3.1.1 The United Nations Sustainable Development Goals

After the United Nations (UN) Millennium Development Goals ended in 2015, the UN established 17 sustainable development goals (SDGs) for the next 15 years. SEE design principles provide a systematic approach to design EEIS for sustainable sanitation and wastewater management to reach the UN goals by 2030. SDGs have different meanings for developed versus developing countries due to their economic development stages. SEE designers should play a critical role in achieving the 17 SDGs. In the international development agenda, poverty eradication, ending hunger, and healthy living are the first three major priorities. For developed countries, however, combating climate change, renewable energy, and sustainable consumption and production are three top priorities. To switch to more sustainable economy and growth pathway, the goal of greater equality and to better protect oceans and terrestrial ecosystems are secondary aims in the developed countries. These 17 SDGs have been ranked as different priorities for developed versus developing countries as shown in Table 3.3 with typical projects for SEE designer.

3.2.1 Challenges

Human social and economic activities have enormous negative impacts on the global environment due to waste and fossil fuels that are proportional to a country’s economic scale measured by gross domestic product (GDP). Annual GDP is the total market value of all final goods and services produced in a country in a given year. Due to different stages of population and economic growth, current GDP ranking may very likely change as predicted in Table 3.4.

In calculating GDP, if market exchange rates are used, it is referred to as a nominal method. On the other hand, purchasing power parity (PPP) is used to compare economies and the incomes of people by adjusting for differences in prices in different countries. The International Monetary Fund (IMF) outlook in October 2016 projected the GDPs of 190 countries/economies at current prices (US dollars) for 2016 and 2020. Gross world product in 2016 is projected at $75.21 trillion, and its GDP in terms of PPP is forecasted at $119.1 trillion. The global economy is 1.58 times greater in PPP terms than in nominal terms. The United States and China are the largest economies in either nominal or PPP terms, respectively. In US dollar terms, the United States shares 24.7% of global wealth. However, in PPP China ranks the first and shares 17.9%. In nominal data, 15 economies have a GDP above $1 trillion, 61 have above $100 billion, and 176 have above $1 billion. The top 5 economies account for approximately 54.28%, top 10 accounts for approximately 67.44 %, while the 153 lowest ranked constitutes only 10% of total. In PPP data, 24 economies, which are 9 more than nominal, have GDP above $1 trillion. Eighty‐one economies have GDP greater than $100 billion and 181 have greater than $1 billion. The top 5 economies add up to over 48% of world’s economy, the top 10 to over 61%, and the top 20 to over 75%. Table 3.5 shows that major growth of GDP would come from developing countries such as Brazil, Russia, India, and China (BRIC) with a total GDP of $66.694 trillion in 2030.

Table 3.5 can be used to divide the top GDP countries into two groups using the PPP in terms of international dollar (ID). The developed countries include the United States, Japan, Germany, and the United Kingdom (AJGE) with a total GDP of $33.79 trillion. The emerging economies include Brazil, India, Indonesia, Russia, China, and Mexico (BRIICM) with a total GDP of 75.79 ID. According to these GDP predictions, major opportunities for SEE designers to make differences exist in BRIICM because there are many EEISs to be designed and built. In the developed countries such as AJGE, retrofitting WWTPs might be the biggest challenging market to make EEIS sustainable.

In the past, energy and materials used to produce GDP were mostly nonrenewable. About 86% of energy and 96% of organic chemicals came from depleting fossil fuels such as coal, oil, and gas. The United Nations Environmental Protection (UNEP) estimated that it may take about 50–80 years for mankind to reach a sustainable level by slowing climate change, preventing pollution, and renewing natural resources from 2015. Over $70 billion of biodiversity is lost due to ecological degradation and water scarcity annually (UNEP, 2016). In terms of gigatons CO₂ equivalent (GtCO₂e), current global GHG 42 GtCO₂e per annum, which is five times higher than the Earth can absorb (WWF), is due to human activities. Figure 3.2 shows the top 10 percentages of CO₂ emissions by country.

3.2.2 Opportunities

Two of the seventeen UN SDGs are universal access to clean drinking water and sanitation. The UN‐Water (2015) defines population using a basic sanitation facility at household level and not shared with other households. In the past, most EEIS were designed to meet discharge standards as required by environmental regulations. The ASCE (2016) rated American EEIS such as WTP and WWTPs as grade “D⁺” because WTPs and WWTPs had suffered significant deterioration after more than five decades service. The combined sewer system exhibited significant deficiencies and caused many overflow incidents of raw sewage into nearby water bodies. In 2009, the EPA reported to Congress that the states had assessed 16% of America’s stream miles and found that 36% of those miles were unfit for use by fish and wildlife, 28% were unfit for human recreation, 18% were unfit for use as a public water supply, and 10% were unfit for agricultural use. Over the next two decades, $298 billion of capital investment is needed for the nation’s water, wastewater, and stormwater systems. Three‐quarters of this requirement is pipes for sanitary sewer overflows, combined sewer overflows (CSOs), and other pipe‐related issues. About one‐quarter of the $298 billion is required for the treatment plants. Specifically, $188 billion is needed for wastewater treatment, pipe repairs, and new pipes; $64 billion to correct CSOs; and $42 billion for stormwater management. Therefore, great opportunities exist for SEE designers to design SEEI in the coming decades. For example, about 3% of the total electricity generated in the United States is currently consumed by EEI such as WWTP and WTPs. Almost all 15 000 traditional WWTPs need to be retrofitted from energy negative to energy positive with an estimate of $600 billion capital investment required by the ASCE in the coming two decades. To show the energy saving potential in retrofitting WWTPs, Figure 3.3 shows that most energy is consumed by aeration, while pumping and anaerobic digestion consumes 13%.

During operation, sludge and aeration require 25 and 23% cost, respectively. Staff account for 19% of the operating cost (Figure 3.4).

According to the World Trade Organization (WTO, 2017), the global market for environmental technologies, goods, and services reached USD 1.05 trillion in 2015. The United States is the single largest market and accounted for USD 303.0 billion of the global market. US environmental companies exported $51.2 billion worth of goods and services in 2015. The US industry for environmental technologies employed approximately 1.6 million people and had revenues of $320.4 billion. China is the largest and fastest‐growing emerging market for environmental technologies. The overall environmental technology market in China (including goods and services) is valued at $60.7 billion (2016). China ranks first overall on the 2016 Top Markets Study (TMS) with a composite environmental technologies score of 100. China also ranks first across all three media categories, with scores of 47.4, 44.9, and 7.7 for air pollution control, water, and waste and recycling markets, respectively.

In 2016, China signed the Paris Agreement on a climate change action plan during the G20 Summit in Hangzhou, China (G20 Hangzhou Summit, 2016). More and more investment will be allocated to air pollution control for the reduction of CO₂ emissions, especially coal‐burning or clean coal technology. The Chinese government is committed to green economy with green finance. China established its Asian Infrastructure Investment Bank (AIIB) with green metrics as key criteria for its investments in European and Asian countries. As new regulations are established, billions of dollars have been allocated to water and wastewater as shown in Figure 3.5.

The major markets are water, wastewater, and sludge treatment and disposal, and an estimated $1.4 trillion would be required in China by 2020. The biggest growth potential lies in soil remediation, solid waste, wastewater, and sludge treatment and disposal. Goldman Sachs reported that the 12th Five‐Year Plan only set aside $4.8 billion to address soil pollution, while $277 billion was allocated by the State Council to reduce air pollution in 2013–2017 (Figures 3.6 and 3.7).

In China alone, the capital expenditure for water and wastewater is projected to grow exponentially (Figures 3.8 and 3.9).

Figure 3.10 shows that equipments such as pipes, automatic control system, pumps, valves, and aeration devices are projected to grow exponentially to $5.6, 3, 2.5, 2.4, and 1.4 billion, respectively, by 2018.

3.3.1 SEE Metrics

Global climate change, energy production, food production, and resource depletion need paradigm shift of EEIS design philosophy. For example, green infrastructure (GI) could be designed generatively to decouple economic development from environmental pollution and to prevent pollution at source according to ecological principles. If all the communities were designed as sustainable communities, environmental stress would be significantly reduced. The best metrics to gauge sustainability, therefore, are material, water, and energy FP. SEE engineers should design EEIS that meet technical and cost objectives based on the criteria of protecting human health and the biosphere. For example, wastewater management is fundamentally linked with a natural system's capacity to achieve sustainability. The US EPA developed the following performance metrics in Table 3.9.

These metrics can be applied in defining SEE design as shown in Table 3.10.

SEE aims to empower designers with tools, models, techniques, and procedures that offer them the ability to solve complex problems involved in embracing the huge market in the coming decades. Stakeholders such as industry, consumers, workers, citizens, and government at all levels must be involved in the early stage of projects. Economic, legal, institutional, technology‐based, and societal‐based barriers must be identified to achieve the desired transformational goals: problem formulations, knowledge of options or solutions, and the ability to evaluate alternative courses of action. SEE designers will be able to develop alternatives that are most resilient under the uncertainty caused by climate change and sea level changing. Alternative solutions other than AS and chlorination should be designed. Adverse effects of technologies such as chlorination and aluminum coagulation should be avoided by promoting vacuum ultraviolet (VUV). To quantify environmental footprints of an SEEI design, LCAs are usually applied and include extraction/synthesis, design, process, product, and disposal/reuse with aid of following assessment tools in Table 3.11.

3.4.1 Principle 1: Integrated and Interconnected System Hierarchy

SEE aims to protect people, the planet, and profit (3P). Therefore, designers should play a leadership role to involve all the major stakeholders. Sustainable EEIS alternatives should be developed by actively engage communities and stakeholders. Implementing and feedback loops of SEE alternatives should be intertwined in achieving environmental, economic, and employment (3E) objectives. The hierarchy to achieve 3E objectives is prevention, reduction, reuse, recycling, recovery, treatment, disposal, and remediation. To rank the effectiveness of these strategies, the relevant data on human and industrial generation of wastes and current EE system is needed to develop waste management engineering alternatives. The life cycle of materials should be taken into consideration to minimize the FT of EEIS. Design alternatives should be assessed and compared in terms of reduction of chemical, biological, and radioactive risks and minimal FP on air, water, soil, and energy. The state‐of‐the‐art design tools should be used to keep the capital cost of EEIS at minimal budget.

Traditional EE design usually has negative FP in the past. For a WWTP using AS process, it is very difficult to bring the operation to energy neutral due to energy intensive aeration process and the huge amount of sludge produced. Typically, performance metrics including the FP of C, N, P, and energy within the design life expectancy are negative. Regenerative design integrates external energy into the system and becomes more sustainable and resilient. Regenerative design requires EEIS to produce more than the waste exergy through utilization of solar energy such as photosynthesis or photovoltaic. In addition, regenerative design should be developed together with the green economy by creating green jobs such as bioenergy, solar energy, and recovery materials. Regenerative design usually combines different innovative technologies by using tools (Table 3.12). For example, tools for integrated water resources management (IWRM) could be used to design regenerative through integrated and interconnected EEIS:

1. EEIS should satisfy governmental regulations to protect human and environment health.
2. Air, water, and solid waste engineering systems should be integrated to achieve zero discharge.
3. EEIS should be interconnected to achieve synergistic functions with minimal material, water, nutrient, and energy FP.
4. EEIS should be designed to fit for purpose and could be centralized or decentralized systems depending upon system boundary.
5. Different water quality such as blue, gray, and black should be considered together for sustainable management of water.
6. GI should be interconnected.

3.4.2 Principle 2: Reliability on Spatial Scale

A well‐defined EEIS is critical to identify 3E objectives on the spatial scale. EEIS could be defined at residential, community, city, regional, and global scales. Stakeholders within the system should be identified and engaged in the planning and implementing phases. The key for an EEIS to be reliable is to fit the purpose and be adaptive to local situations in terms of renewable materials and energy.

EEIS such as WTPs, WWTPs, and GIs should be sustainably designed with consideration of local situation on its spatial scale. Due to geographic differences, renewable energy resources are distributed differently, for example, solar energy in the south and wind energy in north. Treatment will heavily depend upon scale in terms of population equivalent (PE). In general, decentralized WWTP is more suitable for rural areas than metropolitan cities. For residential houses, on‐site wastewater treatment processes such septic tanks and constructed wetlands may hold the key to achieve regenerative design. If the land of a residential house is large enough, zero water, energy, and wastes should be achievable. For a community greater than 1000 PE, energy‐neutral design may be more realistic. For large cities, if energy neutrality cannot be achieved, designers should target maximum recovery and reuse to minimize FP. New urban communities and cities have the opportunity to design and build source‐separating systems optimized for cost‐effective resource recovery using rain harvest and food waste separation from municipal solid waste. In addition, following issues should be considered on spatial scales:

1. Economy of scale should be assessed at the individual, household, community, city, state, and country levels to avoid fit‐for‐all design.
2. Regenerative or zero discharge design should have priority, while negative design should have minimal FP.
3. GI should be implemented as much as possible at residential house, community, city, state, and country levels with different weights of blue, gray, and black water management strategies.
4. Laboratory‐, pilot‐, and full‐scale testing should be validated with known uncertainty to increase the reliability of EEIS. Laboratory‐scale data could be directly used to design the full‐scale system if kinetics and mechanisms were correctly modeled and simulated to eliminate a prototype.

3.4.3 Principle 3: System Resiliency on a Temporal Scale

On temporal scales, EEIS should be resilient at 20, 50, and 100 years depending upon design life expectancy. Furthermore, the uncertainty and sensitivity of the EEIS performance should be quantified under different temporal scales.

EEIS such as WTPs, WWTPs, and GIs should be resilient to more serious drought and flooding due to climate change. Minimum temperature in the north and maximum temperature in the south should be considered in designing EEIS. At minimum temperature, biological activity will decrease by half for every ten‐degree drop. The global warming will have dire consequence for human society due to sea level rising (SLR) and saltwater intrusion (Table 3.13). Therefore, on a different temporal scale, the following issues should be considered:

1. Short‐term versus long‐term operation conditions should be considered.
2. Operating cost and benefit should be quantified to determine the net profitability of EEIS within the project life expectancy.
3. LCA should also consider short‐term and long‐term energy mix.
4. Reaction kinetics is the determining factor in reactor design.
5. Blue, gray, and black water management should be resilient to climate change in 20, 50, and 100 years.

3.4.4 Principle 6: Prevention

Prevention is the most effective way to ensure the sustainability of EEI design. For example, one gallon of gasoline is a useful fuel, while it would cost thousands of dollars to clean up if it leaked into groundwater as evidenced by many underground tank cleanup programs in the United States. On every design scale, an opportunity exists to prevent waste rather than treat it after it is generated.

Waste requires unnecessary expenditure of capital, energy, and resources and has no benefit. The following technologies are important in prevention:

1. The TDPs of green chemistry should be applied to prevent the generation of chemical waste.
2. Anammox should be designed to prevent sludge production in the AS process whenever nutrients such as nitrogen are to be removed.
3. Enhanced coagulation using biodegradable coagulants should be used to prevent lime and aluminum sludge.

Prevention opportunities exist as presented in Table 3.16 in air, water, and soil media.

3.4.5 Principle 7: Recovery

Recovery serves dual purposes. It protects human and ecosystem health by removing the “contaminants” of wastewater while recovering them as useful resources such as water, energy, or materials. In addition, the recovered water can be used for agricultural irrigation, energy to power WRRFs, and nutrients as fertilizer in agriculture. Furthermore, resalable products could bring cities sizeable economic, social, and environmental benefits.

Extensive energy and material are the major costs for EEIS and result in waste, inefficiency, and FT on the environments. Recovery is the most important design strategy to achieve regenerative design. For WWTPs, the most valuable products are reclaimed water, energy, and nutrients. Table 3.17 presents examples designed for recovering nutrients.

Specific rules for recovery are as follows:

1. Recovery is to reuse and recycle mass and energy from components, reactors, and processes of EEIS.
2. Energy and materials such as water, and nutrients in wastewater should be considered recoverable.
3. Solid waste refining should be considered as an alternative in solid waste management systems.

The key technologies for effective recovery are:

1. Anaerobic digestion of sludge and energetic food wastes.
2. Recovery of N and P, for example, through precipitation of struvite.
3. Ion exchange to recover inorganic elements such as precious metals or rare earth.
4. Membrane technology such as ultra‐, micro‐, and nanofiltrations and reverse osmosis.
5. Microbiological fuel cell.
6. Molten salt technology for energy, heat, and hydrogen recovery.

All materials should be considered as recoverable resources. The recovery extent should be determined by the constraints of technology and costs as shown in Table 3.18.

3.5.1 Principle 9: Treatment

When pollutants are neither recoverable nor separable, destructive technologies such as advanced oxidation process (AOP) are better than phase transfer technologies. In treatment, material and energy inputs should be renewable and from readily available sources throughout all life cycle stages.

In most cases, particle size determines the physical treatment process, while the nature of pollutants determines the adoption of either biological or physicochemical treatment technologies. For WWTP, regenerative design is the key to ensure a plant able to operate sustainably. Renewable and nontoxic materials should be used whenever possible. Catalysts should be used to avoid chemicals. Immobilized catalysts should be used to eliminate separation processes. Design for unnecessary capacity should be considered a design flaw because fit for all may not be a sustainable solution (Table 3.20). The following oxidation technologies play a critical role in regenerative design:

1. Anaerobic ammonia oxidation (Anammox) to reduce the aeration intensity of AS.
2. AOPs to replace activated carbon adsorption.
3. UV disinfection and oxidation to replace chlorination.

3.5.2 Principle 10: Retrofitting and Remediation

Due to the unsustainable design of EEIS in the past, 95% of WWTPs were energy negative and consumed about 3% of total electricity generated in the United States. Retrofitting these WWTPs is a major challenge for SEE designers.

In the next two decades, one of the most challenging engineering issues is to effectively retrofit the old energy‐negative WWTPs to be energy‐positive WRRFs all over the world. The US EPA and the Water Environment Research Foundation have produced many design manuals and presented many successful examples. To retrofit WWTPs, the first step is energy audit to identify the greatest opportunity to improve energy efficiency in a WWTP. Second is to replace old devices with new technology to reduce energy consumption. Third is to reconfigure processes so that energy consumption can be reduced by adopting following technologies:

1. Traditional AS should be coupled with Anammox to reduce sludge.
2. MBR could be added in the aeration chamber to increase treatment efficiency.
3. AnMBR could be added in anaerobic digester to increase methane production.

Green remediation principles developed by the US EPA should be implemented to minimize the remediation FP of resources and energy. The Excel‐based software developed by the US EPA will assist the designer to significantly reduce the FP of major retrofitting projects. Green remediation must consider contaminated media, the nature of pollutants, and concentration (Table 3.21):

1. Renewable energy resources could be used to regenerate biomass.
2. Green plants and algae could be used in water remediation.
3. Solar energy could be used for sludge dewatering.
4. Renewable energy should be used in remediation to reduce FP.

3.5.3 Principle 11: Optimization through Modeling and Simulation

The most economical way to optimize EEIS design is through mathematical modeling, which could be then used to simulate. Opportunities of increasing the performance of the system and decreasing costs could be identified through computer modeling and simulation. For example, after the detail mechanism and kinetics of Anammox were established, full‐scale Anammox reactor were successfully designed and built without pilot prototype (van der Star et al., 2007).

Since pilot‐ and prototype‐scale experiments are expensive, computer modeling and simulation could be used to directly scale up a process without design, construction and operation of the corresponding pilot plant. Real‐time monitoring and control are critical to ensure that the performance of the system will not deteriorate during operation. Important technologies are:

1. Supervisory control and data acquisition (SCADA).
2. AutoCAD and SolidWorks for sustainable materials.
3. 3D printing for pilot‐scale testing.
4. Simulink for computer simulation by Matlab.

Optimization of designed systems should be conducted by using computer software to reduce cost (Table 3.22).

3.5.4 Principle 12: Balance Between Capital and Operating Costs

Ideally, future EEIS should be designed and constructed as standardized modules so that the cost and performance of the components, reactors, processes, and systems could be sustainable. Also, standardized modules may be reused when the EEIS is no longer needed. For example, leachate treatment systems after 30‐year service may not be needed; the system could be used at the other landfill sites. Modular design makes products, processes, and systems reusable or recyclable after design life expectancy. Therefore, designers should aim at durability, not immortality.

Regenerative design can ensure beneficial use of recycled components, while standardized modules are the best route to reducing the FP of modern EEIS. Standardized modules should have minimal capital and operation cost as well as minimal environment FP during their life cycle. To achieve sustainability, LCA of components, reactors, processes, and systems should be quantified during all the design phases and operation during its life time by using inherently safe and benign material and energy (Table 3.23).

Innovative approaches are required to create engineering solutions beyond current or dominant technologies. To achieve sustainability requires SEE designer to improve, innovate, and invent new technologies with passion. When TDPs are systematically applied in the early stage of the design, significant cost saving could be recognized by new EEIS design. Staying with problems longer is an excellent way to make a significant contribution. Creative thinking, leadership, and entrepreneurship should be implemented in design phases as shown in following design strategies of innovative technologies:

1. Innovation through new science and technologies is the key for designing sustainable EEIS.
2. Rapid prototyping such as 3D printing and computer simulation is crucial to test the reliability of the product or processes.
3. Market penetration through entrepreneurial spirit would accelerate the adoption of innovative technologies.
4. Incorporating SEE into EEIS design will transform the industry through innovation and entrepreneurship in all the design phases.
5. Innovative technologies should be used as soon as they have been proven on a commercial scale within tested reliability.
6. Entrepreneurial spirit should be reflected in identifying environmental challenges and providing the best solutions for the markets in air, water, and soil quality management (Table 3.24).

3.6.1 Procedure to Implement SEE Design Principles

The driving force for sustainability is the educated SEE human capital to design engineering systems in a sustainable manner. The TDP could be integrated in engineering design phases as follows:

• Step 1: Define objectives on 3E in addition to sponsored goals.
• Step 2: Collect related data on air, water, and land background information related to a project.
• Step 3: Assess the alternatives in terms of FP on material and energy using LCA and FP tools.
• Step 4: Develop alternatives by targeting regenerative design or neutral design, and avoid deficient design under cost constraints.

SEE design can be integrated into three phases of traditional engineering design. Therefore, in phase I for 30% submittal, the following steps are recommended:

1. Collect relevant data for air, water, and soil quality index.
2. Set up a design goal to meet regulatory requirements.
3. Get all stakeholder input and continuously involve them in the design process.
4. Collect sustainable metrics of the unit process in terms of FP on materials and energy.
5. Develop design alternatives that can achieve productive, neutral, or negative energy efficiency.

In the second phase of 60% submittal, the following steps are recommended:

1. Select two design alternatives with stakeholder input according to the TDP of SEE.
2. Quantify material and energy FP.
3. Quantify unit efficiency and compare with design metrics or benchmarks.
4. Estimate project cost.
5. Detail the design of the system.

In the third phase of 100% submittal, the following steps are recommended:

1. Optimize the system.
2. Improve the system by identifying potential for saving energy and cost without reducing efficiency.
3. Develop detailed engineering drawings for constructability.

3.6.2 Integration of SEE into Undergraduate Education

SEE may transform EE education through horizontal and vertical integrations in the 4‐year curriculum with examples, problems, and case studies. Horizontal refers to an interdisciplinary approach, while vertical refers to the integration of SEE throughout the 4‐year curriculum of EE. The TDP could be taught as modules for a multidisciplinary and freshman‐level introduction to engineering or upper‐level WTP and WWTP design. Using SEE principles at the start of the design process could shift the philosophy of EE design towards a sustainable future. Horizontal integration refers to SEE concepts that should be learned together with a specific course in the SEE curriculum according to Table 3.25.

Sustainability has many facets and requires an extremely broad list of possible inquiries related to policy analysis and design. In addition, the final alternative is subject to many constraints such as the economic, environmental, sustainability, manufacturability, ethical, health and safety, social, and political limits. To achieve true SEE design, teaching strategies may require collaboration between many disciplines. For example, chemistry, biology, electrical engineering, and information technology all have their place in the integrated regenerative design of future WRRF. Inter‐ and multidisciplinary pedagogy should be promoted. Multidisciplinary teaching brings together several disciplinary perspectives. For example, regenerative design needs SEE and ecological principles to produce biomass such as algae to produce biodiesel from wastewater. Many facets of sustainability require the breaking of economic, legal, institutional, chronological, and societal barriers to achieve the desired transformational goals. To these ends, SEE should be vertically integrated into the EE curriculum as in Table 3.26.

To accelerate the adoption of SEE, education and training are effective ways to penetrate the SEEI market. SEE could follow the success of GC and GE all over the world. Course projects could be based upon a real EEIS design project at residential, community, or city scales. These projects could be conducted to improve information flow on TDPs and examples. Effective economic and sustainability tools and criteria could be developed to aid the design process. Benchmarks that lead to regenerative products, processes, and systems of EEIS could be developed in the integrated air, water, and land management network. One of effective way is to promote a grassroot movement towards SEE education and practice. Grassroot movement requires students to collect their relevant EEIS data to develop sustainable design alternatives by following the TDPs. Grassroot movement from all the SEE designers will help implement the SEE design principles throughout the EE industry during all design phases. For example, if 15 000 WWTPs in the United States are retrofitted into energy‐positive WRRFs, market drivers will clearly also demand more financially sound design alternatives, so retrofitting the current WWTPs and designing new WRRFs will provide the best sustainable design solutions. At the same time, regulatory frameworks should be created to reduce uncertainty for the industry in adopting SEE TDPs. Institutions such as the UN should adapt the SEE principles to achieve the SDGs. To achieve 17 SDGs, SEE designers may lead engineering design communities across the spectrum by forming alliance with GC and GE. In addition, SEE designers should also team up with mechanical and electrical engineering to design sustainable components needed for automatic and standardized regenerative WWTPs. When three major education and working forces of GC, GE, and SEE come together, innovative technologies could be quickly developed through interdisciplinary research and true sustainable EEIS could be designed for decades to come.

Vertical integration with other curricula is crucial to promote multidisciplinary and transdisciplinary thinking. Government and academic institutions need to come together to create a new generation of trained experts in SEE, building sustainable communities and cities, regenerative WRRFs, and stand‐alone leachate treatment systems. It also needs to create educational, information, and networking tools for innovators to speed up the development of SEE solutions. Students can use the LCA tools of SEE to design new processes and retrofit existing WWTPs. According to the TDP of SEE, the challenges of critical SEE technologies should be solved through research and development and marketed. As a result, innovative technologies such as Anammox, AnMBR, and UV disinfection and oxidation could penetrate markets all over the world.

All the TDPs can be applied to design EEIS of air, water, solid waste, and soil management. The most important is to develop the best EEIS solution to achieve the best performance and minimal FP on the environments at the minimal costs. The major environmental engineering challenges for the SEE designers include residential water and solid wastes in urban and rural areas, industrial wastes, and agricultural wastes. One of the effective way for the SEE designers is to establish benchmark data so that governmental agencies can enforce the TDPs in their bidding documents. With these benchmark data, governments could accelerate the adoption of SEE technologies with effective incentives policies to reward SEE design and construction. State and federal policies could pass legislation to design and advocate innovations that increase the supply and demand for SEE solutions. Funding, incentives, and/or prizes should be awarded to SEE research and commercialization. Through state and federal funding, national SEE research or demonstration centers should be set up to transfer technology and technical know‐how. To ensure the success of the governmental programs, the benefits of SEE to communities and cities should be quantified and publicized to society. SEE business, economic and health benefits, and opportunities and funding should be disseminated. Opportunities and strategies should be identified to jointly develop design criteria and SEE solutions. SEE progress at city, county, state, country, and global scales should be tracked. Why certain SEE products, technologies, and designs have succeeded or failed in the marketplace should be analyzed. Revenues, green job, economic benefits, and trends using SEE TDPs should be documented. Environmental or public works agencies should monitor the effectiveness and usefulness of sustainable EEIS.

3.7.1 Questions

1. What are the six design hierarchies and six dimensions in the TDPs of the SEE?
2. What are the major barriers and drivers in designing sustainable EEIS?
3. What partnerships will have to be built, policies put in place, educational needs met, and investments made to implement SEE at undergraduate and graduate education?
4. What role should the SEE designers take to achieve the 17 UN SDGs?
5. What should the scale of innovation in SEE be?
6. How can the importance of SEE in education and research be evaluated?
7. What are smart policies that support SEE markets, research, and innovation?
8. What is the most important design rule that you would add to each SEE design principle?

3.7.2 Calculation

The paradigm shift in designing sustainable WRRF rooted in the view that wastewater is a resource and water, energy, and nutrients could be recovered. Table 3.27 lists the typical wastewater characters in Miami‐Dade County.

1. If each person in the county is producing 60 gBOD₅ (biochemical oxygen demand consumed over 5 days) in wastewater, which is equivalent to 100 gCOD/person/day, and if the maximal energy content is 14.7 kJ/gCOD, please answer the following:
   1. What would be the theoretical maximal energy content in the wastewater if the Miami‐Dade County population is 2.6 million?
   2. In reality, Miami‐Dade Water and Sewer Department operates three WWTPs with average flow rate of 300 MGD, what are the maximal energy contents in the flow daily?
   3. How much differences are there between the answers of (a) and (b) and why?
   4. On unit volume of cubic meter wastewater, what would be the theoretical unit energy content for biodegradable versus nonbiodegradable portion of organic pollutants in the wastewater of Miami‐Dade County in kWh/m³?
   5. How are your two answers compared with the maximal unit energy contents of 0.70 and 1.23 kWh/m³ estimated by McCarty et al. (2011)? Why are there differences?
   6. If 30% of the maximal energy content were to be recovered as electricity, what would be the unit energy recovered in kWh/m³/day?
2. If EEISs of air, water, solid, and soil quality management are to be designed according to the TDPs, what are the major quantitative indicators such as benchmark of unit energy consumption and chemical efficiency that are needed for each EEIS? In the United States, 15 000 WWTPs need to be retrofitted to energy positive. If benchmarks of unit energy consumption and chemical efficiency were to be established, how would you help your state to develop achievable benchmark data so that retrofitting WWTPs would be practical within realistic budget during a specific time period?
3. To achieve a high atom economy is important for the sustainability of a process. For example, COD can be oxidized to CO₂. If COD is to be converted to methane (CH₄), please answer the following:
   1. How many moles of oxygen is needed to oxidize 1 g COD?
   2. How many grams of COD are there in 1 g CH₄?
   3. Based upon Hess’s law, what would be the overall enthalpy of the following reaction?
      
   4. What would be the theoretical heat content per gram of COD?

3.7.3 Projects