Composting head for inland use? What to do with the urine?

[OliverSnowbird]

Hi,

Our boat has two heads and a holding tank.

The way it is plumbed (from the factory?), the sinks and the showers drain overboard, the heads through a macerator pump into the holding tank.

We are on Lake Michigan, I therefore already feel somewhat uncomfortable that we are discharging gray water overboard.

While our heads still work, they are both old and nasty. I therefore wonder whether a composting toilet would be a good replacement, ideally allowing us to not use the holding tank anymore.

I understand that the solids would have to be emptied only every few weeks, what would be fine, but that the urine tank might have to be emptied every few days and that I can't (and don't want to) just dump it overboard.
A urine diversion kit might be a solution, I would then however still need to use the holding tank, hence not benefit all that much from installing composting heads.

What are your thoughts?

Oliver

[Mike OReilly]

If you don't want to dump it overboard, then you have two viable options*. One is, as you say, to divert urine to a holding tank for later pumping out. Or you can manually dump the urine into existing toilet facilities on shore.

I cruised for many years on the Great Lakes. I dumped into the water. Urine is mostly water (95%), and largely (not 100%, but pretty close) sterile. Nothing is 100% sterile, but if you're concerned about this level of pathogen load, then don't go swimming. Human skin is crawling with bugs!

The biggest negative about urine is nitrogen, but the volumes are tiny. Still, I try to avoid dumping in enclosed areas, or places with lots of other sources around.

To be absolutely clear. Dumping urine overboard in the Great Lakes is illegal. You can pee over the side, but you can't pee into a bottle first, and then dump.


* Actually, there is a third option. Sun-Mar makes composting heads that use a heater to evaporate the urine. I've only ever seen one sailboat with a Sun-Mar installed, and this person swapped it out for a Nature's Head after a couple of seasons. But it is another way to go.

[OliverSnowbird]

Hi Mike,

Frankly, I am not worried about pathogens as all the wildlife is doing just the same, including poo.
I'm probably overthinking this, as I believe that the typical gray water mix of detergent and grease is nastier than a little bit of urine.

[JBP]

I know some people buy multiple liquid tanks and store them until they reach somewhere they can legally dispose of it.

I feel that emptying my holding tank once a week (free, self serve at my marina) is preferable to dumping a liquid tank everyday or storing liquid tanks. While I'm sure some people dump it overboard and can rationalize their justification, it is still illegal and still contributes, even if minimally, to nitrogen pollution causing our toxic algae blooms.

[Mike OReilly]

Ah yes, good point. We carry two urine bottles, so can go about six days between dumps if need be. I rarely need to.

[Mike OReilly]

Originally Posted by OliverSnowbird

Frankly, I am not worried about pathogens as all the wildlife is doing just the same, including poo.
I'm probably overthinking this, as I believe that the typical gray water mix of detergent and grease is nastier than a little bit of urine.

I’m sure you’re correct about the relative impacts. But just know, it is illegal to dump from a container. Although, I’ve never heard of anyone being charged with this kind of offence. Anyone???

BTW, feces is a different scale of impact. This is the stuff that can carry a lot of nasty human pathogens. It’s not so much that impacts the ‘natural’ environment. The real risk is spreading the impact to other humans.

[5BTM]

My guess is tens of thousands of humans go swimming in the Great Lakes during sailing season and I will bet some of them take a whizz while in the water.

[s/v Jedi]

From what I understand, boats with composting toilets store the poo in bags and urine in soda bottles, neatly on a shelf

Then in a marina they throw the poo bags in the trash cans and take the bottles to the bathroom to empty them. I’m glas I managed to escape the couple times I saw one coming as I find the storing and hauling of waste highly unpleasant!

[OliverSnowbird]

Talking about urine, these are my two concerns (again, I'm probably overthinking this):

1.) Discharging urine into the water is technically illegal
2.) Other boaters in the marina might not be too pleased to see a yellowish liquid drain from our boat into the water

[5BTM]

I think you are being more catholic than the pope, technically rolling stops are illegal.

Tied up at the marina, I use the wahrooms.

Depending on your diet, the color could be that of the water algae, just don't have asparagus for supper....

[thinwater]

If there is no pump-out, odds are you are anchored along a wooded shoreline. Walk 30 feet away from the water and dump the pee in the leaves. Through a number of natural processes, the nitrogen will never make it to the water.


Or wait for a dock with a marina rest room.

[Chotu]

Well, this is a reaction video, unfortunately, rather than the real thing, but it’s still very applicable to the thread. Quite entertaining too. ha ha ha

This is what can happen if you add a bottle of pee to the Great Lakes:

Mature subject matter and course language so be warned. you might laugh

https://m.youtube.com/watch?v=L5OrrkyIXr4

[5BTM]

What the heck.....

https://www.youtube.com/watch?v=xIq8EAYP2Qs

[Mike OReilly]

Originally Posted by OliverSnowbird

1.) Discharging urine into the water is technically illegal

Yup.

Originally Posted by OliverSnowbird

2.) Other boaters in the marina might not be too pleased to see a yellowish liquid drain from our boat into the water

If you're in a marina, the better solution is likely to dump it into the land toilet, or just use the land head for that matter. It's not a big deal. The only people who seem to think it is, are those with little or no actual experience with these heads.

[wefleenor]

If you are a gardener, then dilute the urine and apply it as fertilizer. It is done widely over most of the planet - particularly in developing countries. Avoid using it on contact plants such as carrots, radishes, potatoes, etc.