Composting Toilets

[ConradG]

Ussually bacterial activity is related to heat. With large amounts and rapid growth they can produce a huge amount of heat (the animal manure pile is always steaming in our northern winters), but my suspicion is that with intermittent use and below freezing temps, things would be kinda slow in those small units. But, on the other hand, the conventional head wouldn't be able to be used at all in that situation as the holding tank would freeze and break. Face it, the things have to be emptied at some point. I believe Nature's Head states 60-80 uses. If being used regularly, the recent "deposits" won't be composted down. A second base with crank handle is available so one can finnish while the other is being used, you can finnish it in any regular composting way or you can dump it in the trash (it is designed to dump into a small kitchen size trashbag) or overboard outside the limits. The pee bottle will freeze so you better dump it. I think the main attraction to these things is the extended intervals possible before having to find a pumpout, infact, never needing a or to pumpout again! And, as it sounds, Better aroma than the traditional sloshing cesspool...

[Hiracer]

Temperatures in SE Alaska are not that cold. I'll bet the sludge and urine in the holding tanks prevents freezing unless much colder than 32 F (0 C). Further any air in the tank will allow for explansion so cracking the tank is not an issue. Further, my experience is that the water temperature up there is rather warm (40 - 45 F, I used to SCUBA dive out of Whittier and Seward in the winter), unless you are in a river outflow (where surface temperature can drop to 33 F), so the the boat conducts this heat to the interior.

But I do share the concern with slower bacteria activity on account of lower temperatures.

Also, I'll guess that most places in SE Alaska have few pumpout stations, so in fact everybody is just dumping outside the anchages. I know when I had a boat in Seward AK for a time there was no pump out at all--it didn't exist--and once they got one nobody knew about it or used it. Been gone ten years so I realise that things may have changed. Maybe somebody who actually knows can weigh in about pump out stations in SE Alaska. I suspect it's remote enough that there is not much use for them.

Originally Posted by ConradG

Ussually bacterial activity is related to heat. With large amounts and rapid growth they can produce a huge amount of heat (the animal manure pile is always steaming in our northern winters), but my suspicion is that with intermittent use and below freezing temps, things would be kinda slow in those small units. But, on the other hand, the conventional head wouldn't be able to be used at all in that situation as the holding tank would freeze and break. Face it, the things have to be emptied at some point. I believe Nature's Head states 60-80 uses. If being used regularly, the recent "deposits" won't be composted down. A second base with crank handle is available so one can finnish while the other is being used, you can finnish it in any regular composting way or you can dump it in the trash (it is designed to dump into a small kitchen size trashbag) or overboard outside the limits. The pee bottle will freeze so you better dump it. I think the main attraction to these things is the extended intervals possible before having to find a pumpout, infact, never needing a or to pumpout again! And, as it sounds, Better aroma than the traditional sloshing cesspool...

[wildshore]

Ive got to agree with a lot of the comments here, this has been a great and very usable thread. Nicely done, folks.

I've had a fair experience with these things on land (mostly constructing composting toilets for festival and camping areas) and I wanted to kick in a few things based on some of the questions raised on the last nine pages.

First of all, thanks everyone for reinforcing the main thing I've had to get over in convincing my SO that these things DON'T SMELL.

Second, peat is recommended by a lot of the manufacturers as its cheap and available in compressed form, but any decomposable dry material will work just fine, including sawdust, some cat litters (NOT clay or scoopable), dried leaves (crumbled, please), untreated mulch of various ilks, cut up straw or dried grasses.....I've even heard of ground newspaper being used. They're pretty tolerant.

Units like Nature's Head (which, judging by the ones I've seen, is really solidly built) and others make this process easy and simple to handle, but the units are easy to fabricate on your own. As long as urine is diverted from the dry materials, homemade units will work just fine, are cheap, and take up a bit less room than the commercial ones. They also provide you an opportunity to try this out if you're skeptical without dropping any meaningful cash to do so.

Check out the link :

http://www.bvsde.paho.org/bvsacd/cd6...mpost/cap6.pdf

which contains multiple ideas for building land based units that could be marine-adapted.

Lemmeesee, what else....power fans aren't really necessary as long as the lid (including toilet seat) seals and there's a vent into the waste chamber. Composting materials produce heat, causing the air to expand and rise and as long as you have a vent pipe from the waste box up and out, it creates its own negative airflow in the head....I hope I said that in an understandable fashion...I've used this in a number of stationary toilet designs using 30 gal plastic drums as the holding tank, and it works well. I know I've a pdf of the design we've used for years around somewhere and will upload it when i find it.

Thanks for such a useful forum, folks

[ConradG]

There is a readymade seat which diverts the solids from the liquids available relatively inexpensively
Ecovita Privy Kit
I have asked the folks at one of the two manufacturers of the ones made for the rv and boating industry if their unit is specifically approved by the coastguard and they sent me the regs but no specific approval or certification...I don't know if the unit has to be or not. Anyone know for sure?

[wildshore]

I suspect the CG's interest is in whether or not any of this goes overboard....

unit looks nice though, albeit a bit pricy. I do like the apparent vent in the lid. Nice idea.

[hummingway]

I've been using mine about 3 weeks I guess. I've been quite happy with it. We are in the second day of a pretty good blow and it appears the fan can't keep up with the wind. I have a stepped deck and went out the side of the stepped deck with my vent, covering the hole with a clamshell. The smell isn't terrible but I did close the door to the head - which makes it fairly strong in the head. Hopefully it is just the direction of the gale.

[wildshore]

i think venting is a problem with just about ANYthing in high wind. We used to have a land toilet with a vent that positively yodeled in high winds.......and being on a barrier island, that was about half the time....

[ConradG]

That could be a bit of a problem on a boat.
Let us know how it turns out. Is the step forward facing?
For a powerless land model advertised, they use a turbine ventilator, the kind the wind drives faster the harder it blows. Wouldn't work in a hole through a verticle surface though without an elbow and the space....

[knothead]

Originally Posted by hummingway

I've been using mine about 3 weeks I guess. I've been quite happy with it. We are in the second day of a pretty good blow and it appears the fan can't keep up with the wind. I have a stepped deck and went out the side of the stepped deck with my vent, covering the hole with a clamshell. The smell isn't terrible but I did close the door to the head - which makes it fairly strong in the head. Hopefully it is just the direction of the gale.

If you have odor, you aren't using enough cover material.

I don't know how well the composting heads work as far as the actual composting thing goes. I have been composting kitchen scraps and yard stuff in my yard for decades and there are a lot of different ways to do it. There is the Berkley composting method which is a thermophilic process. It is said to produce finished compost in a few weeks.
http://vric.ucdavis.edu/pdf/compost_rapidcompost.pdf
Thermophilic Composting
It also develops temperatures high enough to kill pathogens possibly contained in humanure. I don't think that the Airhead or Natures head works this way and the decomposition will certainly be slower. I could be wrong about that though.

Then there is the tried and true method of piling it up, covering it up and forgetting about it for years. That's the method I've had the best success with. I have actually found it rather difficult to get a compost pile to heat up. The carbon to nitrogen mix has to be about 30 to 1, it has to have just the right amount of moisture and it has to have a lot of oxygen. Which means a lot of turning. Something I would rather avoid if there is human waste involved. I have a compost tumbler a number of compost piles and a couple of wormeries and have done a lot research about the subject and have concluded that all in all, I would rather just have a designated compost area for that "special material" and just let it sit for the two years that is required to make it safe.

I know from personal experience that a normal person can produce at least a five gallon bucket of solid waste in a relatively short period of time. Somewhat less than a month. Since one of the basic principals of composting is that the time of composting is counted from the time of the latest deposit, I think it's unreasonable to expect a composting head to keep up with one's production. I think it is inevitable that one would have to have a way to store the material until it can be added to a land-based compost system. Especially if one is generous in the use of covering material.
I have used a variety of material as a cover and I have found that what I like best is finely sifted leaf compost. It's almost like dirt and immediately stops any odor. Though, the same can be said for just about everything that I've tried. Including ashes. I use a lot more covering than I need because I am trying to get the carbon content of the final mixture up and I have no shortage of the stuff.

I have come to the conclusion that until the price of the commercially produced composting heads come down to a reasonable price, I am going to continue to use my bucket and jug. No venting, no fans. Just a simple system that I can build into a little cabinet to make it secure and less obvious. I will put the lid on the plastic bucket between uses even though there are no odors. I will have a hinged lid on the cabinet to cover the whole shooting match and it will look like a simple locker.

The advantages of a composting head are too numerous not to go that way as long as one can get over the silliness. People think that if they flush it down a tube, they don't ever have to think about it again. Well, maybe they won't, but the poor sucker (pun intended) who has to deal with the pump out has to look at it again.
Now that is plain yucky.

[ConradG]

Another quick question, Hummingway,
I know you aren't out basking in the sun yet, but how's the stink on deck, outside under regular use? Better than the holding tank was?

[wildshore]

Conrad,
If you've used enough cover material and you divert the urine to a separate collector, there should be no stink at all.

BTW here's a lovely little one for household use.

Joseph Jenkins, Inc. Internet Sales*::*Compost*::*LOVEABLE LOO - Eco Toilet

[hummingway]

I haven't noticed any smell on deck and nor has my neighbor and he's here working on his boat quite a bit. I pulled the vent pipe to see and it is pushing odour but it isn't terrible smell like a holding tank and pipes. I think the toilet is working pretty well all in all and it smells better then the smell when I would open the cabinet where the macerator through hull was. I think it's generally the case that the when the vented air mixes with the air outside it's unnoticeable. The step is parallel to my toe rail and the head is on the starboard forward of the salon. There's no smell when I'm underway but I installed the clamshell swept aft abit so with a gale off my stern I think it's catching it.

[ConradG]

Thanks for the firsthand report on your instalation. Perhaps sitting a couple of bricks or something to keep the direct blast away during times you are in a slip or tied to a dock will cure the backup into the cabin. Sounds like it shouldn't be a problem at anchor or when on a mooring. Also good to know that venting should be thought about but that the outside smell is pretty much a non issue.

[knothead]

Originally Posted by wildshore

Conrad,
If you've used enough cover material and you divert the urine to a separate collector, there should be no stink at all.

BTW here's a lovely little one for household use.

Joseph Jenkins, Inc. Internet Sales*::*Compost*::*LOVEABLE LOO - Eco Toilet

That's been my experience as well. Use a lot of cover material. Absolutely odorless. Even when left open and with no vent.
It's mixing the liquids with the solids that causes the bad smells.
If you don't separate them, the only benefit of the composting head is that it doesn't use water. Which on land is reason enough.

My simple bucket and jug in the garage is cleaner, way less smelly, whether in use or just sitting there than the regular toilet in the house and it's ecologically sound.
I agree with Joseph Jenkins when he says that the flushing toilet is the most wasteful invention that man has ever come up with. We simply can't go on indefinitely being as wasteful and oblivious as we have become.

FUN FACTS
about water

• If all the world’s drinking water were put in one cubical tank, the tank
would measure only 95 miles on each side.
• People currently lacking access to clean drinking water: 1.2 billion.
• % of world’s households that must fetch water outside their homes: 67
• % increase in the world’s population by mid 21st century: 100
• % increase in the world’s drinking water supplies by mid 21st century: 0
• Amount of water Americans use every day: 340 billion gallons.
• Number of gallons of water needed to produce a car: 100,000
• Number of cars produced every year: 50 million.
• Amount of water annually required by a nuclear reactor: 1.9 cubic miles.
• Amount of water used by nuclear reactors every year: the equivalent of
one and a third Lake Eries.
Sources: Der Spiegel, May 25, 1992; and Annals of Earth, Vol. 8, Number 2, 1990; Ocean Arks International,
One Locust Street, Falmouth, MA 02540.

WATER, WATER EVERYWHERE
AND IT’S ALL GOING DOWNHILL

• In the mid 1980s, the 2,207 publicly owned coastal sewage treatment works were discharging
3.619 trillion gallons per year of treated wastewater into the coastal environment.
14
• In 2004, 850 billion gallons of untreated wastewater and storm water were released as
combined sewer overflows and between 3 billion and 10 billion gallons of untreated
wastewater from sanitary sewer overflows are released each year in the U.S.43
• In 1997, pollution caused at least 4,153 beach closings and advisories, 69% of which
were caused by elevated bacterial pollution in the water.15
• In 2001, of the 2,445 beaches surveyed by the EPA, 672 were affected by advisories
or closings, most often due to elevated bacteria levels.
• In 2003, there were more than 18,000 days of pollution-related closings and advisories
at U.S. beaches according to NRDC's annual report on beachwater quality. 88% of
the closings and advisories stemmed from the presence of bacteria associated with
fecal contamination. By 2007, the number of closing and advisory days at ocean, bay,
and Great Lakes beaches had topped 20,000 for the third consecutive year. The number
due to sewage spills and overflows more than tripled from 2006 to 2007.
• According to the U.S. Environmental Protection Agency, the primary cause reported
for beach closings is the overflow of combined storm-water and sewage systems with
insufficient capacity to retain heavy rains for processing through sewage treatment
plants.
• In 2002, New York State sued Yonkers over sewage discharges, alleging that thousands
of gallons per day of untreated sewage were discharged into the Bronx River
from at least four pipes owned and operated by the city. Laboratory results showed
that the pollution contained the bacteria fecal coliform, an indicator of raw sewage, in
concentrations as high as 250 times more than allowed by New York State water quality
standards.
• In 2002, a federal judge found Los Angeles liable for 297 sewage spills. From 1993 to
January, 2002, the city reported 3,000 sewage spills. Los Angeles has about 6,500
miles of sewers. The spills end up in waterways, are carried into the ocean and pollute
beaches.16
• United Nations Environment Program (UNEP) studies show that over 800 million people
in coastal South Asia have no basic sanitation services, putting them at high risk
from sewage-related diseases and death.
• In 2000, 55% of U.S. lakes, rivers and estuaries were not clean enough for fishing or
swimming according to EPA testimony before Congress in 2002. In 1995, 40% were
too polluted to allow fishing, swimming or other aquatic uses at any time of the year,
according to the United States Environmental Protection Agency.
• In January of 2005 it was reported that twenty-two percent of U.S. coastal waters were
unsuitable for fishing, based on EPA guidelines for moderate consumption of recreationally-
caught fish.
Joseph Jenkins

[ConradG]

As I think we all can agree, a boat sized composting head isn't going to be doing a complete job of composting in itself. Size matters. One of it's primary advantages as I see it is that even when small, the capacity is huge when compared to most conventional holding tanks. However, if you are adding "cover material" often it deminishes the lenght of time between empties. Not a problem perhaps, depending on your needs. I believe it is one of the reasons Natures Head recomends adding 2 galons of peat (or it's equivolent) once at the beginning of the batch. Suposed to be enough to "cover" with agitation from the crank. Of corse if more is needed it is a simple option to reduce smell, but it will increase emptying intervals. All good stuff to know before installing one. That there can be smell from uncooperative wind inside depending on instalation is good to know also. As is the confirmed asumption that the smell outside is far better than that of the cesspool of regular holding tanks. Thanks.