Urban Landscapes Update – Seattle Building Designed to be Autonomous and Green for 250 Years

Creating “living buildings” requires a new approach to design and construction that recognizes the need to reduce our energy footprint. With this in mind the designers of  the Bullitt Center, a 6-storey headquarters for the Bullitt Foundation, intend to create a sustainable office building that minimizes its environmental footprint.

The new building being constructed in downtown Seattle, and opening in late 2012, uses 1/3 of the energy normally consumed by a standard office building of equal size. The building generates its own electricity using solar arrays, collects rainwater for internal consumption, and treats sewage and wastewater on site. Although still connected to the electrical grid the building systems send power back to the grid when producing beyond the needs of its tenants resulting in net zero electricity usage from utilities.

The builders estimate costs at 33% higher than traditional construction but expect their creation to endure for 250 years. Compare that to the average office building lasting 40 years, more than justifying the extra investment in initial construction.

Located in Seattle, Washington, the Bullitt Center is a commercial building with a net-zero environmental footprint. Source: Metal Construction News

The Bullitt Center will be the largest net-zero office building in the United States. To meet the net-zero challenge the Center includes:

• Roof solar panels extending over the sides of the building and efficient enough to generate power even in a cloudy environment like Seattle
• 26 geothermal water wells, each 400 feet deep in earth to main a constant temperature of  12 degrees Celsius (55 Fahrenheit) for heating and cooling.
• A 56,000 gallon cistern for collecting rainwater from the roof through a special membrane  and ultra filtration and ultraviolet light treatment for purification.
• 10 basement composters for treating sewage which will then be turned into fertilizer offsite.
• Use of timber frames certified as sustainable wood.

The Bullitt Center is one of a few select buildings that are changing the face of the urban landscape to meet sustainability challenges.

Urban Landscapes in the 21st Century – Part 6: The Evolution of Cities

Freshwater is critical to life on this planet. Yet we are a species that treats it with such little regard considering how scarce a resource it truly is. I live in a country, Canada, that has an abundance of it. My home city, Toronto, sits on the edge of Lake Ontario, one of the Great Lakes. Those lakes account for 20% of all the freshwater on the planet. Going from rich freshwater resources to a world of scarcity is one that at times is hard to imagine. But humanity in the 21st century is on a collision course with a new reality. The planet may not have enough freshwater to meet human demands by the mid-century as global population peaks at well over 9 billion.

The largest freshwater resource comes from rivers, lakes and human-engineered catchment reservoirs created by erecting dams and ponds. Human ingenuity has the capacity to overcome freshwater scarcity. We have repeatedly demonstrated this. Take the case of Bermuda. It sits isolated in the middle of the North Atlantic Ocean, surrounded by saltwater. Bermuda has no rivers or natural lakes. Importing freshwater is cost prohibitive. Bermuda has developed a low technology solution to deal with the lack of freshwater – design roofs to capture rainwater and store it in tanks for domestic use. The government has mandated contractors to build roof structures that capture 80% of the rain that falls.

Bermuda has no running water sources and mandates home construction to use roofs to capture 80% of runoff. Source: BuildingBlox

Today, globally, the demand for freshwater is outstripping supply. Between 1900 and 1995, freshwater consumption increased sixfold, twice the rate of population growth.  In a 1997 United Nations study on freshwater availability, medium to high-water stress was reported in countries with one-third of the world’s population. Where there is freshwater stress you find equal stress on agriculture and food supplies. Freshwater stress gets complicated by seasonal variations in climate. Many water stressed countries lie in areas of the world that experience prolonged dry seasons followed by significant rainfall. From water famine  to flood it becomes difficult to develop methods for capturing water from an annual monsoon for use it the parts of the year when no rain falls.

For urban environments in the Developing World, freshwater challenges go beyond drinking water. Polluted water sources reflect a lack of infrastructure to deal with sanitation and wastewater remediation. Polluted water leads to disease. Lack of sanitation makes existing water sources unusable. Where freshwater infrastructure exists Developing World governments regulate pricing keeping it low and making it impossible for the utilities to fund new infrastructure development or maintain existing systems. This leads to dire consequences for the informal urban settlements that are now dominant in these cities. There is a lack of easily accessible freshwater access within these shantytowns, and there is even less infrastructure to deal with wastewater and sanitation.

Agriculture competes with cities for freshwater. And agricultural practices, particularly fertilizer use, contributes to pollution that from field runoff impacts water quality. This is a universal problem affecting the Developed and Developing World. Just this month a study came out from the University of California, Davis, stating that nearly 10% of 2.6 million living in an area of the Central Valley of California are being exposed to nitrate-contaminated water and that the problem is getting worse.  If nothing is done to clean up the problem, according to the report, by 2050, 80% of residents in the Tulare Lake Basin and Salinas Valley will be at risk for thyroid cancer, birth defects and fatal blood disorders brought on by high nitrate levels in drinking water.

Managing Wastewater, Wastewater Treatment and Sanitation in Developing World Cities

The Past

Sewage is the chief contributor to poor water quality in developing countries. Direct discharge of pollutant loads from domestic and industrial sources is the norm. Wastewater treatment is non-existent. Lack of proper water infrastructure leads to the mixing of human excretions with storm water. Although this may dilute fecal and bacterial content it also diffuses its disease carrying properties over larger areas.

Solutions from the Developed World are unsupportable in much of the Developing World. Centralized wastewater treatment infrastructure are far too expensive to implement. The technologies developed by Western cities do not present a good fit with local climates and cultures in the Developing World. There are numerous examples of  “Western,” colonial-built water infrastructure being abandoned because of the lack of local technical support, funding and ongoing maintenance challenges and equipment breakdowns.

The Present and Future

What can work in the Developing World to deal with wastewater and sanitation to maximize freshwater resources?

There are a number of technologies that are and will make a difference to developing cities the 21st century. These include:

1. Decentralizing the treatment of waste by treating it at the source and ensuring only minimum amounts enter the freshwater supply.
2. Building lagoons and wetlands to use natural processes to purify wastewater.
3. Implementing anaerobic treatment technologies and harvesting what is recovered.
4. Building soil aquifer treatment facilities.

1. Decentralized Treatment – In an earlier blog we described EcoTec’s experiment in building homes using recycled plastic bottles. These houses included self-contained sanitation systems for locally treating sewage, recovering the water for gardening and other uses, and using the byproducts from the solids as fertilizer and fuel. The Bill and Melinda Gates Foundation recently awarded eight grants to engineers to invent toilets that do not require connections to freshwater infrastructure. These toilets separate urine from feces. The separated urine gets heated urine to recover the water for reuse, and the nitrogen, phosphorus and potassium salts to use in fertilizer. The separated feces get mixed with materials such as ash, soil and  rice husks and then pyrolized (heated in an oxygen-free chamber) to produce biochar, ash and methane for energy. Decentralized systems like this can be implemented in each house or pooled together to serve a cluster of homes. This type of housing does not require a hookup to sanitation infrastructure making it far more suitable in the informal settlements of Developing World cities. By eliminating domestic sewage from water systems, a major source of pollution of the freshwater supply vanishes.

2. Lagoons and wetlands – Whenever and wherever possible Developing World cities should consider finding natural ways to treat wastewater. One method is creating wetlands where natural chemical and physical processes act on pollutants removing them from the water. Water hyacinths and duckweed remove heavy metals from wastewater. Bacteria and algae purify water. The biggest challenge is finding land in urban centres to create the lagoons and ponds needed to let biology take its course. Wetlands may be unsustainable in dry climates.

3. Anaerobic treatment – Using anaerobic bacteria to breakdown solid waste in water has distinct advantages. It can be as small-scale as a composting toilet as described above, or as large-scale as an upflow anaerobic sludge blanket reactor or UASB as seen in the picture below. This particular UASB serves a community of 4,000 recovering water and bio-solids that are used for fertilizer.

UASB digesters recover water from wastewater sources using anaerobic processes to breakdown solid waste. Source: Wikipedia

UASBs do not require much energy to operate which makes them very effective wastewater treatment systems for Developing World cities.  UASBs can also produce bio-gas that can used as an energy source. UASBs can be combined with other wastewater treatment technologies such as fixed film, an aerobic method of treating wastewater involving the use of a porous medium within a settling tank with repeated exposure to air. Brentwood Industries, a Pennsylvania based company, manufactures hybrid systems that combine various treatment methods for recovering freshwater from wastewater sources.

4. Soil Aquifer Treatment – Also known by the acronym, SAT, injects partially treated sewage effluent into unsaturated soils to use the natural filtering properties of the soil to further filter out pollutants. This method is suitable in dry climate zones such as the Middle East and Saharan Africa. Injected water acts as a groundwater recharge restoring aquifers. The process removes bacterial pathogens and helps reduce the concentration of nitrates in groundwater.

Urban Landscapes in the 21st Century – Part 3: The Evolution of Cities

In our last blog we described how used plastic bottles get recycled as building material in new housing projects in Sub-Saharan Africa and Central and South America. Using products we normally would throw away is one way of dealing with waste and garbage, one of our biggest challenges.

Dealing with Waste in the Urban Environment

Although cities occupy 2% of the earth’s surface, they consume a majority of its natural resources and generate more than 70% of human-activity derived waste. From earliest times we have accumulated garbage where we live or thrown it to the wayside. Archeologists and anthropologists study waste dumps created by our ancestors. Whether in cave dwellings or in early Neolithic sites garbage as a byproduct of urban living has proven to be an effective tool for understanding the way our ancestors lived.

In Classical Greece, cities like Athens handled garbage waste by developing municipal dumps outside the city walls. The Romans also used suburban dumps but added a new wrinkle, organized refuse collection. In Medieval Europe garbage and waste littered the streets of walled towns. Ditches and waterways served as open garbage dumps. Open sewers ran down the centre of many streets where accumulated garbage washed away anytime it rained.

The Industrial Revolution with ever larger urban centres required government and business to come up with better ways to handle garbage and waste management. Options included garbage as landfill, dumping, incinerating and processing to create new products. Garbage was turned into animal feed with little attention to the potential toxicity that could be passed through the food chain..

The solutions of the 19th century carried on into the 20th until well after World War II when environmental science began to influence government policy. Urban explosive growth from the mid-20th century to today has created a garbage crisis in cities in both the Developed and Developing World and sparked recycling and repurposing of garbage and waste.

Toronto,Canada is a good example of a city in transition from dumping to recycling. It took well over a century for Toronto to transition from throwing garbage away to treating it as an environmental concern. In Toronto’s 19th century years landfill sites existed throughout the city. Many buildings and homes occupied sites created from dumping of garbage for landfill. Toronto’s lakefront was a landfill site. In the 1980s Toronto ran out of local landfill and garbage dumping sites and started seeking sites many miles away from the City. That meant trucking garbage to dump it in abandoned mines or landfill dumps even beyond the Province of Ontario’s borders. For more than a decade Toronto trucked its garbage to sites in the State of Michigan. Can you imagine exporting garbage, but that’s what we were doing.

Toronto, today, runs an extensive household recycling program with curbside pickup of plastic, metal, paper and kitchen waste from single family homes throughout the City. For multiple-tenanted dwellings such as apartments and condominiums, municipal recycling remains a work in progress.

Toronto has also initiated a hazardous waste recycling program covering used electronics and paints and  chemicals. The waste we can’t recycle and reuse gets processed and shipped to landfill sites the City has acquired located 200 kilometers to the west. Toronto’ goal for recycling and reuse aims at reducing garbage by 70%.

Dealing with Solid Waste in the Developing World

Urban waste is significantly greater and very different from that produced by humans living in rural environments. The average city resident in the Developed World produces 800 kilograms (1,760 pounds) of waste annually, mostly in the form of paper, plastic and metal. In the Developing World the average waste produced by rural dwellers amounts to 200 kilograms (440 pounds) per year of which 70% is organic. As rural to urban migration increases Developing World cities will face similar garbage challenges to those of the Developed World. Do they have the infrastructure and financial means to deal with increasing amounts of garbage concentrated in urban centres? Take a look at the pictures below to see just how serious the challenge is for Developing World urban and rural environments. These pictures were taken over the last 4 years and are representative of a garbage crisis that needs immediate solutions.

Garbage in the form of plastic waste leaves its indelible footprint in rivers and on beaches throughout the Developed World. Source: Coastal Care

Going clockwise from top left, our first picture, taken in March 2009, comes from a slum in Manila, the Philippines. The shacks on the left are typical of informal urban environments in many Developing World cities. The garbage that looks like a cluttered roadway next to the homes is, in fact, afloat in a municipal creek that serves as a source of drinking water and a sewage dump.

The picture top right is contemporary to the one from Manila. It is a picture of garbage harvesters on the Citarum River, the main source of drinking water for Jakarta, Indonesia.

The picture lower right is also a recent photograph taken by a tourist of a beach in East Africa.

The picture lower left is recent as well and shows volunteers attempting to clear garbage from the water surface of a dam in Krichim, the Philippines.

Developing World cities are two urban environments in one location. The informal settlements consisting of shacks and shanty towns lack basic municipal services including garbage removal and wastewater systems. The commercial urban centres and wealthy and middle-class suburbs have infrastructure to manage waste. In the informal areas garbage harvesters have become part of the informal economy. Whether on water as seen in the pictures above or on land, human garbage scavengers, estimated at 15 million or 1% of the Developing World, recycle items found in municipal waste. This kind of harvesting provides subsistence income but does little to deal with overall growth of garbage in Developing World cities.

What do Developing World cities need to do in the near future in managing waste?

1. Create infrastructure within informal settlements so that recycling, composting, and wastewater can be properly managed.
2. Organize informal harvesting of garbage and educate harvesters to create a works program for the urban poor.
3. Invite informal settlements to come up with local ideas to improve waste management and invest in these proposed solutions.

Practical technology solutions for municipal waste include:

• Reclaiming materials from garbage for building homes and other infrastructure including: recycled paper, wood, tile, glass, tires, and metal. One U.S. company has combined organic materials found in garbage with glues and polymers and injected the result into molds to replace traditional 2 x 4s. Another, Wastaway, is producing Fluff (R), a patented product created from unsorted household garbage that can be extruded for use in building materials, or used as a soil growing medium, or for synthetic fuel production or finally, gasified, to generate energy.

Fluff(R) is recycled unsorted household garbage with many industrial uses. The picture above shows output from 2,500 typical North American households in a week, converting to 60 tons of product. Source: WastAway, LLC.

• Using rainwater runoff off roofs captured in rain barrels, and building grey water recycling systems to maximize the use of water in areas where access to clean water is limited. Evan Gant is the inventor of RainDrops, a system that attaches plastic bottles to existing roof and gutters to collect rainwater.

Evan Gant's Raindrops system is a low technology solution that uses recycled plastic bottles to capture rainwater. Source: Ecofriend

• Using waste as a fuel source for energy generation. Burning garbage has been a traditional approach to getting rid of waste, but burning it to generate power represents a solution for Developing World countries to address two challenges, growing urban waste and the need for energy. Where existing landfill can be tapped, methane can be extracted as an energy source. Garbage can also become a source of biofuel (see our reference to Fluff above). Companies like Zere are developing zero-emission biomass to energy power plants.

In our next blog we will continue our exploration of the urban landscape of the 21st century and will look at technology to deal with water and air pollution.