Here are found more notes on the hippo method of waste management.
Clarification of the term “hippo”
Hippo Sak® is a division of Crown Poly Inc. The company makes Hippo Saks. We have borowed the term “hippo” to describe the way one can use a plastic bag as a human waste disposal unit. However, just about any plastic bag large enough, not just a true Hippo Sak, can be used as a hippo bag. Below we describe using a SuperBio bag as a hippo bag. Yet the company making SuperBio bags is not affiliated with the company making Hippo Saks.
Please refer to the picture above. In the picture are two standard paper shopping bags. Inside each bag is a few days of solid waste mixed with absorbent material and double bagged in Hippo Sak hippo bags. The purpose of the paper outer bag is to further obscure that the bag contains human waste.
These two bags were subsequently placed in a trash bin and were picked up soon after by a local sanitation worker who placed them in a sanitation truck.
Research continues at Softwine.Press on refining the hippo method.
The absorbent material currently being used at Softwine.Press is a combination of pine shavings and cut up hemp husks. Each hippo bag is used to hold several days of waste from one individual.
After each use, the bag is grabbed near the handles and the part below the grip is spun. This creates an air pocket in the bag. While continuing to grasp the spun handles to ensure the bag will not open, the contents of the bag are mixed by shaking it. The bag is re-opened, the air is pushed out, and then the filled part of the bag is spun, followed by twisting the rest of the empty bag into a twisted cord. The cord can be knotted with a slip knot.
The bag is shook to ensure that the waste and absorbent material in the bag are thoroughly mixed.
The sequence following a waste deposit is:
1. Twist the bag shut trapping air inside.
2. Shake the contents of the bag.
3. Open the bag.
4. Push out the air and twist the bag shut and tie a slipknot.
5. Store the bag in the five gallon bucket with gamma lid.
The twisting of the handles during the shake is different than the twisting for temporarily closing the bag between uses.
When the bag is to be stored between uses, the air is forced out of the bag and then the bag is spun, twisted and knotted.
However, during the shake, it is important to leave air in the bag. This empty space in the bag allows the contents to tumble around and mix.
A question which arises is how much absorbent material should be used. This is best determined by trial and error. The general rule is to start out with less, since more can always be added as necessary. The goal is always to reduce the odor from the hippo bag’s contents. So far, experience indicates a few handfuls of pine shavings and hemp go a long way.
The pine shavings give off a pleasant aroma. The hemp is more absorbent than the pine shavings, to the extent to which it seems the hemp, which has only the faintest hint of the smell of fresh cut hay, not only absorbs the foul odors but also the pleasant smell of pine oil. For this reason, the ratio of pine shavings to hemp currently being used at Softwine.Press is 3:1 in order to preserve the pine perfume.
A hippo bag can be used till it is full. The custom here is that after several days when the bag is about one-third full it is time to tie the handles with a strong knot and place it in the five gallon bucket sealed with a gamma lid to await further disposal on the weekly trash pickup day.
Keeping the bag in the bucket inside a building deprives any animals outside or inside the house access to the waste. If instead the waste were deposited in an outside trash bin several days before the municipality was scheduled to pick up trash at that location, this would give wildlife a chance to compromise the integrity of the hippo bag.
While the aroma of waste coming from the bags may be below the threshold noticeable by humans, animals such as ravenous rats have a way of figuring out where there is organic material for them to scour for nutrition. Ideally, the outside trash bin should be metal. If it’s plastic, the rats may detect food inside and gnaw right through the wall of the bin. Human waste often has undigested material, such as corn kernels, that rats like. The fact that the kernel is surrounded by waste, a bag, and a bin doesn’t discourage the rats. In fact, the smell of the waste seems to arouse their interest.
By the way, waste getting into the local environment via being spread by rats is one of the reasons that municipalities regulate waste disposal. Hippoing, when done perfectly, poses a low risk to public health. More on that in the humanure section below.
However, if hippoing were done on a large scale, it is almost inevitable it could lead to an outbreak of deathly infectious diseases such as cholera. Every hippoan has an obligation to themselves and to their community to be exacting while implementing the hippo method. Hippoans must also keep a low profile so as not to draw the attention of regulators.
The air is forced out of the hippo bag whenever it is closed temporarily between uses and also when it is being knotted permanently closed. This is not ideal. This creates an anaerobic environment which encourages the waste to produce noxious odors.
However, for the time span under discussion where the waste is only held at most a week or so before final disposal, the generation of odor from an anaerobic process of waste breakdown is not an issue. The pine shavings and hemp are up to the job of absorbing most of the odor typically encountered during this phase.
Human waste can be a messy business. A diet high in whole grains, quinoa, beans, legumes, etc. can lead to solid waste of just the right consistency to the extent the waste does not soil the exit of the body. But the consumption of certain foods, as well as disruptions to health, can lead to “solid” waste that can be mushy, sticky and/or liquidy. In such cases, depending on circumstances, even an experienced hippoan can find waste splattered on the upper inside of the hippo sak near the handles.
This is undesirable because that is near where the hippo bag comes in contact with the human hip during the waste expulsion phase. The waste can be easily wiped off the wall of the bag with paper so that the bag can continue to be used. Alternatively, when it happens there is waste smeared on the upper wall, the bag can merely be tied up permanently and retired despite it having ample surplus space still available.
The hippo method may seem unsanitary and less hygienic than using a toilet where the waste is quickly and efficiently flushed away immediately. This sentiment is true, but only to a certain extent. A toilet between cleanings potentially harbors harmful bacteria. As the toilet is flushed, small particles of water containing waste and bacteria can be liberated into the air. Studies of toothbrushes in bathrooms bear this out. Furthermore, the toilet surface where skin comes into contact with the seat, unless covered during each use, one presumes can also be a vector for undesirable transmission of organic matter.
Advanced hippo research has led to new developments.
SuperBio bags are compostable in a home compost pile. This allows for a hybrid hippo and composting method of waste management. A Superbio bag can be used as a hippo bag as far as the initial waste deposit. However, the hippoan has two options as to how to dispose of the Superbio bag: as with a Hippo Sak hippo bag putting it out for pick-up by the municipality or by taking the SuperBio bag filled with waste and absorbent material and depositing it in a humanure compost pile in the yard.
Compostable bags have several other advantages over using a Hippo Sak for hippoing. For example, the compostable bags are designed to “breathe” which introduces air into the bag even when it is sealed shut which in turn discourages anaerobic bacteria growth and the undesirable smells that accompany such growth.
The following is based on the description of the SuperBio bag on Amazon:
SuperBio compostable bags
– A bio bag bag has a 13 gallon capacity
– 30 bags per roll
– The bags…
— are certified compostable
— contain no plastic residue
— will degrade to humus, CO2, and water within 180 days when placed in a standard compost pile
— have a shelf life of approximately 18 months
— are 100% compostable and biodegradable
— are guaranteed to remain strong, durable and tear-resistant when used in accordance with the recommended usage directions
– Bag storage & usage: Keep product away from heat and store in a cool, dry place
– Dispose of product within 3 days when bag is holding organic waste, especially that with a strong acidic/alkaline content [we’re going to try to push that time limit]
This is a link to a Youtube video of a homestead that uses reusable buckets for holding waste till it can be composted. One might think that’s a cheaper method than paying $.67/bag for SuperBio bags.
But consider that Doug in the video has 25 buckets with lids. That’s going to cost about $125 at $5/bucket, assuming buying is the way he got the buckets. The reason he has so many buckets is that in the winter it’s harder to open up the compost pile and to clean the buckets.
Roughly speaking, for every bucket over the course of the winter one could have alternatively used one SuperBio bag, for a total cost of about $17 for a winter’s supply of bags.
So while it is cheaper in the long run to use multiple buckets, the initial investment is high and the buckets have to be cleaned. A clear advantage of the buckets for Doug is that he would not have to keep reordering Superbio bags. It is Doug’s goal to achieve total sustainability without being dependent on anything outside his homestead.
Softwine.Press, however, is in suburbia, where the bags are a worthwhile option because they allow for surrepititious composting. With the SuperBio bag, I can tuck the waste into the compost pile quickly and unobtrusively. Any prying inspector making a cursory inspection would find what may intially seem to be just a bag containing clumps of pine shavings and hemp, peels from fruits and vegetable, eggshells, etc. (I also add kitchen scraps to the SuperBio bag.).Or, they’d find a decomposed bag with hummus.
There are other brands besides SuperBio that are selling these compostable bags, and quite cheaper, too. Here is one. Here is another one.
The question I had is whether these bags live up to their hype. This article says they do.
A refinement of the hippocompo method is as follows:
1. A Hippo Sak is used as a hippo bag for depositing the waste.
2. A SuperBio bag is kept inside a five gallon bucket with a gamma lid.
3. When the Hippo Sak hippo bag is about a quarter full, it is emptied into the SuperBio bag. To do that, the bucket is opened and the SuperBio bag inside is opened and fit over the rim of the bucket. The contents of the Hippo Sak are shook into the SuperBio bag. The SuperBio bag is closed and the bucket is closed. The emptied Hippo Sak continues to be used for the initial depositing of waste.
4. When the SuperBio bag in the bucket is full, it is added to the compost pile.
The advantage of the refined hippo-composting method is that the SuperBio bag is completely filled before composting it. This method is also suitable for when several hippoans will be sharing a single five gallon bucket.
In summary, human waste disposal can potentially be a limiting factor when living on a suburban farm. A suburban farm intern can relatively easily set up a tent, and bring in water and food for a few days. Fuel, portable stoves and ovens can also be brought in for keeping warm in the cold and for cooking the food. The hippo method takes care of the human waste management aspect of the operation obliviating the need to go in the main building to use the bathroom there.
I purchased The Humanure Handbook by Joseph C. Jenkins. I skimmed through it. I learned that my approach to humanure has been too simplistic.
Composting human waste is a complicated process. The human actions required to start the composting are straightforward. But a thorough understanding of the microbial process is required to avoid contamination of food and water the compost may come in contact with before any harmful components in the compost are completely neutralized.
Solid and liquid human waste can contain many harmful ingredients: harmful bacteria, viruses, worms and worm eggs. When waste is treated right, all risks can be mitigated. Also, when it is known there is a high probability of pathogens in human waste then protective gear should be worn when composting. Treatment and subsequent release of waste into water is effective also, but that approach is not as effective as composting at making the waste harmless. The amount of time to compost the waste thoroughly depends on factors such as temperature of the compost pile and aeration. Too much liquid in the pile can starve the pile of oxygen. When all is said and done, the goal while composting is to avoid contaminating groundwater, streams, fields, gardens, etc. However, even without treatment, two years of the waste just sitting is sufficient to completely purify the waste even of worm eggs which seem to have the longest longevity of the harmful ingredients.
I can attest to much of this. I had a five gallon bucket of human waste I accumulated early on in my journey. I didn’t know what to do with it. I put it in the yard with a gamma lid on top. A few years later I wanted to deal with this bucket and I wondered what was inside. I opened it to find a crumbly, odorless, rich humus.
Something I learned from the Humanure Handbook: low heat can destroy viruses, bacteria, eggs etc. Waste does not have to be boiled or heated very long. It seems to me that a medium sized solar oven could pretreat human waste for a small group of people. This would take care of virtually all the health concerns associated with humanure. Alternatively, on a larger scale with a larger group of people, there will be enough compostable material every week to make a large enough compost pile that it can reach temperature quickly and thus will kill most harmful elements in the compost if the pile is aerated sufficiently.
About the smallest size for a compost pile that will reach heat quickly is a cube that is three feet on a side. I have found that a One Ton Bag is perfect for making a cube of compostable material. Plus the One Ton Bag keeps all the compostable material away from the ground. Rebar poles are useful to hold the bag open when filling it. Amazon sells bags similar to the One Ton brand bags. Rebar to hold the bags open can also be purchased on Amazon, but it is cheaper get rebar at a local hardware store like Home Depot or Lowes.
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