Oysters in Virginia

Oysters are the Chesapeake Bay's best natural filters. A single adult oyster can filter up to 50 gallons of water a day. Oysters also provide essential habitat for fish and other Bay creatures. The eastern oyster is one of the most iconic species in the Chesapeake Bay. For more than a century, oysters  made up one of the region’s most valuable commercial fisheries, and the oysters which are filter-feeders continues to clean our waters and offer food and habitat to other animals.

In the 1850s, more than 150 million oysters were harvested from the Bay each year; three decades later, this number jumped to 2,000 million. At the turn of the twentieth century, the Bay’s oyster fishery was one of the most important in the United States. However over-harvesting led to the demise of the Bay’s healthy reefs. Over the decades the reefs were scraped away by dredging, oyster beds were reduced to flat, thin layers of dead shell and live oysters spread over the Bay’s bottom. These damaged habitats offer less surface area for reef-dwelling oysters to inhabit, and can be easily buried by sediment. The result has been that many wild populations of oysters are now considered “functionally extinct” because of severe habitat losses.

There is good news. The University of Virginia researchers, in partnership with The Nature Conservancy, have just published a 15-year study that demonstrates that restored reefs can match natural reef oyster populations in about six years and continue to hold strong thereafter. Oyster reefs in nature are built by the hinge-shelled mollusks. The reefs form along sand bars and muddy tidal flats, molding to contours at water’s edge and serving as a bulwark against erosion. As sea levels rise, so do the reefs – if they are healthy.

The researchers at University of Virginia found that at 16 sites in coastal Virginia, composed of 70 reefs, the researchers studied the Crassostrea virginica variety of oyster. This species better known as the Eastern oyster or the Atlantic oyster is vitally important to the seafood economy found on the Eastern Seaboard. 

Where the reefs were spared or have recovered, waters are clearer and cleaner. The oysters and bivalve mollusks, suck in surrounding water, consuming plankton and any silt and debris, then eject the water back out, free of impurities. The scientists note the oysters ability to mitigate the impact of fertilizer seepage. Oyster reefs also provide habitat for crabs and fish, supporting coastal fisheries. The study also found that these ecosystem benefits that restored reefs provide can catch up with the natural reefs within a decade—meaning cleaner and clearer water as well as habitat that supports coastal fisheries.

 “Our study shows that restoration can catalyze rapidrecovery of an imperiled coastal habitat and help reverse decades ofdegradation,” said the study’s lead author, Rachel Smith, a postdoctoralresearcher in the Department of Environmental Sciences at UVA.

Now, the Nature Conservancy and scientis are working to manage harvests, establish sanctuaries, overcome the effects of disease and restore reefs with aquaculture -hatchery-raised seed in an effort to bring back the oyster. In 2010, Maryland and Virginia embarked on a tributary-based restoration strategy that will build, seed and monitor reefs in several Maryland and Virginia waterways. This commitment was incorporated into the Chesapeake Bay TMDL restoration plan. By 2015, six Chesapeake Ba tributaries had been selected for oyster restoration: Harris Creek and the Little Choptank and Tred Avon rivers in Maryland, and the Lafayette, Lynnhaven and Piankatank rivers in Virginia. Read more about thisprogram here.

Arbor Day at Pace West School

On Wednesday, May 11, 2011 The Pace West School in Gainesville celebrated Arbor Day. I was fortunate to be able to participate on behalf of the Prince William Soil and Water Conservation District. Pace West will be moving by fall, so this year’s Arbor Day class each received a seedling to take home and care for. The seedlings came from the Virginia Forest Service.

Though Arbor Day is typically observed the last Friday in April, a day of tress is now observed around the world at different times based on ideal planting season. Wednesday, was a perfect day for planting trees in Gainesville, Virginia. Arbor Day was an early recognition of the need for sustainability in how we live on the earth.

Arbor Day was founded in Nebraska by J. Sterling Morton in 1872 when a million trees were planted in a single coordinated effort to counteract the deforestation that had occurred as trees were harvested to support the growth of the nation. In his speech to the school children who had planted and later cared for many trees, Mr. Morton described the great oneness of nature in all its parts. Man is dependent on plants for life, for the wealth, beauty and luxuriance of harvest fields, orchard fruits, forest glades, and for the recycling nutrients into the earth. Before the first Arbor Day, wood had been harvested, the lands stripped of trees, without planting to repair the waste. This had resulted in floods and droughts, infertile and barren soil, and even the extinction of entire communities as the land seemed to be used up and blown away across the prairie.

Each generation of humanity takes responsibility of the earth as trustees to hold until the next generation becomes the successors in trust. The next generation will inherit a very crowed earth in need of great care and stewardship. Trees are the first step in caring for the earth. We need to nurture and care for the trees so they in turn can sustain us. According to The Tree Folk “A single mature tree can absorb carbon dioxide at a rate of 48 lbs/ year and release enough oxygen back into the atmosphere to support 2 human beings.”

Forests which are really treed ecosystems now cover 10 million square miles of earth. There was a time when forests extended much further. Most of the cultivated and inhabited lands of today were once forests or estuaries. The demand to covert ever more land to agriculture to support the increasing human population causes the loss of the forest ecosystem and increased soil erosion and flooding. The loss of large portions of the rain forest is believed by some to be a major contributor to the increase in carbon dioxide in the atmosphere.

Trees can also reduce air conditioning and heating needs by providing shade and providing a wind shield for winter and reducing our overall use of carbon based fuels. Trees also act as natural pollution filters. Their canopies, trunks, roots, and associated soil filter polluted particulate matter out of the runoff flow towards the Chesapeake Bay. Trees also use and recycle nitrogen and phosphorus which are contributing to the decay of the Chesapeake Bay and its estuary.

Sustainable Living, Human Environmental Damage and Climate Change

Sustainable living by societies is about managing environmental resources without overexploiting what initially appeared as inexhaustibly abundant. As mankind migrated across the globe waves of extinction and over exploitation of environmental resource followed. Ancient societies have collapsed many believed to have been triggered by the destruction or exhaustion of environmental resources. Normal fluctuations in resource levels between years or decades tend to mask the signs of depletion of resources, as the current heavy rains have done in California. The complexity of ecosystem makes it difficult to know, understand and predict the consequences of human actions. Some water can be pumped from the groundwater basin and diverted from rivers without significantly impacting the water balance and ecology of the area. However, diverting all the water, over pumping the groundwater until the land subsides will destroy the ecology and watershed.

Mankind does not learn restraint easily. This is classically illustrated by “The tragedy of the Commons,” by Garreth Hardin was published in Science, December 13, 1968. The concept from the article that has survived is that what is a free and common resource is abused. Hardin said “Freedom in the commons brings ruin to all.” Because of fluctuations in “renewable” resources it is easy to mask or ignore signs of the beginnings of destruction of the water resources that California depends or any other resource that a society depends on. Fluctuations in climate or rainfall and imperfect measurements and vantage points mask trends from clear view. Despite knowledge that there are always droughts after wet years, Californians and the Western States maintain policies for rural and urban/suburban use of water and water allocations drawn up during the wet El Nino years. These are assumed to be the “normal” water allocations. In California agriculture is entirely based on profligate use of irrigation water, the vast three crops a year agri-industrial empire of this semi-arid state is based on irrigation. Water costs less than the real resource cost, so farmers plant and grow as much as their water allocation and any groundwater available can produce as the state continues down the path of ruin. Our technology and engineering have allowed us to mine the water and allow the west to expand beyond the carrying capacity of the land and the water. Vast amounts of energy are needed to deliver unsustainable amount of water to farmers and the southern cities of the state. Hard choices and restraint will be delayed until ecological and financial bankruptcy.

The "American Clean Energy and Security Act” also know as the Waxman-Markley energy bill is dead. The bill included a cap-and-trade global warming reduction plan designed to reduce carbon dioxide emissions in the U.S. It set an overall cap on such carbon dioxide emissions that decreased over time reducing what can be emitted. This was intended to push utilities and industry to release less carbon dioxide by utilizing cleaner energy sources or increasing efficiency of the existing ones. However, it probably would have achieved it’s goal by exporting carbon burning, jobs and business and the bill is probably dead because of unintended consequences to the economy. It is unclear what impact if any this failure will have on the earth’s ecology. Climate change is constant. As seen in the geological record, throughout earths’ history climates become hotter or colder, wetter or drier, more or less variable because of natural forces like volcanic eruptions, changes in the orientation of the earths axis, variation in the heat put out by the sun (it is not constant), changes in the continents. There have been ice ages millions of years ago, the often cited “Little Ice Age” from the fifteenth to the nineteenth century, climate disruptions caused by volcanic explosions, vanishing of the rivers and lakes from the Sahara leaving it a desert. Archeologists, geologists, and the human record tell us that the climate of earth is constantly changing, but there does not appear to be a single cause that explains these changes. In each change of the climate there are those societies that fail and those that thrive. The idea that we are experiencing global warming caused by man seems a little arrogant. To think that mankind, like the Sun has the power to change the climate or prevent climate change is a naïve view of the world and the forces at play. Certainly, mankind is engaged in exploiting and overexploiting the earth’s resources and there will be local ecological collapses. How we harness technology, trade and the human capacity to adapt to changing environment to respond to these changes will determine the fate of our society and others. The future will tell us if a society that has depleted its resources can survive the further depletions of resources and environment due to changes in climate.

LEED and Your Home

The U.S. Green Building Council (USGBC) are the people who created and maintain the LEED standards, the familiar Certified (used to be Green), Silver, Gold or Platinum rated buildings. LEED is the leading green building certification system, intended to verify that a building or community was designed and built using accepted generalized strategies aimed at: energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources. The standards tend to be fairly generalized and not region specific, but should be appropriately applied to produce an environmentally responsible building. LEED provides building owners, operators and buyers a concise and measurable framework for identifying, implementing and comparing green building design, construction, operations and maintenance. The USGBC has expanded these basic standards from commercial construction to operations to single family homes and now have created REGREEN Residential Remodeling Guidelines. Not all of us can rush out and buy a LEEDS certified home. There is a tremendous amount of existing housing in the United States and the REGREEN guidelines can offer a roadmap to improving the environmental performance of our existing homes. Green remodeling also reduces the environmental impacts of remodeling, including energy, water, and materials consumption; waste generation; and harmful emissions, both indoors and out. If you want to take a look at some of the things you could do to improve the environmental performance of your home, explore the ideas and recommendations on the USGBC site. An example is “Reflective (high-albedo) roofing materials can help improve the thermal enevelop of your home.

There are eight areas of consideration in a LEEDS home. How these aspects are actually measured and quantified is the basis of the LEED scoring system. The first area is indoor air quality, a LEED home is designed to maximize fresh air indoors and minimize exposure to toxins and pollutants. This involves addresses air circulation, mixing and off gassing from building materials and furnishings. The second area is energy efficiency. In general LEED homes are built to use 20-30% less energy than the standard size typical home. Larger homes and homes that do not meet the goals in other areas can up their score by reducing the energy footprint of the home with energy generation. Most of the glamorous LEEDS homes you see need to meet a very strict home energy rating index because their footprint exceeds the reference size. An expensive, but quick way to neutralize size in LEEDS score is to shoot for a net zero home.

The next area is water efficiency; here is one of many areas where the standards lean towards urban and suburban issues. According to the USBGC wasteful water use is both costly and risky and tied to wasteful energy use: According to the U.S. Department of Energy, as much as ¼ - ½ of the electricity used by most U.S. cities is consumed at municipal water and wastewater treatment facilities. The LEED home standards encourage limiting water use and encouraging water reuse with grey water systems. In reality, water availability is a local issue. My water is supplied by a private well drilled into an incredibly productive aquifer. My wastewater is treated on site by an alternative on-site septic system. Thus my water is directly recycled back into the watershed. Water shed protection is the issue I worry about not water efficiency, though two decades in California has left me incapable of wasting water and our household water use is actually very low. Site Selection is another area where the standards judge based on old preconceptions. LEED encourages homes that are close to schools, shopping, work and transit. However, my husband and I live, work, and relax from home. Access to high speed internet, cable, and food supply sources were the important location issues we considered. In truth, I leave the house on average, three times a week. Coming from California, I worried about water availability, water quality and protection of the water shed.

The other areas of the LEED scoring system are site development, materials selection, resident awareness and innovation. It is essential that building a home and living in it not cause erosion, interfere with natural habitats and pollute waterways through storm water runoff and other actions. How you live in your house is just as important as how the house was built. At the end of the process, a home is awarded points in each area. Based on the number of points it receives, the home can be certified at one of the four levels: Certified, Silver, Gold or Platinum. LEED certification is both cool and desirable; however, it is not enough to ensure an environmentally responsible and sustainable existence. That is the result of all the elements of your life. The LEEDS tools especially the REGREEN guidelines are great tools for knowing what choices we have for our homes, but the sustainability and environmental impact of our lives is based on the total of all our choices.

Irrigation and Sustainability in Water Use

"Development that meets the needs of the present without compromising the ability of future generations to meet their own need is sustainable." (World Commission of Environment and Development, 1987)

Irrigation has the potential to increase farm yields dramatically. Irrigated land is far more productive than the same lands fed only by rainfall. However, irrigation can also impact the condition of natural resources (riparian zones, wetlands, etc), while impacting the balance of surface and ground water. Not all irrigation is bad nor is it good. Irrigation like all agricultural practices must be preformed sustainability and often it is not.

In 1996 it was estimated that developed countries, irrigate on average 10% of their agricultural area, and countries in development irrigated 23% of their agricultural land, and that combined they irrigated 18% of the total agricultural area. Chronic water scarcity is away of life in large parts of Africa and the Middle East, the northern part of China, parts of India and Mexico, the western part of the USA, north-east Brazil, and in the former Soviet Union and the Central Asian republics. China, India, the United States and Pakistan have the largest quantity of land in irrigation; however, the United States with the largest total area of cultivated land has only about 9-10% of that land in irrigation. (FAO AGROSTAT Database 1998)

In 1900 the world’s population was 1.6 billion; by 1950 it had increased to 2.5 billion and 6.1 billion by the year 2000. Despite a general decline in human fertility rates world wide, world population is still growing. It is projected that world population will reach more than 7.5 billion by 2050. This alone will increase demand for food and place enormous pressure on the environment. The increased need for water to support the growing population is becoming urgent, and environmental degradation related to water usage is serious.

Fresh water (not locked in ice caps) represents less than 2% of all water on earth. Agriculture is the major user of freshwater, with a world’s average of 71% of the water use. In agriculture water is used for irrigation, and small quantities for watering animals. There are large regional variations in water use. In Africa 88% of fresh water is used for agriculture and less than 50% in Europe. The USGS estimates that 40% of fresh water in the United States is used for irrigation. There are huge variations in water use across the country. In California it is estimated that 80% of fresh water is used for irrigation that is approximately 30,700 million gallons a day for irrigation. In Virginia, in the far wetter southeast, agriculture uses only 1.5% of the annual fresh water used annually, which translates to 21 million gallon a day for irrigation. The differences between the states is the climate, California is semi arid and requires irrigation on almost all crop land, but can produce several crops a year. It rains in Virginia, but the growing season is confined to the warmer half of the year.

What the above data tells us is that California needs to get more agricultural value out of their water usage. They are producing more than three time the revenue per agricultural acre but it is requiring 123 times the water for each dollar of revenue. California is mining their water. They are using more water than is renewably available. Water is a resource that needs to be valued. The nominal price of water in California does not reflect its value and scarcity, nor does it reflect the amortized cost for mining this resource. They are misallocating this resource. The price of the food produced does not reflect to costs to produce it.

The large and growing proportion of the population living in urban areas will put considerable pressure for continued transfers of water out of agriculture to supply growing urban centers in California and the rest of the world. Other competing uses include hydroelectricity, protection of aquatic ecosystems (e.g., restoration of Delta estuary), and recreation will put severe pressure on fresh water supplies. It is important that our farming practices as well as all of man’s activities have the smallest impact on the natural balance; we can only do this by valuing and allocating our resources appropriately.

Sustainable Living with a Lifecycle Approach

The carbon footprint and IPAT approach failed to encompass the balance with which we live with the earth. When I lived in the city I did not often think about all the resources of the earth pulled to support the city entity itself. I never considered if urban living was more or less sustainable than country or suburban living. Certainly, when we worked in the city, living within walking distance of work seemed more sustainable. The work I did in environmental evaluations and redevelopment of Brownfield properties was clearly improved use or re-use of the land and a sustainable form of land use. How does the work you do contribute to the sustainability of your life? What is the cost of supplying cities with power, water and food? Is the ecological impact of a city greater than the ecological impact of the individuals merely because of the concentration of population? These are truly tough questions, and I do not have the simplicity of an answer that measuring a carbon footprint would. Truly measuring your ecological footprint and choices accurately might require some of the computing power of NASA.

All resources are finite. As humans our resources consist of money, time, passion and energy. In the end, where, how and when we deploy these resources will determine our comfort and happiness with our lives. Living within your personal means, financial means and your ecological means would be a sustainable life. The problem is how to determine what is or should be your ecological means, what is sustainable in a dynamic and interconnected environment. A useful model in sustainable living could be a great tool in decision making. In the real world of finite resources, careful consideration must be given to how and when we expend our resources. Recently, I came across an article by Phillip E. Savage, PE of the University of Michigan, “What Does It Mean To Be Green.” In the literature cited was a book, “Caring for the Earth: A Strategy for Sustainable Living,” written/published in 1991 by the International Union for Conservation of Nature (IUCN), United Nations Environment Programme (UNEP) and the World Wide Fund for Nature (WWF). Thanks to the internet excerpts from the book were available to read as well as a summary of the book. It appears to be a guide to the principles and actions of sustainable living on this earth. The first part of the book was even called “principals of sustainable living.”

There is a “popular adoption” of the book called “Caring for the Earth: A Strategy for Survival.” That is the book I ordered. The book summary reads in part, “The principles of sustainable living are respect and care for the community of life, improvement in the quality of human life, conservation of the earth's vitality and diversity, reduction of nonrenewable resource depletion, (and) maintenance of the earth's carrying capacity… Changes in community attitudes and practice in the care of their own environments, a national framework for integrating development and conservation.” Sounds like powerful and encompassing view that I hope has not been made obsolete with the passage of 18 years. Hopefully, I will find universal principles to evaluate choices.

Until I find a truly workable model of sustainable living I will try to stumble through life’s choices, balancing wants and desires with resources and trying to make good choices for us and the earth. Following a systematic plan to reduce the non-renewable the energy footprint of our home and lives. Living within the limits of the hydraulic system of the Culpeper Basin. Acting as responsible stewards of the watershed. Making responsible choices on how we spend the money we have available. For example, I will admit that for health and taste reasons (and because I evaluated the environmental impact of CAFOs in the northwest and Texas) I buy meat from what my husband refers to as the meat underground. Every six weeks or so, I drive my little hybrid on a 35 mile roundtrip to pick up my meat order from the appointed pickup location that the husband always describes this as “under a bridge by the river.” It is actually at the end of a cul-de-sac. My meat is more expensive than what could be bought in groceries (with the exception of the grass feed organic meat at Whole Foods that I buy when we are in California). My meat co-operative is a relatively local Shenandoah Valley Farmer, Joel Salatin of Polyface Farms. Just recently, Mr. Salatin and Polyface Farms received a Heinz Family Foundation Award for helping to bring about a cleaner, greener and more sustainable plant. After reading that in the local “Co-op Currents” I feel really good about all the money I spend on meat. Since I calculated that I have about 28,000-30,000 more meals to cook for my husband, they might as well be tasty, healthy and sustainable.

By the way, just in case you care, Salatin rotates his livestock’s location on the farm, so that different species are helped by the proximity of the other animals. He uses portable infrastructure and equipment, and does not use chemicals or fertilizers, instead using composting and pigs as aerators. He is too ornery and libertarian to jump through hoops for organic certification, so you take it or leave it with his guarantee. For anyone who has not spent time at concentrated feed lots or by their official government name “concentrated animal feeding operations, CAFOs, I recommend Michael Pollen’s excellent book, “An Omnivore’s Dilemma: A Natural History of Food.”

Sustainable Living and Your Carbon Footprint

All resources are finite. As humans our resources consist of money, time, passion and energy. In the end, where, how and when we deploy these resources will determine our comfort and happiness with our lives. While there are some basic truths, the optimal allocation of your resources is based on your values and goals. Living within your means and your ecological means would be a sustainable life. The problem is how to determine what is or should be your ecological means. In the real world of finite resources, careful consideration must be given to how and when we expend our resources.

A very popular viewpoint right now is sustainability is tied to the individual and national carbon footprint. Carbon dioxide is a by product of combustion, all combustion. Human beings exhale it at over 3 pounds per day for the average sedentary adult. Carbon dioxide is also released when we burn fossil fuels such as gas, coal or oil. In a natural carbon cycle, carbon dioxide is used by plants and trees. However, the belief is that we are producing more carbon dioxide than can be absorbed by the plants and trees currently available to use it because we are burning too much fuel. The fuel represents carbon dioxide that was trapped under the earth's surface for millions of years. It is believed that the human population by breathing and burning fuels has caused the increase in the carbon dioxide content in the atmosphere from approximately 250 parts per million (0.025%) to 386 part per million (0.039%) in the past 100 years.

The popular belief is that this increase in carbon dioxide in the atmosphere has caused the under 1 degree Fahrenheit increase in average global temperature since 1900. (It is to be noted that that increase was 1.3 degrees Fahrenheit when measured in 1998 and 2005, but the average temperature has fallen somewhat since then.) This theory further postulates that the overall temperature of the planet is increasing (global warming) at a faster rate now and causing the earth’s climate to change in unpredictable ways (from floods and hurricanes to heat waves and droughts). The strongest adherents to this belief, hold that the burning of fossil fuels must be reduced immediately. The goal of Cap and Trade legislation is to reduce the amount of carbon dioxide released into the atmosphere by capping the amount of carbon dioxide that can be emitted by all industry, reducing that amount each year and allowing the industrial sector to reduce their releases off the base and sell each other release permits, thus reducing the burning of fuels. The belief is that if we could reduce our carbon dioxide emissions enough we could stop the climate of the earth from changing. The models predicting this are at the earliest stages of development because our knowledge of our environment is really limited, hard data points especially for the oceans has been limited in quantity and duration.

There is a price to reducing our emissions of carbon dioxide and we need to the costs and benefits in terms of comforts, services, possessions and environmental balance before we act. It is likely very important to reduce the burning or fossil fuels and increase the planting of trees; however, we should approach this in the most cost effective manner. It is not clear how regulations to limit point source carbon dioxide release, to reduce our carbon footprint (reduce our burning of fuels) will of its self make living more sustainable. Certainly, the current fuel usage in the United States will decrease and may make the climate of the earth more stable if carbon dioxide emissions do not increase else where in the world. In addition, as the previous review of global warming research showed some research suggests that climate change may have components that are other than of anthropogenic (human) causes. Certainly, anthropogenic activity has been a contributor to the 136 parts per million (0.014%) increase in carbon dioxide in the atmosphere over the past 109 years. The exact relationship of increases and decreases greenhouse gasses to climate change is unknown, if mankind were suddenly wiped off the face of the earth as in Alan Wisman’s February 2005 essay “Earth Without People”, climate change would not stop. The climate is neither static nor fixed, but without mankind it would certainly be different.

Building a bureaucracy to measure, control and tax carbon dioxide will have unintended consequences and consume resources and energy. There is real benefit to increasing the efficiency in energy use by selecting technologies, like hybrid or dimpled cars, ground source heat exchangers, solar panels or wind turbines. There is tremendous benefit to improving insulation in buildings and homes, passive use of solar and wind. Changes in how we live; urban dweller, rural dweller, suburban dweller; whether or not we commute or if we commute using public or private transportation, alone or in a groups, our purchasing and activity choices all will impact our “carbon footprint.” However, this approach only looks at one aspect of the carbon cycle and fails to identify what is a carbon budget if such a thing exists, it does not consider the other resources of the earth. Legislating the measurement of carbon dioxide release in all things will cost money and resources and of itself will not make our lives more sustainable. Limiting carbon dioxide emission by industry might reduce the use of energy in the United States by industry. Energy will become more expensive, a reduction in use will be achieved by a rationing of energy and products by price. A greater allocation of my resources to heating, electricity and food will make me poorer though not necessarily more sustainable in my living on this earth. Too many important aspects of sustainable life are missing from this viewpoint.

Sustainable Living Rethinking the Approach

When I moved from city living to the outer edge of the suburbs sustainable living became a much more complicated topic and approach to life. In the city, sustainable living had been straight forward low impact green living. Work as an environmental consultant, recycle, choose well in purchases (local food, wine and other products), conserve water, limit travel, limit car use, live without heat or air conditioning (which is not particularly difficult in San Francisco). My footprint on the earth felt small. However, here on the outer edge of the suburbs the topic becomes much more complicated and I no longer have a firm definition of what sustainable living is, and I need to rethink sustainability and expand my view. First the easy, we do not commute beyond the walls of our home, but sustainable living is a complicated topic that needs to be fully explored.

Over the next several days let’s look at the various definitions of sustainable living. Sustainability has its earliest roots in the tools developed to assess the environmental, social and economic activities of life. The first approach that I am aware of was IPAT.
Impact = Population × Affluence × Technology
Affluence and technology were believed to worsen the impact of humanity on the natural world. This theory is attributed to Barry Commoner, Paul R. Ehrlich and John Holdren in 1971. The equation was developed in the 1970s during the course of a debate between them. Commoner who argued that environmental impacts in the United States were caused primarily by changes in its production technology following World War II, while Ehrlich (Population Bomb, 1968) and Holdren while emphasizing the role of population growth, argued that all three factors were important. There was a strong movement in the 1970’s for zero population growth and John Holdren and Paul Ehrlich strongly supported population control.

The past 28 years have given us the opportunity to evaluate these point of views. Despite widespread fears amongst environmentalists that populations would continue to expand at an exponential rate until checked by plague and famine, in recent years world population growth has slowed as women are having fewer children. This phenomenon is believed to be a result of a variation in the demographic transition theory in developed nations, as people become richer, mortality rates drop and they have fewer children. As a result, the UN believes that human population might stabilize around 9 billion by 2100. Of course, the supporters of population control questions if the earth can support 9 billion people in a sustainable fashion. I do not know what life on earth a hundred years from now will be.

History shows that Barry Commoner was more right than wrong. As time goes on we see the power of technology of production and living to change our impact on the earth. Affluence and technology have worked together in the United States to promote pollution prevention, remediation and environmental awareness. It is in the rich, developed countries that the air becomes clearer, the streams cleaner and the forests and preserves more expansive. It appears that after industrial development the next stage of an industrialized society, is environmentalism. The environmental movement and technology join together to reduce and prevent pollution in a number of industries. Waste reduction and point source reduction are the great successes of the second stage of industrial revolution. Technology can potentially take the next step into product reduction, by delivering services electronically. Consider, information and music. Just as we moved from vinyl, to CD’s to electronic music files, I am afraid that IPAT approach is very vinyl in this analysis. It appears that technology will deliver new aspects of life that are more electronic than physical, efficiencies will improve.

Currently, sustainability is tied in the public consciousness with ecological or carbon footprint. Next we will look at the carbon footprint as a method of determining an maintaining a sustainable existence.

Groundwater Use and Septic Recharge a Green Solution

It is a Common perception that Septic Systems are highly consumptive. However as studies by the USGS, North Carolina Division of Water Quality and the Dutchess County Water & Wastewater Authority have clearly shown, when designed for the correct densities and recharge rates, well (or even surface water) use combined with septic systems is highly sustainable and ecologically sound (Draper, 2006; USGS, 2002). Surface-water resources and groundwater treated in Septic onsite wastewater treatment systems are non-consumptive because they increase base flow into the watershed, and the water can be reused. Properly designed and managed traditional septic systems, alternative septic systems and clustered septic system are an effective method of waste disposal and trod lightly on the earth’s resources. According to the US EPA alternative septic systems, both single family and clustered, exceed the standards for sewage treatment plants and replenish existing groundwater systems, returning clean water to the earth’s water cycle. These alternative onsite systems can be more sustainable to the surrounding ecosystem than sewers and centralized waste treatment and are certainly less expensive for the homeowners in sparsely populated areas. However, the systems need to work properly and alternative systems with multiple tanks, compressors and various parts require consistent maintenance to continue working properly. Remember though, what goes into your septic system goes into the earth. Think carefully about the products you use to clean your house. Paint, solvents, gasoline, insecticides and poisons should never go down your drain. Every chemical you pour down your drain is buried in your yard. In a multitude of ways your yard is part of the earth’s yard.

The 2006 USGS study of water use and recharge in the Atlanta area (before the watering ban) found that average household indoor water use was 200 gallons per day and in the summer months the total water use increased to about 300 gallons per day including outdoor water use. Sustainability should be examined in light of that level of usage. The Dutchess County Water & Wastewater Authority commissioned a study by the Chazen Company at about the same time to better understand County-wide aquifer recharge rates and to provide guidance for setting sustainable development densities specifically related to the use of individual wells and conventional individual septic systems based upon average aquifer recharge. While the quantitative results of the study would apply to the soil types, rainfall and temperature ranges specific to the watershed studied, extrapolations can be made to nearby locations. The weather from New England to the Mid Atlantic to the South becomes warmer and wetter. Currently, average rainfall for New York is 39 inches per year while for Virginia it is more than 45 inches per year. The hydrologic soil groups present in New York are the same groups present in Virginia, but I would guess there is a higher concentration of C/D and D areas. The predominant area of the study, Wappinger Creek is C and C/D soil category. Chestnut Lick, a large creek, behind my house has similar soil hydrologic properties, but the soils on the acres surrounding the house contain a higher proportion of clay. This may be natural or due to the excavation associated with development of the lot and road.

Shallow groundwater flow, or groundwater runoff, intercepts the land surface, feeding springs, and creeks and seeping back into the surface waters as the perennial flow or streams, rivers and other freshwater bodies such as swamps, lakes and ponds. Deep groundwater flow also known as groundwater runout, does not intercept the land surface, flowing instead directly into the ocean. Of all the Earth’s water, only 3% is estimated to be freshwater. Groundwater is estimated to be more than 30% of the freshwater. Precipitation is the source of all groundwater, both shallow and deep. Hydrology is a young science and the modeling of the water cycle is not complete. The recharge rates and water cycle of the shallow groundwater in humid environments is much better modeled and understood than the deep earth sources of groundwater. So, while the entire water cycle is essential to man’s survival, only the shallow cycle will be discussed here.

Aquifer recharge consists of the portion of rain and snow (mostly rain in Virginia) that seeps through the soil to the saturated water zone, the aquifer. Another form of recharge is interflow which is infiltration water that flow along clay and bedrock layers, and roots to reach surface stream without entering the aquifer. Only the aquifer recharge supports wells and septic system dilution, while both recharge and interflow support the surface water supplies. In watersheds with high clay content in the soils a large portion of the rains is lost in runoff creating seasonal streams and high creek and river flow during the spring and fall rainy season. The average daily aquifer recharge (from rain and snow only excluding septic recycling) for Soils C, C/D and D in Prince William Virginia are estimated 326-583 gallons per acre. It is essential in a sustainable system that the groundwater level be maintained with recharge and adequate surface water is supplied to maintain the ecology even during drought years. My property totals more than 10 acres and our total indoor and outdoor household water usage was clocked during the early summer at between 100 and 150 gallons a day. We do not water our garden; trying to plant only what will thrive in the natural environment unaided. Virginia gets plenty of rainfall and it seems silly to plant anything that requires irrigation. Thus, not only is my septic system non-consumptive, the recharge rate vastly exceeds our water usage (and hopefully our neighbors since our water supply is dependent on total demand and recharge of the aquifer).

Though as demonstrated by the USGS studies, septic is a non-consumptive use of water, it is important that the septic system is designed and operated in a way that protects the environment. Whatever goes down the toilet or the drain goes into the earth. (See Septic Systems and the Ecologically Sustainable Life.)The Dutchess County report used nitrate concentrations at half the drinking water level as a proxy to achieve adequate dilution and natural attenuation of all contaminants. Historically, horizontal and vertical setbacks were developed without consideration of the dilution for wastewater components like nitrate, pharmaceutical residue, caffeine and other substances we humans consume, process or produce. The NY Department of Health separation distances were assumed (and these are almost identical to the Virginia setbacks), but the overall regional density of septic systems was examined to ensure that groundwater resources would not be overwhelmed by the total load of contaminants. The density recommendations were developed based on the nitrate concentration in traditional septic wastewater. Nitrate was used as a proxy because all humans produce about 10 pounds of nitrate per year, it does not easily break down and there is a drinking water standard. The target concentration was half the drinking water level to ensure all outcomes are safely below the standard since household size varies tremendously.

The Dutchess County study and the NC study found that overall average density of on-site waste disposal should not exceed one unit per 2-3 acres for an average size house to ensure water quality and recharge in groundwater supplies. The controlling factor in minimum lot size requirements in the northeast appears to be maintaining water quality, not groundwater recharge. Adequate dilution, soil filtration and time are necessary to ensure sustainable water quality. An interesting point is that it is not cost effective to install central water or waste disposal on parcels larger than about a half acre, since the cost of the piping (line connections) between parcels becomes much too high. Clustered or conservation subdivisions can be built, but need to maintain the overall density by maintaining open space. Those who live in dense population areas might want to look to the sustainable ideas of Adam Matthews and Siobhan O’Connor in Good magazine, the water issue, though, I find their idea of a composting toilet in any environment to be really scary from a public health perspective.

Septic Systems and the Ecologically Sustainable life

Your carbon footprint is not the only measure of the sustainability of your lifestyle. An ecologically sustainable life is in natural balance and respectful of humanity's dependence on the Earth's natural ecological cycles. Preserving precious water resources, clean air and open land are necessary to maintaining the earth’s ecological cycles. One of the steps that a large portion of us can take is to understand and maintain our septic systems. It is estimated by various sources that 25-35% of all US homes use septic systems.
There are many different types of septic system designs. The most common type used for single family homes consists of a septic tank and leach field. A septic tank can be an anaerobic (without air) tank or an aerobic tank (with air). The anaerobic system is a single chamber tank that receives the toilet and drain waste from the house and allows the solids to settle down to the bottom of the tank where the anaerobic bacteria that live in the tank digest the organic materials while the effluent (water around all that stuff) flows out to the leach field to be purified by passing through soil until it reaches the groundwater. Scum consisting of oil and grease floats on top of the water layer and can be pulled into the leach field limiting its effectiveness.
The septic tank effluent water is either pumped or allowed to flow to a leach field or other soil absorption system, where it percolates into the soil, which provides final treatment by removing harmful bacteria, viruses, and nutrients. Suitable soil is necessary for successful waste water treatment. The “percolation rate” is the rate at which water moves through soil. The acceptable rates are between one minute and one hour per inch of soil. Take either more or less time for the water to pass through your soil and the natural soil is unsuitable for treatment of the waste water. If the water moves too slowly through the soil the leach field will flood with contaminated, foul smelling water or the water will back up into the house. If the water moves too quickly thought the soil the water will be untreated and contaminate nearby ground or surface water.
An aerobic system consists of a multi chamber tank or several tanks. After separation of solids in the first tank waste is forced through a filter into a second chamber or tank where air is pumped in to enhance aerobic bacteria which decomposes the organic material. The waste then flows into a third chamber or settling chamber which collects the bacteria and passes the liquid on to the leach field or drip field. Aerobic systems can remove more than 90% of the organic material and suspended solids within the tanks themselves, but require much more maintenance. (These systems are like the British sports cars of the septic world.) The biological load delivered to the leach field or other absorption system is much reduced and would allow (if permitted under regulation) the successful treatment of septic waste where soils are rocky, impermeable or groundwater is particularly shallow.
Indoor water use in the typical single-family home is between 50-70 gallons per person per day. Septic systems are sized by bedrooms, which is an estimate of the number of people living in a home. However, even if the number of people living within your home is appropriate for the size of the septic system, you can still overload the system. Use too much water in a short period of time and the system will be overwhelmed. Each time the system is overwhelmed untreated sewage will leave the tank and begin to clog the leach field. A leaky toilet alone can add as much as 200 gallons of waste water to the system each day. The less water used the less water enters the septic system, and reduces the risk of failure. If the amount of waste water entering the system is more than the system can handle, the waste water containing raw sewage eventually backs up into the house or yard and creates a health hazard. By the time you can smell or see a problem, however, the damage to the leach field might already be done. Replacement of a leach field can run to the tens of thousands of dollars. So caring for your septic system not only cares for the earth but also cares for your wallet. By limiting your water use and spreading out peak demands on the system you can reduce the amount of waste water your system must treat. When you have your system inspected and pumped as needed, you reduce the chance of system failure.
The US EPA’s Homeowner’s Guide to Septic Systems is a terrific basic guide to caring for and maintaining your septic system. Follow the Dos and Don’ts and your septic system may last forever. Remember though, what goes into your septic system goes into the earth. Rethink the products you use to clean your house. Paint, solvents, gasoline, insecticides and poisons should never go down your drain. Every chemical you pour down your drain is buried in your yard. In a multitude of ways your yard is part of the earth’s yard.