One of the issues I currently have with the boat is the toilet, and black water system in general. The current toilet (for those marine purists…I consider the “head” to be the equivalent of the bathroom, not specifically the toilet itself) is a Groco manual, a brand which seems to have a pretty good reputation. But it is pretty old and not quite working as well as it should, and really needs to be rebuilt. As well, the survey pointed out that the waste lines need to be replaced, and since the survey mentioned it, my insurance carrier (BoatUS) is insisting on it. On top of that I was shocked to find out how fast the holding tank (20 gallons?) fills up, although that may have partially been due to over exuberant pumping.
Keeping in mind that I will eventually be living aboard, and that getting pumped out in the winter months could be problematic I was left with a few decisions.
One: Fix the current system, plan on pumping weekly in season, and not using the waste system at all in the winter months. This would include a rebuild of the current head, and a replacement of all the waste lines and the overboard discharge seacock (only used well offshore).
Two: Make some changes to the current system, plan on pumping weekly in season, and not using the waste system at all in the winter months (a little Déjà vu there). I was thinking either an electric macerating toilet or a Lavac system in addition to the waste lines and seacock. There would still be the holding tank limitation, though.
Three: Doing something different. In this case a dry composting toilet. In fact, after a lengthy conversation with the designer of the Nature’s Head toilet at the US Sailboat Show in Annapolis, this is exactly what I decided to do and I bought one there on the spot. While pretty expensive, I believe it would in the end be cheaper than option two, and not all that much more than option one.
There are several advantages to the dry composting toilets (there are a few designs out there that work more or less the same way).
- Urine is separated from solids with a clever diverter design which dramatically slows how fast the main tank (built into the toilet) fills, allowing a claimed 60-80 uses between emptying (more if you don’t throw the toilet paper in the tank, although that would generate a whole new set of issues).
- There is no offensive odor, although depending on how ventilation is handled there might be a musty peat mossy scent.
- There is no need of a holding tank or associated waste plumbing or through-hulls simplifying the system and opening up more space.
- With the holding tank gone, I will have room to install a new 20 gallon (more or less) water tank, an important addition for when I can finally leave on some extended traveling.
- I don’t have to worry about pump-outs.
Of course, TANSTAAFL (There Ain’t No Such Thing As A Free Lunch). There are drawbacks, too.
- It is unfamiliar to most people (women in particular) who might not feel comfortable using it.
- While the solids tank should last a long time, the liquids will have to be emptied every day or two. Of course, this can be done in any toilet, or for any anarchists out there, discreetly overboard (warning: while there is little to no environmental risk that I’m aware of to this, and while people pee directly overboard all the time without thinking twice, while within the three mile limit this is illegal).
- Eventually the solids tank will have to be emptied. Assuming there hasn’t been any extremely recent “deposits” this shouldn’t be too offensive or difficult a job (I doubt it is worse than a pump-out); but neither will it be pleasant.
- While the Nature’s Head guys suggest bagging the stuff (they call it dirt) and throwing it in the trash, it is unlikely that it would be fully composted, and this may very well be illegal (although no more illegal than throwing dirty diapers away). Buying a five gallon “Homer Bucket” from Home Depot, putting the waste in that along with a cup of bleach, and sealing it turns it into “treated” instead of “untreated” waste and may make it all legal. This is unclear; but so far it doesn’t seem to be a big issue. The other option is to store it (perhaps in a vented Homer Bucket) for a year or two, or dump it on a composting pile somewhere until it finishes doing its’ thing, at which point it is excellent fertilizer (it is recommended not to use it on food plants…just in case). If offshore, of course, it is completely legal to just dump it overboard when outside the three mile limit. I don’t think there is any harm no matter the method; but in the interests of not self incriminating I think I’ll keep my choices to myself.
- Occasionally there have been known to be issues with flies. This is not universal and there are ways of dealing with the problem; but it does happen.
I’ve actually been thinking of this system for a few years as I was trying to find a way to shoe horn it into my Seafarer 24 (it’s a pretty bulky, and in particular, tall system), so I think I have a pretty good feel for the pluses and minus. It’s new to me, though, so I might not tear out the old tank too fast, or seal up the through-hulls until I feel happy with the system, allowing me to revert to a wet system should I feel like it. Or not. I’m still thinking on it. The good news is that the majority of people I know (on web forums, mostly) who have tried a dry composting head have been extremely pleased with the results. I do have my concerns for the fairer sex, though, as I do like to keep them happy and impressed.
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