UPDATED: 12/07/99 UPDATED: 12/07/99 
MICROBIOLOGY | GENETICS | MEDICAL
INFANT DIARRHEA VACCINE 12/8/98
Snakes and Lizards and Salmonella: 11/16/99
Some bottled water is not pure 3/30/99
Water is essential for the well being of all living organisms. Evidence indicates that #life originated in the primitive ocean approximately 3.5 billion years ago. The blood in our veins closely approximates the composition of sea water. Some biologists even consider terrestrial life an extension of the ocean that has developed the means of packaging sea-water so that it can navigate on dry land or in fresh water (Discover Oct. 1995 pg. 76). Water has shaped evolution so that biochemistry must be considered from the perspective of its relationship to water. In earlier chapters I stressed the concepts of the #hydrophilic and hydrophobic nature of biological molecules; emphasizing that they are always described in terms of this relationship to water. These water-loving/hating interactions ultimately determine the shape of biological molecules and in so doing, decide the #SPECIFICITY that is a universal principle of living processes. You have seen how the change in a single base pair in #DNA that results in a subtle alteration in the shape of a crucial molecule can produce a genetic disease. Such alterations usually reflect minuscule interactions between a molecule's components and water.
All microbes live in an aqueous environment. Without water they either perish or become inactive. The ecology of aquatic environments is complex and our understanding of them is limited. Most aquatic environments are teaming with life. #Microbes have evolved that can live in saturated salt (sodium chloride) solutions at temperatures from below freezing to >110oC; they thrive in waters full of toxic substances like copper, cyanide, lead, silver, gasoline, oil, benzene, and a plethora of other noxious natural and man-made substances. It is a NEAR NATURAL LAW that where liquid water, an energy source and basic nutrients exist, you will find living microbes. This is why the scientific community is so interested in finding water on Mars or any other planet/moon in our solar system.
Water is of vital importance to man for several reasons. First, as with all other life forms, it is required to MAINTAIN human existence. A person may survive for weeks without food, but only a few days without water. Water is crucial for the growing of our food and the operation of all our industries. Finally, it is a major vehicle of a number of water borne diseases that have shaped history in the past and will certainly continue to do so in the future. For example, the Middle East, where we recently went to war, is mostly a desert with a rapidly growing population of diverse people who really don't like one another. The Jordan River, the major source of water for Israel, Jordan and Syria, is, by standards here in the WATER-RICH Northwest, a trickle that we'd laughingly call a "river". Yet, the US is willing to defend one or more of the countries in this region, when their survival depends on this tiny TRICKLE OF WATER that's not much larger than the South Fork of the Palouse that runs through Pullman. Many people consider it likely that the next war in the Middle East may be over WATER and not OIL.
The importance of water in our lives is often overlooked because of its seemingly endless supply. Here in the NW water literally rains down upon us much of the year and if we drive a few miles in any direction we cross humongous rivers, plugged by tremendous damns and spanned by impressive bridges, that they tell us once contained a plethora of fish. Further, a half day's trip takes us to the Pacific Ocean, whose immensity and water content boggles the mind. Finally, 70% of the earth is covered with water, which is a whole lot of WET by anyone's definition. Surrounded by this plentiful supply of moisture it is hard to imagine that we could ever be short of water.
However, as I will demonstrate, the addition of three descriptive terms in front of the word WATER changes the entire picture. These words are: POTABLE, POLLUTED and FRESH. We will be considering water from the microbial perspective of disease, but really we're talking about pollution and when we're discussing water pollution we're really talking about poop, feces, excrement etc. Time, unfortunately does not permit the examination of other related areas such as the diversity of microbial forms in aquatic habitats and their influence on the ecosystem.
Gentle reader I have a problem I need help with. In these next two chapters I use the term "poop" liberally when discussing fecal pollution in water and food. I admit to doing this for its "attention getting value" and in an attempt to lighten up the subject a bit, but some of my more delicate readers have complained about being "uncomfortable" with that term. In fact I've been told I'm "poop obsessed" (perhaps an event in my childhood). Give me your thoughts on this and if you don't like the term let me know what I can use in its place that will equally catch your attention.
Because of a need for a stable water supply humans always built their communities on or near a water supply. However, this has also led to an unfortunate tendency to dispose of our wastes in the same place where we obtain our drinking water. This presented little problem when the population was small and nomadic, for when the stink of a camp became offensive, our nomadic ancestors picked up and moved the tribe a few miles up or down stream or over the hill to the next stream. Mother nature then stepped in and rapidly recycled the few wastes left behind. With the coming of AGRICULTURE, PERMANENT SETTLEMENTS and LARGE POPULATIONS, it became impossible to move people to a clean habitat; besides someone usually was already there and they generally took serious umbrage when the new arrivals told them to move on. This probably accounts for the bad attitude of the American Indians towards the settlers. Find out about life in the Middle Ages.
This then sets the scenario: A BURGEONING HUMAN POPULATION UNABLE TO MOVE AWAY FROM ITS WASTE. The following are recent cases that affect us directly:
Even a mild case of diarrhea costs ~$280 for treatment and diagnosis.
In 1993 the Cryptosporidium outbreak in Milwaukee cost
$55 million.
In 1997 the Pfiesteria outbreak in Chesapeake Bay cost
$43 million dollars in economic losses.
During 1996 there were 3,700 beach closing and advisories due to contamination.
WATER FACTOIDS
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POTABLE
(CLEAN) WATER = Water that is free of all objectionable
material, including pathogens, tastes, odors, color, minerals, toxins, radioactive
material, organisms, oils, gases etc. It can contain high concentrations of some minerals
(e.g. calcium and magnesium) and gases like carbon dioxide; the key word being OBJECTIONABLE. That is, it doesn't
have to be toxic or contain pathogens for it to be non-potable.
FRESH
WATER = non-salt or -sea water.
POLLUTION = Anything that makes water NON-POTABLE (does not have to be a poison or
pathogen).
SEWAGE = The combined community waste or all the GARBAGE that mother nature and we dump
into the sewers of a community.
TOTAL AVAILABLE FRESHWATER:
Wt = Wc + Wp
NUMBER OF HUMANS:
H.
AMOUNT OF FRESHWATER POLLUTED BY HUMAN ACTIVITY:
U.
AMOUNT OF NATURALLY POLLUTED FRESHWATER:
N
AMOUNT OF POLLUTED FRESHWATER HUMANS CONVERT TO POTABLE WATER:
O
AMOUNT OF AVAILABLE FRESHWATER PER HUMAN FOR ALL THEIR ACTIVITIES:
Wa = Wt/H
AMOUNT OF POLLUTED FRESHWATER:
Wp = U + N - O
TOTAL AMOUNT OF POTABLE WATER:
Wc = Wt - Wp
DECLINING. AMOUNT OF POTABLE FRESHWATER PER HUMAN:
Wpw = Wc/H
EXTRA CREDIT
COMMENTARY: 17A
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Our ancestors may have been technologically challenged, but they were not stupid. It was easy to deal with human waste when all you had to do was step a few yards into the woods to answer the call of nature, but as towns and the population grew in size, the woods became too distant for routine visits. People soon realized that a little bit of human excreta goes a long ways, aesthetically speaking. As the odor, and the flies, increased, they eventually decided that something had to be done about getting rid of the unmentionable stuff. So communities came together to work out what to do with all the...well you know what....that was piling up and driving down property values. It might be that TAXES were the result of communities having to pool their resources to build defensive barriers to keep out their neighbors and sewage systems to remove their wastes. There are people today who intimately link taxes and feces.
The first recorded toilets and sewers were built around 3,000 BC in several parts of the world, including the Orkney Islands and India/Pakistan. A system of channels on the Orkney Islands drained wastes from toilets in the homes into the sea, whereas cities in India/ Pakistan built open drains 2 ft deep by 7-10 inches wide along major streets through which the wastes were flushed away; many of these open sewers are still in use today. Cities in Iran/Iraq had communal toilets in 2,300 BC and the Minoans of Crete had toilets and elaborate sewage systems in their palaces about the same time. Athens in 400 BC piped the wastes from homes to cesspools in the streets.
The Romans, being a social people, favored communal toilets that could seat 10 to 20 people in public lavatories located over flowing water to carry the wastes away. It is reported that they carried out business and politics in these facilities. Perhaps this led to the idea expressed by many that politics is "in the toilet". Toilet paper equivalents were a problem and it's likely that most people used a communal cloth and a pot of water (YUCK), reusable sponges attached to a stick (YUCK again), moss, hay/straw (probably where the term "HARD ASS" originated) and/or grass (OUCH). Real toilet paper appeared in China in 589 AD, but it did not become wide spread until about 100 years ago. It is probably true that EVEN TODAY most people on the planet do without toilet paper, which may explain why so many people are in a bad mood much of the time. Larger Roman cities had extensive, often underground, sewage systems, some of which still function today. The larger drains in Rome were big enough to drive a horse and cart through. In Pompeii one can see the sewage drains running down the center of the streets. Freiburg Germany (where I spent a sabbatical) has a system of channels with flowing water running through the town (in which the community's children now play); these are now "decorative", but in earlier times they served as the town sewers.
Figure 1. Functional European water systems in Germany and Italy. The picture on the left shows a flowing channel that runs through the city of Freiburg, Germany; it is for show & is not officially used as a sewer. Those channels are hazards for drunk drivers, who frequently end up in them. The picture on the right shows a fountain in an Italian community that still supplies water; note the support bars where buckets are placed when being filled. Behind the fountain is a channel/drain running down the center of the street.
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As the population and towns grew in size, the problem of obtaining fresh, clean water also increased. The Roman world is festooned with aqueduct ruins, some of which still work, at least over short distances. A major consideration of every Roman leader was insuring that the citizens of Rome had a constant clean supply of water. Water was brought to Rome from the mountains via an extensive system of aqueducts that spanned mountains and valleys. There were over 250 miles of water conduits inside Rome proper feeding a system of fountains that supplied citizens with fresh water. These fountains are still scattered throughout Rome today. Slaves, labored constantly repairing and maintaining the water system. In India and Pakistan remains of water pipes of clay sealed with asphalt dating back to 2,700 BC have been found. Copper water pipes were used in Egypt as early as 2,450 BC. For more details on ANCIENT TECHNOLOGY read "Ancient Inventions" by P. James & N. Thorpe.
Every water supply system is constantly in danger of contamination. Before the #Germ Theory of Disease few people recognized, other than from an aesthetic standpoint, the need for a "clean" water supply. You have seen how, by using statistics, #John Snow, in 1855, connected polluted water with human disease. We realize today that throughout history most humans routinely drank contaminated water and that this situation still applies to the majority of humans on the planet. When the population was small and scattered, the outbreaks of water borne diseases were confined to concentrations of humans such as those in a single city or army. However, as population increased and travel accelerated, the combination of improved disease transmission, crowding, poverty and ignorance resulted in extensive water
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borne epidemics and in the water being increasingly contaminated with human fecal waste containing pathogens. Microbes have #evolved to take advantage of water as a mode of transmission of intestinal disease. Consider the advantage in transmission for an intestinal pathogen to induce massive diarrhea in a host. (Evolution of Virulence, Sci. Am. Apr. 1993 pg., 86; Discover Mag. Oct. 1995, pg. 111)
Following the collapse of the Roman empire vestiges of the Roman water technology continued being used throughout Europe. Many villages and towns piped water to central fountains from nearby streams or springs, or diverted streams through channels in the towns. Centrally placed wells also supplied water in many cities. Sewage disposal continued to be a severe growth-problem as the size of cities grew. Many people, lacking toilets, used chamber pots which they emptied every AM in the streets or alleys. The stench in London in the summers throughout the middle ages and beyond was reported to cause grown men to faint and horses to collapse in their harnesses. Slowly however, the idea of sanitation began to take hold in the 1700s and accelerated through the 1800s. However, Queen Victoria's husband is reported to have died in 1861 of typhoid, indicating that even the Royal family apparently drank fecal polluted water. The idea of supplying water to the inhabitants of cities developed along with iron technology that made the manufacturing of inexpensive pipes possible. Private water companies were formed throughout Europe to supply communities. The idea of filtering polluted water through sand to purify it appeared first for private homes of the wealthy and later for municipalities. With the establishment of the relationship between bacterial pathogens and water polluted with human wastes in the late 1800s, and worldwide communication that spread the stories of epidemics, people began demanding safe water; even if it involved taxation. To meet these demands it, in turn, became necessary to do something about the prodigious quantities of RAW SEWAGE spewing forth from cities and industries into the local water sources. As a consequence, sewage treatment technology developed in the early 1900s, but it was only applied throughout the US in the last 30 years through the passage and enforcement of federal laws like the Clean Water Act. As a microbiologist it is my responsibility to suggest that SERIOUS CONSIDERATION should be given before removing federal regulations on water pollution and water standards. Another review of the history of plumbing; another short history of how we human handle our waste; If you're xenophobic here's a history of plumbing in America.
TRIVIA QUESTION: Who is considered the inventor of the modern flush
toilet? ANSWER: Thomas Crapper. People said that "he
was flush with success". Consider that if you want your name to roll off
the lips of millions of people everyday what you have to do. Don't find a cure for cancer
or AIDS, or win a war, but invent a better toilet. Then people will constantly refer to
you. Like; "You're full of C......" or "That's a lot of C......"
or,..... well you can think of other examples I'm sure (COOL). Visit this information-filled site on T. Crapper
(if you have the stomach for it); here's another Crapper
site; meet T.
Crapper.
In spite of a SCIENTIFIC UNDERSTANDING of the need for potable water, obtaining and maintaining an unpolluted water supply remains a major problem, even in the DEVELOPED WORLD. Why should this be the case when surely no one wants to drink polluted water; especially water containing human or animal excrement (DUH!)?
The answer is complex. One problem, discussed above, is that people see so much apparently "clean" water around them that it is INCONCEIVABLE that water is in short supply or that it should cost serious MONEY. Another major problem is the PERSPECTIVE that things like water, air and wilderness areas all are part of the COMMONS to be exploited by the many and the RESPONSIBILITY of no one. Finally, there is the problem of the:
"Frog in the Frying Pan".
Did you hear about the witch who parked her broom in a NO PARKING zone and she was toad! |
A stable potable water supply for a population can only be achieved through community action involving taxation. Unless people see a "clear and present danger" (their personal threshold is exceeded), they are generally resistant to increasing their tax burden. As the demands for water increase, the conflicts over its use and the increased cost of keeping it unpolluted or removing the pollutants will continue to cause stress in our society. It is going to take all of our ingenuity to solve these dilemmas.
For example, take the situation of WETLANDS. Even the definition of what constitutes a "wetland" is controversial. Is it LAND that is wet all year long or only PART OF THE YEAR? If the latter, how much of the year does it have to be wet to be defined as a wetland? For this example I will define a WETLAND as: An area that is underwater or swampy all the time or for several (6 to 8) months of most years, but when under water, the water may not always be deep. Ecologists have shown that "wetlands" play an important roll in the ecology of the water cycle and in the economy of the nation. These are listed below:
Wetlands act as huge sponges ABSORBING excess water during
periods of heavy precipitation and flooding.
By serving as a place where EXCESS WATER from rivers and lakes
collects and is absorbed, wetlands DECREASE destructive flooding. Coastal wetlands provide important buffers absorbing the
force of waves from fierce storms thereby minimizing beach erosion.
The soaking up of the water in wetlands
recharges underground water sources.
Wetlands, especially coastal ones, serve
as the habitat for a large number of species that do not exist elsewhere, such as
alligators, numerous fish species, and large numbers of aquatic birds. Saltwater marshes
are the zones of the HIGHEST BIOLOGICAL PRODUCTIVITY on earth. About 75% of the US's economically important fish stock is dependent
at some point in their life on wetlands.
Water fowl, like ducks, rely upon
wetlands for breeding, feeding and over-wintering.
Wetlands are the largest, LEAST EXPENSIVE and MOST EFFICIENT water purification
systems known. The abundant microbial and plant life in wetlands removes vast quantities
of pollutants, producing virtually pollutant-free water.
Commercial and sport fishing now
contribute $152 billion to the country's economy and provide jobs for about 2 million
Americans.
FAQ: "With all these benefits, why are wetlands so controversial?"
ANSWER: "Wetlands are often commercially very (I mean serious, big megabucks) valuable.", to whit:
Because wetlands are usually FERTILE, FLAT & SHALLOW they
make prime farm land that are inexpensively drained.
Because of their vast area, often on
the SEA SHORE or NEAR CITIES, they offer a ready
source of inexpensive, flat land that can be economically filled in (e.g. San Francisco
Bay) for commercial use (read: instant boodle for the speculators and developers).
Because wetlands are seen as COMMERCIALLY UNPRODUCTIVE (birds,
fish and insects don't pay taxes) because they don't directly contribute to personal or
business taxable income, they are generally viewed as being "WASTE LANDS".
Coastal wetland are prime areas for
commercial and recreational development; the lure to turn "seemingly unproductive, mosquito-ridden-swamp land" into homes, factories, shopping malls and hotels is powerful as it means
jobs, homes and tax money for a region and profits for the developers in the short term.
Because current ENVIRONMENTAL LAWS prevent commercial development of many wetlands, even those owned privately, there is IMMENSE PRESSURE to remove these restrictions. Senate bill 1373 (offered Fall of '95), for example, would have allowed the commercial development of huge areas of wetlands across the country, but it did not become law. However, similar legislation to remove protection from the remaining wetlands come up every year in Congress. Currently it is estimated that approximately 50% of the wetland of the US have been lost and we are continuing to lose wetlands at the rate of 117,000 acres a year.
Deciding the balance between keeping and commercializing wetlands is difficult. Destruction of duck habitat, for example, lowers bag limits, shortens the duck hunting seasons and negatively effects the businesses supported by that sport. The increased flooding of lands adjacent to rivers because of the loss of wetlands costs society and individuals money in the form of DAMS & DIKES to control the flooding and DISASTER PAYMENTS for people hurt by the floods, as well as funds to CLEAN UP after floods. All this money comes from the GENERAL TAX FUNDS (that's you and me folks). Polluted water that is purified by passage through wetlands washes directly into rivers, lakes and the ocean once the wetlands are eliminated, which in turn, destroys fisheries and recreational shorelines. The USERS of that polluted water now have to pay for the building of additional WATER-PURIFICATION PLANTS to remove the EXTRA pollutants (more TAXES). The loss of fish from the pollution and destruction of the of the saltwater marsh fish-nurseries is reflected in a DECLINE IN FISH CATCHES with a resultant increase in the PRICE of fish and the LOSS OF FISHING JOBS and the sports fishing industry. It is not easy to determine if the increased taxes and job income that results from the conversion of the wetlands to commercial usage completely covers these losses. It will be most interesting to see the outcome of this struggle.
EXTRA
CREDIT COMMENTARY: 17B DIANA BAKER dmbaker@wsunix.wsu.edu If the wetlands help to purify the water then maybe there could be a way to prevent the floods without the extra expense of the clean up after floods. Is there a way to find a balance between the wetlands and commercial usage? The loss of the wetlands can cause a large impact on local fish gaming and the jobs that surround fishing. Wouldn't that cause more taxes and increase the price of fish later? I think that the government should control gaming to protect jobs and the sport of gaming. Not all the water purification plants actually clean the water completely. Most systems seem to flaws, so isn't it safe to say that natural resources would be a better filtering system? I believe that it would be a losing battle if there was a conversion of the wetlands to commercial usage. Rebecca Pavlicek bpavlicek@hotmail.com I do not believe the destruction of the wetlands is an economically sound idea because the developing companies are not looking at the long term financial costs to the community. The developers build their malls and houses, collect their money, and then move on to another place. They do not seem to care about the problems which are later faced by the people who move to these filled in areas. Many people have come to realize the value of wetlands which is apparent because many countries are spending mass amounts of money to build and rebuild wetlands to combat many of their problems, especially the big problem of erosion. Also people are coming to realize the potential gold mine that wetlands can be when you bring in the hunters, fishers, and related sports industries. I just hope that these people can combat the developing industries before it is to late and all of our wetlands and related animals are gone. I believe that if you want a new place to live rebuild one of those old run down areas that you commonly find in the city areas because everyone knows that those places need a face-lift. Erin Merk emerk@mail.wsu.edu I feel this issue is one that will be very hard to solve, and one that will not be solved for a long time either. Both sides have great benefits, but is there a way for compromise? Can we save enough wetlands to save the ecology of our water cycle and commercialize some to create jobs and help boost our economy? I feel I will have to leave my questions to experts. Both sides are so important and I think money will play a large role in the determining factors. Holly Cutler eatchoklit@yahoo.com I think it is sad the way most Americans view nature because it is a beautiful thing that contributes so much to our lives. Growing up in Washington I have come to appreciate all types of landscapes including the ocean, mountains, lakes, rivers, farmland, cities, dry desert like areas and even wetlands which most consider to be swamps. Commercial areas are important but nature needs to be preserved as well. Wetlands have many functional purposes like the net-text expressed and cleaning polluted water is the most important to me. Unfortunately I don’t think many people know this benefit and it should be more widely advertised. I often hear people claim the only reason wetlands are needed is for wildlife and human needs are more important. If these individuals knew the wetlands contributed something to their lives they would be more supportive in protecting them. Polluted runoff is the largest cause of water contamination in the United States and having wetlands could significantly decrease the pollution and provide more clean water (Sibbing). An increase in the supply of potable water would benefit all humans. Organizations like the Clean Water Network should advertise such information rather than taking the animal approach to gain more support. Furthermore, I view it as the government’s job to decrease the acres of wetlands being destroyed. Permits have to be issued before the land can be filled or drained so the government has an easy way to limit construction. They have done a poor job but strengthening the Clean Water Act should help change the problem. In 1996 99.7 percent of applications submitted to develop a wetland were granted (Sibbing). Saving only 0.3% will only destroy the environment and the effects will be felt within our lifetime. Lastly, people living in the Northwest see a large amount of wetlands, which give the impression they are in abundance. Over half of the wetlands in the United States have already been destroyed however and citizens need to realize the impact of their loss (Filter the Truth Out of Wetland Myths). The Northwest has already seen a sharp decline in the number of fish, which is an important industry. Overall citizens should realize that just because a large amount of water is around loosing some would still hurt the environment. Works Cited Filter the Truth Out of Wetland Myths http://www.sierraclub.org/planet/199710/myths.htmlSibbing, Julie. Wetlands: Nature’s Filters for Clean Water. http://www.cwn.org/docs/facts/wetlands.htmBrian BloomfieldBloomfieldbrian@hotmail.com I definitely know that wet lands are not "WASTE LANDS," but I don’t think that the answer is to make all wet lands a non-building zone. My grandfather is personally faced with this exact same problem. My grandpa owns a bunch of timber. Every once in a while he logs some of his land, getting a substantial part of his income from the timber. Lately environmentalist have been pushing to make 20 to 30 percent of his land, wet lands. This means that he would never be able to do anything with this land. My question is: Who is going to pay for the lost timber and the lost land, and why should a person still have to pay taxes on this land? We must remember not all wet lands are being consumed by multimillion dollar corporations, but some peoples income come from the they own. Where I live flooding is a major-major problem. Let me give you an example of how bad it is: I-5 is approximately ten feet under water, and I have seen water completely over two story houses. I really don’t know if wet lands would soak up that much water. Once the ground is saturated it will not absorb any more water. The major problem I see with flooding is the disaster payments. I guarantee, almost every year there are people who obtain money from the government for the clean up of their houses. People should not get paid for there stupidity. In our town there are people who are still building in obvious flood zones. People can build within a one hundred year flood zone, but the thing is, in the past four or five years we have had two, hundred year floods. You would think the statistics might change and people would not be able to build in these areas. There is a law that has been voted on or might be voted on that says: people can not be reimbursed for a flood more than twice, this would be a good thing. If we keep eliminating wetlands we are going to live with the penalties. We already are starting to see some of them. A perfect example of this is a buffer zone, for building around all lakes, ocean property, and other water sources. An interesting thought that I would like to end on is this, my grandpa was telling me about the old Hooverville in Seattle. He said it started right about where the King Dome is, and it was nothing more than a huge marsh. Where would cities like Seattle be located in today’s would if we were not to commercialize some wet lands? Rachel Silva: rsilva@mail.wsu.edu It sounds to me that wetlands have a lot to offer and can benefit many people and the environment as well. Wetlands are very commercially valuable and without them many farmers could be out of jobs, recreational activities would lessen and animal environments/habitats would be narrowed down. Because wetlands are very fertile, flat and shallow farm works is less expensive and have a better growing environment for foods that we consume everyday. The Destruction of wetland is a very selfish thing to do and people should learn that wetlands benefit the entire earth in some way shape or form. Just think without these wetlands there would be less food and everyone would suffer. People are so money hungry and need to look at the bigger picture. This land is large enough to have many buildings and wetlands. Ryan Sullivan: backstop16@hotmail.com Finding a balance between wetland preservation and commercial development is a sensitive issue. When attempting to tackle this problem one has to tread lightly. However, when dealing with irreplaceable resources society must place preservation ahead of the almighty dollar. As beautiful as strings of mini-malls and fast food chains are the ecological yield of wetlands far out-weigh the profits of any commercial economy. Wetlands provide habitat for wildlife, act as a water purifier, and provide a place for excess floodwaters as well as many other functions. These functions are priceless. Developing wetlands for commercial use threatens to throw off the whole ecological balance of our environment. Joey Cottrill joeycottrill@hotmail.com Since wetlands are made of vegetations, animal life, and water that stimulates human use and benefits, I feel that if there were more man-made wetlands that are constructed, it would benefit natural wetlands for wastewater treatment to be more easily maintained. With this kind of treatment, there would be more reliable in which it could handle a very large or small amount of water, and it's quite inexpensive to operate or construct. Even though constructing wetlands for a wastewater treatment is down the road, I feel that there would be a decline in fish loss, which in turn Americans could keep their fish-related jobs. There would probably be an increase in taxes but that is okay because every American has to pay their taxes regardless and plus keeping pollution out and finding out some new sort of treatment to keep everything in control would be beneficial to everyone.
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A thorough knowledge of this next section will make you the HIT of your next social event. An erudite discussion of the design & operation of the various types of sewage treatment plants is sure to impress your friends and make you the center of attention, not to mention insuring that you will be invited to all future social occasions.
A sewage treatment plant is nothing more than a LARGE MICROBIAL CULTURE FLASK. When a microbiologist inoculates a flask of bacterial medium with a culture the intent is usually to produce more bacteria. However, it can be VIEWED IN ANOTHER WAY. The purpose could be to "USE UP THE NUTRIENTS IN THE MEDIUM" by #METABOLIZING them. During the growth of microbes in a medium, the nutrients are oxidized to produce energy and new microbes. The result of this process converts most of the nutrients to chemicals like carbon dioxide, nitrate, sulfate, phosphate; i.e., minerals.
Raw sewage is rich in organic nutrients such as human excrement, and food and industrial wastes. The purpose of a sewage treatment plant is to provide the optimum conditions for SELECTING & UTILIZING MICROBES to convert EASILY BIODEGRADABLE ORGANIC MATTER (EBOM) to mineral forms like carbon dioxide, nitrate, sulfate, and phosphate. This process is also called MINERALIZATION. Since microbes grow and utilize nutrients most efficiently under AEROBIC CONDITIONS, sewage treatment plants are designed to provide excess OXYGEN for the microbes.
Finally, there is always some material that can not be easily degraded by microbes which SETTLES OUT at various stages in the treatment process. This material is called SLUDGE and it must also be disposed of as part of the sewage treatment process. There are TWO major designs of SECONDARY sewage treatment plants (STP). These are called the ACTIVATED SLUDGE and the TRICKLING FILTER systems. Each of them achieve the SAME EFFICIENCY of treatment, but they use different DESIGNS for doing so.
STEP I: The first two stages in BOTH designs are the SAME. The first stage is the PRELIMINARY TREATMENT. In this treatment the raw sewage coming out of the end of the sewage line runs into a large tank. While in this tank the sewage flow slows down enough so that heavy materials like sand and rock settle out and it passes through bars or screens which collect large floating debris like cloth, sticks etc. The EFFLUENT (any liquid that flows OUT of one container and INTO another) flows into the PRIMARY SETTLING TANK.
STEP II: The PRIMARY SETTLING TANK is a large tank where the flow of sewage slows down to the point where LARGER PIECES OF ORGANIC MATTER settle out as SLUDGE. These tanks also contain a skimmer that picks up smaller floating material, the majority of which are used condoms. We will deal with the sludge later.
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STEP III: The third step in the process involves the AEROBIC metabolism of the EBOM. In the TRICKLING FILTER design this is achieved by spraying the effluent from the primary settling tank over a 4 to 6 foot pile of large inert blocks of material such as rocks, cement blocks, redwood blocks etc. (Fig. 5A & B). The spraying saturates the effluent sewage with oxygen and air circulates between the blocks. The inert blocks become coated with a layer of microbes that are SELECTED because they GROW WELL in the sewage (Fig. 5B). This is another example the evolutionary principle of "#SURVIVAL OF THE FITTEST". These microbes absorb the nutrients from the sewage as it trickles over them and oxidizes (metabolizes) the EBOM to minerals. Finally the effluent flows into the SECONDARY SETTLING TANK (Fig. 6). Also 99.9% of the pathogens are killed during this step.
STEP IV: The tank's design is similar to that of the primary settling tank (Fig 4). Large debris, consisting mostly of chunks of microbial growth that flakes off the inert blocks, settles out in this tank as sludge. The effluent next flows into the CHLORINATION BASIN.
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STEP V: Sufficient CHLORINE is added to the effluent of the secondary settling tank to kill most the common bacterial pathogens that have survived the previous treatments. The treated effluent is then released into the environment, usually a nearby stream, river, lake or the ocean. This treatment however, does not kill (STERILIZE) all of the pathogens present so it is unwise to frolic in the water around the sewage outfall.
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Steps I, II, IV & V are the same as those described for the TRICKLING FILTER treatment, only step III is different. The principle behind the activated sludge treatment is the ADDITION of a microbial inoculum to the effluent from the primary settling tank composed OF HUNGRY MICROBES that have been SELECTED for their ability to grow vigorously on the sewage nutrients in the raw sewage. This selection is achieved by COLLECTING THE SLUDGE from the secondary settling tank (step IV, Fig. 7) and mixing approximately 10% of it with the incoming effluent from the primary settling tank (Fig. 4). This sludge consists of large gelatinous clumps (FLOCS) of microbes that grow in the aeration tanks. When this is done properly the microbes in the sludge are healthy, but RAVENOUSLY HUNGRY; something like college students after a full day of exciting learning. These famished sludge microbes chow down with unrestrained enthusiasm on the juicy sewage (a sort of microbial beer and pizza meal) to which they are added. The entire mixture is mixed vigorously in large 20 feet deep tanks through which enormous quantities of air are BUBBLED; sort of like a huge fish tank without the fish. These tanks are called AERATION TANKS, for obvious reasons. As a result of this the microbes rapidly convert (oxidize) most of the EBOM to the mineral state and in the process most of the pathogens die.
FAQ: "In newspaper articles on sewage I frequently see the term "BOD"; what does it mean?"
Answer: BOD = Biochemical Oxygen Demand. It is a way of quantifying the amount of EBOM (pollution) a given sample of sewage contains. BOD is the amount of oxygen microbes use (demand) in five days of eating (digesting) a given quantity of sewage. The higher the BOD, the more oxygen was used because there was more EBOM in the sample; i.e., it was more polluted.
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Anything that SETTLES OUT and is subsequently collected during the sewage treatment process is called SLUDGE. All of the sludge is collected in one place and treated separately from the rest of the sewage material. Sludge treatment involves an ANAEROBIC PROCESS that converts 50% of the organic sludge mainly into methane gas, and some carbon dioxide. To do this the sludge, a disgusting-looking thick black soup, is pumped into large ENCLOSED tanks. Here it is allowed to FERMENT for several weeks while being gently stirred. During this time anaerobic bacteria convert 50% of the organic matter into methane gas.
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You can usually spot a sewage plant by the presence of one or more large round tanks with a continuous flame burning beside it; this flame is kept burning by the continuous production of the METHANE gas. More modern sewage plants utilize this methane for useful purposes from running city vehicles to heating buildings.
At this point 50% of the original sludge's organic material remains UNDIGESTED and must be DISPOSED of. Usually this sludge, which comes out a very thick black soup, is pumped into shallow excavations in the ground and allowed to dry. Alternatively, if it is safe, it can be pumped onto crop land and used as fertilizer. The dried material is called DRIED SLUDGE (talk about a lack of imagination!). In Pullman and Moscow this is not a lot of this muck, but in places like L.A., Seattle and New York the amount of daily dried sludge produced is so huge that it threatens to cover the city or at least a nearby county or two. Disposing of this sludge presents a really interesting challenge; you might even say large cities are "SLUDGE CHALLENGED". It can be burned (contributing to air pollution), buried into TOXIC LAND FILLS (contributing to ground water pollution) or dumped into the ocean (contributing to their degradation). If it is safe (no heavy metals, toxic organic chemicals and the pathogens killed) it makes an excellent fertilizer for lawns and farms.
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A FAQ is "Which of the two STP designs is the best?" and "Why chose one over the other?"
ANSWER: Both designs are EQUALLY EFFICIENT at removing about 85 to 95% of the input EBOM and both destroy about 99.9% of the pathogens. Both FINAL EFFLUENTS have the same composition and are rich in mineral nutrients like phosphate, nitrate and sulfate. Their initial and operational costs are however different. Generally, TRICKLING FILTER plants are less expensive to build and to run if land is not EXPENSIVE as they do not require the pumping of large quantities of air into aeration tanks. Conversely, activated sludge systems are more expensive to build and operate. However, the advantage of the activated sludge system is that it can treat LARGER VOLUMES of sewage in a SMALLER SPACE than can TRICKLING FILTER systems and it is more flexible. Activated sludge aeration tanks can be stacked up in buildings whereas TRICKLING FILTER systems can not. Since most land near cities (where the sewage is!) these days is darn near worth its weight in gold, activated sludge systems are replacing TRICKLING FILTER systems. A prime example of that is seen in Moscow where they have installed an activated sludge system to supplement the TRICKLING FILTER system.
Neither of the two secondary treatment plants do the following:
They do NOT KILL ALL THE PATHOGENS, particularly certain
viruses and protozoan spores that survive passage through the entire plant.
They do NOT DIGEST MANY MAN-MADE ORGANIC CHEMICALS such as
pesticides and herbicides.
They do NOT REMOVE TOXIC METALS like cadmium, mercury, and
lead. Rather these chemicals, which usually come from industrial processes, end up in the
sludge.
It does NOT PRODUCE POTABLE WATER. Any water that comes out
of the pipe of a secondary sewage treatment plant must be further treated before it is
safe to drink; (If you saw the movie Water World, the opening scene illustrated the
recycling of waste).
They do NOT
REMOVE RADIOACTIVE MATERIALS. Treatment may change its chemical form but
the radioactivity is a characteristic of an atom.
Given that the vast majority of fresh water on this planet is polluted, what can be done to remove the pollutants INEXPENSIVELY? The last word in the previous sentence is very important as we are once again talking about that four letter word (in most people's minds) TAXES. As water treatment facilities are community based they are supported by a combination of user fees (your water bill) and taxes. At first it might seem perfectly logical that the whole thing could be paid for by USER FEES, since the more water one uses the more you should pay; like gas for your car. It is not that simple however. The largest users of water are agriculture and industries. They have successfully argued that they should NOT be charged the same rate as plain citizens as they use that water to provide food and jobs for society. The difference then is made up by a combination of HIGHER HOUSEHOLD USER FEES and/or TAXES on everyone. What do you think is the most fair way?
Another component of the problem harks back to the matter of perspective discussed previously. People resent paying high fees for something that seems in abundant supply. Further, they resent limitations on their use of water for lawns and washing their cars.
How many of you would
not take a job in a community that wouldn't let you wash your car or have a lawn?
When your water source is polluted it obviously must be purified before you will use it in your homes. However, the purification process costs significant money (e.g. user fees and/or taxes). Also the supply systems required for bringing water to homes and for removing the waste water are expensive and need occasional repairs. Since most of us obtain our water from surface sources (e.g. rivers and lakes) how do we control the pollution of these sources? For example, suppose your community's water comes from a river that runs by a city in another state that city DUMPS RAW SEWAGE into the river thereby SAVING ITS CITIZENS the money it would take to build a sewage treatment plant. This means your community has to pay extra to remove the pollution added by the people upstream. What do you do about that? Go to war with the other city? Pay the extra price and shut up? Sue the SOBs? Move to the city upstream? Fortunately, this is currently not a problem because of the Federal & state regulations that require communities to clean up their waste waters. However, some people are suggesting that this might change if this control is returned to the States. What do you think? Will Idaho citizens tax themselves to clean up their wastes so Washington citizens won't have to spend money removing the Idaho pollutants? Recently a local politician was quoted as being "unable to see how cattle grazing in the wild could be a pollution problem"; obviously the cattle this person was familiar with were toilet-trained & didn't poop near any streams.
STORE the polluted water in reservoirs for several weeks. During storage many of the PATHOGENS DIE, some of the EBOM is METABOLIZED and the heavier particles SETTLE to the bottom.
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CHEMICAL
FLOCCULATION. In this process (also called coagulation) certain
nontoxic metal salts like IRON or ALUMINUM
are mixed with the water. Then a chemical is added that forms a HEAVY PRECIPITATE (called a floc)
that traps particles, including viruses, bacteria, clay etc. and settles to the bottom as
sludge.
The cleared effluent is then FILTERED through beds of GRADED SAND AND ROCK to remove the
majority of the remaining particles.
The filtered effluent is treated with
chlorine to kill any remaining pathogens. It does not render the water sterile however and
some pathogens are resistant to the normal levels of chlorine used.
These water purification facilities can be placed in large buildings; the sand beds being stacked one on top of the other. However, this treatment does not remove such pollutants as radioactive elements, many organic chemicals and some heavy metals. A common problem around the US today is that the high pollution of many water supplies OVERPOWER the ability of the current purification plants to entirely remove pollutants. Thus, in many cities of the US the citizens are told NOT TO DRINK THE TAP WATER, but to drink bottled water. This obviously presents a dilemma; while paying taxes to build improved water purification facilities may seem undesirable to many, having to buy bottled water amounts to a "TAX". Alternatively, larger doses of chlorine may be added to correct the deficiencies of the purification plant. When the quality of tap water is suspected or when it contains high amounts of chlorine, many people install home purifying systems. Again, this amounts to a hidden TAX for pure water. In addition, a problem with these home-water-purification units is that home owners are unable to VERIFY that the units are DOING THEIR JOB, whereas the municipal facilities have to follow rigorous purity regulations (State & Federal) that require frequent testing of the water for pollutants by trained laboratory personnel. Some people are concerned that if Federal water quality regulations are relaxed the US water quality will further deteriorate. Does this possibility concern you?
In many areas of the US, tap water is not considered SAFE TO DRINK because it is polluted. That is, it is not POTABLE WATER. In these places, usually large cities, the problem is often that the community has not been able, or willing, to build needed water purification facilities because of a lack of tax money. What frequently happens is that as the water supply upon which a community is dependent becomes more polluted, while the thirsty population has increased. This increases the demand for potable water, however current water purification facilities are unable to meet the demand and the citizens have decided, through their representatives, that increasing the capacity of the water purification plants is not a high priority. To meet the added demand for water, the rate of THROUGHPUT is increased. That is, the amount of water "purified" is increased by passing the polluted water through the purification system FASTER. When this is done, the purification process becomes inefficient and the water is NOT PURIFIED. Often the plant's operators simply increase the amount of chlorine added to the final effluent in an attempt to kill any pathogens that may have passed through the MODIFIED treatment process. However, since they are working at the "edge" of safety, they recommend that citizens should only drink "PURE BOTTLED WATER".
Because bottled water is INCONVENIENT and EXPENSIVE many people install "HOME PURIFICATION SYSTEMS" to remove pollutants. I'm unable to go into a detailed description of the design of these products as there are too many of them and more are appearing all the time as the problem grows. However, the bulk of these units involve ONE OR BOTH of the following components: a FILTRATION SYSTEM to remove microbes and other particles from the tap water and/or ION EXCHANGE RESINS or ACTIVATED CHARCOAL to remove the soluble dangerous minerals (lead, cadmium, mercury.) and/or organic compounds (pesticides, industrial pollutants). The ion exchange resins are the same things used in water softening tanks. Activated charcoal is a form of carbon that has the characteristic of ABSORBING large quantities of organic matter. The filters filter out particles based on the size of the holes in the filters.
FAQ about the Home
Purification Units are "Are these units
effective? and Are
they worth buying?":
Some of them are VERY EFFECTIVE when USED AS DESIGNED. That is, you have
to KNOW EXACTLY what
you are doing before you decide to purchase one of these units. If for example, you are
concerned about DANGEROUS METALS like
lead, you must purchase a unit (a) that is designed to remove METAL pollutants and not something else (like
viruses) and (b) that will remove these pollutants at the RATE you use the water.
All these units FAIL eventually. The more pollutants
in the water the sooner they FAIL; the more water you put through them the sooner they FAIL. This means you must REPLACE THE CRITICAL COMPONENTS,
usually some form of expensive cartridge, at intervals. When they fail they can CAUSE a pollution problem. A major
question you should ask before purchase is "How
do you know when a unit is no longer working?"
The buyer must take the RESPONSIBILITY of deciding the kind
of un
Figure 2. Remains of Roman aqueducts. These are remains
of Roman aqueducts. The one above, behind that handsome family, is in Yugoslavia, whereas
the one below is in Italy. At least one Roman aqueduct is still in operation in Spain. 
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