricity production to drive this car, then it is obvious that the emissions have only been shifted from one part of the system to another.

The system boundary definition is therefore crucial in addressing this question. In addition, we also need to understand why we have the emissions in the first place. It is not because we are careless (or not in most cases), but because of the basic thermodynamic laws. Emissions and wastes arise because of the inefficiencies and losses in both material and energy uses. At the present stage of the technological development, wer are not able to utilize materials and energy at a 100 percent efficiency. Unless there is a revolutionary change in the way we go about using materials and energy, we will never be able to achive zero emission, because there will always be some wastes and emissions produced. However, what we can do is strive to reduce these emissions and wastes to a minimum in a concerted action in which all the implications of the technology use are assessed on a global level.

Why Zero Emission is Critical to Sustainability

To understand why Zero emission (or discharge) is a critical component of sustainability, it is important to recognize that one principle of sustainability is the efficient and wise use of resources, especially with regard to limiting the amount and types of resource extraction and subsequent pollution loadings. To see how these are related, it may help to think of a cycle with three parts: sources, systems, and sinks.

• The sources include raw materials such as minerals, water, topsoil, and fossil fuels. On this planet, these are limited but have huge external reserves.
• The systems are our ability to manipulate energy to turn source materials into finished products. Economic and industrai systems are limited only by imagination.
• The sinks are the global waste bins. The ultimate long-term sink is the deep trenches of the oceans; short-term sinks are biosystems such as the atmosphere, rivers, wetlands, and the land. The ability of the sinks to handle wastes is limited; most show adverse effects of pollutant loading in just a few years .

The most restricting rate-limiting component in this three-part model is the sinks. Currently, the depletion of resources is rarely the driving force for resource substitution; instead, change is driven by process innovation to beat the competition, or regulatory intervention imposed from outside. But given the limitations of the sinks, the pressure for modification of an industrial system will increasingly come from the need to reduce loadings to environmental sinks.

To achieve sustainability, the Earth’s enviromane must be protected in multiple ways. For example, planners must aim to minimize or eliminate anthropogenic changes to climate, net increases in acidification, loses of topsoil, and withdrawals of fossil water; moreover, biodiversity must be preserved, and buildup of toxic metals and other nonbiodegradable toxics in soils or sediments must be stopped. Zero emission technologies attempt to accomplish these goals by reducing resource extraction and loadings to sinks. The objective is a closed loop in the economic subsystem, so that wastes inevitably created by human activities do not escape to contaminate the environment. Zero emissions proponent Gunter Pauli, the founder and former director of Zero Emission Research Institute, also notes that in the effort to eliminate waste, Zero Emissions “is nothing more than a persistent drive to cut costs.” Waste is a form of inefficiency, and an “economic system cannot be considered efficient, or ultimately competitive, if it generates waste” (Pauli 1996).

Zero Emissions leave behind the linear “cradle to grave “ concept of materials use (Figure X-1 ) and embraces a cyclical, “cradle to cradle” vision, in which wastes become value-added inputs and the raw materials for other production cycles. This is how natural systems dispose of waste, and according to Pauli, the only way to achieve sustainability.

Graphics courtesy of Super OfficeOpens in new window

Meanwhile, the biological sinks are not increasing in capacity. Existing industries will keep operating and generating wastes – some of these wastes, as will be discussed later, containing richer concentrations of recoverable materials than virgin ones. In the interim, there will be a demand for technologies to manage and convert today’s wastes into usable feedstocks. Chemical process design engineers and consulting firms will provide focal services to meet this demand through technology development, system integration, and facility operation.

Economic development is the best response to this challenge—but we need a new kind of development that follows the seven guidelines of eco-efficiency:

Businesses that do this will create bottom line benefits from:

• creating new products and services that meet the aspirations of most of the world’s consumers for prosperity and a clean and healthy environment.

• reducing the costs and liability associated with resource consumption, waste, and end of pipe pollution control (which are likely to rise as a result of environmental taxes and other measures).

According to the World Business Council for Sustainable Development (WBCSD, 2000), eco-efficient materials are those materials that ensure the use of less material in a given application, ensure the use of less energy both in the production or transformation of the material (low embodied energy materials) and in the operation time within the application (low operational energy), are nontoxic and recyclable, and last more time within the application.

Similarly, eco-efficient systems are those that ensure a reduction in the material intensity of goods or services, a reduction in the energy intensity of goods or services, reduced dispersion of toxic materials, improved recyclability, maximum use of renewable resources, greater durability of products, and increased service intensity of goods and services.

What Is Special about Eco-efficiency?

Of course, many environmental concepts and initiatives emphasize the importance of resource productivity or doing more with less. It is central, for example, to the United Nations Environmental Programme’s concept of cleaner productionOpens in new window. There are also many proven approaches to achieving it, such as design for environment (DFE), pollution prevention, and product stewardship.

While eco-efficiency draws upon and has much in common with these and other approaches it has several distinctive features. These can be summarized as:

1. an emphasis on value creation
2. an emphasis on stretching, long-term, targets for improvement
3. linking environmental excellence to business excellence; and
4. considering sustainable consumption as well as sustainable production.

1.     Value Creation

Eco-efficiency harnesses the business concept of creating value and links it with environmental concerns. The goal is to create value for society, and for the company, by doing more with less over the entire life cycleOpens in new window, that is, from creation of raw materials to disposal of products at the end of their life. The idea is captured in Procter & Gamble’s statement:

Our goal is to provide more consumer performance and value with the use of less resources, including energy, and the creation of less wate.Procter & Gamble's Mission Statement

By promoting change toward sustainable growth, eco-efficiency enables a company’s business to grow in a qualitative way (by adding value), while reducing adverse effects on the earth. It also signals a significant shift in focus to concentrate on real customer needs.

This emphasis on creating and adding value is clearly to society’s benefit. Further, it’s often in line with the changing dynamics of the marketplace. Consumers everywhere want higher performance and increased value, at lower cost.

2.     Setting—and Meeting—Stretch Targets

Eco-efficiency asks companies to consider long-term trends and make ambitious long-term commitments in response. One way of making this concrete is by emulating the quality concept of zero defectsOpens in new window.

Although this was often not a practical target, it provided a concrete goal that created a constant dissatisfaction with the present. Over time, that dissatisfaction resulted in more and more improvements that were previously thought impossible.

The environmental equivalent of zero defects is zero emissions of hazardous or potentially hazardous substances from a facility or product. Although strictly speaking this is impossible—the laws of thermodynamics state that there must be some wastes from every process—in practice it provides a clear sense of direction. Monsanto and 3M are two companies that have introduced zero emissions as a long-term aspiration—and introduced medium-term stretch targets to move a long way toward it. Xerox Corporation too has set the goal of waste-free products from waste-free factories and introduced clear targets for reducing solid wastes, air emissions, hazardous wastes, wastewater discharges, lower energy usage, and the inclusion of 25% postconsumer recycled materials in parts and packaging. And Dow has recently announced aggressive 10-year reduction goals for environmental performance and resource conservation.

1. Environmental Excellence Is Business Excellence

Eco-efficiency is a management philosophy that links environmental excellence to business excellence and is synergistic with general trends in leading edge businesses. For example:

• More and more companies are seeing shared values and a common sense of purpose among their staff as a key success factor. Making an environmental and social contribution can be an important element of these.
• Eco-efficiency has close affinities with total quality management— “zero defects,” as we have seen can be translated into “zero emissions.”
• Eco-efficiency’s emphasis on collaboration with suppliers, customers, and stakeholder organizations provides a practical example of the strategic collaboration that many management theorists are now advocating.

1. A Sense of Purpose

Almost all social forecasters agree that more and more people, especially in the developed world, are searching for meaning in their lives—something traditionally provided by established religion or traditional communities and families. For a growing number, helping to protect the environment for future generation is an important part of their “sense of purpose.” This will drive their purchases—and favor the businesses whose own behavior and values resonates with their own.

More and more companies too are realizing that the best performance comes from staff or associates who share and commit to common values. 3M, for example, bases its success on consistent application of four key values:

• Satisfying customers with innovative products, superior quality, and value,
• Providing investors with an attractive return,
• Respecting the social and physical environment,
• Beign a company employees are proud to be part of.

These values provide employees with a sense of business purpose, based on meeting the requirements of stakeholders and making a broader contribution to the communities and countries they operate in.

Eco-efficiency contributes to this sense of purpose by providing a transcendent goal—respecting nature and helping to create a fairer world—that is in harmony rather than in conflict with business objectives. This same combination of long-term purpose and practical focus on current requirements is also attuned to the needs of customers, who will increasingly want both rather than one or the other.

Of course, to be effective, the everyday manaifestations of core values must stand up to the test of reality. If an organization professes and emphasizes sustainable business practices, it must condut its business accordingly or risk a loss of credibility and stature with regard to all its values from internal and external constituencies alike. Eco-efficiency does not require organizations to be environmentally perfect—but it does require them to be honest about their achievements and aim for continuous improvement.

1. Total Quality Management

Eco-efficiency has many affinities with total quality management (TQM). We have previously discussed how the idea of zero defects can easily be converted into one of zero emissions—a concept that, although impossible to achive in practice, can provide a clear sense of direction. An emphasis on pollution prevention is also an environmental application of the central total quality tenet of dealing with causes rather than symptoms of defects. Both approaches also place great emphasis on continous improvement and the value of measurement and targeting as means of achieving this. Eco-efficiency’s stress on the importance of stakeholders too can be seen as an application of the TQM view that every process has a customer whose needs must be satisfied. In this perspective, regulators, NGOs, and others are “customers” for a company’s environmental management and innovation processes. Finally, both approaches place great emphasis on the importance of cross-functional collaboration. This can identify opportunities for improvement and build information and commitment for effective implementation.

There are many examples of the successful application of quality approaches to the environment. Take, for example, Thomson Crown Wood Products, a small manufacturer of wood and wood-finished audio and television cabinets and storage units. The company employs about 700 people at its Mocksville, North Carolina, plant. In the early 1990s a number of teams within its overall quality initiative focused on environmental issues—and achieved considerable success. As is often the case these teams had frivolous nicknames but serious intent.

• The “Hazardous Five” team analyzed the quantity and origin of liquid hazardous waste streams. They realized that the hazards were create by a relatively small amount of material that could be separated out. Doing this meant that 5.7 million liters of water a year was no longer contaminated and could be used for recycling. It also created annual savings of $100,000 a year at a cost of only $26,000.
• The “Millroom Madness” team made a small process change so that a piece of fiberboard cut out of a speaker panel could be used as a shelf for the same cabinet, saving $15,000 a year at no cost.
• The “OOC/Fineliners” team addressed and resolved the gluing problems that were resulting in about twenty-one finished panels being sent to landfill. This saved around $250,000 a year.
• The “Mix-Ups” team researched coating guns and identified one that would meet its specifications and reduce waste. This reduced wastage of coatings by over 50,000 liters a year and had a two-month payback.

Total quality management has brought many benefits. But busness academic Richard Schonberger believes that there are many more still to be achieved. The barriers are continuing divides between internal functions and departments, and between companies and their suppliers and customers. He calls for much greater “strategic collaboration’ within and between companies to reduce these barriers and achieve even better customer service.

Once again eco-efiiciency is synergistic with this goal. It too seeks to reduce functional barriers by extending environmental initiatives into all areas of a company and to better integrate supply chains through life cycle management and design for environment.

1. Sustainable Production and Consumption

Agenda 21—the blueprint for sustainable development that emerged from the 1992 Rio Earth Summit—states:

Dealing with the unresolved challenges of sustainability now means shifting the emphasis beyond sites to industrial systems and society as a whole. This involves a trasition from the site-based approaches of pollution control, process integration, and whole facility (multimedia) planning. The emphasis is shifting to integrating environment throughout product chains—through ideas such as life cycle management and industrial ecology (in which one company’s wastes are used as inputs by others)—and the development of sustainable communities, cities, and regions. This means environment is not just a challenge for producers but for consumers, too.

A recent report by the WBCSD argues that business can best respond to the challenges of sustainable production and consumption by:

• Taking account of the entire life cycle of goods and services—design and engineering, purchasing and materials management, production, marketing, distribution, use, and waste management
• Applying the principles of eco-efficiency to create increased value for customers through the sustainable use of resources
• In its role as consumer, procuring and requesting products and services that have less environmental impact
• Making accurate, scientifically sound environmental information available to customers and the public so that they can make informed decisions about purchasing, use, and disposal.

Contrasting Brown and Green Priorities

Both green and brown proponents have reason to criticize many existing approaches to urban environmental managementOpens in new window, even if their priorities differ. At a superficial level, the brown and green agendas are in direct opposition to each other.

For example, the brown agenda would seem to call for more water use, more sewage connections, more waste collection, more urban residential land and more fossil fuel use (to replace smoky biofuels).

By ways of contrast, the green agenda would seem to call for water conservation, less water-borne sewerage, less waste generation, less urban expansion and less fossil fuel use.

While these potential contradictions should not be ignored, a review of existing policy problems indicates that the trade-offs need not be as sharp as such generalizations seem to imply.

Water

Urban water supply planning has been preoccupied historically with how to increase supplies to meet growing demand, given the physical and financial constraints of the city. By and large, demand has been assumed to be beyond the influence of water sector policies.

For those households and businesses connected to piped water systems, water is generally provided far below its full cost. For example, there is little incentive for users to conserve or encouragement to the industries that are the largest water users to recycle waste water or seek less water-intensive systems of production.

In some of the wealthier cities, subsidized water supply systems have brought major benefits to most of their populations, including a high proportion of their lower income populations.

For instance, there has been a considerable expansion in the proportion of the population with piped water supplies in many of the wealthier Latin American cities. In cities such as Sao Paulo, Belo Horizonte, Curtiba and Porto Alegre, most of the population receives piped water supplies to their homes (Jacobi, 1994; Mueller, 1995).

However, the proponents of the green agenda can rightly point to the serious consequences this often brings. The emphasis on increasing supply and keeping the price of water ‘affordable’ has resulted in major cities throughout Africa, Asia and Latin America overexploiting local water resources. For instance, in many coastal cities local aquifers have been overpumped, resulting in saltwater intrusion.

Overexploitation of underground water has also caused serious problems of subsidence for many buildings and sewage and drainage pipes in many cities (Damian, 1992; Postel, 1992). As local ground and surface water sources are overused (or polluted), meeting rising city demands generally means having to draw on ever more distant and expensive water resources.

This can be to the detriment of the populations (and often ecosystems) in the areas from which the water is drawn and with the higher water costs rarely reflected in higher prices for the largest city water users.

Proponents of the brown agenda often share this green agenda concern for unrealistically low water prices.

They can point to how the discrepancy between water utilities’ costs and revenues (from water sales and public subsidies) often inhibit expansion to low income areas and help to ensure that high proportions of the population in most cities remain unconnected to piped water systems.

Indeed, a combination of price controls and very limited public funds is a recipe for intragenerational inequities, with the subsidies that do exist flowing, along with the water, to those who least need them. Even for those low income groups who have access to connections, water supplies are often irregular or of poor quality or difficult to access – for instance, as dozens of households share each standpipe.

At least 300 million urban dwellers in Africa, Asia and Latin America remain without piped water supplies (WHO/UNICEF 1993) and tens of millions of those whose governments include in their statistics as having access to piped supplies still face inadequate, irregular or unsafe supplies which are often difficult to obtain (Satterthwaite, 1995; WHO, 1996).

While the water-related priorities of the green and brown agendas are different, their goals are not inherently incompatible. The often unmet minimum daily needs for health (about 30 litres per capita) amounts to about two flushes of a conventional toilet or one slowly dripping faucet.

The international standard of 150 litres per capita per day is only a small fraction of the typical usage in affluent cities in the North. Providing sufficient water for health needs is not the reason that many cities are overtaxing their water supplies.

Indeed, in many cities programmes encouraging water conservation and ensuring the better management and repair of piped water systems can often free up sufficient new supplies to allow regular piped water supplies to be extended to unserved households with no overall increase in water use. Intragenerational water inequities need not be solved by creating intergenerational or transboundary water inequities or vice versa.

It is politics and policy instruments, not physical imperatives, that create a stark trade-off between environmental health and ecological sustainability. Moreover, for most cities it is relatively clear whether environmental health or ecological sustainability ought to be the more pressing concern.

Sanitation

Proponents of the green and brown agendas can also point to problems in provision for sanitation, although, as in water supplies, they emphasize different problems. Here the conventional approach has been to promote water-borne sanitation systems, or steps in that direction, with the ultimate aim of providing all households with a flush toilet connected to a sewer.

Again, households obtaining connections receive considerable benefits, often at subsidized prices. But in most urban centres, sewage systems are characterized by significant inequities, relevant to both the brown and green agendas.

There are some cities in Latin America, Asia and parts of Africa where most of the population is adequately served by sewers. These are also generally the cities with low infant mortality rates and high life expectancies. However, the (generally) high unit costs of such systems also means that these cities are in the minority and very few cities have sewerage systems that serve most of their residents.

In many cities, sewers only serve a small proportion of the population (generally those in the more centrally located and wealthier areas). Most small urban centres have no sewer systems at all.

Estimates suggest that close to one-half the urban population of Africa, Asia and Latin America lack adequate provision for sanitation. Tens of millions of urban dwellers have no access to any form of sanitation or have only such poor quality, overcroweded public facilities that they have to resort to defecation in the open.

Proponents of the green agenda point to the environmental costs that conventional sewer systems can bring, especially the large volumes of water used to flush toilets and the problem of disposing of large volumes of sewage.

In Latin America, Asia and Africa only a small proportion of sewage is treated before disposal (WHO/UNICEF, 1993; WHO, 1996; Bartone et al, 1994). Untreated sewage is a major contributor to highly polluted water bodies in most cities, although it is generally difficult to determine its contribution relative to that of untreated industrial wastes and storm and surface run-off.

Fisheries are often damaged or destroyed by liquid effluents arising from cities. Thousands of people may lose their livelihood as a result as some of the largest cities are close to some of the world’s most productive fishing grounds.

Sewage systems also require large volumes of water to function and, as such, help to build into city sanitation systems high water demands. And although there are many examples of cities where some of the sewage is used for crop or fish production, the proportion of sewage used in such a way is limited by the sheer volume of such wastes and the difficulties (and costs) of transporting them to areas where they can be used productively.

Proponents of the green agenda often point to alternative sanitation systems that do not require sewers. These include many that bring ecological advantages such as requiring no water at all and some that are designed to allow the conversion of human wastes into safe fertilizers, allowing the recycling of nutrients in the food system.

These limit water demand and remove the problem of sewage disposal. Simple sewerless sanitation systems are also generally much cheaper than sewered systems, especially when account is taken of the cost of sewage treatment.

But here there is a serious potential conflict between the brown and the green agenda. Proponents of the brown agenda can point to the hundreds of millions of urban dwellers who currently rely on sanitation systems that do not use water—for instance, pit latrines—which bring serious health risks and often contaminate groundwater.

They often contaminate piped water supplies too, as inadequate maintenance of the piped water network means many cracks and leaks and water pressure is not constant (many city water supply systems have irregular supplies, with water available in many districts for only a few hours a day), so sewage seeps into the pipes.

Pit latrinesOpens in new window can be particularly hazardous in areas that regularly face floods as the pits become flooded and spread human excreta everywhere. There is also the problem in many cities of the lack of services to empty them (or the high price that has to be paid for doing so), while space constraints inhibit provision for solutions which limit this problem — for instance, twin vault systems or larger pits.

There is also the question of cost; in many cities, even a good quality pit latrine within their home (or plot) is an unattainable luxury for many low income households. This includes the large proportion of low income groups who rent accommodation and for whom there is no rented accommodation that they can afford with adequate provision for sanitation.

A stress on sewerless latrines may mean that the importance of adequate water supplies are forgotten (the latrines may need no water, but the households who use them certainly do, including the water needed for washing and personal hygiene).

A stress on dry latrines may also mean that the problem of removing waste water is forgotten; one of the key advantages of a sewer system is that it also conveniently and hygienically removes waste water other than sewerage after its use for cooking, laundry or washing.

Brown agenda proponents can also point to instances where the unit cost of installing sewers was brought down to the point where they no longer far beyond the price that low income households could pay (Orangi, 1995) and to community level sewer systems that do not require high levels of water use and with local treatment which greatly reduceds the ecological impact of the effluents on water bodies.

In assuming that all waterborne sanitation systems have unacceptable ecological impacts, there is a danger of promoting alternative sanitation systems that bring inconvenience, higher maintenance costs and greater environmental risks to the users, or of simply producing latrines that the population do not use.

In short, an excessive reliance on conventional water-borne sewerage intensifies the discrepancies between the brown and green agenda: as a tool of urban environmental management it can reduce intragenerational inequities, but typically at the cost of transboundary and intergenerational inequities.

Undoubtedly there are many instances where extending water-borne sewerage systems is justified, especially in high-density residential areas. There are also the measures that can be taken to reduce greatly the ecological disadvantages of such systems, as noted above.

However, proponents of both the brown and the green agendas can take issue with measures that subsidize sewerage systems for relatively affluent urban dwellers, diverting public funds from low income dwellers and imposing environmental costs on those living downstream and even future generations.