by Annie Birdsong
  

Modern man is ingenious, but history may still call us fools. We have harnessed the power of the atom and discovered ways to communicate instantly and travel almost effortlessly across the ether to the farthest reaches of the globe, yet we still wash human and animal waste into our bodies of water.

Consider the impact these wastes are having on a body of water that was once among the world's richest estuaries—the Chesapeake Bay in the mid-Atlantic region of the United States.

Its skies were often darkened by blizzards of snow geese and immense flocks of great blue herons, swans, diving ducks, terns, pintails, mallards, Canada geese, osprey, bald eagles and more.

The naturalist John James Audubon wrote in 1840 that when the air in the Chesapeake "turned crisp and the leaves fell from the trees, the skies filled with a million to a million and a half ducks." He described a profusion of underwater grasses that provided food for the waterfowl throughout the winter.

It was the Indians who first called this estuary Chesapeake, which means great shellfish bay—a name given for its abundance of blue crabs, soft shell clams and immense beds of oysters that filtered the entirety of the bay’s water every three or four days.

The Chesapeake Bay watershed with water treatment facilities noted as black dots. Click image for larger graphic. Graphic courtesy Chesapeake Bay Foundation.

The Great Decline

The Indians lived off the bounty of the Bay 20,000 years without degrading the water quality; but modern man brought the ecosystem to the edge of collapse in the blink of an eye—a few short decades—with modern sewage systems, agribusinesses, chemicals, large-scale, high-polluting technologies and free trade practices.

Today, oyster beds are one percent of their historic high and more than 40 percent of the waters are dead zones—too starved of oxygen to sustain aquatic life. Crabs scramble to the beaches just to breathe, the bloated bodies of dead fish wash up on the shores, and watermen pull up crab pots full of dead crabs.

And today, the seagrasses have drastically declined, just as they have across the world—a sign our water bodies are dying. Of the 600,000 acres of seagrass that once provided oxygen to the water and formed the base of a rich ecosystem, only 69,126 acres remain in the Chesapeake.

Crabs have lost a source of food: the tiny zooplankton that lived on the leaves of the seagrasses; without this food, they sometimes "starve or eat each other," and the "underfed female crabs don't have enough energy to reproduce," says Dr. Ronald Eisler, a senior research biologist at the U.S. Geological Survey's Patuxent Wildlife Research Center. Young fish, young crabs and molting crabs have lost shelter and refuge from their predators.

The underwater grasses used to be the main food for waterfowl, said Dr. Matthew Perry, a habitat management specialist also with the Patuxent Wildlife Research Center, adding that without this food source, "many ducks don't make it though the winter."
Some species of waterfowl in the Bay have declined significantly—especially redhead ducks, which have declined by 96 percent, and black ducks, which have declined by 67 percent.

As the grasses disappear, the water turns muddy. There is nothing to slow the wind-caused currents or keep the sediments from resuspending.

In the summer of 2003, fishermen reported a record
number of dead fish and crabs—excess nitrogen is to blame.
Photo courtesy Chesapeake Bay Foundation.

Awash in Waste

Scientists say one of the most significant causes of the decline of seagrasses and oxygen is both treated and untreated human excreta and animal waste. Wastewater flows into the bay from the toilets, showers, sinks and washing machines of 16 million people—around 1.5 billion gallons every day from almost 500 sewage treatment plants situated on the 48 major rivers and hundreds of smaller creeks, streams and rivers that empty into the Chesapeake from parts of New York, Maryland, New Jersey, Pennsylvania, Delaware, Virginia, and West Virginia.

The bay also receives immense quantities of manure from large-scale animal farms in the watershed. In the Delmarva Peninsula alone, there are more than 2,700 chicken farms with 623 million birds and at least 800,000 tons of waste per year.

When all areas in the watershed are included, 88 billion pounds of manure from chickens, hogs, cattle and turkeys are generated every year. Manure is often stored as a liquid in lagoons the size of several football fields. These can leak and overflow into rivers, creeks and streams, along with runoff from fields where immense quantities of manure is sprayed simply to dispose of it.

The nutrient-enriched water causes an explosive growth of tiny plants and animals that coat the leaves of the seagrasses. This film prevents photosynthesis by keeping the sunlight from penetrating the leaves and the vegetation dies.

Also, as the sewage and manure rot, the bacteria use up the oxygen in the water. The nutrients from waste, the farm fertilizers, and the nitrogen in air pollution also cause anoxia—oxygen depletion—by stimulating an overgrowth of algae; when the algae die and fall to the bottom, the bacteria that thrives on the dead algae depletes the oxygen.

In July 2003, the Chesapeake Bay Foundation led a largescale
volunteer underwater grass planting across the Chesapeake.
Photo courtesy Chesapeake Bay Foundation.

Female Urine and Feminized Fish

Another staggering problem with water treatment plants is that the urine they dump into waterways contains synthetic estrogens from birth control, which is feminizing male fish—a problem reported in the United Kingdom, but not restricted to that area. Researchers with the U.S. Geological Survey reported that waterways in the United States have levels of these substances equivalent to those levels found to be harming fish in the U.K.

Researchers with the agency detected 15 sex and steroidal hormones in U.S. streams, as well as 22 veterinary and human antibiotics, 19 human drugs such as antidepressants, and 39 industrial and household wastewater products, including plasticizers, detergents, insecticides, solvents, and disinfectants.

Dr. Susan Jobling with Brunel University in the U.K. said across England, high proportions—up to 100 percent—of male fish have been feminized to some extent, with eggs in their testes and/or female reproductive ducts.

Scientists with the U.K.'s Environment Agency said in some rivers, half the fish can no longer produce sperm and thus have a diminished capacity to reproduce.

The Breaking Point

Aquatic biota are among the most endangered of species. In the United States, 51 percent of crayfish, 69 percent of freshwater mussels, 18 percent of dragonflies and damselflies, and 43 percent of stoneflies are at risk—either endangered, threatened, presumed extinct, possibly extinct, critically imperiled, imperiled or vulnerable—according to the Natural Heritage Network, which collects information from thousands of biologists and has survey centers in all 50 U.S. states, 11 provinces and territories of Canada and in many countries and territories of Latin America and the Caribbean. The centers are often affiliated with universities or government research institutes, and the data compiled by the network is widely viewed as the most complete and detailed source of information on biodiversity in the United States.

The problem of nutrient enrichment is compounded by other sources of contaminants, such as hazardous effluent from industry, toxic runoff from roads, and herbicides. Underwater grasses began to die when the use of herbicides doubled and then tripled in the watershed, which receives runoff from 60,000 farms and countless lawns. Herbicides also volatilize into the air and are carried to the bay as gases or particulates in the fog, wind, clouds, dust, snow and rain.

Researchers from the U.S. Department of Agriculture's Beltsville Agricultural Research Center in Maryland detected 18 kinds of pesticides in the waters of the Chesapeake in the late 1990s. They also found that herbicides such as atrazine, simazine, cyanazine and metholachlor were present throughout the year, with individual concentrations higher in the late spring and summer and declining in the fall.

Sewage systems and animal farms are a threat even to the oceans. As water from bays mixes with ocean water, human and animal waste makes its way to the ocean floor. In other places there are microorganisms that can break it down, but in some places, there are few or no microorganisms because of oxygen depletion. Marine microbiologists are asking at what point we will have dead oceans. Will it be 50 years? Will it be 20 years?

A large black rat snake crosses a tidal inlet
in the marsh grass along Chesapeake Bay.
Photo by Mary Hollinger, courtesy NOAA.

Sweden Leads the Way to Sustainability

The Swedish International Development Agency has been working to promote a
variety of less "environmentally abusive" alternatives to sanitation by pulling together a network of experts, organizations and agencies across the North and South through an organization called EcoSanRes, which is managed by the Swedish Environment Institute.

"Water should not be a sink for waste," says EcoSanRes, adding that "even advanced sewage treatment plants" are degrading ecosystems and the quality of surface and groundwater with pathogens and nutrients.

The Cycles of Nature

The organization seeks to "link people and soil" by teaching them to see that once properly composted, human waste is a valuable recyclable material that can be used in agriculture to improve human nutrition—a concept the organization calls "closing the loop on nutrients." To be sustainable, the same amount of nutrients taken from a field should be returned to it in the form of compost, says EcoSanRes.

Composting human feces and urine for use in agriculture began in China during the 12th Century or before. The idea spread to Japan, probably when Zen Buddhists traveled to China to study.

Japanese farmers were greatly impressed with the gains in productivity when they used humanure as a fertilizer. They began paying people for their excreta, keeping the urban areas clean and disease free.

The Chinese composted this waste along with animal waste, grass clippings, soil brought into the village and huge amounts of mud from the canals, which was rich in organic matter from the snails and other aquatic biota that lived in the water. Using this organic matter, they were able to maintain the fertility of the soil for 3,000 years in spite of the intense usage of the land due to severe population pressures.

In contrast, the United States has "exhausted strong virgin fields" in three generations, wrote F.H. King, a professor of agricultural physics and chief of the division of soil management with the U.S. Department of Agriculture, who visited these countries in the mid 1920s and wrote a classic book called Farmers of Forty Centuries: Or Permanent Agriculture in China, Korea and Japan.

EcoSanRes says feces and urine that are composted become humus/compost that "smells like good earth" and has many benefits for the soil because it:

• Teems with microorganisms that break down organic matter and return nutrients to the soil all through the growing season, including trace nutrients such as boron, manganese, iron, copper and zinc.
• Increases the water-holding capacity of the soil to help plants withstand drought.
• Helps neutralize toxins and heavy metals in the soil so that plants do not absorb them.
• Helps plants withstand attacks by disease and insects by enhancing naturally occurring microbial agents.
• Reduces the amount of plant parasites and nematodes in the soil.
• Reduces the effects of soil/borne pathogens.

The ArborLoo portable latrine in Zimbabwe, surrounded by a superstructure made of reeds and fertilizer bags. Photo by Peter Morgan.

Ecological Toilets

The organization shares information on a variety of ways ecological toilets might be made. The most common is a urine diverting toilet, also called a dehydrating toilet, that collects urine in a separate chamber—perhaps a tank under the house.

The organization says after being stored about six months, the urine might be collected by farmers, diluted with water and used as a plant fertilizer on agricultural crops, since urine contains 60 percent of the excreted nitrogen, phosphorous and potassium.

The feces in the dehydrating toilet is sanitized in the chamber by drying it and by adding lime, soil, wood ash or other material after each use. The use of lime may enhance pathogen destruction by raising the PH.

Usually, there are two chambers for the feces, one for storage and one for active use. The material is not sanitary enough to use as a fertilizer until it has been stored for several months.

There are also composting toilets. In these, soil or wood ash are used to prevent fly breeding, reduce odor and promote composting. Screened ventilation pipes may be used to aerate the chamber with oxygen and control moisture. Layers of leaves or other organic matter are sometimes added to speed decomposition.

The more versatile ArborLoo composting toilet is similar to the other composting toilets except that it is portable and uses a pit dug in the earth to hold the waste. When the pit is three-fourths full, it is sealed with dirt, a tree is planted in it and the toilet is moved to another site in the yard.

A floating pump in New Zealand dairyland sends a slurry of water and manure to small irrigators that pull themselves across a field using water power.
Photo by Bryan Petrucci, courtesy Grassfarmer.com.

The Traditional Japanese Method of Sanitation

Many Japanese are turning to the environmentally degrading Western flush toilets that use pipes to centrally collect sewage. But in the 20th Century, the dominant Japanese tradition of handling human excreta was to collect the dry deposits in tanks below homes. A truck comes and vacuums out the tanks every month. The material is taken to one of the country's 1,800 night soil treatment plants where it is treated using one of the most advanced technologies in the world, including membrane separation for completely removing bacteria and viruses and controlling odor, as well as a process for denitrification.

An area that collects excreta in this manner might opt to treat it in an anaerobic digester, without oxygen, then in an aerobic digester, with oxygen, to reduce the bulk of the material by 80 or 90 percent and transform it into an excellent compost for farm fields.
In contrast, solids skimmed off during the sewage treatment process for flush toilets is not fit for use on farm fields because of high to very high contamination by heavy metals, such as mercury, lead, cadmium and zinc, says EcoSanRes. These substances enter sewage flows as businesses dump industrial wastes down the drain and the waste treatment process concentrates them in the sludge. According to the U.S. Environmental Protection Agency, these heavy metals can not be broken down or degraded. EcoSanRes says soil can not sustainably produce healthy, high quality food if it accumulates heavy metals, yet in many areas, including many areas in the United States, treated sewage sludge is being applied to farm fields.

Renewable Energy from Waste

The anaerobic digestion process produces a valuable renewable source of energy—methane, also called biogas, that can be used for heating water and buildings; cooking; generating electricity; drying crops; operating water pumps; running gas refrigerators; and powering vehicles. There are about 100 biogas plants in Sweden, most of them in sewage treatment plants or at landfill sites. In Malmo, Sweden, 200 city buses, 50 percent of taxis and municipal vehicles run on methane.

In Vietnam, many families have simple digesters that generate compost and biogas for cooking purposes from human excreta and pig waste. They mix the waste in a concrete container which has an opening at the bottom that allows liquid to flow into a long, submarine-shaped plastic bag, where it ferments. The methane gas flows out of the bag through a rubber pipe attached to the top of the bag into another submarine-shaped plastic bag that is affixed or floats on the ceiling of the kitchen. The methane flows out of the bag though a rubber pipe to a burner on the stove, where it is burned to cook food. A belt around the plastic bag in the kitchen can be tightened to increase the flow of methane to the burner.

Millions of digesters are in use in China, India, Vietnam ,Cuba and other countries. They are often underground and are used not only to produce compost for farm fields and biogas for cooking, but also to boil water to make steam that turns a turbine and generates electricity. These digesters help prevent deforestation, since biogas rather than wood is used for cooking.

Anaerobic digesters convert agricultural and animal wastes into fuel—and are projected to be a $14 billion industry in the United States once fully adopted. Photo courtesy Microgy Cogeneration Systems.

Cow Power and Cleaner Waterways

Some farmers are making big money off manure. Minnesota farmer Dennis Haubenschild puts the 20,000 gallons of manure generated daily by his 850 cows in an anaerobic digester that heats it to 90 or 95 degrees for about 20 days to speed the rotting process, eliminate odors and capture the methane.

When the process is complete, an engine burns the methane to generate electricity. Haubenschild sells two-thirds of the electricity—enough to power 78 homes—to an electric cooperative, which pays him the retail rate of 7.3 cents per kilowatt hour. Federal legislation passed in the U.S. in 1978 requires utilities to buy power at a reasonable rate from independent producers. Haubenschild makes over $4,300 per month.

He uses one-third of the electricity to power his electric milking parlor. And the waste heat given off when the methane is burned to generate electricity is collected to heat water that is circulated to warm the barn and heat the digester.

The digestion process leaves behind a high quality composted manure that has the consistency of crumbly cake, as well as a liquid slurry that he sprays on crops. This slurry—also called a liquor—is high in nutrients that are more readily available to crops than fresh manure. Also, if the rain washes the liquor or compost off the fields into the waterways, it won't deplete oxygen the way fresh unfermented manure does.

Haubenschild's digester cost $345,000, which he paid for with grants from Minnesota state agencies. Digesters will be used more widely when people realize that such technology need not be expensive or complex, can be made locally and can be used not only by farms, but also by homes and communities.

If we fail to implement such alternatives for dealing with animal and human waste, aquatic biota could very well go extinct, exposing huge gaps in the web of life: There would be no salmon for the bears, no trout for the eagles, no crayfish for the raccoons, no mayflies for the ducks and little or no food for uncountable numbers of species.

Fossil records show that a large loss of tiny aquatic plants the size of a grain of sand, called plankton, once caused a mass extinction where about two-thirds of life on earth died. It took the earth 10 million years to recover.

It’s better to leave future generations a rich inheritance of clean water bodies teeming with a wide variety of life.

Annie Birdsong recently graduated from the University of Maryland with degrees in political science and journalism and a minor in environmental studies. She is now getting started in free-lance writing.

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