The
term, "ecological engineering," was first coined by Howard T. Odum in
1962. Howard Odum is now professor emeritus at the University of Florida, where
his work in systems ecology has flourished.
Ecological
engineering, he wrote, is "those cases where the energy supplied by man is
small relative to the natural sources but sufficient to produce large effects
in the resulting patterns and processes." (H.T. Odum, 1962, "Man and
Ecosystem" Proceedings, Lockwood Conference on the Suburban Forest and Ecology.
Bulletin Connecticut Agric. Station)
Another
definition that follows from that relates to ecosystem management by human society
(Center for Wetlands, University of Florida) :
"Ecological engineering is the design of sustainable ecosystems that integrate
human society with its natural environment for the benefit of both. It involves
the design, construction and management of ecosystems that have value to both
humans and the environment. Ecological engineering combines basic and applied
science from engineering, ecology, economics, and natural sciences for the restoration
and construction of aquatic and terrestrial ecosystems. The field is increasing
in breadth and depth as more opportunities to design and use ecosystems as interfaces
between technology and environment are explored."
Another
definition seeks to use the ecological paradigm to construct ecologies to solve
vexing world-class problems, such as pollution:
It
is predicated on the believe that the self-organizing order found in stable ecosystms
is so universal that it can be applied as an engineering discipline to solve the
pressing problems of global pollution, food production and efficient resource-utilization,
while providing a high quality of life for all human society. (David Del Porto)
In
this definition, the ecological paradigm reveals how to safely utilize the polluting
components of unwanted residuals, or "wastes," to ultimately grow green
plants that have value to human society, but not at the expense of aquatic and
terrestrial ecosystems. Planning, design and construction with the ecological
paradigm as a template is the work of ecological engineers.
The
Agricultural Solution to Importing Petroleum, a paper by David Del Porto [click
here for PDF]
Definitions
In
1995, Carol Steinfeld and David Del Porto wrote some definitions for Gale Publishing's
Encyclopedia of the Environment. A Sustainable Strategies engineer posted them
to the web page, simply to the boost the content. There they stayed, and over
the years, many people have told us that they found these definitions valuable.
So, to continue the tradition...
Phytoremediation,
Sanitation, Sustainable Architecture, Permaculture
Phytoremediation
Phytoremediation combines the Greek word "phyton", (plant), with
the Latin word "remediare", (to remedy) to describe a system whereby
certain plants, working together with soil organisms, can transform contaminants
into harmless and often, valuable forms. This practice is increasingly used to
remediate sites contaminated with heavy metals and toxic organic compounds.
Planning, engineering and design with the ecological paradigm as our template
is the work of Sustainable Strategies. For example, the ecological paradigm reveals
how to safely utilize all of the polluting components and water of human and animal
wastewater to ultimately grow plants that have economic value.
We use
the term Wastewater Garden to describe our phytoremediation and evapo-transpiration
approach to effluent management problems. The objective is to drain pretreated
wastewater into an appropriately engineered gardens or forests of phreatophytes:
plants known for fast growth and high water usage rates. These plants and their
microbially-active rhizosphere will transform pollutants, including the nutrient
nitrogen, into valuable biomass and use up the remaining water via evaporation
and transpiration.
Phytoremediation takes advantage of plants' nutrient
utilization processes to take in water and nutrients through roots, transpire
water through leaves, and act as a transformation system to metabolize organic
compounds, such as oil and pesticides. Or they may absorb and bioaccumulate toxic
trace elements including the heavy metals, lead, cadmium, and selenium. In some
cases, plants contain 1,000 times more metal than the soil in which they grow.
Heavy metals are closely related to the elements plants use for growth. "In
many cases, the plants cannot tell the difference" says Ilya Raskin, professor
of plant sciences in the Center for Agricultural Molecular Biology at Rutgers
University.
Phytoremediation is an affordable technology that is most
useful when contaminants are within the root zone of the plants (top three to
six feet). For sites with contamination spread over a large area, phytoremediation
may be the only economically feasible technology. The process is relatively inexpensive
because it uses the same equipment and supplies used in agriculture.
Soil microorganisms can degrade organic contaminants. This is called bioremediation
and has been used for many years both as an in-situ process and in land farming
operations with soil removed from sites.
Dr. Raskin also demonstrated
the utility of certain varieties of mustard plants in removing such metals as
chromium, lead, cadmium and zinc from contaminated soil and used hydroponic plant
cultures to remove toxic metals from aqueous waste streams.
Plants can
accelerate bioremediation in surface soils by their ability to stimulate soil
microorganisms through the release of nutrients from and the transport of oxygen
to their roots. The zone of soil closely associated with the plant root, the rhizosphere,
has much higher numbers of metabolically active microorganisms than unplanted
soil. The rhizosphere is a zone of increased microbial activity and biomass at
the root-soil interface that is under the interface of the plant roots. It is
this symbiotic relationship between soil microbes that is responsible for the
accelerated degradation of soil contaminants.
The interaction between
plants and microbial communities in the rhizosphere is complex and has evolved
to the mutual benefit of both organisms. Plants sustain large microbial populations
in the rhizosphere by secreting substances such as carbohydrates and amino acids
through root cells and by sloughing root epidermal cells. Also, root cells secrete
mucigel, a gelatinous substance that is a lubricant for root penetration through
the soil during growth. Using this supply of nutrients, soil microorganisms proliferate
to form the plant rhizosphere.
In addition to this rhizosphere effect,
plants themselves are able to passively take up a wide range of organic wastes
from soil through their roots. One of the more important roles of soil microorganisms
is the decomposition of organic residues with the release of plant nutrient elements
such as carbon, nitrogen, potassium, phosphate and sulfur. A significant amount
of the CO2 in the atmosphere is utilized for organic matter synthesis primarily
through photosynthesis. This transformation of carbon dioxide and the subsequent
sequestering of the carbon as root biomass contributes to balancing the effect
of burning fossil fuels on global warming and cooling.
Compounds are
frequently transformed in the plant tissue into less toxic forms or sequestered
and concentrated so they can be removed (harvested) with the plant. For example,
mustard greens were used to remove 45% of the excess lead from a yard in Boston
to ensure the safety of children who play there. The sequestered lead was carefully
removed and safely disposed of. Besides mustard greens, pumpkin vines were used
to clean up an old Magic Marker factory site in Trenton, New Jersey. Hydroponically
grown sunflowers were used to absorb radioactive metals near the Chernobyl nuclear
site in the Ukraine as well as a uranium plant in Ohio. The mustard's hyper-accumulation
results in much less material for disposal. The composting of plant material can
be another highly efficient stage in the breakdown of contaminants removed from
the soil.
When large plants such as willows, poplars and bamboo are
used, the idea is to move as much water through them as possible so that they
take up as much of the contaminants as possible. In 1991 the Miami Conservancy
District Aquifer Update, No. 1.1 reported that a single willow tree can, on a
hot summer day, transpire over 19 cubic meters of water (5,000 gallons)!, One
hectare of a herbaceous plant like saltwater cord grass evapotranspires up to
80 cubic meters (21,000 gallons) of water per day. Once the heavy metals are absorbed,
they are sequestered in the plants' leaves and/or roots. Any organic compounds
that are absorbed are metabolized.
Absorption of large amounts of nutrients
by plants (and only a small amount of plant toxins that might be harmful to them,)
is the key factor. Plants generally absorb large amounts of elements they need
for growth and only small amounts of toxic elements that could harm them. Therefore,
phytoremediation is a cost-effective alternative to conventional remediation methods.
Cleaning the top 15 centimeters (six inches) of contaminated soil with phytoremediation
costs an estimated $2,500 to $15,000 per hectare (2.5 acres), compared to $7,500
to $20,000 per hectare for on-site microbial remediation. If the soil is moved,
the costs escalate, but phytoremediation costs are still far below those of traditional
remediation methods, such as stripping the contaminants from the soil using physical,
chemical or thermal processes according to Dr. Scott Cunningham, a scientist at
Dupont Central Research for Environmental Biotechnology.
Plants are effective
at remediating soils contaminated with organic chemical wastes, such as solvents,
petrochemicals, wood preservatives, explosives and pesticides. The conventional
technology for soil cleanup is to remove the soil and isolate it in a hazardous
waste landfill or incinerate it.
"Phytoremediation", says Dr.
Ray Hinchman, botanist and plant physiologist at Argonne National Laboratory,
is "an in-situ approach," not reliant on the transport of contaminated
material to other sites. Organic contaminants are, in many cases, completely destroyed
(converted to CO2 and H2O) rather than simply immobilized or stored.
Salt-tolerant plants, called halophytes, have reduced the salt levels in soils
by 65% in only two years in one project involving brine-damaged land from run-off
from oil and gas production in Oklahoma. After the salt was reduced, the halophytes
died and native grasses, which failed to thrive when too much salt entered the
soil, naturally returned, replacing the salt-converting plants.
The establishment
of vegetation on a site also reduces soil erosion by wind and water, which helps
to prevent the spread of contaminants and reduces exposure of humans and animals.
Classes of organic compounds that are more rapidly degraded in rhizosphere
soil than in unplanted soil include:
· Total petroleum hydrocarbons;
polycyclic aromatic hydrocarbons
· Chlorinated pesticides (PCP, 2,4-D)
· Other chlorinated compounds (PCBs, TCE)
· Explosives (TNT,
DNT)
· Organophosphate insecticides (diazanon and parathion)
·
Surfactants (detergents)
· Nutrients (N,P,K) and organic compounds
Some plants used for phytoremediation are:
· Alfalfa (symbiotic
with hydrocarbon-degrading bacteria)
· Arabidopsis (carries a bacterial
gene that transforms mercury into a gaseous state)
· Bamboo family (accumulates
silica in it's stalk and nitrogen as crude protein in it's leaves)
·
Bladder campion (accumulates zinc and copper)
· Brassica juncea (Indian
mustard greens) (accumulates selenium, sulfur, lead, chromium, cadmi um, nickel,
zinc, and copper)
· Buxaceae (boxwood) and Euphorbiaceae (a succulent)
(accumulates nickel)
· Compositae family (symbiotic with Arthrobacter
bacteria, accumulates cesium and strontium)
· Ordinary tomato and alpine
pennycress (accumulates lead, zinc and cadmium)
· Poplar (used in the
absorption of the pesticide, atrazine)
Sustainable Architecture by Carol Steinfeld
Sustainable architecture
refers to the practice of designing buildings which create living environments
that work to minimize man's use of resources. This is reflected both in a building's
construction materials and methods and in its use of resources, such as in heating,
cooling, power, water, and wastewater treatment.
The operating concept
is that structures so designed "sustain" their users by providing healthy
built environments, improving the quality of life, and avoiding the production
of waste, to preserve the long-term survivability of the human species.
Hunter and Amory Lovins of the Rocky Mountain Institute say the purpose of sustainable
architecture is to "meet the needs of the present without compromising the
ability of future generations to meet their own needs."
The
term, however, is a broad one, and is used to describe a wide variety of aspects
of building design and use.
For some, the term applies to designing
buildings that produce as much energy as they consume. Another interpretation
calls for a consciousness of the spiritual significance of a building's design,
construction, and siting. Also, some maintain that integral to this approach is
that buildings must foster the spiritual and physical well-being of their users.
One school of thought maintains that, in its highest form, sustainable
architecture replicates a stable ecosystem. According to noted ecological engineer,
David Del Porto, a building designed for sustainability is a balanced system where
there are no wastes, because the outputs of one process become the inputs of another.
Energy, matter, and information are cas-caded through connected processes in cyclical
pathways, which by virtue of their efficiency and interdependence, yield the matrix
elements of environmental and economic security, high quality of life, and no
waste. The constant input of the sun replenishes any energy lost in the process.2
"Sustainability," as it relates to resources, became a widely
used term with Lester Brown's book, Building a Sustainable Society, and
with the publishing of the International Union on the Conservation of Nature's
"World Conservation Strategy" in 1980.
Sustainability then
came to describe a state whereby natural renewable resources are used in a manner
that does not eliminate or degrade them or otherwise dimish their renewable usefulness
for future generations, while maintaining effectively constant or non-declining
stocks of natural resources such as soil, groundwater, and biomass. (World Resources
Institute)
Before "sustainable architecture," the term "solar
architecture" was used to express the architectural approach to reducing
the consumption of natural resources and fuels by capturing solar energy. This
evolved into the current and broader concept of sustainable architecture, which
expands the scope of issues involved to include water use, climate control, food
production, air purification, solid waste reclamation, wastewater treatment and
overall energy efficiency. It also encompasses building materials, emphasizing
the use of local materials, renewable resources and recycled materials, as well
as the mental and physical comfort of the building's inhabitants. In addition,
sustainable architecture calls for the siting and design of a building to harmonize
with its surroundings.
The United Nations lists the following five principles
of sustainable architecture:
1. Healthful Interior Environment.
All possible measures are to be taken to ensure that materials and building systems
do not emit toxic substances and gasses into the interior atmosphere. Additional
measures are to be taken to clean and revitalize interior air with filtration
and plantings.
2. Resource Efficiency. All possible measures
are to be taken to ensure that the building's use of energy and other resources
is minimal. Cooling, heating and lighting systems are to use methods and products
that conserve or eliminate energy use. Water use and the production of wastewater
are minimized.
3. Ecologically Benign Materials. All possible
measures are to be taken to use building materials and products that minimize
destruction of the global environment. Wood is to be selected based on non-destructive
forestry practices. Other materials and products are to be considered based on
the toxic waste output of production. Many practitioners cite an additional criterion:
that the long-term environmental and societal costs to produce the building's
materials must be considered and prove in keeping with sustainability goals.
4. Environmental Form. All possible measures are to be taken to relate
the form and plan of the design to the site, the region and the climate. Measures
are to be taken to "heal" and augment the ecology of the site. Accomodations
are to be made for recycling and energy efficiency. Measures are to be taken to
relate the form of building to a harmonious relationship between the inhabitants
and nature.
5. Good Design. All possible measures are to be taken
to achieve an efficient, long-lasting and elegant relationship of use areas, circulation,
building form, mechanical systems and construction technology. Symbolic relationships
with appropriate history, the Earth and spiritual principles are to be searched
for and expressed. Finished buildings shall be well built, easy to use and beautiful.
Examples of sustainable architecture include:
· The NMB Bank
headquarters in Amsterdam, The Netherlands. Constructed in 1978, this approximately
150,000 square-foot complex is a meandering S-curve of 10 buildings, each offering
different orientations and views of gardens. Constructed of 'natural' and low-polluting
materials, the buildings feature organic design lines, indoor and outdoor gardens,
passive solar elements, heat recovery, water features, and natural lighting and
ventilation. Built for an estimated 5% more than a conventional office building,
the NMB building's operating costs are only 30% of those of a conventional building.
· The Solar Living Center in Hopland, California, employs both passive
and photovoltaic solar elements, as well as ecological wastewater systems.
The rice straw bale and cement building is constructed around a solar calendar.
Sustainable Architecture as a Movement
Some maintain that sustainability,
as it relates to architecture, refers to a process and an attitude or viewpoint.
Sustainability is "a process of responsible consumption, wherein waste is
minimized, and buildings interact in balanced ways with natural environments and
cycles, balancing the desires and activities of humankind within the integrity
and carrying capacity of nature, and achieving a stable, long-term relationship
within the limits of their local and global environment." (Rocky Mountain
Institute)
However, sustainable architecture does not necessarily mean
a reduction in material comfort. Sustainability represents a transition from a
period of degradation of the natural environment (as represented by the industrial
revolution and its associated unplanned and wasteful patterns of growth) to a
more humane and natural environment. It is doing more with less.
Proponents
of sustainable architecture occasionally debate the broader applications of the
term. Some say that sustainable buildings should generate more energy over time
(in the form of power, etc.) than was required to construct, fabricate their materials,
operate and maintain them. This is also referred to as "regenerative architecture,"
which John Tillman Lyle sums up in his book, Regenerative Design for Sustainable
Development., as "living on the interest yielded by natural resources rather
than the capital." Others simply see it as an approach to making buildings
less consumptive of natural resources.
Spiritual Aspects of Sustainable
Architecture
A spiritual viewpoint is that sustainable architecture is "stewardship,"
a recognition and celebration of the human environment as a vital part of the
larger universe and of humankind's role as caretakers of the earth. Viewed in
this way, resources are regarded as sacred. Another perspective is that the creation
of a building in the likeness of a living system as akin to religious, as a divine
entity creates a living order.
Although the term communicates slightly
different meanings to various audiences, it nevertheless serves as a consciousness-raising
focus for creating greater concern for the built environment and its long-term
viability. Rather than representing a return to subsistence living, buildings
designed for sustainability aim to improve the quality and standards of living.
Sustainable architecture recognizes people as temporary stewards of their environments,
working toward a respect for natural systems and a higher quality of life.
Sources:
Orr, David W., Ecological Literacy, State University of
New York Press, 1992.
World Resources 1992-93: A Guide to the Global
Environment. New York: Oxford University Press, 1992.
World Resources
Institute, "Dimensions of Sustainable Development," a report. Washington,
DC: WRI, 1990.
Nebel, B.J., Environmental Science: The Way the World
Works, third edition. New York: Prentice Hall, 1990.
D. Barnett and
W. Browning, "A Primer on Sustainable Building," a report. Colorado:
Rocky Mountain Institute, 1995.
Tillman Lyle, John, Regenerative Design
for Sustainable Development. New York: John Wiley & Sons, Inc., 1994.
Kremers, Jack, "Sustainable Architecture," Architronic, World
Wide Web page: http://www.saed.kent.edu/Architronic/v4n3.03.homepage.html, December
1996.
Permaculture
by Carol Steinfeld
Permaculture is an approach to land management that creates high-yielding, low-energy,
self-perpetuating systems whereby the functions of animals, plants, humans and
the Earth are integrated to maximize their value and create sustainable human
habitats.
Permaculture brings together disciplines relating to food,
shelter, energy, water, waste management, economics, and social sciences. It aims
to maximize a site's productivity, while maintaining ecosystems and restoring
damaged land to a healthy, life-promoting state.
The term was first coined
by Bill Mollison of Tasmania, Australia in 1972, by merging the terms, "permanent"
and "agriculture." Although originally developed for small subsistence
farms, the practice has expanded to apply to gardens and urban settings. Some
consider it a lifestyle as much as a design approach.
Permaculture principles
focus on designs for small-scale intensive systems that are labor-efficient and
use biological resources instead of fossil fuels. These designs stress ecological
connections and closed energy and material loops. The core of permaculture is
integrating working relationships and connections between all things. Each component
in a system performs multiple functions, and each function is supported by many
elements.
Key to efficient permaculture design is observing and replicating
natural ecosystems, whereby designers maximize diversity with polycultures, stress
efficient energy planning for houses and settlements, and use and accelerate natural
plant succession.
The philosophy behind permaculture is one of working
with, rather than against nature, of looking at systems in all of their functions,
and using them for multiple purposes. It is a system of agriculture that aims
to endure without constant human inputs and does not deplete the land.
According to Mollison, its basic characteristics are:
1. It makes the most
of small landscapes, using intensive practices. Ideally, nothing is wasted, and
everything is arranged so the least amount of effort is exerted and the highest
yield from the systems is gained.
2. Systems are designed that use and complement
the natural systems that are present, e.g. storm water is controlled with planted
swales, not concrete drains. The design harvests the natural flows of energy through
the landscape (sunlight, rain, plant and animal behaviors, etc.).
3. Promoting
diversity in plant species, varieties, yield, microclimate and habitat. It maintains
that, in a monoculture, a single species cannot make full use of all of the available
energy and nutrients. Wild or little-selected animal and plant species are used.
4. Each element performs many functions in the system, e.g., a fruit tree provides
not only a crop, but wind shelter, a trellis, soil conditioning, shade and roosting
for birds.
5. The long-term evolution of the land is recognized, and those
changes are incorporated in planning.
6. Agriculture, animal husbandry, extant
forest management and animal cropping, as well as landform engineering are integrated.
7. Difficult landscapes (rocky, marshy, marginal, steep) not typically suited
to other systems are utilized.
8. It involves long-term and evolving land-use
planning, using diverse flora and fauna in various ways at different times, recognizing
that different species use different nutrients and resources.
Permaculture
systems typically feature:
· passive energy systems and minimal external
energy needs
· climate control on site
· planned future developments
· provision for food self-sufficiency on site
· wastes safely disposed
of on site
· low-maintenance structures and grounds
· water
supply assured and conserved
· fire, cold, excess heat and wind factors
controlled and directed
Permaculture started as a strategy for designing
systems for "permanent" or perennial agriculture, by creating agroforestry
systems using tree crops, shrubs, vines and herbaceous plants in highly productive
symbiotic assemblages. The practice was originally oriented to subsistence farms
in Tasmania, which typically were small and on poor land. It was then extended
to include other landscapes, urban settings and climates worldwide, and has even
been applied to other systems, such as houses and factories.
Permaculture
as a Life Philosophy
Some consider permaculture a life philosophy. In this
context, permaculture emphasizes putting oneself in a symbiotic relationship with
the earth and one's community. Permaculture is oriented to place, with reliance
on native plants and a close awareness of the ecosystem. It revolves around self-reliance,
growing food and building attractive energy-efficient structures from local materials.
Designing a permaculture landscape begins with assessing a site's native
features (from soil structure, microclimates, cycles of decay, existing flora
and fauna) in order to take advantage of existing resources and to select and
adapt technologies (methods of composting, gardening, irrigation, generating electricity)
to the site.
Multi-functional living systems abound in a typical permaculture
design. The following are examples of some specific permaculture practices and
approaches:
Animals
Animals are raised for their value as producers
of food, skins and manure, and as pollinators, heat sources, gas producers, earth
tillers and pest control. For example, rabbits raised in a rabbit hutch are fed
kitchen scraps; their droppings fall to worm bins (vermiculture) as fodder for
worms. The resulting worm castings are used to fertilize gardens. In the winter,
the rabbits are harvested for their meat and fur. Also, a movable chicken hutch
can be used to place chickens in gardens where they effectively till and fertilize
the soil.
Plants
Particular varieties of trees are chosen for their
fuel, forage, material (for fences, structures and shelters), heat reflector and
windbreak values, as well as crop diversification. When they are young, the trees
may act as hedgerow, then grow to serve as a fuel source. Plants act as trellises
for other plants, screen and shade other plants, provide nutrients to plants,
cross-fertilize plants (such as varieties of plums and nuts), help repel pests,
prevent erosion and provide spare parts (grafts) for plants. Fruit trees and vines
are planted strategically around a house to provide shade. In a home's front yard,
attractive gardens feature high-yielding food, medicinal and culinary plants where
they are easily accessed. Some crops are planted for their self-propagating patterns,
such as leeks, onions, potatoes and garlic.
Water
Water harvesting
is an essential function in a permaculture landscape, and is supported by as many
components as possible. Filtration of water for animals may be provided with shells
and water plants. Water pathways are traced, and systems are created for collecting
it. Swales may direct rain water and run-off to fruit trees. Run-off water from
culverts may be directed to ponds where water plants and fish are raised, and
where it can be used for irrigation and firefighting. Water can be collected from
roofs. Composting toilets and septic systems with planted leaching beds may be
employed.
Soil Health
Insects and crops are used to aerate the soil.
Mulching, green crops, composting and strategic planting are employed to build
soil health. Permaculture grows forests and schrubs to protect the soil, and uses
plows that do not turn the soil. Food crops, such as corn and legumes, are chosen
for their low-maintenance qualities and their ability to fix nitrogen in the soil.
Shelter
Permaculture emphasizes reactive homes, sheltered from cold
winds with windbreak planting; oriented on an east-west axis facing the sun, usually
with a greenhouse; and well sealed. They should use few resources not found on
site. Shelters can be built into the earth, with living turf roofs. Also, living
trees and plants are sometimes used to create shelters.
Mollison has
written five books on the topic, including Introduction to Permaculture,
Permaculture A Designer's Manual, Permaculture One, Permaculture Two
and Permaculture: A Practical Guide for a Sustainable Future. Several
permaculture organizations and model projects exist around the world.
Permaculture offers an environmental design practice for making better use of
resources in a variety of growing settings. What started as a method for cultivating
desert land has grown into a system that integrates living systems, fostering
greater consciousness of ecosystems and helping to ensure economic and ecological
sustainability for its practitioners.
For more information about permaculture,
contact:
Permaculture Resources, 56 Farmersville Road, Califon, NJ 07830.
800-832-6285
The Permaculture Activist, P.O. Box 1209, Black Mountain,
NC 28711
Cross Timbers Permaculture Institute conducts workshops on permaculture
designs, from small animal systems to strawbale house construction. Route 1, Box
210-A, Glen Rose, TX 76043. (817) 897-9402
Gap Mountain Permaculture
Institute offers programs. 50 Bullard Road, Jaffrey, NH 03542. (603) 532-7321
Sources:
Barnes, Lee, "The Permaculture Connections,"
Southeastern Permaculture Network News
Mollison, Bill, Permaculture:
A Designer's Manual, Permaculture One, and Permaculture Two, Australia:
Tagari, 1979.
By Carol Steinfeld
Sanitation by David Del Porto
Sanitation can be defined the
measures, methods and activities that prevent the transmission of diseases and
ensure public health.
Specifically, "sanitation" refers to
the hygienic principles and practices relating to the safe collection, removal
and disposal of human excreta, refuse and waste water.
For a household,
sanitation refers to the provision and ongoing operation and maintenance of a
safe and easily accessible means of disposing of human excreta, garbage and waste
water, and providing an effective barrier against excreta-related diseases.
The problems that result from inadequate sanitation can be illustrated by
the following events in history:
1700 BC: Ahead of his time by a few
thousand years, King Minos of Crete had running water in his bathrooms in his
palace at Knossos. Although there is evidence of plumbing and sewerage systems
at several ancient sites, including the cloaca maxima (or great sewer) of ancient
Rome, their use did not become widespread until modern times.
1817: A
major epidemic of cholera hit Calcutta, India, after a national festival. There
is no record of exactly how many people were affected, but there were 10,000 fatalities
among British troops there alone. The epidemic then spread to other countries
and to the United States and Canada in 1832. The governor of New York quarantined
the Canadian border in a vain attempt to stop the epidemic. When cholera reached
New York City, people were so frightened, they either fled or stayed inside, leaving
the city streets deserted.
1854: A London physician, Dr. John Snow, demonstrated
that cholera deaths in an area of the city could all be traced to a common public
drinking water pump that was contaminated with sewage from a nearby house. Although
he could not identify the exact cause, he did convince authorities to close the
pump.
1859: The British Parliament was suspended during the summer because
of the stench coming from the Thames. As was the case in many cities at this time,
storm sewers carried a combination of sewage, street debris and other wastes,
and storm water to the nearest body of water. According to one account, the river
began to "seethe and ferment under a burning sun."
1892: The
comma-shaped bacteria that causes cholera was identified by German scientist,
Robert Loch, during an epidemic in Hamburg. His discovery proved the relationship
between contaminated water and the disease.
1939: Sixty people died in
an outbreak of typhoid fever at Manteno State Hospital in Illinois. The cause
was traced to a sewer line passing too close to the hospital's water supply.
1940: A valve [that was] accidentally opened caused polluted water from the
Genessee River to be pumped into the Rochester, New York, public water supply
system. About 35,000 cases of gastroenteritis and six cases of typhoid fever were
reported.
1955: Water containing a large amount of sewage was blamed
for overwhelming a water treatment plant and causing an epidemic of hepatitis
in Delhi, India. An estimated one million people were infected.
1961:
A worldwide epidemic of cholera began in Indonesia and spread to eastern Asia
and India by
1964; Russia, Iran, and Iraq by 1966; Africa by 1970; and
Latin America by 1991.
1968: A four-year epidemic of dysentery began
in Central America resulting in more than 500,000 cases and at least 20,000 deaths.
Epidemic dysentery is currently a problem in many African nations.
1993:
An outbreak of cryptosporidiosis in Milwaukee, Wisconsin, claimed 104 lives and
infected more than 400,000 people, making it the largest recorded outbreak of
waterborne disease in the United States.
The problem of sanitation in
developed countries who have the luxury of adequate financial and technical resources
is more with the consequences arising from inadequate commercial food preparation
and the results of bacteria becoming resistant to disinfection techniques and
antibiotics. Flush toilets and high quality drinking water supplies have all but
eliminated cholera and epidemic diaherrheal diseases.
However, in many
developing countries, such as the Pacific islands, inadequate sanitation is still
the cause of life or death struggles.
In 1992, the South Pacific Regional
Environment Programme (SPREP) and a Land-Based Pollutants Inventory stated that
"[t]he disposal of solid and liquid wastes (particularly of human excrement
and household garbage in urban areas), which have long plagued the Pacific, emerge
now as perhaps the foremost regional environmental problem of the decade."
High levels of fecal coliform bacteria have been found in surface and coastal
waters. The SPREP Land-Based Sources of Marine Pollution Inventory describes the
Federated States of Micronesia's sewage pollution problems in striking terms:
The prevalence of water-related diseases and water quality monitoring data indicate
that the sewage pollutant loading to the environment is very high. A recent waste
quality monitoring study (as part of a workshop) was unable to find a clean, uncontaminated
site in the Kolonia, Pohnpei area.
Many central wastewater treatment
plants constructed with funds from United States Environmental Protection Agency
in Pohnpei and in Chuuk States have failed due to lack of trained personnel and
funding for maintenance.
In addition, septic systems used in some rural
areas are said to be of poor design and construction, while pour-flush toilets
and latrines-which frequently overflow in heavy rains-are more common. Over-the-water
latrines are found in many coastal areas, as well.
Eutrophication
In the Marshall Islands, signs of eutrophication-excess water plant growth
due to too much nutrients-resulting from sewage disposal are evident next to settlements,
particularly urban centers. According to a draft by the Marshall Islands NEMS,
"one-gallon blooms occur along the coastline in Majuro and Ebeye, and are
especially apparent on the lagoon side adjacent to households lacking toilet facilities."
Stagnation of lagoon waters, reef degradation, and fish kills resulting from the
low levels of oxygen have been well documented over the years. Additionally, red
tides plague the lagoon waters adjacent to Majuro.
Groundwater
Pollution
There is significant groundwater pollution in the Marshall
Islands as well. The Marshall Island EPA estimates that more than 75 percent of
the rural wells tested are contaminated with fecal coliform and other bacteria.
Cholera, typhoid and various diarrheal disorders occur.
How Conventional
Systems Fail
With very little industry present, most of these problems
are blamed on domestic sewage, with the greatest contamination problems believed
to be from pit latrines, septic tanks, and the complete lack of sanitation facilities
for 60 percent of rural households. As is often the case, poor design and inappropriate
placement of these systems are often identified as the cause of contamination
problems. In fact, even the best of these systems in the most favorable soil conditions
allow significant amounts of nutrients and pathogens into the surrounding environment,
and the soil characteristics and high water table typically found on atolls significantly
inhibits treatment. In addition, the lack of proper maintenance, due a lack of
equipment to pump out septic tanks, is likely to have degraded the performance
of these systems even further.
Forty percent of the population in the
Republic of Palau is served by a secondary sewage treatment plant in the state
of Koror, which is generally thought to provide adequate treatment. However the
Koror State government has recently expressed concern over the possible contamination
of Malakal Harbor, into which the plant discharges. Also, some low-lying areas
served by the system experience periodic back-flows of sewage which run into mangrove
areas, due to mechanical failures with pumps and electrical power outages. In
other low-lying areas not covered by the sewer system, septic tanks and latrines
are used, which also overflow, affecting marine water quality.
Rural
areas primarily rely on latrines, causing localized marine contamination in some
areas. Though there have been an increasing number of septic systems installed
as part of a rural sanitation program funded by the United States, there is anecdotal
evidence that they may not be very effective. Many of the septic tank leach fields
may not be of adequate size. In addition, a number of the systems are not used
at all, as some families prefer instead to use latrines since the actual toilets
and enclosures are not provided with the septic tanks as part of the program.
Pollution from Livestock Operations
Wastewater problems also
result from agriculture. According to the EPA, pig waste is considered to be a
more significant problem than human sewage in many areas."
Sanitation
Requirements in Developed Countries
Because sanitation has become
a social responsibility, national, state and local governments have adopted regulations
that, when followed, should provide adequate sanitation for the governed society.
However, the very technologies and practices that were instituted to provide better
health and sanitation now have been found to be contaminating ground and surface
waters. For example, placing chlorine in drinking water and waste water to provide
disinfection, has now been found to produce carcinogenic compounds called trihalomethanes
and dioxin. Collecting sanitary waste and transporting them along with industrial
waste is central sewers to inadequate treatment plants costing billions of dollars
has failed to provide adequate protection for public health and environmental
security.
A New Paradigm for Sanitation
Increasingly,
the solution seems to be found in methods and practices that borrow from the stable
ecosystems model of waste management. That is, there are no wastes, only resources
that need to be connected to the appropriate organism that requires the residuals
from one organism as the nutritional requirement of another. New waterless composting
toilets that destroy human fecal organisms while they produce fertilizer, are
now the technology of choice in the developing world and have found a growing
niche in the developed world, as well. Wash water, rather than being disposed
of into ground and surface waters, is now being utilized for irrigation. The combination
of these two ecologically engineered technologies provides economical sanitation,
eliminates pollution, and creates valuable fertilizers and plants, while reducing
the use of potable water for irrigation and toilets.
Back to the
Basics
Simple hand washing is now re-emerging as the most important
measure in preventing disease transmission. Handwashing breaks the primary connection
between surfaces contaminated with fecal organisms and the introduction of these
pathogens into the human body. The use of basic soap and water, not exotic disinfectants,
when practiced before eating and after defecating may save more lives than all
of the modern methodologies and technologies combined.
Sources:
Pipeline, Summer 1996; Vol. 7, No. 3; Plumbing and Mechanical Engineer.
Salvato, J., Environmental Engineering and Sanitation, 4th ed.
Fair, Geyer, and Okun, Water and Wastewater Engineering, vol. 1.
"Sanitation Problems in Micronesia," a report. Concord, Mass.: Sustainable
Strategies, 1997.
