Composting toilets again!

[Doodlebug]

I hope I am putting this in the right section. I did think it should go in equipment, but its aimed to be answered by liveaboards, so thought I should post it here.

 

I know this topics been discussed a few times, but i've been through them all and cant find the answer to what I want to know.

 

So...

 

I'm fed up with our cassette toilet. It looks horrible, isn't pleasant to use, and I hate having to empty it every week.

 

Not to mention the distinctive smell that comes up when its in use, and the splashing that happens when its being emptied!

 

So I would like to make a change to the set up, a pump out isnt practical, both from the cost point of view, and the lack of space we have. If we had a pumpout the boat would tip massively one one side when its empty, and then tip the other side when its full.

 

What I would really like, is a composting toilet. Now, I know that trying to get everything that goes down there to compost is a nightmare for liveaboards, needing constant electricity in an attempt to dry it all out. And that the amount of urine that goes down there means the toilet cant cope.

 

So what I would like is to make myself a toilet that separates the matter into two areas. Ill end up with a bottle full of urine every week, which ill still have to empty, but this seems far better than what I have to do at the moment.

 

The solid waste would all go into a largeish container, where it would fill up, and eventually need to be disposed of.

 

I did my calculations, and I think it could be up to 3 months before it has to be emptied. Which sounds good to me!

 

Now, the part I am somewhat confused on, is how to get the stuff in the toilet to break down and not smell. I know people add sawdust and turn it over every so often. I wondered if drying the stuff out would help, or hinder the composting. I thought of adding wood pellets, which would absorb water and turn into sawdust. Would this help? Or would it end up being too dry. Should water be added to help it break down?

 

Also, bacteria needs to be in there to break it down. What do people use to make this happen. I remember seeing composting liquid in b and q. Is this full of bacteria. Its supposed to be added to the compost heaps in gardens. What about yeast? I'm thinking it will smell.

 

Weirdly, I wondered if some sort of yogurt, like yakult would help. All that 'friendly bacteria'?

 

In terms of storing the 'compost' after its been taken out of the toilet, I understand it has to sit for a while before it can be put anywhere. Could I use it in flowerpots on the roof, and grow flowers in it, until its broken down enough?

 

Please dont say these ideas are ridiculous unless you've had a composting toilet! These things are only ideas, so if things (like the flowerpots on the roof idea) are plain stupid, dont be too harsh on me! I have used a composting toilet on land, and was surprised that it actually smelt quite nice. - Woody.

 

The only problem I can see is getting the conditions right for it to break down properly. Drying it out isn't the problem. As long as the urine doesn't go down there it will last a long time between empties, and shouldn't have any issues with moisture.

 

Thanks for any ideas!

 

Doodlebug

[Grace and Favour]

I don't have a composting loo, but I'm sure there are loads of articles on the web which will answer all your questions.

 

However, whether you have a pump-out, or a composting unit - - you'll still be putting weight into your boat in a tank of some sort. (although if the tank is central, the boat wouldn't tip of course)

a composting unit does, of course, consume a reasonable amount of electricity - unlike pump-out or cassette

[sueb]

I thought there are composting toilets already produced that work by separating liquids and solids. Some posters on this forum would have you believe it is only pump outers who splash

[BlueStringPudding]

There are. I've read about them on here somewhere

[Chris Pink]

Not really a comment on composting loos but cassette toilets only smell if you keep the trap shut. Leave it cracked a bit and the good li'l aerobic digesters will eat the smelly bits.

 

Oh and no formaldehyde ( blue) no no no

[Caprifool]

The moden compost toilets do separate feces and urine. It's the whole secret of keeping it odourless. The 12 volt Separett runs for two weeks on a ordinary car/leisure battery.

 

I use peat, the kind you get from garden centres in mine. A handful every other go.....or so. We empty a 12 litre container of urine in the garden once a week. And if you put the paper in the stove, it takes about three months before we need to change feces container. When we change it, we ad a good shovel of ordinary dirt on top and store it for six months or so, depending on temperatures. And yes, we use it as our permanent toilet.

 

If you'd rather make a DIY version there's Dass Isak and a nother version that Separett sells in the UK. Dass Isak is better looking and more "home like" according to me.

 

I'd be happy to answer any questions via PM also. Good luck!

 

Edited to add: Ps, the other one I mentioned is called Separett Privy. You'll find it here http://littlehouse.co/ and somewhere on the site there's a link to a couple of boaters who have built a DIY compost loo on their boat.

Edited January 13, 2013 by Caprifool

[twbm]

A machine for taking the piss automatically. Now that's technology at it's finest.

[ziggy]

You can try www.lilo.org.uk its a lowimpact abord site, its full of advice on the greener side of life

[Doodlebug]

Ive found some more threads about them, but I still have a couple of questions,

 

Caprifool, how large is the solids container, everyone says it takes three months between empty's but how big is the container being used.

 

Also why cant toilet paper be put down there? I have read about a few who put the paper down as well. Surely it just degrades in the same way as the sawdust.

 

Is it worth putting a thermometer inside the toilet? Should I be keeping an eye on the temprature. How do I know if the water content is right.

 

Also, how do people turn the pile over? Any tips? Is it just a case of swirling it around with a stick, or is there more to it than that!

 

Thanks for the links everyone,

 

Doodlebug

[barroca grande]

Hi Doodlebug

 

toilet paper is fine but will fill it up quicker so consider putting pee paper into a separate bin lined with the inside of cereal packet (waxy and giving it a reuse element) which you can then burn on solid fuel fire or throw in rubbish. Solids container is not huge but is fine in the ready made unit I empty it every six weeks or so into secondary container for further composting. DIY would probably use one of those beer making buckets. In the ready made unit the pee bottle takes one woman 3 days to fill so again would need a larger container for transferring into if more than 1 person using. I have found a large 20 litre diesel fuel container lasts a week for taking around to the elsan.

 

No need for thermometer.

 

I don't use the electric fan on the unit but do have a solar vent on roof to draw the air through and that is enough. If DIY don't bother turning it in my opinion just layer it.

 

Rather than sawdust use horse bedding such as Aubiose or BLISS (other hemp/rape seed/straw) to soak up liquid. Bliss bales in the summer months come with citronella oil in to keep flies out of the stables can't remember what the winter bales are infused with lavender I think. A bale lasts me around 2/3 years (I originally used it as cat litter but the cat died last year so could last me longer now). I don't use much of it just a layer at the bottom of the solids container - I tend to use compost from the recycling place to mix with the solids on a daily basis.

 

Having seen link to the Little house I wish I had found it when building my boat as I would definitely gone the DIY route. I love my unit but it is a little annoying at times and I think simpler is better.

 

enjoy your refit.

[Doodlebug]

Ok, do you know how many litres the solids area is? I was thinking of having something bigger than a beer bucket, maybe a large plastic storage chest. Obviously the bigger the better, but theres space to consider. I was thinking of having a step up to the seat, so I can get more height into it.

 

Horse beddings a good idea, and I'm sure adding some fragrance oil would help overcome any woody smells. I was going to get the little house seat, but now I'm thinking I can just use a toilet seat and a funnel, as long as its the right size. The fuel containers a good idea, would be easier to pour and you wouldn't see whats inside!

 

I read about someone who puts some sort of tablet inside the liquids funnel. Do you think they were talking about the tablets used in urinals? Do they stop crystallisation?

[barroca grande]

Hi I have the Natures Head model but the website doesn't give me the litre size for the solids. It is a basically a box around 15" square (approx) so not huge. A beer container would be more than enough (you've have got to lift it out at some point after all) and if you had two one would compost fully while the other is being used. Size as they say isn't everything!!!

 

http://www.blissbedding.com/

 

I can confirm a funnel works fine (my after purchase amendment to the Natures Head!)

[Cosmic]

A comparative newcomer in the field of composting toilets is Loowatt.

 

They have developed a waterless toilet, primarily designed for use in third world countries where water is at a premium, combined with an anaerobic digester that can be used to produce gas, electricity and/or compost. One of their team is a boater, and they have designed the toilet to be suitable for installation in a narrowboat. As I understand it, the digester part would need to be on land and would be suitable, for example, for use in a marina.

 

They have recently set up a system in Madagascar, where it provides an income for a local businessman who maintains the toilets and sells electricity for charging phones and hot water for showers.

[Caprifool]

Snipp....Caprifool, how large is the solids container, everyone says it takes three months between empty's but how big is the container being used.

 

Also why cant toilet paper be put down there? I have read about a few who put the paper down as well. Surely it just degrades in the same way as the sawdust.

 

Is it worth putting a thermometer inside the toilet? Should I be keeping an eye on the temprature. How do I know if the water content is right.

 

Also, how do people turn the pile over? Any tips? Is it just a case of swirling it around with a stick, or is there more to it than that!

 

Oh, I don't know.....about the same side as a 30 litre fermentation tub, perhaps? Perhaps the technical spec. could answer that. You "can" put paper in it. It's just that it fills up faster then. We stick it in the stove or in a bin lined with a paper bag that we burn outside. In my Separett manual, it says it works best above 18C. Never checked the humidity. Never turned the pile either. I just chuck a shovelful of dirt over and store it.

[Bat & Frog]

Hi, I have been using the Separatt 9010 for about 18 months now. A few things.

1. I only find it smells for the first couple of days after a bucket change. I do have the fan connected.

2. You can't really leave the "material" in the bucket on the roof or anywhere else exposed as if it rains it will eventually overflow and also when it gets to wet the composting process stops as needs oxygen.

3. The container you use for the urine needs to be low as the outlet is about 9" off the floor.

4. I don't put the paper in it as have found it can take longer to decompose.

5. For a while I was drying my clothes in the shower room using a dehumidifier and the composting slowed down, think the dehumidifier was drawing to much moisture out of the air.

6. The solids bin is 23 litres and the system rotates it everytime you sit down (the seat is off-centre to the bucket so you get a better fill). Takes about 3 months to fill.

7. I use a non-peat compost to start and a little sprinkle ever couple of days, never had a problem apart in winter when the full container was stored on front deck under cover, to cold and didn't decompose.

8. Men need to sit (visitors to my boat shouldn't drink from the discoloured plastic pint glass on showerbase )

 

If I was doing it all again I would design and build my own unit as think you could save some space and money but would definitely have another composting bog

 

http://www.separett.eu/default.asp?id=2128&ptid=2052

Edited January 16, 2013 by Bat & Frog

[Caprifool]

Hi, I have been using the Separatt 9010 for about 18 months now. A few things.

1. I only find it smells for the first couple of days after a bucket change. I do have the fan connected.

2. You can't really leave the "material" in the bucket on the roof or anywhere else exposed as if it rains it will eventually overflow and also when it gets to wet the composting process stops as needs oxygen.

3. The container you use for the urine needs to be low as the outlet is about 9" off the floor.

4. I don't put the paper in it as have found it can take longer to decompose.

5. For a while I was drying my clothes in the shower room using a dehumidifier and the composting slowed down, think the dehumidifier was drawing to much moisture out of the air.

6. The solids bin is 23 litres and the system rotates it everytime you sit down (the seat is off-centre to the bucket so you get a better fill). Takes about 3 months to fill.

7. I use a non-peat compost to start and a little sprinkle ever couple of days, never had a problem apart in winter when the full container was stored on front deck under cover, to cold and didn't decompose.

8. Men need to sit (visitors to my boat shouldn't drink from the discoloured plastic pint glass on showerbase )

 

If I was doing it all again I would design and build my own unit as think you could save some space and money but would definitely have another composting bog

 

http://www.separett.eu/default.asp?id=2128&ptid=2052

 

2. They did not include the lids? I have 6 bins and all included lids.

3. A 12 litre poly can laid on it's side works nicely. Cap keeps it from sloshing about while walking to where you dump it.

4. We have a little pedal bin lined with a paper bag. A few times per week the paper bag goes in stove.

8. Just sit! How hard can it be? No pun intended.

[Doodlebug]

Thanks for the suggestions and ideas, we are about to build one so will post our experiences after a few weeks use.

 

[wandering snail]

Our 12v Separett 'Villa' works perfectly with no smell and no hassle. It even looks good! Think I put a pic in the gallery here a while ago.

[Bat & Frog]

2. They did not include the lids? I have 6 bins and all included lids.

3. A 12 litre poly can laid on it's side works nicely. Cap keeps it from sloshing about while walking to where you dump it.

4. We have a little pedal bin lined with a paper bag. A few times per week the paper bag goes in stove.

8. Just sit! How hard can it be? No pun intended.

 

2. they did include lids, just found when lid on and sealed it didn't compost well.

4. Same as.

8. to lazy to drop trousers and seat cold !

[His Misses]

There was a programme on Channel 4 - Kevin McClouds Man Made Home. He made a composting toilet, albeit he was using it to get the methane for cooking, however maybe of some help for you in your project.

Try viewing 4oD series 1 episode 3

[kevinl]

Forget it, if your boat is too small for a pump out then you'll not fit a composter in either. As has been said you need to separate liquid and solid so you'll still have to carry the liquids in the suitcase to the elsan. For the liquids, say 1.5 litres a day each, 2 people 3 litres a day (average), that's when you've found a way to split the liquid out, bottle for you, "shewee" for her (if you don't know what this is they're for sale for between £6 and £12 on Amazon) Oh! best buy a spare for and lady visitors, not something you'd want to share.

Then the solids; you have to keep them moving (with small motor), keep them ventilated (with a fan) and keep a them at an optimum temperature of 70F not less than 55f (with a heater). OK if you have unlimited power, then as necessary you stil have to empty the composted poo too. Paper, use both sides then wash it?

Storage for the peat you need to chuck on it each time you use the loo, keep in the the cratch with the straw bale you both pi** on? Great suggestion whoever made it but not practical on a boat.

Composting may well be the future, it makes a lot of sense but in the confines of a narrowboat it's really a non-starter.

I still stick with a suggestion I made a while ago, take a load of Imodium before the trip then colonic irrigation when you get back but are you then a pump out or a cassette fan?

[peterboat]

Hi I have the seperate villa I have been using it for over 2 years it works well. I use coconut powder in the solids bit and the urine runs into a shower pump out which then pumps it into a remote 25 litre container heavy but means that it is not to often a chore to sort. The solids is about 2 months between empties the low wattage fan ensures that any smell is removed outside and helps dry the waste. I use a spray after every wee which is 50% water and 50% asda biodegradable toilet cleaner never smells so must work? If I changed boats I would do the same again had a pumpout on last boat and that was a disaster boat leaned and occasional blockages and smells!! The solids go into a bucket which is lined with a biodegradable bag just take it out seal it and my friend puts it in his composting bid perfik!! PS have no problems with power as I have 1.5 kws of solar panels with mppt controllers running into 1500 amp hours of full traction batteries no shore power for me yippee

 

Peter

[mrsmelly]

Go to any Marina or moorings or simply do a poll on here and ask how many liveaboards or for that matter hobby boaters have a composting bog. It is the only research you need to do as it tells its own story.

 

Tim

[Caprifool]

That some boaters lack vision enough to see more than two available options? ;-)

[IainW]

there is a free 'humanure' book download available here