Off Grid Waste Management and Sanitation, by Brother A.

Wednesday, Dec 28, 2011

Recently, due to financial considerations, we decided to end our garbage collection service. It wasn't a large expense, but our budget is tighter than ever these days and with some planning we realized that it was actually a luxury, not a necessity. Besides, those of us who are preparing for the likely future of a breakdown in society shouldn't really expect to have convenient curb waste disposal services, now should we? How were you planning on handling that day when it comes? You have 500 trash bags and you're just going to stack bags of trash in some out-of-the-way corner of the barn for vermin to sort through and spread health hazards? What about sanitation? When your water service cuts off and your toilet won't flush you can pump or haul water, or maybe you have plans to dig an outhouse. Let me propose some better solutions to you.

Now, I live in a rural area, in the unincorporated area of a county and not within any city limits, so much of what I propose is applicable to my situation here and will not apply to city dwellers. You need land to be sustainable in any real sense. Over years of living a preparedness lifestyle, I have realized that in the long run preparedness blends into sustainability. I have solar and wind power, a wood stove, a biofuel vehicle, a large garden, and now a composting toilet not because I'm an extreme environmentalist, but because the less I depend on the infrastructure of society, the less it matters to me whether it's there or not. If/when “something bad happens”, I don't have to do anything special. My fuel supplies stay stocked, my food supplies are rotated constantly as part of “normal life”. If the grid goes down suddenly the extent of my panic will be to turn on the shortwave and scanner to start collecting news. However, in this article I will try to contain myself to discussing the subject at hand, which is waste management.

The first step to dealing with “waste” is mental. You need to adjust your thinking to realize that hardly anything is truly “waste”. Almost everything can be reused or recycled, and then it's not “waste” any more, it's useful. Also, on the front end the less packaging and non-recyclable items you bring into your life to begin with the less you'll have to deal with on the back end. As our family lifestyle became more sustainable over time, I was amazed at the reduction in volume of “trash” that we had. I'll now cover each disposal method in turn.

First, there is burning. Let's say you just pulled out a frozen dinner to eat, or a new product from the package. Most likely the package was either paperboard or corrugated cardboard, perhaps wrapped in plastic (we'll get to the plastic). Let's start with the obvious: paper and cardboard burn very well and fairly completely if given sufficient oxygen. In our house we have a wood stove, and I use waste paper and cardboard as kindling to light it. Now that we're in the heating season I can dispose of quite a lot of paper waste this way. Several months before heating season starts I begin stockpiling all the paper, paperboard and corrugated containers, newspapers, and non-glossy sales circulars so we will have sufficient kindling all winter long. A note to stove owners: newer catalytic stoves are picky about what you feed them. Check your owner's manual for information about burning paper, because you don't want to poison the stove catalyst. My understanding is that if you stick to non-colored paper such as office paper this should be okay even in catalytic stoves. The rest of the paper and combustible waste I burn in the burn barrel. My wood stove ash gets used to make lye, and then lye soap with, so I try to only burn clean materials without brightly colored inks or glossy paper, as these could contain undesirable chemicals. The remaining depleted ash has less potassium content but is still a useful fertilizer, so I spread it on the lawn and around trees. A side note: I once calculated the fuel value of the paperboard container of a package of macaroni and cheese. It's easy enough to weigh the empty box with a kitchen scale, and the resulting weight is pure dry carbohydrate biomass, with an energy content of 4 Calories (that is, kilocalories or 4184 J) per gram. I discovered the box had about 200 Calories of energy! If you burn the box, that's less Calories of food energy you have to consume in winter to stay warm. Think of all the extra heat you're missing, just lurking in everyday “waste” products....

Now, the old familiar burn barrel has been well known ever since shortly after the introduction of steel 55 gallon drums. It suffers from low combustion temperatures and limited oxygen, leading to dirty and incomplete combustion. I have constructed a “turbo” burn barrel with a few simple modifications. I took an old rusty open-top drum and cut a 4-inch round hole in the side just above the bottom. This is easily accomplished with a power drill and jigsaw with a metal cutting blade. Even this one improvement will go a long way toward making the barrel burn better since air can now flow in the bottom, but this wasn't all I had in mind. I then attached a length of 4-inch aluminum flexible duct, the kind that's used on clothes dryers, and a small blower motor. I had a bathroom vent-type blower left over from another project, and it handily fits onto a 4 inch flex duct. Now what you have more closely resembles a blacksmith's forge than a regular burn barrel. Of course, for true off-grid use you'd need a DC blower instead, but I have about half a dozen different ways to generate AC. For 12 VDC, I'm sure a salvaged automotive ventilation blower could be modified to fit the bill, or perhaps even a computer-style axial fan, some of the larger ones can move quite a bit of air.

Regardless of the air source, you now have a burn barrel that breathes much better and will combust materials much more completely. It's perfect for disposing of any combustible waste materials including paper and yes, most plastics. If you look at the recycling symbol found on most plastic packaging you will learn what it's made from. Here's a quick guide:

1 - PETE (polyethylene terephtalate), combustible
2 - PE-HD (high density polyethylene), combustible
3 - PVC (polyvinyl chloride), non-combustible
4 - PE-LD (low density polyethylene), combustible
5 - PP (polypropylene), combustible
6 - PS (polystyrene), combustible
7 - Other (often polycarbonate or ABS), non-combustible

Remember that plastics are made from oil. Most forms of plastic, under proper high-temperature combustion with adequate oxygen, happily just melt and burn like oil. The problems with plastics are the ones containing chlorine in the formulation somehow. This includes plastics like PVC. If these are burned, hazardous chlorine compounds are formed. If no other means of disposal is available, these plastics will have to be given the second disposal method, burial or landfilling.

I am not technically qualified to offer advice on landfilling, but US Army Field Manual 21-10, “Field Hygiene and Sanitation” does offer some guidelines. Some items will have to be landfilled, such as the ash left over from the burn barrel, and those plastics which are not safely combustible. Currently, I am still able to drive to a nearby town and pay for disposal by the pound, so right now I am not having to landfill anything.

The next disposal method I will cover after burning and burying is composting. Any organic material can and should be composted. Composting is nature's own recycling mechanism, capable of turning waste back into useful materials and neutralize a wide variety of harmful substances! A properly built compost pile will heat up to sterilizing temperatures and not only kill bacteria and other harmful organisms but also neutralize many harmful chemicals too. All kitchen scraps, yard and garden waste, dead small animals, waste oil and grease, and other organic materials should go in the compost pile. Yes, many compost experts have long advocated the “don't” list of forbidden materials in the pile, normally including things like meat, fats, and pet and human wastes. At this point let me stop and strongly advocate that you go and read “The Humanure Handbook” by Joseph Jenkins. It's available free online, or you can buy a printed copy inexpensively from the usual sources. I can't recommend this book highly enough. In it the author does a thorough job of debunking many of the compost myths. He quotes a long list of sources and research studies to prove his points. In fact, most of the book is about composting in general, not just the title topic. Please do yourself and your family a favor and read this book.

[JWR Adds an Important Caveat Lector: While some of the advice given by Jenkins in his Humanure Handbook is good, I soundly reject his assertion that "humanure" can be used in vegetable gardens in all climates and at all times of the year. Outside of the tropics, in three seasons there is simply too much risk of disease transmission. Unless all of the waste from carnivores and omnivores gets above the viability temperature for bacteria, then it is a biohazard. If you must use "humanure", then use it only for flower beds and shrubbery. And for that, be sure to use a separate, dedicated set of spades and buckets that have their handles marked with red tape. Never use those tools in your vegetable garden!]

After reading the book, I constructed a three-bin compost system similar to the one shown in the book. Each bin is about 5'x5'x4'. You start constructing a pile by laying down a foot or more of absorbent organic material as a buffer. In my case, I had numerous cubic yards of wood chips left over from other projects, so that's what I used. Then on top of that you start building your compost pile, adding to it a little at a time as materials become available. The active materials stay covered with a thick blanket of dry high-carbon materials (think hay or straw) on top to retain heat. A long-stem compost thermometer is a useful tool to tell you how your pile is doing, and within days mine had heated up over 120 degrees. Most days it hovers between 120 and 140, and this is even with the arrival of fall weather and cooler temperatures. All known gastrointestinal pathogens die within 24 hours at temperatures of 120 degrees..

This ties in naturally with my next topic, sanitation. As part of my long-term sustainability plans I have a rainwater collection system and a large cistern, but if I lose my utility water supply my quantities of water will be very limited. Even with a modern efficient toilet, flushing water is still a major demand. I had been researching for a long time to find better alternatives when I learned about the humanure handbook and got an education in composting. However, my plans for a “plan B” got accelerated when my old gravity flow septic system started having problems. I won't describe all the details, but now we are at the point where it barely works and the choices are either to dig up and replace the drain field at huge expense or decommission it. Enter “plan B”, front and center. My old farm house already had a gray water drain connected to the clothes washer, but now I have rearranged the plumbing so the kitchen sink, dishwasher, and shower drain into it as well. Thank goodness for an old pier and beam farmhouse, and a generous crawl space, that makes retrofits like this possible.  For the toilet, I constructed the "lovable loo" according to the plans in the book.  You can also buy it pre-made online if you don't like woodworking.  It uses 5 gallon buckets as the collection receptacle, but all the composting happens in the large pile in the yard where it can be done efficiently at high temperatures.  It's amazing, but just adding some dry high-carbon material to the bucket to cover after each use keeps the contents aerobic and completely stops odor, flies, and other problems traditionally associated with portable toilets and outhouses.  Sawdust, leaves, straw, newspaper, finely shredded mulch, all work perfectly well.  It just needs to be relatively dry (to offset the moisture content of what's going in the toilet) and have a high carbon/nitrogen ratio (to offset the high nitrogen content of what's going in the toilet).  What else can I say?  It works.  Read the book.

Another aspect of sanitation is feminine hygiene. Instead of stockpiling large amounts of necessary products ahead of time, we found it made more sense to just go sustainable instead. Plans are available on the internet to make your own feminine pads, but for the time involved I think it just makes more sense to buy instead. Many thanks to the folks at Naturally Cozy, we can testify to the quality of their products. That's one less thing to have to worry about. For actual washing, we have a number of options but normally choose to use the spin-type pressure hand washer from Lehman's for small amounts of soiled articles like this that you might not want to mix with your regular loads of laundry. This works for future off grid use as well, since it's hand powered. More or less the same should apply to families with young children in diapers too. It doesn't make sense to stockpile the large quantities needed, and then to have a waste disposal problem on the other end. The best way to dispose of waste is not to have it in the first place.

For large-scale clothes washing in a grid down situation, we should still be able to use our electric washer (but not dryer) since we have several ways to generate electricity. We have two generators, one truck with a beefy inverter, and a large 120 Volt AC inverter on the solar power system. Any of these should run the washer at least occasionally. We have a significant stock of detergent and a very nice clothes line. For return on dollars invested on renewable energy improvements, you can't beat the good old fashioned clothes line.

Okay, we have dealt with the combustible trash and plastics, but what about metals and glass? Currently there are recycling centers close by, and some of these materials can even put a little money back in your pocket, but in the future these will need to be dealt with differently. For aluminum, probably the best “disposal” method is melting and casting. I am not currently equipped to do this, although it is one of the next areas of preparedness/sustainability I plan to tackle. A small furnace can easily reach aluminum melting temperatures. In fact, my turbo burn barrel can probably reach aluminum melting temperatures. Hmmm, use trash to dispose of trash? Now there's an idea...

I have not seen much in the way of glass melting and casting/blowing information, but I know that people do this for a hobby so information has to be available. Reusing existing glass bottles, jars, and containers as much as possible is probably the best interim solution, but what do you do with extras, or broken pieces? Being able to turn them back into useful goods would be much better than landfilling.

After all that has been dealt with, there is still hazardous waste. Broken electronics, batteries, chemicals, and other things we don't want to mess with. For now it usually possible to turn these in at special hazardous waste collection centers, or at special “collection drives” that our local governments sponsor a few times a year. When this is no longer possible, encapsulation and storage will probably be the only option. I should also note that any very old painted wood could possibly contain lead-based paint, which should not be burned. It probably shouldn't be landfilled anywhere except in a properly designed landfill either, so if you have some, get rid of it now or you may be stuck with a problem. Computers can be parted out into components and the remaining circuit boards take up much less space. There is nearly a pound of aluminum in an average hard drive, and one or two really useful rare earth magnets.

A disclaimer: we don't live completely off grid for electricity or water. We have a 600W photovoltaic array and small wind turbine that together run a 900 Ah battery bank and Sun Frost 12 Volt DC refrigerator and SunDanzer 12V freezer. The rest of the house is on utility power. If the utility goes down, the food stays cold even without me having to start the generator. I designed the system for 12 volts instead of 24 so I can recharge the battery bank from a vehicle if necessary, or even jump start a vehicle from the constantly-charged battery bank. Likewise, we use utility water but I can throw two valves and in a matter of minutes run the house plumbing from a 10,000 gallon cistern with rain water. The pumps (two, double redundant) can be run directly from the PV system, and the water goes through 5 micron filtration and a Sterilight UV sterilization system. In other words, the grid is still “Plan A”, but I can implement “Plan B” very rapidly and have tested it.

Living off grid doesn't have to be onerous. In most cases it's more work than the convenience of living on grid, but then what do you do when the grid goes down? Besides, the work is mostly good exercise and enjoyable. I like cutting and splitting wood. I love the warm radiant heat of the wood stove. I love the security of having my own power company, my own water utility, and my own gas station. Most people just rent their lifestyle month by month, but I own mine outright. Take away either the monthly income or the infrastructure, and “plan A” ceases to work rather rapidly.


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