PYROLYSIS TECHNOLOGY

Pyrolysis is the thermal decomposition of complex organic matter in the absence of oxygen to simpler molecules that can be used as feedstocks for many processes. The main products produced by the pyrolysis process are

• activated carbon,
• biodiesel and 
• syngas.

Pyrolysis always consists of the endothermic reaction, though general combustion is done by the generation of heat reaction in the system

that produces solid, liquid, and gas, heating it at moderately high temperatures under a no oxygen or low oxygen atmosphere.

Biodiesel produced by the process of pyrolysis can be used purely as a fuel or for other petroleum products. The syngas is typically used for

combustion or to run turbines for power generation, including running the plant itself.

The biomass used in pyrolysis is typically composed of cellulose, hemicellulose, and lignin. The main parameters that govern the pyrolysis

process are 

• temperature, 
• heating rate, 
• solid residence time, 
• volatile residence time, 
• particle size and 
• density of particles.

Pyrolysis is, therefore categorised into three major types:

• flash,
• fast and 
• slow pyrolysis 

and are respectively based on

• temperature,
• heating rate and 
• residence time. 

The products of pyrolysis thus vary dramatically according to type. Cellulose is converted to

biochar and volatile compounds.

Tackling E-Waste

‘Electronic Waste’. Electronic waste covers everything from home appliances like TVs, air conditioners, and fans to IT devices like computers and mobiles that have been replaced or have reached the end of their life cycle and need to be disposed of.

Waste electrical and electronic equipment (WEEE) is becoming a major threat to the whole world. Its toxic emissions mixed with virgin soil and air and causing harmful effects to the entire biota either directly or indirectly. Direct impacts include the release of acids, toxic compounds including heavy metals, carcinogenic chemicals and indirect effects such as biomagnification of heavy metals. Many private firms are involved in collecting, dismantling, separation and exporting e-wastes for recyclers. However, strict regulations are currently being followed as on approval of such firms such as e-steward certification by Basel action network in the USA, they also involved in public awareness programs; this review is based on collected information from various journal articles, websites including the technical note by Greenpeace international. Further, it analyzes the current progress on e-waste management worldwide.

Here’s an example to understand the scale of the problem, according to estimates by Ceylon Waste Management there are 7.6 Million CRT TVs and Monitors in Sri Lanka, and only 10% of that will be properly disposed. The remaining 90% will be around 67500 metric tons of CRTs, of which 8840 tons will be lead and 110 tons of arsenic. That’s a massive amount of poison that could leach into our ecosystem endangering both human and animal lives. Other methods must be employed to dispose of this waste.

What Happens to Devices at the End of Their Useful Life

Unfortunately, the majority of these electronic products end up in landfills, and just 12.5% of e-waste is recycled. According to a UN study, over 41.8 million tons of e-waste was discarded worldwide, with only 10%–40% percent of disposals appropriately done. Electronics are full of valuable materials, including copper, tin, iron, aluminum, fossil fuels, titanium, gold, and silver. Many of the materials used in making these electronic devices can be recovered, reused, and recycled—including plastics, metals, and glass. 

In a report, Apple revealed that it recovered 2,204 pounds of gold —worth $40 million—from recycled iPhones, Macs, and iPads in 2015. 

Benefits of E-Waste Recycling

Recycling e-waste enables us to recover various valuable metals and other materials from electronics, saving natural resources (energy), reducing pollution, conserving landfill space, and creating jobs. According to the EPA, recycling one million laptops can save the energy equivalent of electricity that can run 3,657 U.S. households for a year. Recycling one million cell phones can also recover 75 pounds of gold, 772 pounds of silver, 35,274 pounds of copper, and 33 pounds of palladium.

On the other end, e-waste recycling helps cut down on production waste. According to the Electronics TakeBack Coalition, it takes 1.5 tons of water, 530 lbs of fossil fuel, and 40 pounds of chemicals to manufacture a single computer and monitor. 81% of the energy associated with a computer is used during production and not during operation.

The Electronics Recycling Process

Electronics recycling can be challenging because discarded electronics devices are sophisticated devices manufactured from varying proportions of glass, metals, and plastics. The process of recycling can vary, depending on the materials being recycled and the technologies employed, but here is a general overview.

Collection and Transportation: Collection and transportation are two of the initial stages of the recycling process, including for e-waste. Recyclers place collection bins or electronics take-back booths in specific locations and transport the collected e-waste from these sites to recycling plants and facilities.

Shredding, Sorting, and Separation: After collection and transportation to recycling facilities, materials in the e-waste stream must be processed and separated into clean commodities that can be used to make new products. Efficient separation of materials is the foundation of electronics recycling. Shredding the e-waste facilitates the sorting and separation of plastics from metals and internal circuitry, and waste items are shredded into pieces as small as 100mm to prepare for further sorting.

A powerful overhead magnet separates iron and steel from the waste stream on the conveyor and then prepares it for sale as recycled steel. Further mechanical processing separates aluminum, copper, and circuit boards from the material stream—which now is mostly plastic. Water separation technology is then used to separate glass from plastics. The final step in the separation process locates and extracts any remaining metal remnants from the plastics to purify the stream further.

Preparation For Sale as Recycled Materials: After the shredding, sorting and separation stages have been executed, the separated materials are prepared for sale as usable raw materials for the production of new electronics or other products.

Electronics Recycling Associations

• ISRI (the Institute of Recycling Industries): ISRI is the largest recycling industry association with 1600 member companies, of which 350 companies are e-waste recyclers.
• CAER (Coalition for American Electronics Recycling): CAER is another leading e-waste recycling industry association in the U.S. with over 130 member companies operating around 300 e-waste recycling facilities altogether throughout the country.
• EERA (European Electronics Recyclers Association): EERA is the leading e-waste recycling industry association in Europe.
• EPRA (Electronic Products Recycling Association): EPRA is the leading e-waste recycling industry association in Canada.  

Current Challenges for Electronics Recycling Industry

The E-waste recycling industry has a significant number of challenges, which the primary one being exporting to developing nations. Exporting e-waste, including hazardous and toxic materials, is leading to serious health hazards for the workers working for dismantling electronic devices in countries without adequate environmental controls. Currently, 50%–80% of e-waste that recyclers collect is exported overseas, including illegally exported e-scrap, which is of particular concern. Overall, the inadequate management of electronics recycling in developing countries has led to various health and environmental problems.

Although the volume of e-waste is increasing rapidly, the quality of e-waste is decreasing. Devices are getting smaller and smaller, containing less precious metal. The material values of many end-of-life electronic and electrical devices have therefore fallen sharply. Electronics recyclers have suffered due to sagging global prices of recycled commodities, which have decreased margins and resulted in business closures.

Another problem is that as time goes on, many products are being made in ways that make them not easily recyclable, repairable, or reusable. Such design is often undertaken for proprietary reasons, to the detriment of overall environmental goals. Organizations such as ISRI have been active in promoting policies to broaden the range of authorized companies allowed to repair and refurbish smartphones to avoid their needless destruction. The current rate or level of e-waste recycling is definitely not sufficient. The current recycling rate of 15%–18% has much room for improvement as most e-waste still is relegated to the landfill.

Electronics Recycling Laws

Currently, 25 U.S. states have laws mandating statewide e-waste recycling, and several more states are working toward passing new legislation and improving the existing policy. State e-waste recycling laws cover 65% of the U.S. population, and some states, including California, Connecticut, Illinois, and Indiana, e-waste is banned from landfills. 

Potential Initiatives in Sri Lanka

Despite these initiatives, Sri Lanka is still far away in terms of e-waste management compared to most countries. Thus, existing bottlenecks need to be addressed in order for Sri Lanka to be a sustainable e-waste recycler. Strengthening policy and legislation is vital. Apart from the existing policy and regulation, the government could reinforce regulations, specifically on the imports of EEE. For instance, regulations should be enacted on discouraging the imports of used EEE, and to import equipment that has less hazardous elements; for example, LED/LCD monitors can replace CRT monitors, since CRT has more hazardous elements. In addition, suitable technology and skills need to be implemented in order to streamline the sustainable e-waste recycling system in the country. Proper mechanisms should also be developed to take out the informal market for e-waste recycling in the country. Improving the knowledge on e-waste within the community is crucial. Conducting programmes which highlight the social and ecological impacts of improper handling of e-waste, and the importance of disposing e-waste in proper places and in proper ways can be effective in raising public awareness. This can be provided through the public health staff, starting from grassroots levels. Also, the media can play a pivotal role in disseminating the message and making the mass community aware of the impacts of improper handling of e-waste as well as the proper mechanisms in recycling and its benefits.

‘E-waste’ should not be considered as normal ‘junk’. It may not impact you instantaneously, but could do so later in life. Therefore, much attention should be paid to this issue, considering the many health impacts that could be instigated by the e-waste around us.

Construction waste

Construction activities can generate large amounts of waste materials that then need to be disposed of. In addition, at the end of a building's life, it may be deconstructed or demolished, generating significant amounts of waste. Construction waste includes the waste that is generated during construction activities (such as packaging, or the products of demolition) and materials that are surplus to requirements (as a result of over-ordering or inaccurate estimating).

Typical construction waste products can include:

Insulation and asbestos materials.

Concrete, bricks, tiles and ceramics.

Wood, glass and plastic.

Bituminous mixtures, coal tar and tar.

Metallic waste (including cables and pipes).

Soil, contaminated soil, stones and dredging spoil.

Gypsum.

Cement.

Paints and varnishes.

Adhesives and sealants.

Increasingly, there are options available in terms of reusing and recycling materials, and reducing the amount of waste produced in the first place, but despite this, a large amount of construction waste is still disposed of in a landfill. 32% of landfill waste comes from the construction and demolition of buildings and 13% of products delivered to construction sites are sent directly to the landfill without having being used (ref. Technology Strategy Board)

This can be an expensive process, as the 1996 Finance Act introduced a tax on waste disposal on all landfill sites registered in the UK. 

To help tackle this, a site waste management plan (SWMP) can be prepared before construction begins, describing how materials will be managed efficiently and disposed of legally during the construction of the works, and explaining how the re-use and recycling of materials will be maximised. For more information, see Site waste management plan.

It may be possible to eliminate a certain amount of construction waste through careful planning. For example, steel formwork systems might be capable of being used for concrete works which can then be reused elsewhere on the project/s in place of timber formwork which is classed as waste once it has been used.

Other types of construction waste may be capable of being minimised; for example, products which are provided with reduced packaging or those which are composed of recycled materials. There can also be opportunities to re-use materials and products which are in a suitable condition (e.g. doors, windows, roof tiles and so on), or exchange them for other materials with a different construction site.

Materials and products which cannot be eliminated, minimised or reused may have to be disposed of as waste. Before sending waste for disposal, it should be sorted and classified to allow waste contractors to manage it effectively and ensure that hazardous waste is properly handled.

The Problem

Disposal of public fill at public filling areas and mixed construction waste at sorting facilities or landfills has been the major approach for construction waste management. For sustainable development, we can no longer rely solely on reclamation to accept most of the inert construction waste. As such, the government is examining ways to reduce and also to promote the reuse and recycling of construction waste. Nevertheless, there will still be a substantial amount of materials that require disposal, either at public fill reception facilities or at landfills.

Today, we are running out of both reclamation sites and landfill space. With the current trend, our landfills will be full in mid to late-2010s, and public fill capacity will be depleted in the near future. In 2013, the mixed construction waste accounts for about 25% of the total waste intake at the three existing landfills. If there are insufficient public fill capacity and waste reduction measures being implemented, more public fill would probably be diverted to landfills and the landfill life will be further shortened.

Wastewater Treatment Process

Urban Wastewater Management

Water Waste Treatment Process

Step 1: Sanitary Sewer                                    Step 4: Aeration Tanks

Step 2: Grit Chamber                                       Step 5: Secondary Treatment Tank

Step 3: Primary Treatment                          

The image above shows the layout of a typical treatment work. Ideally, wastewater treatment in a municipal treatment works involves four stages: preliminary, primary, secondary and tertiary treatment. There are two end products from the treatment process; sludge solids and liquid effluent. The treatment process reduces the effluent so that it will not adversely affect the quality of the receiving waters.

Preliminary treatment takes large solids and floating debris from the raw wastewater.

Primary treatment separates the smaller solids.

Secondary treatment uses microorganisms to remove the biodegradable or organic waste.

Tertiary treatment includes nutrient removal and filtration. 

                   

Urban Waste Water Treatment Directive

Urban wastewater can be described as a mixture of domestic and industrial wastewater and runoff rainwater. The level of treatment wastewaters receive depends on the size of population served. In urban areas, a network of pipes and pump stations carries wastewater from homes and industry to a municipal treatment plant. This treatment of the sewage (the contaminated wastewater) involves primary, secondary and tertiary treatment:

1. solids are separated from the wastewater
2. dissolved biological matter is converted to solid mass using micro-organisms
3. solids are then neutralized and reused or discarded
4. treated wastewater is discharged to receiving waters

The proportion of wastewater subject to secondary treatment has increased significantly from 26% between 1998-1999 to 90% in the 2006-2007 period.  This is mainly due to the new waste water treatment plants at Ringsend (Dublin), Cork City, Limerick City, Galway City and Dundalk.   Furthermore, because of major investments in recent years, construction of secondary treatment facilities at many locations around the country is advanced. This is expected to deliver significant improvements in the quality of urban waste water discharges.

The National Urban Waste Water Infrastructure Study was published in August 2005. It is the most extensive examination to date of Ireland 's public waste water infrastructure. The study involved the collection, collation, mapping and analysis of urban drainage systems including waste water treatment facilities and an assessment of future waste water requirements.

The Urban Waste Water Treatment Directive is designed to ensure that sewage collection systems are established for domestic and industrial waste waters and that this waste water receives appropriate treatment to reduce its environmental impact before being released into our waterways

Wastewater Treatment Process
Adelaide’s three major metropolitan wastewater treatment plants process more than 250 megaliters of wastewater every day. The plants are located at: Christie's Beach Glenelg Bolivar Wastewater comprises a mixture of domestic sewage (waste from household toilets, sinks, showers and washing machines), industrial effluent, occasional run-off of surface water and ground water which has infiltrated into the sewers. Wastewater is 99.99% water, with a small amount of dissolved or suspended solid matter. At our treatment plants the wastewater undergoes a multi-stage treatment process to clean it before discharge or reuse. Preliminary Treatment  The first stage of the treatment process uses screens to remove the larger solid inorganic material such as paper and plastics. This is followed by the removal of particles such as grit and silt which are abrasive to plant equipment. Primary Treatment Following preliminary treatment, wastewater is passed through a primary sedimentation tank where solid particles of organic material are removed from the suspension by gravity settling. The resultant settled primary sludge is raked to the centre of the tank where it is concentrated and pumped away for further treatment. Secondary Treatment This next stage is a biological process which breaks down dissolved and suspended organic solids by using naturally occurring micro-organisms. It is called the activated sludge process. The settled wastewater enters aeration tanks where air is blown into the liquid to provide oxygen for mixing and to promote the growth of micro-organisms.  The “active biomass” uses the oxygen and consumes organic pollutants and nutrients in the wastewater to grow and reproduce. From the aeration tanks, the mixture of wastewater and micro-organisms passes into a secondary sedimentation tank (also known as a clarifier) where the biomass settles under gravity to the bottom of the tank and is concentrated as sludge. Some of this sludge is recycled to the inlet of the aeration tank to maintain the biomass, hence the name for the process – activated sludge. The remainder is pumped to anaerobic digesters for further treatment. The clarified wastewater is discharged from the secondary clarifier and passes through for Tertiary Treatment. Tertiary Treatment All wastewater treatment plants use disinfection for tertiary treatment to reduce pathogens, which are micro-organisms which can pose a risk to human health. Chlorine is usually dosed into the treated wastewater stream for disinfection. However, Bolivar uses large ponds in which sunlight and other micro-organisms reduce the pathogens. Additional treatment may be required if the treated wastewater is reused for purposes such as irrigation of food crops or where close human contact may result. Tertiary treatment, such as that provided at Bolivar through the Dissolved Air Flotation Filtration (DAFF) plant, produces a much higher standard of treated wastewater suitable for these purposes. The DAFF plant filters and disinfects the wastewater from the ponds allowing it to be used for direct irrigation of crops through the Virginia Pipeline Scheme. Sludge Treatment Sludge collected during the treatment process contains a large amount of biodegradable material making it amenable to treatment by a different set of micro-organisms, called anaerobic bacteria, which do not need oxygen for growth. This takes place in special fully enclosed digesters heated to 35 degrees Celsius, where these anaerobic micro-organisms thrive without any oxygen. The gas produced during this anaerobic process contains a large amount of methane. At the Christies Beach plant it is used to heat the digesting sludge to maintain the efficiency of the process. Elsewhere the gas fuel is used to generate electricity, with the waste heat used to maintain the digestion process. This electricity is used in the plant, reducing our use of non-renewable energy sources. Once the micro-organisms have done their work water is removed from the digested sludge through mechanical means such as centrifuging, or by natural solar evaporation in lagoons. The liquid remaining at the end of the process is usually pumped back into the aeration tanks for further treatment. The stable, solid material remaining, or biosolids, looks, feels and smells like damp earth and makes ideal conditioner for soil.    IFAS IFAS (Integrated Fixed-film Activated Sludge) is an innovative treatment process used to reduce nitrogen in existing wastewater treatment plants. IFAS involves introducing small free floating plastic cylinders into the aeration tanks where they provide a large surface area to which biological growths attach, thereby increasing the treatment capacity of the plant.

Wastewater Management in Rural Areas

Management of rural wastewater mostly involves on-site treatment as there is often no interconnecting means of treating numerous residences in the countryside. In Ireland , wastewater from approximately 418,000 dwellings is treated by on-site systems (CSO, 2006). On-site systems can be subdivided into two broad categories: mechanical aeration systems and septic tank systems.

The mechanical aeration systems include biofilm aerated (BAF) systems, rotating biological contactor ( RBC ) systems, and sequencing batch reactor ( SBR ) systems. In these systems micro-organisms feed on organic materials to stabilise them, and reduce biological oxygen demand and suspended solids in the wastewater.

The septic tank system consists of a septic tank followed by a soil percolation area. As an alternative to a conventional percolation area the effluent from a septic tank can be treated by filter systems such as mound or reed beds with sand, peat, plastic or reed filters followed by polishing filters. These polishing filters reduce the level of micro-organisms and nutrients in the wastewater.

In 2009, the EPA issued a Code of Practice for wastewater treatment and disposal systems in single homes seeking planning permission. Nevertheless, none of these on-site systems are currently regulated.   Because there is a constant threat of groundwater pollution by a faulty treatment system, urgent action is required at national and local authority levels to ensure that all on-site wastewater treatment systems are constructed and maintained in a suitable manner.

Septic Tank System

Synchrotron helping transform biosolids into fertiliser

ECOS MAGAZINE

Scientists at the CRC for Contamination Assessment and Remediation of the Environment are using the Australian Synchrotron to develop a way of turning biosolids from urban sewage into a safe nutrient source for farm soils. Associate Professor Enzo Lombi and Dr Erica Donner, both also affiliated with the University of South Australia, are involved in the project. They aim to make available the phosphorus, nitrogen and potassium from biosolids, as well as organic carbon and micro-nutrients such as copper and zinc. They also want to ensure that toxic metals such as cadmium and lead in biosolids are not able to re-enter the food chain, as their presence is a major obstacle to the widespread reuse of biosolids as soil improvers. The researchers hope that urban waste can supply nutrients to help maintain the fertility of Australian soils in the face of growing global nutrient scarcities and soaring fertiliser prices. ‘Australia’s sewage works produce more than 300 000 tonnes of biosolids every year, derived from the settling process in primary treatment and the waste bacteria from secondary treatment,’ says Assoc. Prof. Lombi. ‘Most biosolids material is simply stored in huge dumps, where it poses a long-term management issue.’ The team is using the synchrotron to study the chemistry of the bonds that bind toxic metals to particles within the waste. This will enable them to pioneer new ways to bind the metals, preventing their mobility into the environment – a lower-cost solution than separation and removal.

The 3 R's of Sustainable Site Design

The 3 R's of Sustainable Site Design

I think just about everyone knows the 3 R's - "Reduce, Reuse, Recycle".  My 6 yr old has been known to recite it on occasion, and to his credit he understands at least the basics of it.  Recycling certainly gets the most air time and for the most part I think everyone associates the 3 R's with trash.  Reducing often requires some sacrifice which most of us don't like and in our expendable society reuse is more often than not ignored.  Recycling our trash is admirable and we should all do our best to do this very simple green task.  But I believe that the 3 R's have merit beyond just our consumables.  As a civil engineer and site designer I started thinking about how Reduce, Reuse, Recycle could be applied to what I do the most - site design.  Here is what I came up with - the 3 R's of Sustainable Site Design.

REDUCE
Reduce is probably the most impactful of the 3 R's - after all it is listed first.  The more we can reduce (consumption, development, etc) the less we will need to reuse and recycle.  This applies to development and construction projects as well.  If we first reduce, then we spend less time, money and energy trying to reuse, recycle, control etc.  In the early phases of our site designs we, as design professionals need to be thinking about how we can reduce:

• Impervious area - Almost always when we develop a previous undeveloped site (more on that below) we increase the impervious surface area.  By replacing pervious areas (grass, forest, brush etc) with impervious area (asphalt, concrete, roofs etc) we increase stormwater runoff, reduce groundwater recharge, increase surface temperatures and create a host of other problems.  If we first focus on REDUCING impervious area we can reduce the amount of work it takes to counteract these effects.
• Disturbance - Land disturbance damages the soil ecosystems, destroys vegetation, alters stormwater patterns and pollutes runoff.  Some of these affects can be remedied or counteracted, but if we first REDUCE the area disturbed we can reduce the impact as well. 
• Runoff - Both of the items listed above contribute to increased stormwater runoff, so the first line of defense it to reduce impervious area and land disturbance.  But you can only reduce those so much and still develop and build, but you can still focus additional attention on reducing runoff.  Many stormwater ordinances and practitioners still focus solely on flow rate reduction and not volume reduction.  To reduce the impact on groundwater resources, erosion and the hydrologic cycle we need to also REDUCE runoff volumes to at or below pre-development levels. 

REUSE

If we are to assume that reduce has the most impact judging by its place in the 3 R's then we can also assume that reuse has the second greatest opportunity for impact - which I believe is true.  In many ways reuse and recycle are interchangeable, but here we are going to consider that reuse does not require re-manufacturing, processing etc.  Can we apply this to site design?  I think so and here's how we can - reuse:

• Development sites - REUSING previously developed sites is one of the best ways to limit the environmental degradation caused by the development process.  In addition to preserving a green field site that would be used for your project you are also able to take advantage of existing infrastructure and hopefully limit the impact associated with transportation to a more remote site.
• Natural features - The natural features of a site; topography, water features, vegetation, etc have been refined over time in a way that is difficult or impossible to replicate.  Rather than working against these natural features we should concentrate on REUSING them for the benefit of the site.  This could include improving and reusing an existing wetland for stormwater management or using existing tree canopy to shade buildings and hardscapes. 
• Artificial features - As with natural features its often possible and beneficial to REUSE any existing artificial features on the site.  If there is an existing farm pond, road or parking lot on site, try to REUSE those features rather than demolishing them and starting over.  Doing this eliminates demolition waste and saves on raw materials and labor associated with rebuilding them.

RECYCLE

Last and maybe least (depending on your viewpoint!) of the 3 R's is recycle.  Recycling is certainly important, it can reduce raw material consumption, energy use and landfill space among other benefits.  It's also one of the easiest and most visible green things that you can do.  There are a lot of things you can do as a designer that the general public won't understand or appreciate but people can relate to recycling and that can propel more people to act sustainably.  So beyond our trash, what can we as site designers recycle?

• Stormwater - Traditional/conventional civil engineering wisdom was/is to get stormwater off site as quickly and efficiently as possible.  But why not RECYCLE it?  Stormwater can be captured and RECYCLED for gray water in buildings, irrigation, fire protection or habitat creation and restoration.  
• Materials - There are a myriad of opportunities for RECYCLED materials use in site development.  Recycled asphalt pavement, fly ash replacement in concrete and recycled rubber and plastic appurtenances are just a few of the products that can be specified and used in the site development process. By doing this we are encouraging recycling of materials and reducing raw material extraction and energy.
• Waste - Almost all site development projects require some sort of demolition or clearing.  Rather than hauling off this waste we should consider the opportunities for RECYCLING that waste on site.  For example, demolished concrete can be used as aggregate base for paved surfaces, cleared trees can be chipped/mulched on site and used for erosion control or landscaping and demolished asphalt can be RECYCLED into new asphalt surfaces.

I am sure that are points that I missed here so please send your ideas my way if you have any thing to add.  Ultimately, I think that the 3 R's are a good example that going green and creating more sustainable spaces doesn't have to be complicated.  In engineering school the most important thing that they teach you is how to break down a problem into simple parts - and that's what the Reduce, Reuse, Recycle mantra helps us do.  And if you're not a civil engineer or site design professional hopefully you can use the 3 R's to make your life and work more sustainable.