How to improve Environmental Impact Assessment (EIA) Effectiveness

John Kakonge                                                                                                                                                            

In this piece John Kakonge unpicks the necessary but unforced task of carrying out Environmental Impact Assessments for development programming.

Environmental impact assessment (EIA) is now a global tool for ensuring that environmental concerns are integrated into the development project or programme planning process. In Africa, for example, it had started to be widely used after African ministers of environment endorsed its operability at the ministerial conference (AMCEN) in 1995. The effectiveness of EIA has been mixed and, in some cases, has fallen below expectations. There are many reasons for this. Given that a great deal has already been written on this subject, this article will focus on only a few of the related concerns, namely, corruption and management, the quality of the EIA, follow-up mechanisms, capacity-building and communication of EIA results.

Corruption and mismanagement

One of the challenges in explaining why EIA has not been effective involves civil and corporate corruption, , and mismanagement of the EIA process. For example, Shepherd (2012) notes that in Thailand, the EIA practise is frequently seen as illegitimate and fraudulent and the resultant recommendations are often overlooked unless complaints are taken up in the form of legal challenges. Shepherd adds that many developers negotiate in an opaque manner, that is behind closed doors, and local residents are rarely consulted. Similarly, Ridl (2012) acknowledges that KwaZulu-Natal Wildlife, a conservation agency in South Africa that was formerly an organization with international standing and prestige, is now corrupt and its officials are arrogant and at times openly obstruct the EIA process by refusing to adhere to the statuary time frames for responses. In addition, in Nigeria, Yusuf (2008) indicates his disappointment that the EIA practice has become a showcase for corruption and infraction of the EIA Act of Nigeria. This is due to the regulatory authority, which is the Ministry of Environment, Housing and Urban Development, being not fully transparent in terms of providing relevant information and data. According to Yusuf, the Ministry exercises power arbitrarily and unlawfully, resulting in corruption and blithe disregard for EIA regulations. As explained by King (2009), many EIAs have come to be mismanaged and corrupt and are often used to “lull government agencies and the public alike into thinking all’s well with a proposed project, while serious environmental impacts are swept under the rug”. Conversely, King (2009) argues that, in the United States, the consulting firms that prepare EIAs and other related work often end up forming part of their clients’ planning teams and their clients are almost invariably the proponents of the very projects that they are analysing. Accordingly, their analyses and results often end up being influenced by this relationship. This is most unfortunate, as it makes a mockery of the whole exercise and represents a breach of contract.

Generally, developing countries are particularly prone to mismanagement and environmental impact often has a low priority in their national policy and the required skills are not readily available. As stipulated by Winbourne (2002), leaders from developing countries “would rather sacrifice clean air and water, bio-diversity and forests if they can turn them into profitable businesses and support short-term political agendas and medium-term economic benefits”. Such actions, however, are especially detrimental, in that they perpetuate the mismanagement of the EIA process while leaving the country vulnerable to corruption and unexpected environmental consequences in the future.

Instead, EIAs should be properly managed to ensure the health and future sustainability of the environment and its resources. As demonstrated by Abaza (2004), environmental impact management is not implemented solely for future reward; it can also cut current costs dramatically and improve stakeholder relations. Accordingly, if managed appropriately, EIAs can provide for a healthier environment and sustainable economic growth, benefiting both present and future generations.

Quality of EIA reports

A second reason for the continued ineffectiveness of the EIA process can be attributed to the low quality and inconsistency of the EIA reports. From the available information, it can be seen that the quality of EIA reports vary widely from project to project. According to UN/ECA et al. (2007), some EIA reports are of very low quality and may also be excessively long and hard to understand regardless of the reader’s level of education or expertise. For instance, the EIA for the Tana Delta Integrated Sugar Project in Kenya is 412 pages long and couched in turgid technical and scientific language, with extensive chemical equations, complex economic graphs and Latin binomial species nomenclature (Mumias, 2007). This kind of report is way beyond the comprehension of many local officials and leaders.

In addition, independent comments received from the Kenya Wetland Forum in 2008 noted that the Tana Delta EIA study had huge gaps in vital information relating to hydrology and biodiversity, thus calling into question the report’s scientific soundness and accuracy. Another example may be seen in India, in the 1996 EIA for the Allain Duhangan project which was limited to a technical assessment of geological and engineering components, with little discussion of impact, in addition to a number of other flaws (Martin, 2007). Interestingly, even with these limitations, the Government of India gave its approval for the project to go ahead. As revealed by Lawrence (2003), many EIA reports fail to provide explicit and comprehensive solutions to negative envrionmental effects. In addition, lack of transparency on how to mitigate and monitor the environmental impact of projects has resulted in widespread frustration, thus also causing “inconsistencies in EIA quality and an EIA process that can be difficult to understand or reproduce.”

There are many reasons behind the poor quality of EIA reports, but one major cause stems from the simple fact that too many EIA reports are prepared with limited environmental information and data. As noted by the World Bank (2012), “the need for vast numbers of EIAs coupled with an absence of baseline environmental data resulted in mass production of EIAs of poor quality and little value.” In this context, we can refer to the recent South African conference on the topic “Ten Years of EIA in South Africa”, which was specifically designed to review the effectiveness of EIAs and whether or not they are worth the investment (Komen, 2011). Although the conference recognized the inadequacies of many EIAs (e.g., lack of environmental resources and government support), it concluded that EIAs are marginally effective and still a worthy investment. The World Bank (2012) also revealed that poor EIA reports are the products of poorly trained EIA practitioners. Too many EIAs are being conducted by practitioners with limited capacity and environmental information, resulting in poor-quality reports.

Nevertheless, the aforementioned examples seem to illustrate that there is no consensus regarding the quality of EIA reports. As O’Riordan and Turner (1983) point out, “it is not easy to produce good environmentally sensitive proposals which are satisfactory to all reasonably minded people, let alone to placate the objections of the less reasonably minded”. Regardless of the various viewpoints and acknowledging that no EIA report will ever be entirely infallible – there will always be an element of subjectivity in their preparation – there is still a need for more training packages for environmental practitioners, for not only to upgrade the quality of EIA reports but also to make the EIA process more effective.

Follow-up mechanism

To continue to have EIAs that are useful and strategically significant, there must be adequate follow-up mechanisms. Lack of these mechanisms is currently one of the weaknesses of the EIA process. Once an EIA has been prepared and approved by government authorities, it is supposed to include an environmental management plan for follow-up implementation. There are several reasons why EIA management plans are not subsequently implemented, including allocation of funds by the proponents, lack of enforcement staff from the government to make sure that this is done, lack of quality information and data, and lack of government commitment to carry out the follow-up activities, given other competing priorities.

Interestingly, Harmer (2005) notes that, even in the United Kingdom, the effectiveness of EIA follow-up needs to be revisited. According to Harmer’s study, the EIA consultants whom she interviewed, confirmed that there were sufficient controls elsewhere to ensure that follow-up was performed and there was therefore no need to spend time and more money on gathering new data. Thus, Harmer concludes that in order to lend credibility to the follow-up of the EIA system, the follow-up process should be made mandatory. In a similar vein, a workshop of African experts on the effectiveness of the EIA process, organized by the United Nations Economic Commission for Africa (UN/ECA) along with other organizations, also concluded that the responsibility should rest not only with the regulatory body but also with the private sector, working as a team ( UN/ECA et al., 2007).

As observed by Morrison-Saunders (2007), monitoring and evaluating the impacts of a project are “essential for determining the outcomes of EIA. By incorporating feedback into the EIA process, follow-up enables learning from experience to occur. It can and should occur in any EIA system to prevent EIA being just a pro forma exercise” (Morrison-Saunders, 2007). The report on the African Experts Workshop on Effectiveness of EIA

Systems 2007 also explains that “effective and efficient follow-up requires the capability to easily verify environmental management conditions” (UN/ECA et al., 2007). For this reason, an effective follow-up process requires a certain level of skill and capacity, which can really only be obtained through experience. Thus, follow-up not only boosts the effectiveness of current projects but also ensures the heightened effectiveness of future projects in that they have the added value of learning and skill development.

Capacity-building

Many developing countries can draw on the services of professionals with knowledge of EIAs and other related areas. The challenge faced by these countries, however, is that, after completing college or university, some of these professionals gain no practical experience and are not involved in projects requiring the conduct of EIAs. According to the above-mentioned report on the African experts workshop on EIA effectiveness (UN/ECA et al., 2007), the capacity building problem cuts across the entire Africa region and, to address it, the experts recommend that EIA practitioners and experts should be accredited in consultation between the government and the private sector. The information provided by experienced and seasoned EIA experts should be referred by the government and regional bodies or organizations.

Moreover, in some cases, the national and regional EIA experts should team up with more experienced or seasoned experts from other regions in carrying out EIA reports. Case histories from Bangladesh and Guatemala show how many agencies have established registers of consultants, technical specialists and firms to carry out EIAs (World Bank, 2012). The World Bank (2012) adds that, in the above countries, the environmental agencies seek to issue certification or provide courses for EIA practitioners in order to improve the queality of EIAs. In fact, the Review of the Application of Environmental Assessments in Selected African Countries (2005) concluded, among other things, “Overcoming capacity constraints remains a major obstacle to the effective institutionalization and application of EIA in Africa”. The required capacity for the conduct of EIAs should include knowledge of procedures, analytical work, and technical and social skills. Consequently, the World Bank (2012) recognized that, “capacity building should be accompanied by practical experience development through integration and engagement of local expertise in undertaking EIA for large-scale development assistance projects”.

On the other hand, the capacity within the approving regulatory agencies in many of the developing countries is very important. A number of studies indicate, however, that many developing countries lack the capacity to review the EIA reports submitted to them and this in turn has resulted in a serious backlog. For example, in El Salvador, the World Bank (2012) noted that, in 2007, there was a backlog of 2,500 EIAs and this turned the EIA process into a bottleneck. Ideally, where the agencies do not have the capacity, funds should be made available to engage independent consultants to review these EIAs. In addition, the staff of these agencies should be upgraded to enable them to carry out their work faster and more effectively.

Communicating EIA results

In most African States, there are still challenges related to relaying EIA results to the stakeholders, communities and decision makers. Although the EIA reports are published for public inspection, this alone is not sufficient as a means of communicating the substance of the EIA and, as a consequence, the EIA loses its value and ends up being merely a fruitless legal requirement (Wood, 2003; Kakonge, 2006). There is no question that the communication of EIAs both horizontally and vertically plays a crucial role in reducing confusion, conflict and misconceptions about the project. This view is supported by Hughes (1999) who argues that communication of the EIA ensures that the EIA process addresses the main issues, harnesses local knowledge, improves the project’s capability to respond to the communities’ needs, reduces transaction costs (of conflict) and improves the acceptability of projects. The ineffective communication of EIAs in Africa can be primarily attributed to factors such as the complex and technical form in which the EIA reports are presented, language barriers, illiteracy, lack of availability of the reports for public review, and over-reliance on foreign experts in the EIA process (Wood, 2003, Kakonge, 2006). Admittedly, such reports and studies will never be mass circulated, or become best-sellers, yet attempts must be made to make them available to a wider audience.

One of the main impediments to the efficacy of EIAs in developing countries is the elaborate and technical manner in which the results are presented. For example, EIAs for complex technical or scientific projects such as infrastructure, industry (mining, oil and extraction) or hydropower production are presented in large volumes written in recondite scientific language. Unfortunately, this makes it difficult for both the local government authorities and the local communities to decipher them (Wood, 2003, Kakonge, 2006). A typical example is the 412-page EIA report on the Tana Delta Integrated Sugar Project described earlier (Mumias, 2007). The presentation of EIAs in such a technical form fails to communicate their message to readers who are not specialists and does not adhere to the United Nations Environment Programme principle of “providing (EIA) information in a form useful to decision makers” (UNEP, 1999).

Secondly, there are no formal requirements in most African countries for the systematic communication of EIAs to the stakeholders and the public (Wood, 2003; Omondi, 2008). Various strategies have been propounded in order to ensure effective communication in the EIA process. Wood (2003, p. 11) and Omondi (2008, p. 75) suggest the use of local experts to prepare EIA reports in Africa, as these experts would be able to engage in dialogue with local communities and leaders about the local impacts of the projects. This has clear advantages since local leaders and experts would have a better appreciation of the main issues and the reports would be more receptive to input from the communities. The EIA executive summary should also be provided to the media so that it can be published in the relevant local languages. The governmental environment agencies should also translate and post the relevant information by using printed media, newsletters, leaflets and/or booklets for the benefit of stakeholders and those members of the public (teachers, pastors, local counsellors, chiefs and others) who are literate. In order to reach the illiterate members of the community, however, it is important that other forms of mass media be used. These could include public debates, public enquiries, use of visual aids, billboards, television programmes, theatrical shows and radio broadcasts to reach as many people as possible (Robinson, 1996; Kakonge, 2006).

Conclusion

Clearly, the application of the EIA process and its practise vary from country to country and the process often serves solely to gain planning approval. Ironically, because of financial costs, there is no compliance at all with some of the EIA elements. For example, in Belize, there is no procedural provision to hold a public meeting, which limits the opportunity for the public to question or give comments on the project in question (World Bank, 2012). Public participation is, however, made possible through judicial review, but this does not lead to the revision of a decision. In the case of Jamaica, the National Resource Conservation Authority (NRCA) manages EIA procedures without formal requirements, meaning that NRCA has the discretion to decide whether an EIA is necessary or not (World Bank, 2012).

Moreover, the quality of EIA reports depends on whether the predictions contained in them can be monitored or audited. Regrettably, most of the available EIA reports are not easy to interpret and some suffer from information gaps. Although many training efforts have been made to upgrade the skills of EIA experts in developing countries, there has been little visible benefit obtained from this training, partly because of the heavy turnover of staff. Ways and means should be found to retain the available and experienced EIA experts. The regulatory ministry or agencies should provide incentive packages to EIA experts, including bonuses from planning permits and fines paid for those developments that do not meet the approval permit recommendations.

As mentioned earlier, developers or proponents are concerned more with the costs of EIA studies and the associated long delays before receiving approval from government authorities to proceed with the project. If the governments of developing countries are committed to the EIA process, they should build capacity in their regulatory agencies or ministries to ensure that the entire EIA is not only adhered to but it is also transparent, efficient and effective. In addition, once the results of EIA studies are available, the media should enter the process as a stakeholder and help to have the summaries of these studies translated into the necessary official and local languages and communicated to the public.

In short, EIAs are inevitably costly in terms of both money and time but, regardless of this, the process should be taken seriously and should not be compromised. At the same time, there is no pressure to carry out the EIA if it is not a legal requirement, including enforcement responsibility. Be that as it may, as recommended by the International Association for Impact Assessment/Institute of Environmental Assessment (IAIA/IEA 1999), there is a need to develop best-practice examples of EIAs, and the entire process should, among other things, be practical, cost effective, efficient, focused, participatory, interdisciplinary and transparent. Considerations well worth taking on board by both governments and practitioners alike.

Thanks http://www.globalpolicyjournal.com

References

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Assessment: Towards an Integrated Approach.” UNEP. Available from

http://www.unep.ch/etu/publications/textONUbr.pdf

ECA, CLEAA, IUCN EARO and The Cadmus Group. (2007). “African Experts Workshop

on Effectiveness of Environmental Impact Assessment Systems.” Available from

http://www.encapafrica.org/documents/cleaa/African_Experts_Workshop_on_Review_of_Effectiveness_of_EIA_Systems_April_2007.pdf

Harmer, C. (2005). “Is Improving the Effectiveness of Environmental Impact Assessment

in the UK Dependent on the Use of Follow-up? Views on Environmental Consultants.” Available from

http://www.uea.ac.uk/env/all/teaching/eiaams/pdf_dissertations/2005/Harmer_Clare.pdf

Hughes, Ross (1999). “Environmental Impact Assessment and Stakeholder Involvement.”

International Institute for Environmental Development. Available from

http://pubs.iied.org/pdfs/7789IIED.pdf

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Assessment. (1999). Available from

http://www.iaia.org/publicdocuments/specialpublications/Principles%20of%20IA_web.pdf

Kakonge, J. O. (2006). “Environmental Planning in Sub-Saharan Africa: Environmental Impact Assessment at Crossroads.” Yale School of Forestry & Environmental

Studies, United States. Available from

http://environment.research.yale.edu/documents/downloads/vz/wp_9_africa_eia.pdf

King, T. (2009). “The Corruption of Cultural Resource Management and Environmental

Impact Assessment and What to Do about It.” Rowman and Littlefield Publishing Group. Available from http://rowmanblog.typepad.com/rowman/2009/01/the-corruption-of-cultural-resource-management-and-environmental-impact-assessment-and-what-to-do-ab.html

Komen, M. (2011). “Review of Environmental Assessment & Management.” Available

from http://www.custodianproject.co.za/index.php?option=com_k2&view=item&id=8:strategy-for-environmental-assessment-management

Lawrence, D. (2003). “Environmental Impact Assessment: Practical Solutions to Recurrent

Problems.” Available from

http://www.wosco.org/books/Ecology/Lawrence_D.P.,Lawrence%20B.Environmental_Impact.pdf

Martin, T. (2007). “Muting the Voice of the Local in the Age of the Global: How

Communication Practices Compromised Public Participation in India’s Allain Dunhangan Environmental Impact Assessment.” Available from

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Mumias, S. (2007). “Environmental Impact Assessment Study Report for the Proposed

Tana Integrated Sugar Project in Tana River and Lamu Districts, Coast Province,

Kenya.” Available from

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Omondi, N. O. (2008). “Improving Kenya’s Environmental Impact Assessment and Strategic Environmental Assessment for Sustainable Development.” Available

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Ridl, J. (2012). “Ezemvelo KZN Wildlife on Its Knees.” The Nation. Available from

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Robinson, J. R., Ross, A., Walton, W. and Rothnie, J. (1996). “Public Access to

Environmental Information: A Means to What End?” Journal of Environmental Law (8)1:19-42.

Shepherd, J. (2012). “One Way or Another, EIA Process Must Change.” The Nation, 26 November. Available from http://www.nationmultimedia.com/opinion/One-way-or-another-EIA-process-must-change-30195006.html

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to Green: A Sourcebook of Pollution Management Policy Tools for Growth and Competitiveness. Available from http://siteresources.worldbank.org/ENVIRONMENT/Resources/Getting_to_Green_web.pdf

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Yusuf, T. A. (2008). “The Environmental Impact Assessment Practice in Nigeria: The Journey So Far.” Available from http://www.nigeriansinamerica.com/articles/3105/1/The-Environmental-Impact-Assessment-Practice-In-Nigeria-The-Journey-So-Far-/Page1.html

Computer Recycling

Computers are an integral part of daily life, but as they and other electronic devices become obsolete more and more quickly, we're faced with the growing problem of disposing of all our e-waste properly. A UN initiative called StEP (Solving the E-waste Problem) estimates that by 2017 there will be 65.4 million tonnes of e-waste generated globally every year. And Australians contribute more than their fair share of that, with each of us generating 25 kilos a year.
e-waste, discarded computer equipment comprises monitors, printers, hard drives and circuit boards. Such items should on no account be thrown out with your household rubbish because they contain toxic substances, and are effectively hazardous waste. E-waste often ends up in the developing world, and the UN’s Environment Programme is alarmed by the amount of electronic goods which is improperly disposed of overseas. There is increasing concern about the pollution caused by hazardous chemicals and heavy metals in Africa, Asia and South America.

What’s in my PC?
Material	Proportion
Plastic Ferrous metals Non-ferrous metals Electronic boards Glass	23% 32% 18% 12% 15%

A single computer can contain up to 2kg of lead, and the complex mixture of materials make PCs very difficult to recycle.

Electronic products thrown into landfill leak toxic materials into soil and water, resulting in contamination of the food chain. Additionally, rare and non-renewable materials are wasted instead of being re-used. New government-backed recycling efforts have been put in place across most of Australia to meet the national e-recycling target of 80 per cent by the end of 2021.

Where to donate your computer to be refurbished in Australia

If your computer's not too old and still in good nick, there are some community recycling initiatives that refurbish computers and offer them to nonprofit groups.
Some Technical Aid to the Disabled organisations are registered refurbishers, while others may accept donations on a case-by-case basis. Contact your state or territory's branch and ask if they accept computer donations.

Other computer refurbishers include:

• Business to Community Recyclers (Vic) 
• Computerbank (Vic)
• Computerbank (Qld)
• Computerbank (Newcastle)

Planet Ark's Recycling Near You website lets you search by area or product to find a local recycling centre.
Give Now has a list of places that can refurbish computers nationally.

Why is e-waste so bad?

Toxic materials and hazardous chemicals are often used in the manufacture of computer and electronic equipment, and when parts are disposed of improperly these chemicals can leach into soil and water and lead to environmental contamination.
To prevent hazardous chemicals from leaking into soil and storm water drains, computer and electronic equipment must not be thrown out with your rubbish. Also avoid leaving computer waste standing outside for long periods, particularly during wet weather.
While manufacturing methods are said to have improved, many companies continue to use toxic chemicals and primary materials over recycled parts.

What chemicals are in my e-waste?

The roll call of toxic materials is long and includes:

• Mercury (used in LCD screens)
• Lead 
• Cadmium (used in batteries) - known to cause cancer in humans
• Beryllium (found in motherboards) - a known carcinogen and can cause lung disorders if inhaled
• Chromium (used to prevent corrosion) - can cause liver and kidney damage as well as skin reactions
• Antimony - can cause gastrointestinal disorders
• Arsenic - a known carcinogen
• Brominated flame retardants (used in circuit boards, cables and plastic casing) and polyvinyl chloride (PVC) (used in casing and connectors) - toxic when burned and can collect in the environment.

What are solid waste fuels?

Waste-to-energy is an important part of the waste industry in Europe. Significant demand for heat means efficient and tightly controlled waste incinerators are common. However, Australia lacks an established market, with low levels of community acceptance and no clear government policy encouraging its uptake.

But the federal announcement, coupled with an uptake in state funding, a New South Wales parliamentary inquiry and several new projects in the pipeline, signals a growing interest in waste-to-energy and waste-to-fuels.

But what is solid waste fuel, and where does it fit in a sustainable future for Australian waste management?

What are solid waste fuels?

Australians are becoming more wasteful. The amount of rubbish we produce is growing more rapidly than both our population and our economy.

Recycling has been the main approach for recovering resources and reducing landfill over the past 20 years, but a lot more needs to be done.

One part of the solution is “waste-to-energy”: using a range of thermal or biological processes, the energy embedded in waste is captured, making it available for the direct generation of heat and electricity, or for solid fuel production (also known as “processed engineered fuel”).

Waste-to-fuel plants produce fuels from the combustible (energy-rich) materials found in waste from households and industry. Suitable materials include non-recyclable papers, plastics, wood waste and textiles. All of these typically end up in landfill.

These materials are preferably sourced from existing recycling facilities, which currently have to throw out contaminated matter that can’t be recycled.

Solid waste fuels are produced to specified qualities by different treatment methods. These include drying, shredding, and compressing into briquettes or fuel pellets. Fuels can be specifically tailored for ease of transportation and for different uses where industrial heat is required. This make them suitable alternatives to fossil fuels.

What are solid waste fuels used for?

As a replacement for coal and gas, solid waste fuel can be burned to generate electricity with a smaller carbon footprint than fossil fuels.

In addition to the power sector, other industries requiring high-temperature heat use solid waste fuels – for example, in cement works in Australia and around the world. There may also be scope to expand their use to other energy-intensive industries, such as metals recycling and manufacturing industrial chemical products.

What are the key benefits?

The primary environmental benefit of solid waste fuel comes from the reductions in landfill emissions and fossil fuel use.

Biodegradable carbon sources decompose in landfill, creating methane. This is a greenhouse gas with a warming potential 25 times that of carbon dioxide. Technology already exist for capturing and converting landfill gases to energy, but waste-to-fuel is a complementary measure that limits landfill in the first instance.

Waste-derived fuel can also have a smaller carbon footprint than fossil fuels. This depends on the carbon content of the fuel, and whether it is derived from biological sources (such as paper, wood or natural fibres). Even though carbon dioxide is emitted when the fuel is burned, this is partly offset by the carbon dioxide captured by the plants that produced the materials in the first place.

In these cases, solid waste fuels are eligible for renewable energy certificates. More advanced closed-loop concepts achieve even better carbon balances by capturing the carbon dioxide released when the fuel is used. This can used for other processes that require carbon dioxide as an input, such as growing fruit and vegetables.

Further environmental benefits can come from the management of problem wastes such as treated timbers, car tyres, and e-plastics. Converting them into fuel prevents the leaching of harmful substances into the environment, and other potential problems.

What are the challenges?

Communities are legitimately concerned about energy recovery from waste owing to public health risks. Without appropriate emission control, burning solid fuel can release nitrous oxides, sulphur dioxides, particulate matter and other harmful pollutants. But, with solid regulation and the best available pollution-control technology, these emissions can be managed.

The recycling industry is also worried that energy recovery has the potential to undermine existing recycling by diverting waste flows. Famously, solid waste fuel is so important to Sweden it actually imports garbage from other European countries.

These challenges point to the importance of investing in the appropriate infrastructure at the right size, and creating regulations that balance the needs of existing recycling processes. With careful planning, waste-to-fuel can be an important part of a broad strategy for transitioning towards a zero-landfill future. 

The cement industry, in cooperation with the waste management sector, has developed pre-treatment practices, such as screening, blending and shredding, to produce suitable materials from waste that meet cement kiln requirements. This close cooperation with the waste industry allows selected waste streams to be converted for use in cement kilns. Acceptance of these materials requires strict compliance with the agreed specifications. Examples of waste used by CEMBUREAU members include used tyres, solid recovered fuels, used oils, animal meal, sewage sludge, foundry sands, fly ashes and filter cakes. Extensive monitoring of all the input materials is a feature of modern cement production. This high standard of quality control ensures our cement products are manufactured in compliance with European Cement Standards.
The alternative materials are fully consumed in the cement clinker manufacturing process. The combustible part provides the heat needed for the process and the mineral part is transformed into cement. In this way co-processing in the cement industry provides society with significant benefits: safe and efficient local waste treatment options, diversion of waste from landfill, energy recovery, recycling of discarded resources, district heating and all using existing facilities and infrastructure.
thanks
 http://amp.weforum.org/

What is Wastewater Treatment

 

The principal objective of wastewater treatment is generally to allow human and industrial effluents to be disposed of without danger to human health or unacceptable damage to the natural environment. Irrigation with wastewater is both disposal and utilization and indeed is an effective form of wastewater disposal (as in slow-rate land treatment). However, some degree of treatment must normally be provided to raw municipal wastewater before it can be used for agricultural or landscape irrigation or for aquaculture. The quality of treated effluent used in agriculture has a great influence on the operation and performance of the wastewater-soil-plant or aquaculture system. In the case of irrigation, the required quality of effluent will depend on the crop or crops to be irrigated, the soil conditions and the system of effluent distribution adopted. Through crop restriction and selection of irrigation systems which minimize health risk, the degree of pre-application wastewater treatment can be reduced. A similar approach is not feasible in aquaculture systems and more reliance will have to be placed on control through wastewater treatment.

Before you go on to read about the individual technologies discussed later in this document, it is helpful to understand some of the basics of wastewater treatment. You will see terms like BOD, total suspended solids, nitrification, and denitrification frequently when discussing wastewater treatment. It is important to understand what each of these terms mean and how each relates to the wastewater treatment process. Some very basic processes of wastewater treatment are also briefly discussed. If you understand the theory behind these basic treatment processes it is easy to see how and why the processes are applied in the various alternative technologies discussed later.

Basic Constituents of Wastewater

Biochemical oxygen demand

One of the most commonly measured constituents of wastewater is the biochemical oxygen demand, or BOD. Wastewater is composed of a variety of inorganic and organic substances. Organic substances refer to molecules that are based on carbon and include fecal matter as well as detergents, soaps, fats, greases and food particles (especially where garbage grinders are used). These large organic molecules are easily decomposed by bacteria in the septic system. However, oxygen is required for this process of breaking large molecules into smaller molecules and eventually into carbon dioxide and water. The amount of oxygen required for this process is known as the biochemical oxygen demand or BOD. The Five-day BOD, or BOD₅, is measured by the quantity of oxygen consumed by microorganisms during a five-day period, and is the most common measure of the amount of biodegradable organic material in, or strength of, sewage.

BOD has traditionally been used to measure of the strength of effluent released from conventional sewage treatment plants to surface waters or streams. This is because sewage high in BOD can deplete oxygen in receiving waters, causing fish kills and ecosystem changes. Based on criteria for surface water discharge, the secondary treatment standard for BOD has been set at 30 mg BOD/L (i.e. 30 mg of O₂ are consumed per liter of water over 5 days to break down the waste).

However, BOD content of sewage is also important for septic systems. Sewage treatment in the septic tank is an anaerobic (without oxygen) process; in fact, it is anaerobic because sewage entering the tank is so high in BOD that any oxygen present in the sewage is rapidly consumed. Some BOD is removed in the septic tank by anaerobic digestion and by solids which settle to the bottom of the septic tank, but much of the BOD present in sewage (especially detergents and oils) flows to the leaching field. Because BOD serves as a food source for microbes, BOD supports the growth of the microbial biomat which forms under the leaching field. This is both good and bad. On the one hand, a healthy biomat is desired because it is capable of removing many of the bacteria and viruses in the sewage so that they do not pass to the groundwater. The bacteria in a healthy biomat also digest most of the remaining BOD in the sewage. Too much BOD, however, can cause excessive growth of bacteria in the biomat. If the BOD is so high that all available oxygen is consumed (or if the leaching field is poorly aerated, as can be the case in an unvented leaching field located under pavement or deeply buried) the biomat can go anaerobic. This causes the desirable bacteria and protozoans in the biomat to die, resulting in diminished treatment of the sewage. Low oxygen in the biomat also encourages the growth of anaerobic bacteria (bacteria which do not require oxygen for growth). Many anaerobic bacteria produce a mucilaginous coating which can quickly clog the leaching field. Thus, excess BOD in sewage can cause a leaching field to function poorly and even to fail prematurely.

Many of the enhanced treatment technologies discussed later in this document were designed specifically to reduce BOD in treated sewage. BOD removal can be especially important where sewage effluent flows to a leaching field in tight soils. Tight soils are usually composed of silts and clays (particle size < 0.05 millimeter). These small soil particles are tightly packed and the pore space between them is small. Reducing BOD means that the sewage will support the growth of less bacteria and therefore the effluent will be better able to infiltrate tight soils. Many enhanced treatment technologies that remove BOD were designed specifically to enhance disposal of effluent in tight silt or clay soils.

BOD is fairly easy to remove from sewage by providing a supply of oxygen during the treatment process; the oxygen supports bacterial growth which breaks down the organic BOD. Most enhanced treatment units described incorporate some type of unit which actively oxygenates the sewage to reduce BOD. This unit is often located between the septic tank and the leach field. Or, it can be located within the septic tank in a specific area where oxygen is supplied. Reduction of BOD is a relatively easy and efficient process, and results in sewage of low BOD flowing to the leaching field. It is important to note, however, that low BOD in sewage may result in a less effective biomat forming under the leaching field.

It is also important to note that BOD serves as the food source for the denitrifying bacteria which are needed in systems where bacterially-mediated nitrogen removal takes place. In these situations BOD is desired, as the nitrification/denitrification process cannot operate efficiently without sufficient BOD to support the growth of the bacteria which accomplish the process.

Total suspended solids

Domestic wastewater usually contains large quantities of suspended solids that are organic and inorganic in nature. These solids are measured as Total Suspended Solids or TSS and are expressed as mg TSS/ liter of water. This suspended material is objectionable primarily because it can be carried with the wastewater to the leachfield. Because most suspended solids are small particles, they have the ability to clog the small pore spaces between soil grains in the leaching facility. There are several ways to reduce TSS in wastewater. The simplest is the use of a septic tank effluent filter, such as the Zabel filter (several other brands are available). This type of filter fits on the outlet tee of the septic tank. It is made of PVC with various size slots fitted inside one another. The filter prevents passage of floating matter out of the septic tank and, as effluent filters through the slots, fine particles are also caught. Many types of alternative systems are also able to reduce TSS, usually by the use of settling compartments and/or filters using sand or other media.

Total nitrogen

Figure 1. The Nitrogen Cycle

Nitrogen is present in many forms in the septic system. Most nitrogen excreted by humans is in the form of organic nitrogen (dead cell material, proteins, amino acids) and urea. After entering the septic tank, this organic nitrogen is broken down fairly rapidly and completely to ammonia, NH₃, by microorganisms in the septic tank. Ammonia is the primary form of nitrogen leaving the septic tank. In the presence of oxygen, bacteria will break ammonia down to nitrate, NO₃. In a conventional septic system with a well aerated leaching facility, it is likely that most ammonia is broken down to nitrate beneath the leaching field.

Nitrate can have serious health effects when it enters drinking water wells and is consumed. Nitrate and other forms of nitrogen can also have deleterious effects on the environment, especially in coastal areas where excess nitrogen stimulates the process known as eutrophication. For this reason, many alternative technologies have been designed to remove total nitrogen from wastewater. These technologies use bacteria to convert ammonia and nitrate to gaseous nitrogen, N₂. In this form nitrogen is inert and is released to the air.

Biological conversion of ammonia to nitrogen gas is a two step process. Ammonia must first be oxidized to nitrate; nitrate is then reduced to nitrogen gas. These reactions require different environments and are often carried out in separate areas in the wastewater treatment system.

The first step in the process, conversion of ammonia to nitrite and then to nitrate, is called nitrification (NH₃ NO₂+ NO₃). The process is summarized in the following equations:

Nitrification Process

It is important to note that this process requires and consumes oxygen. This contributes to the BOD or biochemical oxygen demand of the sewage. The process is mediated by the bacteria Nitrosomonas and Nitrobacter which require an aerobic (presence of oxygen) environment for growth and metabolism of nitrogen. Thus, the nitrification process must proceed under aerobic conditions.

The second step of the process, the conversion of nitrate to nitrogen gas, is referred to as denitrification. This process can be summarized as:

Denitrification

This process is also mediated by bacteria. For the reduction of nitrate to nitrogen gas to occur, the dissolved oxygen level must be at or near zero; the denitrification process must proceed under anaerobic conditions. The bacteria also require a carbon food source for energy and conversion of nitrogen. The bacteria metabolize the carbonaceous material or BOD in the wastewater as this food source, metabolizing it to carbon dioxide. This in turn reduces the BOD of the sewage, which is desirable. However, if the sewage is already low in BOD, the carbon food source will be insufficient for bacterial growth and denitrification will not proceed efficiently.

Figure 2. Denitrification

Clearly, any wastewater treatment unit that is going to remove nitrogen by the nitrification/denitrification process must be designed to provide both aerobic and anaerobic areas so that both nitrification and denitrification can proceed. As you look at the nitrogen removal technologies discussed later in this document, you will see how various designs have attempted to solve this problem in some unique and interesting ways.

Phosphorus

Phosphorus is a constituent of human wastewater, averaging around 10 mg/liter in most cases. The principal forms are organically bound phosphorus, polyphosphates, and orthophosphates. Organically bound phosphorus originates from body and food waste and, upon biological decomposition of these solids, is converted to orthophosphates. Polyphosphates are used in synthetic detergents, and used to contribute as much as one-half of the total phosphates in wastewater. Massachusetts has banned the sale of phosphate-containing clothes washing detergent, so phosphorus levels in household wastewater have been reduced significantly from previous levels. Most household phosphate inputs now come from human waste and automatic dishwasher detergent. Polyphosphates can be hydrolyzed to orthophosphates. Thus, the principal form of phosphorus in wastewater is assumed to be orthophosphates, although the other forms may exist. Orthophosphates consist of the negative ions PO₄^3-, HPO₄^2-, and H₂PO₄^–. These may form chemical combinations with cations (positively charged ions).

It is unknown how much phosphorus is removed in a conventional septic system. Some phosphorus may be taken up by the microorganisms in the septic system and converted to biomass (of course, when these microorganisms die the phosphorus is re-released, so there really is no net loss of phosphorus by this mechanism). Any phosphorus which is removed in the septic system probably is removed under the leaching facility by chemical precipitation.

At slightly acidic pH (as is found in the soils of Cape Cod and most of New England), orthophosphates combine with tri-valent iron or aluminum cations to form the insoluble precipitates FePO₄ and AlPO₄.

Insoluble Precipitates

Domestic wastewater usually contains only trace amounts of iron and aluminum. However, the sandy soil of Cape Cod frequently contains significant amounts of iron bound to the surface of sand particles. It is likely that this iron binds with phosphorus and causes some removal of total phosphorus below the leaching facility.

One caveat must need be added here. If the soil below the leaching facility becomes anaerobic, iron may become chemically reduced (changed to the Fe²⁺ form), which is soluble and able to travel in groundwater. In this case, the iron phosphate compounds may breakdown and phosphorus may also become soluble. Anaerobic conditions under the leaching facility can occur when the leaching facility is not well aerated, when there is a small vertical separation to groundwater, or when BOD in the sewage is so high that all oxygen present is depleted to oxidize BOD. In the conditions found on Cape Cod, the best method for maximizing phosphorus removal is probably to locate the leaching facility well above groundwater (>5 feet vertical separation) thereby providing a well-aerated area under the leaching field. To date, no alternative on-site technologies are capable of significant phosphorus removal. However, many are trying to achieve this goal and it is likely that within the next few years we may begin to see some technologies that are successful at phosphorus removal.

Basics of Sewage Treatment

The treatment of sewage is largely a biochemical operation, where chemical transformations of the sewage are carried out by living microorganisms. Different environments favor the growth of different populations of microorganisms and this in turn affects the efficiency, end products, and completeness of treatment of the sewage. Sewage treatment systems, whether they are standard septic systems or more advanced treatment technologies, attempt to create specific biochemical environments to control the sewage treatment process.

Three basic types of biochemical transformations occur as sewage is treated. The first is the removal of soluble organic matter. This is composed of dissolved carbon compounds such as detergents, greases, and body wastes, which make up much of the BOD content of the sewage. The second is the digestion and stabilization of insoluble organic matter. These are the sewage solids, such as body wastes and food particles, which make up the remainder of the BOD. The third is the transformation of soluble inorganic matter such as nitrogen and phosphorus.

The two major biochemical environments in which sewage treatment is carried out are termed aerobic and anaerobic environments. An aerobic environment is one in which dissolved oxygen is available in sufficient quantity that the growth and respiration of microorganisms is not limited by lack of oxygen. An anaerobic environment is one in which dissolved oxygen is either not present or its concentration is low enough to limit aerobic metabolism. The biochemical environment has a profound effect upon the ecology of the microbial population which treats the sewage. Aerobic conditions tend to support entire food chains from bacteria up to rotifers and protozoans. These microbes beak down organic matter using many metabolic pathways based on aerobic respiration with carbon dioxide as the main end product. Anaerobic conditions favor the growth of primarily bacterial populations and produce a different variety of end products, discussed below.

Anaerobic Digestion of Sewage

Solids in sewage contain large amounts of readily available organic material that would produce a rapid growth of microorganisms if treated aerobically. Anaerobic decomposition is able to degrade this organic material while producing much less (approximately one-tenth) biomass than an aerobic treatment process. The principal function of anaerobic digestion is to stabilize insoluble organic matter and to convert as much of these solids as possible to end products such as liquids and gases (including methane) while producing as little residual biomass as possible. It is for this reason that sewage treatment in a conventional septic tank is designed to be an anaerobic process. Organic matter treated anaerobically is not broken down to carbon dioxide; final end products are low molecular weight acids and alcohols. These may be further converted anaerobically to methane or, if sent to an environment (such as the leaching field) where aerobic bacteria are present, further broken down to carbon dioxide. Anaerobic digestion of organic matter is also a much slower process than aerobic digestion of organics and where rapid digestion of organic matter is needed an aerobic treatment process must be used.

As discussed above, an anaerobic environment is also necessary for denitrification, as the bacteria which carry out this process require anaerobic conditions to reduce nitrate to nitrogen gas. Many nitrogen-removal technologies are designed to provide an anaerobic treatment chamber as part of the treatment process.

Aerobic Treatment of Sewage

As the name implies, this process utilizes aerobic bacteria to break down sewage. The principal advantage of aerobic sewage treatment is its ability to rapidly and completely digest sewage, reducing BOD to low levels. Most of the alternative treatment technologies discussed in this document utilize some form of aerobic treatment of sewage. This process is used primarily to reduce BOD and, in systems that remove nitrogen, to nitrify the waste so that it can later be denitrified. Because the BOD in raw sewage is usually high, and available oxygen is rapidly consumed by the sewage, most aerobic treatment units are designed to supply supplemental oxygen to the sewage to keep the treatment process aerobic. Some units, such as the JET Aerobic system, use extended aeration to more completely digest the sewage solids. Most aerobic treatment units provide some type of artificial medium as a surface on which the sewage- digesting bacteria can grow. A variety of basic designs can be used for this purpose.

Attached culture systems are designed so that wastewater flows over microbial films attached to surfaces in the treatment unit. The surface area for growth of the biofilm is increased by placing some type of artificial media, such as foam cubes or various convoluted plastic shapes with high surface area, in the treatment chamber. This artificial media may sit in the treatment chamber with the effluent circulating through it, usually with supplemental air supplied so that treatment remains aerobic. This is the principal used by the JET Aerobic and FAST systems. Or, the media may be located outside the treatment chamber and wastewater is passed over the biofilm in intermittent doses. These designs are known as trickle filters and are one of the most common types of on-site treatment unit using attached cultures. Some technologies which employ trickle filters, and which are discussed in more detail later, include the Bioclere, Orenco trickle filter, and the Waterloo biofilter. Intermittent and recirculating sand filters, while located in separate chambers, can also be considered a form of trickle filter where sand is used as the media for bacterial growth. Because attached culture systems are generally aerobic, a complex community of microorganisms, including aerobic bacteria, fungi, protozoa, and rotifers, develops. These systems are capable of efficient removal of BOD. Being aerobic they will support the growth of nitrifying bacteria and can be used to nitrify wastewater, the first step in nitrogen removal.

Other aerobic systems utilize suspended culture of microorganisms to aerobically treat the sewage. This type of treatment assumes that a resident population of bacteria are present in the solids and sludge in the treatment unit; vigorous mixing of the sewage in the treatment compartment causes these bacteria to stay in suspension where they can aerobically digest the sewage. This principle is used by the Cromaglass and Amphidrome units as part of part of the batch reactor treatment process. It is also used in many large municipal sewage treatment plants.

The activated sludge process is similar to suspended culture in that it also utilizes the resident population of bacteria in the solids and sludge in the treatment unit, again, usually by mixing of the sewage so that the bacteria are kept in suspension. In the activated sludge process, however, there are usually periods where mixing ceases, and the solids are allowed to settle. It is then assumed that the sludge will become anaerobic and the anaerobic bacteria in the sludge will denitrify the waste. This is the principle used by batch reactors. As the name implies, batch reactors treat sewage in batches. A batch of sewage is allowed to settle so that solids are removed; the batch of sewage is then aerated and mixed and then allowed to settle for a period of anaerobic treatment (this process may be repeated several times on the same batch). When treatment is complete, the finished batch of sewage is pumped out and the next batch enters the unit to begin treatment. The Cromaglass and Amphidrome systems are examples of batch reactors.
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References

Grady, C.P. Leslie and Henry C. Lim, 1980. Biological Wastewater Treatment. Marcel Decker, Inc., N.Y

Peavey, Howard S., Donald R. Rowe, and George Tchobanoglous, 1985. Environmental Engineering, McGraw Hill Inc., N.Y.