AboutDavid L. Russell, PE Expertise I`m a Chemical,Civil and Environmental Engineer and have a number of projects in all phases of the environment.
I have worked in the chemical industry and am active in professional societies, and am currently on an industrial wastes committee for the Water Environment Federation, and have taught courses in remediation in the US and abroad.
I have written one book on Remediation of petroleum Contaminated Sites, and have a second book on PRACTICAL WASTEWATER TREATMENT to be published by John Wiley in September, 2006. I've also written over 30 articles on various elements of environmental problems and cleanup. Most Recently, I have addressed a NATO Scientific and Techical Conference on Ecoterrorism, and have worked with the same group on remediation of sites contaminated with Chemical Warfare Agent materials and othe materials as well. . I can answer q`s about Chemical and Environmental Engineering, land development, air pollution, water pollution, soil and water cleanup, combustion, international environmental problems, industrial processes chemical processes. Civil and Environmental and Chemical Engineering. Overall, I have over 35 years of experience in this area. Note: I do not answer homework questions
Experience I love work in the third world and developing areas
because it is challenging and one can get a sense of accomplishment.
Question QUESTION: I would value you your opinion on this product, the Enviro Loo. www.swsloo.com
Thanks,
Bev McCreless
ANSWER: Interesting technology.
It appears that the thing making it work is the tall stack and the rotating ventillator cap on the surface which draws air in and helps the solids dewater.
I would guess that it is not totally odor free, however, because the stack is raised above your nose level, and there will be some odors, but like lots of other things, if you are drying something quickly enough after a time it does not smell much. I would not necessarily recommend this for an in-house installation however, unless you put the stack through the roof and vent it well to outside.
It is innovative and may be a good temporary solution for certain locations because as humans we produce only a few liters of urine per day, and a few grams of solid fecal material per day. So, it looks good.
Good luck, let me know what you decide to do with it. I must comment before I leave that it is not maintenance free as some of the other units on the market are. The typical out house goes a number of years without any maintenance, and you may find that you have to be careful when you remove the screen as it may present a special disposal problem because it has a fecal origin. it will not be bacteria free nor suitable for fertilizer. you may want to contact the manufacturer and find out what and how to dispose of the screenings and the liquids when it gets full. I suspect that I know, but I'll let you find out for yourself.
good luck.
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QUESTION: The ones I have seen installed have not had any odor. It works by separating the liquid waste from the solid waste, evaporating and dehydrating. The only maintenance involved (with average usage) is to rake the solid back for further drying. If there was over usage with high urine output, it may have to be pumped. What screen are you referring to being removed? I have been told that because the unit heats to a high temperature, bacteria, etc. are killed, and it might be safe for fertilizer.
Answer Bev:
1. The enviro loo cannot really heat up to disinfection temperatures without melting the plastic. look up the melting temperature of polyethylene- depending upon the type: from Wikipedia:
Depending on the crystallinity and molecular weight, a melting point and glass transition may or may not be observable. The temperature at which these occur varies strongly with the type of polyethylene. For common commercial grades of medium- and high-density polyethylene the melting point is typically in the range 120 to 130 °C ((250 to 265 °F). The melting point for average, commercial, low-density polyethylene is typically 105 to 115 °C (220 to 240 °F).
Because the system has water and depends upon sunlight, it will not, repeat not approach 180 F and I'd be surprised if it hit 150F. At temperatures requiring good disinfection, the structural activity of the unit would be in question as it would be near or at the melting point. Besides, the water (urine) in the bottom would have evaporated.
So, sorry to burst your bubble, but it will not reach disinfection temperatures to adequately kill spores and some other bacteria.
With regard to the odor issue, you said that you had not detected any odor. You will notice that the product, even when shown with an indoor installation, is vented to the outside. That is for asthetic reasons. The stack looks as if it is several feet (maybe 10 feet or more above ground, and with the amount of air it would be possible to use the ventillator cap to diffuse the slight odor (or strong odor for all that I know) so that you might not smell it unless you are directly downwind.
Now about maintenance: See the FAQ sections 3 & 4: quoted below:
3.Question: What kind of maintenance does the Eloo require?
Answer: The Eloo should be monitored closely for the first several months to determine usage. Do not add anything to the Eloo that has not been eaten first! Under normal usage, the Eloo should not need to be pumped out for 2-4 years, possibly longer.
4. Question: Who cleans out the unit? Who can handle the discharge?
Answer: In the US, licensed septic haulers – pumper trucks – are licensed to clean out the Eloo. The discharge is taken to a regulated location – municipal wastewater plant or licensed landfill by that licensed hauler. County and State regulations apply to the disposal of the waste removed from the Eloo.
This tells me that it is a "regulated sanitary waste". The state has determined that the solids and liquids should be treated as septage, in the same category as septic tank solids. that should give you a big hint!
Quoting further from their brochure: e-loo works, I was slightly in error when I said they used a screen: They use a plate. see the quotes below:
The Enviro Loo, although not a composting toilet, provides the right environment to treat and stabilize human waste by the natural processes of dehydration and evaporation. The waste is reduced into an inoffensive and harmless, dry ashlike material, which is then disposed of according to county, state, and Federal regulations.
The Eloo operates by separating the liquid and solid waste. This waste is subjected to ambient heat and directed airflow to achieve the necessary dehydration and evaporation to convert this waste, with ancillary bacterial and biological activity, into the dried ashlike material which is approximately 5-10% of its original mass (solid waste). Approximately 100% of the liquid waste evaporates.
The liquid waste drains into the trap area below the solid waste drying plate (see above drawing). By separating the solid and liquid waste, anaerobic conditions (cause of odor) do not occur . Constant, directed air flow through the intake pipes, around and over the drying tray, then up through the vent pipe facilitates both the dehydration and evaporation of the waste. The turbine on top of the vent pipe aids in the air flow and dehydration processes.
Think of the process of installing a plate under your bottom instead of using the water seal on the toilet which we all do now. You would be left with solids and liquid which will run off. the liquid is urine. The solids is fecal materials which are unappitizing and do contain bacteria.
What this unit does is gathers sunlight from exposure to the black plastic and provides a low temperature roasting (perhaps roasting is too strong a word- let's use drying) low temperature drying of the fecal solids.
Under the righ circumstances, with continuous exposures to temperatures above 70C for a period of 3 weeks or more the EPA says that you can provide a kill for pathogens in compost. This process does not achieve that type of temperature because when the sun goes down it reaches ambient temperatures, and the part which is on the ground is always at 10C or slightly less.
So will it work, maybe as described, but don't believe the hype. It still is a toilet which you willh have to have someone clean out every so often. The manufacturer's claims are not made for sterilizing the waste, and he would be negligent if he did so. The state thinks that the wastes need to be handled like septage, and that should be a tip off that you don't want to use the material in your garden because of the possibility of putting fecal bacteria in contact with your crops. For certain crops which are above ground it may be fine, but what happens when you are planting crops and you have an open cut or you excavate your potatoes with a tyned fork which breaks the skin? It could be very bad news and an invitation to a nasty parasite infection.
In the end, however, it's your call as to what you wanted to do. I believe that I have answered your questions and if that busts your bubble, I'm sorry but I have an obligation to call the facts as I see them from the manufacturer's literature. it may be a very successful product but the manufacturer recognizes his own limits and one of them is that the product does not provide disinfection.
Good luck.
