(This paper is distributed courtesy of NOVA Y2K and Ingrid Shulze. It may be copied and distributed freely as long as it is printed in its entirety and no fee is charged)
Imagine what could happen if Year 2000 computer problems were to disrupt either the flow of water needed to flush away wastes or the ability of sewage treatment plants to process them. Breakdowns in either water supply or sewage treatment could soon threaten public health and the environment into which untreated sewage might flow.
Wastewater Treatment and Y2K
Consider the number of times per day that each person uses the toilet to flush away human wastes or turns on the faucet to wash or rinse something. Americans commonly produce more than 60 gallons of wastewater per person per day through personal and home consumption. For example, we may use 25 gallons for a bath or shower, 10 gallons for dishwashing, 25 gallons for flushing toilets and 5 gallons for hand washing, etc. In addition, businesses such as restaurants, hospitals, manufacturers and many other types of businesses and industries all generate wastewater, some in very large amounts. Most of this wastewater eventually ends up flowing through municipal sewage treatment facilities, where it is treated, separated from solid contaminants, disinfected, analyzed and released back into natural waterways.
Sewage Treatment Facilities
Sewage treatment facilities can be affected by the Year 2000 technology problem both directly at the facility and indirectly through external factors. At the facility, Y2K problems can potentially affect computers and software, e.g., customer billing and materials tracking systems, as well as a large array of equipment using embedded computer chips and real-time clocks (EPA). Potentially vulnerable systems include those controlling pumps, filtration systems, treatment and disinfection processes and aerators, monitoring and heating/ventilation equipment. According to the Water and Wastewater Equipment Manufacturers Association, treatment plant "equipment built since the early 1990s is Y2K compliant, equipment from the late 1980's to early 1990's needs to be tested, and equipment installed prior to the late 1980's may need to be replaced".
Municipal wastewater treatment also depends on
According to EPA, there are 16,000 publicly owned wastewater treatment facilities in the country. About 2400 of these serve populations of 10,000 people or more, of which 304 serve more than 100,000 people. At the time this is being written (2/1999), there does not appear to be very much publicly available information about the Y2K readiness of wastewater facilities.
The only existing survey of the wastewater industry's Y2K readiness is one undertaken in June and October of 1998 by the Association of Metropolitan Sewerage Agencies (AMSA). Seventy six of AMSA's 206 member agencies responded to the June 1998 survey, and 43 responded to the October followup survey. Of the 43 utilities responding to the October survey, only 25% had completed the assessment phase of their Y2K work and less than 5% had completed any system repair or testing. According to the EPA Office of Water Y2K Sector Action Plan, assessment is
the most crucial and perhaps the most difficult stage [of a utility's Y2K compliance program]. The assessment stage is when a utility performs an inventory of all its computer systems, communications, and electrical equipment and determines what problems exist where, and what potential impact the problems will have. .. Locating all of a facility's computers and embedded chips with real-time clocks can be difficult. Things that look like a computer are easy to find but control equipment, including Programmable Logic Controllers (PLCs) and equipment with embedded chips can be almost anywhere. Some problems may not be readily apparent, but may cause system failure.
Clearly, the wastewater utilities responding to AMSA's survey have a long way to go to reach Y2K compliance. In addition, the responding utilities were only a small subset of all wastewater utilities. Neither the survey questions, nor the size distribution of responding utilities or the survey responses by size of utility were publicly available at AMSA's website.
For these reasons, and because the AMSA study was a voluntary survey involving self-reported data, it is difficult to assess its meaning in terms of wastewater utility Y2K readiness. While this may change over the coming months, based on the presently available information, there is little reason to be encouraged about the Y2K readiness of the wastewater treatment industry.
Solid waste disposal and Y2K
Americans generate more than 4 pounds of municipal solid waste per person per day. This solid waste consists of both materials and products. Materials include paper and paperboard (38 percent) followed by yard waste (13 percent). Food wastes, plastics, metals, glass, and wood, in rank order, each represented between 10 and 5 percent of the total waste stream. Products are divided into durable goods (e.g, appliances), nondurable goods (e.g., newspapers) and containers and packaging. In terms of products discarded in the municipal waste stream, containers and packaging make up the largest single percentage (33%). Nondurable goods comprise about 27 %, and durable goods 15%. Between 55 and 65 percent of the total waste stream in 1996 was residential waste, while business and commerce was responsible for 35 to 45 percent. Most of this waste was landfilled (55%) or burned in incinerators (36%), and the remainder (27%) was recycled.
Internally, the Year 2000 technology problem can affect solid waste management through Y2K related failures of computers, software and embedded systems at waste transfer stations, incinerators and sanitary landfills, and vehicles used to collect and transport wastes. Equipment that must be checked for Y2K problems include: security systems, safety shutdown systems, automated leak detection devices, groundwater monitoring data transmission systems, laboratory analytical equipment, electronically controlled valves, emissions monitoring equipment and control devices, waste treatment operating equipment, landfill gas flares, and various kinds of recordkeeping, reporting and tracking systems.
Solid waste collection and disposal is also vulnerable to external failures of vendors and suppliers, other waste generators and waste management companies, waste transporters to and from sites, loading and distribution systems (e.g, fleet and route management), external financial and insurance systems, and utility providers (electricity, telecommunications, natural gas, water, sewage, etc.) Note particularly the dependence of waste management companies on the transportation infrastructure. Many communities do not operate their own waste disposal sites, and wastes are transported by truck, rail or ship to faraway landfill or incinerator sites. (For example, New York City transports some of its municipal waste to Virginia).
At present (2/1999) there do not appear to be any publicly available industry studies of the Y2K readiness of the solid waste management industry.
Why Prepare for Potential Disruptions in Solid Waste and Wastewater Disposal?
Wherever humans live in dense populations, protection of public health and the environment requires careful planning for the disposition of liquid and solid wastes. For the most part, American communities depend on municipal sewage treatment plants to collect and treat liquid wastes, and municipal disposal facilities to collect and process solid wastes. Based on the publicly available information at the time of writing (2/1999), there was little evidence that the wastewater treatment and solid waste disposal industries are very far advanced in their Y2K remediation programs. If the lack of information available to the public means that these industries are only beginning their remediation work in 1999, this suggests that there are considerable possibilities for increases in accidental releases and pollution incidents until these industries do become compliant.
From the standpoint of personal preparedness, Y2K compliance problems at landfills, for example, may not show up in the near term, but disruptions in sewage treatment plants or upstream industrial facilities have the potential to affect downstream drinking water quality rather immediately. Also, an inability to transport solid wastes to distant landfill or incinerator sites could cause wastes to accumulate locally or require use of some less desirable local disposal sites.
What You Can Do to Prepare for Possible Disruptions in Sewage and Solid Waste Disposal
The possibility of doing without a flush toilet and regular garbage collection for more than a day or two is something that most Americans would rather not think about. However, it can be done, if two basic ideas of environmental pollution prevention are followed: separating different "waste" streams, and reducing, reusing and recycling wastes as much as possible.
Household waste can be divided roughly into solid waste, recycling, hazardous waste (e.g. pesticides, solvents, used motor oil), and sewage. The focus of this paper is on presenting safe waste disposal alternatives in the event of Y2K related disruptions in sewage collection and treatment, and in collection and disposal of solid and hazardous wastes. In the first section we will focus on what people can do if garbage pickup is unreliable or absent for a time due to Y2K problems, and after that, we will discuss alternative approaches if water supply or sewage treatment problems disrupt the disposal of household sewage.
Alternatives for Solid Waste Disposal
Almost one fourth of the municipal solid waste stream is yard clippings and kitchen scraps. Almost a third is paper. Together, these organic (vegetable or animal derived) wastes constitute about half of the municipal waste stream. Thus, the very first thing anyone who has the space and physical ability should do is to learn how to become a competent composter. Composting transforms yard waste, kitchen scraps, etc., into a rich fertilizer called humus through the natural activity of soil organisms. Composting also happens to be the right thing to do environmentally. Composting yard waste, kitchen scraps and other organic "wastes" is environmentally desirable in at least 3 ways: it turns what would have been waste into a recycled resource, it saves increasingly scarce landfill space, and it recycles nutrients back into the soil. In a situation where garbage pickup is unreliable for any length of time, properly composting organic wastes can also help reduce the health risks associated with piles of uncollected garbage, which can attract animals such as rats and insects and spread disease.
Many good books on composting exist and are usually available at local libraries and bookstores. While many different techniques and devices for composting are recommended, the basic principles are not complex. A good compost pile needs air, water, creatures to do the composting, and something for them to compost. The creatures are microorganisms (bacteria, fungi) and macroorganisms (earthworms, insects) that are already present in soil. Their "food" consists of dry, brown, carbon-rich materials such as dry leaves, straw, woody yard trimmings, newspapers, etc; and damp green stuff that is rich in nitrogen, such as food scraps, grass clippings, fresh weeds (preferably before they set seed), and manure. A compost pile should also be moist (about 50-60% moisture), but not sopping wet. Finally, a compost pile needs oxygen, that is, it needs to be aerated. Without oxygen (for example, if a compost pile gets very wet and soggy), aerobic or oxygen-loving bacteria cannot survive. Anaerobic bacteria, which do not require oxygen, will take over the composting, and the compost pile will start to stink. There are different schools of thought about the need to turn and mix compost piles to aerate them. Some composters find that turning is not necessary if enough coarse material--which has spaces that trap air--continues to be added . Finally, composting can be either fast or slow. Fast or "hot" composting occurs when a pile has approximately the right proportion of carbon to nitrogen, as well as enough air and water. Hot composting is called that because the compost pile actually gets hot (up to 130 F or more), and is due to the presence of thermophilic (heat-loving) bacteria that actually thrive at higher temperatures. In contrast, a cold compost pile will also rot eventually; it just does so more slowly.
Another type of composting, which is particularly suited for use by apartment dwellers or others who cannot do outdoor composting, is vermicomposting, or composting with worms. The virtue of vermicomposting is that it can be done in very small spaces (as small as 2 cubic feet) either indoors or outdoors. Also, the worms do the heavy labor of turning and aerating the compost.
In order to do vermicomposting, you first need the right kind of worms. These are not regular garden earthworms, but a kind of worm that is naturally suited to processing large quantities of organic matter every day. The worms that are most commonly used for vermicomposting are red worms, also known as manure worms, red wrigglers and tiger worms. Latin or scientific names for types of red worms include Eisenia fetida or Eisenia andrei. (Use of the Latin name reduces confusion due to local differences in worm names). Red worms can be bought from commercial growers. (One way to find growers is to search on the Internet under "vermicomposting". Worm growers also advertise in Organic Gardening magazine.)
The following instructions to begin vermicomposting are adapted primarily from the Brooklyn Botanic Garden's book, Easy Compost. You will need a suitable container (a 12 gallon container is good to start with), a pound or more of redworms, suitable bedding for them, a quart of garden soil (not sterile commercial soil), and some food scraps. Be sure to assemble the bin with bedding, soil, and food scraps before you receive the worms. All kinds of containers will work as worm bins, but they must have holes in them, so the worms get enough air. Commercial vermicomposting units can be purchased, but you can easily make your own container, say, from a 12 gallon plastic or wooden container in which you drill aeration holes in the sides and lid. Worm bedding holds moisture and gives worms a place to live. Note that redworms only need a little soil, which provides grit for their gizzards. The soil is also a source of microorganisms that help decompose the food scraps. Good kinds of bedding are: shredded newspaper (about 5 pounds, torn into lengths about 1-2 inches wide, for a 12 gallon bin), machine shredded office paper, leaf mold, horse manure, or some mixture of the above. The bedding should be watered until it is damp but not wringing wet. If paper is crinkly, it is too dry. Plastic containers retain more water than wooden ones; so they need less water than wooden composting containers.
To set up the worm bin, put the shredded paper and soil in the bin and add 1 ½ - 2 gallons of water, and mix it till most of the paper is wet. Empty the worms and the medium they were shipped in on top of the bedding. Then move enough bedding aside in order to add about a quart of food scraps, spread the bedding over the garbage and put the lid on the container. Bury garbage in the worm bin once or twice a week in a different spot each time. Monitor the bedding to see if it is sufficiently damp once or twice a week. Add some water if it is dry. The food scraps will disappear after several weeks . After two or three months you should have twice as many worms as you started with. These can be left in the bin, given to a neighbor, or used to go fishing. When the material in the worm bin becomes dark and crumbly, about two thirds of the vermicompost can be taken out and used to fertilize plants; more newspaper can be added, and the process continued.
Some kinds of household trash are not compostable, including such things as glass, plastic, metal, hazardous wastes, and discarded products made of composite materials, etc. In a situation where garbage pickup is irregular or absent for a period of time, noncompostable items should be separated and stored safely away from living quarters.
Obviously, the best solution is to generate less waste. Indeed, if computer problems in 2000 do disrupt the flows of goods for any significant length of time (more than a week, say), people may find that they naturally produce less trash, because goods may become more expensive and there may be fewer things to buy for a time. People may also use products more sparingly in an effort to make them last as long as possible, and they may find innovative uses for things that they otherwise would have thrown away. Many items that are seen as throwaways in this country are reused in other parts of the world. For example, newspapers can be used, among other things, as wrapping paper and as toilet paper. The most problematic wastes are hazardous materials, which would need to be stored safely, in closed containers away from living quarters, according to the package instructions until disposal is possible.
Alternatives for Wastewater Disposal
Residential sewage as it comes out of a house into the main sewer lines is a mixture of toilet water and "grey water." Water that is flushed down the toilet consists primarily of large quantities of water mixed with human wastes (urine and feces) and toilet paper. Grey water is wash or rinse water which goes down sink or tub drains or runs off when washing a car, etc., and consists primarily of water mixed with soaps and whatever substances and detritus that gets washed off.
Nowadays in the city, grey water goes into the same sewers as toilet water. In some rural homes, grey water may go into a septic system, or possibly into a leaching pit, if the homeowner uses a waterless disposal method for human wastes (e.g., a composting toilet.). In the past, grey water (then known as wash water) was simply tossed into the yard. If sewage treatment systems are disrupted for any length of time in 2000, city and suburb dwellers would really have no choice but to dispose of grey water in the yard or street. However, people would by necessity have to minimize their water use anyway, so they would be producing considerably less grey water.
Waterless disposal and treatment of human wastes.
If Y2K-related water supply or sewage treatment disruptions should occur, local governments would presumably inform communities about acceptable approaches to emergency sanitation. If toilets cannot be flushed at all, then some form of waterless or dry disposal and/or treatment of human wastes is necessary. Generally, these can be either chemical or biological methods, i.e., ones that use chemical disinfectants or biological methods that use decomposition of wastes by microorganisms, worms, etc.
Chemical methods for treating human wastes
The basic bleach method.
FEMA recommends the following approach to waterless treatment and disposal of human waste. The supplies needed are: medium-sized bucket(s), heavy duty plastic garbage bags and ties, household chlorine bleach (Clorox), soap, liquid detergent, toilet paper and towelettes.
If the toilet bowl is usable, place a garbage bag inside the bowl. If the toilet is completely backed up, line a medium sized bucket with a garbage bag and put an old toilet seat on or improvise one with two boards placed parallel to each other across the bucket. After each use of the toilet, pour a disinfectant (see below) such as bleach into the container. This will help avoid infection and stop the spread of disease. Cover the container tightly when not in use.
The recommended disinfectant is a solution of 1 part liquid chlorine bleach to 10 parts water. Other commercial disinfectants include HTH (high-test calcium hypochlorite), available at swimming pool supply stores; portable chemical toilets, which are available through recreational vehicle supply stores, and powdered chlorinated lime, which is available at building supply stores.
To dispose of waste, bury garbage and human waste in a pit two or three feet deep and at least 50 feet downhill or away from any well, spring or water supply. If garbage cannot be buried immediately, strain any liquids into the emergency toilet. Wrap the residue in several layers of newspapers and store it in a large can with a tight fitting lid. Place the can outside until it can be buried.
Portable chemical toilets.
After natural disasters where water supplies are disrupted, governments often provide portable chemical toilets ("porta-potties") in public places, like the ones that are used at large outdoor events. These portable toilets usually contain chemicals for odor control and a biocide such as formaldehyde or a quaternary ammonium surfactant (a very strong antibacterial soap) to disinfect human wastes . After a certain number of uses, the contents of these toilets must then be pumped out and transported to a wastewater treatment facility.
Various kinds of portable or chemical toilets are also on the market that can be purchased for household emergency use. These include chemical toilets for the recreational vehicle (RV) market and those in camping and emergency preparedness stores and catalogs. The simplest emergency toilets consist of a five gallon bucket with a toilet seat attached. RV toilets usually use chemicals such as formaldehyde or quaternary surfactants to disinfect and deodorize wastes; though they may also use enzymes to help digest wastes. Wastes are then disposed of at RV dumping stations at campgrounds or elsewhere, from whence they are taken to a wastewater treatment facility.
Chemical Toilet Disadvantages
Chemical toilets and chemical waste disinfection methods are certainly very useful, but they have a number of serious disadvantages for large scale use (for example, if operation of a sewage treatment facility serving a large metropolitan area is disrupted for more than a day or two). Chemical toilets require a continuing supply of chemicals to function and, except for products containing enzymes, they do not actually break wastes down, they merely disinfect or deodorize them. Thus, the resulting brew needs to be disposed of, and usually ends up at a wastewater treatment plant. Formaldehyde, one of the chemicals commonly used in portable toilets (because it is inexpensive), has fallen out of favor in some areas because it can damage wastewater treatment systems. In large enough quantities, it kills the bacteria used to treat wastewater. Use of formaldehyde in chemical toilets is actually illegal in some places because of these concerns.
Thus, if prolonged water supply disruptions were to occur, or if adequate amounts of the toilet chemicals are not available, or in situations where proper disposal of the contents of portable toilets is difficult or impossible, it is preferable to have other alternatives for treating or disposing of human wastes. These are situations where various on-site biological waste treatment/disposal methods become vitally important.
On-site biological treatment/disposal of human wastes
Most of the people who have ever lived on the planet have used some type of on-site biological waste disposal method. Even today, poor people in some parts of the developing world have no access to even the most rudimentary toilet facilities , and a pit latrine with an outhouse over it is considered an improvement over what they have.
On-site biological treatment of human wastes can take a number of forms. Methods range from a simple hole in the ground to fancy composting toilets that cost a thousand dollars or more. What these methods have in common is that they use microorganisms (bacteria, fungi) and/or other creatures (e.g., worms) to break wastes down and turn it into compost.
Microbiological waste digester products
A number of bacterial and enzyme formulations are sold that can be used in portable toilets instead of chemicals. Some products are specifically sold for use with pit and composting toilets in remote parks, campgrounds, and other locations with no access to public water. These types of products also speed decomposition of human wastes when used in the field, e.g., by backpackers. While such microbiological methods of human waste treatment tend to be more expensive than chemicals such as formaldehyde, they do not require transport of wastes to a dumping station or waste treatment facility (though wastes treated with these products are accepted at most dumping facilities). Related products are dog stool digesters such as Lim'nate or similar products. These are specific formulations of enzymes and bacteria to be used in what are basically small backyard septic tanks for dog wastes. They can be purchased from pet supply stores or catalogs. Dog stool is deposited in the tank, and bacterial cultures and enzymes are used to liquify the stool, which is then permitted to slowly leach into the ground. In an emergency situation, any of these methods of accelerating the natural breakdown of wastes may be safe alternatives to chemical toilets.
One of the simplest disposal methods for human wastes is described in the Boy Scout Handbook. This method relies on the natural decomposition of wastes by soil microorganisms in the rich upper layer of topsoil, and can be either a "cathole" or a trench latrine. Both are simply holes in the ground that are no deeper than 6 inches, in which human wastes are buried, covered with soil, and allowed to decompose over several days.. The cathole is a small hole in the ground, and should be used only by a small number (5-6) of people for one or two days. Trench latrines can be used for a larger number of people and should be several feet long, six inches wide and only 6 inches deep. If a larger trench is needed, it should be made longer, not deeper, since the soil microorganisms that decompose the waste are present only in the top layer of soil. Ideally, both catholes and pit latrines would be used only away from populated areas (i.e., not in a suburban yard), at least 200 feet from any campsite, trail or water source.
Commercial composting toilets
The Cadillac of biological waste disposal methods is the commercial composting toilet. These toilets are approved for use in both the United States and Canada, and are often used in remote homes or cabins that lack running water, or by people who wish to conserve water for environmental reasons. They have been used in Scandinavia for at least twenty-five years. The multrum mouldering toilet, invented by a Swedish engineer in the 1960s, is one of the most popular models. In general, composting toilets use slow, cool decomposition by microorganisms (hence "mouldering") to turn human feces and urine into compost over a period of many months to one or more years, and require no further interaction between users and their excrement, other than to empty out the resulting compost after a year or more. Other than the expense of buying and installing one (commonly $1000+), the main drawback of mouldering toilets is that composting occurs at cool temperatures. As a result, eliminating all potentially pathogenic (disease causing) microorganisms from the compost may take a fairly long time, and it is usually recommended that the compost not be used on vegetable gardens.
The home-made composting toilet.
Only one kind of homemade composting toilet will be mentioned here, and that is the "sawdust toilet". The theory and practice of using sawdust toilets is described in detail in The Humanure Handbook by Jenkins. The virtue of this method is that it is inexpensive and requires no special equipment or chemicals, and it recycles a waste material into something of value, i.e., compost. While Jenkins and his family have safely employed the method for more than 15 years, it could be argued that backyard composting of human wastes in urbanized areas would only be appropriate in rather desperate circumstances, since it requires considerable responsibility on the part of the user (i.e., careless composting could potentially be a nuisance and a danger to the health of neighbors).
Briefly, Jenkins' waste disposal method involves collection of human feces and urine in a container (e.g, a 5 gallon bucket with a toilet seat on it) and after each use, covering the wastes with an organic cover material such as sawdust (or peat moss, dried leaves, or even dirt if it is dry enough to be absorbent), and when the container is full, transfer of the contents to a compost bin (preferably a bottomless, two-chambered one). The cover material serves a dual function of suppressing odors and providing the carbon needed by decomposer organisms to balance the nitrogen present in urine. Each time the waste/sawdust mixture is transferred to the compost bin, it is covered with a sufficient amount of coarse organic material such as straw, hay, leaves or weeds. Kitchen garbage and yard waste are put in the same compost bin, and the contents of the bin are allowed to compost for a year in one side of the bin and age for another year on the other side of the bin before use. Done correctly, this approach to human waste disposal does not smell bad.
The key to Jenkins' method is hot composting of wastes, etc., by thermophilic (heat-loving) bacteria. These bacteria thrive in human feces, animal manure, and compost heaps, among other places, and prefer temperatures above that of the human body, from 104*F to 149* F or higher. The virtue of thermophilic composting, as opposed to composting at lower temperatures (also referred to moldering), is that the high heat rapidly kills pathogenic (harmful) microorganisms in human waste, which naturally prefer temperatures around that of the human body (98.6 F).
Hot composting is facilitated by the presence of thermophilic bacteria in human feces, by the moisture and rich supply of nitrogen in urine (nitrogen can otherwise be the limiting factor in a compost heap), and the continuing aeration of the compost pile by addition of coarse cover materials (with air spaces) each time the toilet bucket is emptied. As Jenkins points out, hot composting actually only occurs in the upper layer of the compost bin where the fresh wastes are deposited. Lower sections of the compost pile are undergoing cooler decomposition by other organisms such as fungi and earthworms. Jenkins also emphasizes that the compost pile should not be turned, which is somewhat contrary to conventional wisdom, except possibly to move materials on the outside to the center so they get hot enough. Compost temperature can be measured with a compost thermometer, or by poking a piece of metal into the compost pile. If it is hot to the touch, then the pile is probably hot enough.
Basic cleanliness when water is limited
Basic sanitation supplies that should always be part of any emergency kit, whether for earthquakes, hurricanes, or Y2K include:
Keeping clean is essential to good health. When water is limited, it may be necessary to reserve it for drinking. A wet washcloth can be used to wash hands, face and body. Water substitutes that can also be used for cleansing include: rubbing alcohol, lotions containing alcohol, shaving lotion, face creams and lotions, and moist towelettes. In an emergency situation, it is especially important to clean hands before preparing food, to avoid transmitting disease.
At the present time, the likelihood of wastewater or solid waste collection failures due to the Year 2000 problem is impossible to estimate from the publicly available information. In any case, having some emergency sanitation supplies handy and learning to compost are two small investments of time and money that are well worth making. In addition, as discussed in detail in the NOVA Y2K Water Paper, it is also prudent to store some water (a minimum of 1 gallons per person per day for 14 days) and to have some means of disinfecting water (such as plain household bleach) for drinking purposes.
.1. This statement is from testimony of Al Pesachowitz, Chief Information Officer of the Environmental Protection Agency, on October 7, 1998, to Congress on the Y2K readiness of the drinking water and wastewater utility sector.
(2. See http://www.epa.gov/year2000/testimony.htm). For a complete list of devices and systems at drinking water and wastewater facilities that need to be checked for date-sensitive embedded chips, see the EPA Office of Water Y2K Sector Action Plan (http://www.epa.gov/year2000/ow.htm).
.3. Testimony of Al Pesachowitz to Congress, October 7, 1998.
.4. See AMSA's testimony to Congress on October 7 and December 18, 1998, both at http://www.amsa-cleanwater.org/y2k/.
.5. According to AMSA, their members include wastewater utilities ranging in size from ones serving 5000 people to the wastewater utilities of New York and Los Angeles.
6. .See http://www.epa.gov/year2000/ow.htm.
.7. Based on the publicly available information, it is not clear whether the October survey respondents were a subset of the June respondents, so the response rate of the survey is unknown.
.8. Questions about these issues have been submitted to AMSA and when answers become available, this paper can be revised. Distribution of responses by size is important because larger utilities serve a larger proportion of the U.S. population. If many large utilities are making good progress in their Y2K work, the aggregate risk of failure is reduced. Larger utilities are often more automated than smaller utilities, but also more Y2K aware.
.9. See: Characterization of Municipal Solid Waste in the United States: 1997 Update. Prepared for US EPA, Report No. EPA530-R-98-007. Municipal solid waste does not include municipal sludge, industrial, agricultural, mining, oil and gas, or construction and demolition waste..
10. .See Waste Management and Y2K, at http://www.epa.gov/epaoswer/osw/y2k/y2k.htm.
11. "Waste" is in quotation marks here to highlight the fact that spent or used materials or products are only waste if they are not reused or recycled. Thus, anything that is composted is recycled (by Nature) and is therefore a valuable resource rather than a waste.
.12. Backyard Composting. Harmonious Technologies, Harmonious Press, Ojai, California, 1992.
.13. Two good ones are Backyard Composting, and Easy Compost from Brooklyn Botanic Garden, Inc., Brooklyn, NY, 1997.
14. Food scraps should always be buried in the compost pile, rather than thrown on top, to avoid attracting animals. Also, meat and dairy products should be avoided in compost piles because they are more likely to attract pests, plus they tend to stink when they decompose.
15. If vermicomposting is done outside in winter, the compost bin should be partially buried in the ground so that the worms don't freeze. If you keep the bin inside and it has holes in the bottom, a tray may need to be placed underneath to catch any liquid that drips through the holes. If your family is large or eats a lot of fresh fruits and vegetables, a larger compost bin will be required.
.16. Easy Compost, Brooklyn Botanic Garden, 1997.
17. Since Year 2000 problems are most likely to begin in winter, in colder areas of the country it may make sense to dig one or more holes in the yard for burying wastes before the ground freezes.
19. On site treatment/disposal means that wastes do not have to be pumped out and transported (e.g., to a dumping station or wastewater treatment facility).
20. Bacterial or enzyme formulations cannot be used in unventilated toilets , as the action of the microorganisms and enzymes generate gas that must be vented. Also, use of bleach or formaldehyde in a portable toilet is not compatible with use of microbial methods. The purpose of chemical disinfectants is to kill microorganisms, and they will kill benign microorganisms used to degrade wastes as well as pathogenic (disease-causing) organisms.
.21. For example, see http://www.microbialogic/com/rtb_700.htm
22. .See The Humanure Handbook, JC Jenkins, Jenkins Publishing, Grove City, PA, 1994; also the Real Goods Solar Living Sourcebook, Chelsea Green Pub., White River Junction, VT, 1996.
23. This should not be sawdust from pressure-treated wood, since it contains arsenic, which is poisonous..
24. A temperature of 122*F for 24 hours is adequate to kill all pathogens ( ).
.25. Real Goods Solar Living Sourcebook.