It is called human waste and many other names. The whatever unmentionable stuff that is coming out from our bodies. The stuff we need to get rid of, but according to a "new" Swedish law from 2015 we just can't discharge into the seawater, like we used to not too long ago. In 2020 we made it a part of our "Zero Waste Policy" onboard and have lived by it since then.
Just three deciliters of urine can fertilize 1.000 liters of water with toxic algae. An experiment from Stockholm University clearly shows why we should not forget that the sea is not endless when we need to pee.
The experiment was carried out by Ellen Schagerström and Lena Kautsky at the Askö laboratory in Trosa Archipelago, in August 2017. Four large tanks were filled with 1,000 liters of water from the nearest bay in the Baltic Sea. One tank was left unaffected and 3 dl, 6 dl, and 12 dl of urine were poured into the rest. 12 dl of urine corresponds roughly to what an adult person produces in a day. In each tank, they also hung a tuft of green algae, a common algae species that often cover rocks in the archipelago.
The difference after 10 days: Left – water with no urine. Right – water with urine. Photo: Ellen Schagerström, Tångbloggen.
After a week, the water in the tanks was compared. In the control tank, the water was still completely clear, while in the tank with 12 dl of urine, it was strongly green and so cloudy that the bottom could not be seen. The algal tuft in the tank with urine had grown predominantly larger and denser. Se Swedish article from 2017.
This is the short story on how we deal with it onboard:
First of all, our boat does not have a toilet with a tank that can be emptied at the pump stations that are becoming more and more accessible along the coastline. We have a portable toilet (Porta Potti) as a base but we separate wet and dry waste:
We separate our needs – wet (shi-shi) and dry (do-do) waste.
We collect it in separate "containers" and store it temporarily onboard.
We dig the dry waste down with a planting spade into the soil in forests on remote islands or on the mainland.
We poor out the shi-shi in forests on islands or on the mainland. Sometimes we empty our containers with shi-shi into toilets at marinas. We have also found a few marinas with a dedicated "station" where you can empty a portable toilet or container. Mostly these stations are found at marinas that offer parking spaces for mobile campers as part of their services.
Separate the wet and dry waste. A paper bag vid a little sawdust or dry grass in the bottom. Then we put the bag into a solid container with a super-safe lid. Some sawdust or dry grass in the bottom helps keep it dry and easy to empty and clean/rinse.
How hard can it be? We all have to poop and pee and have done so since the beginning of time. We have tried and learned how easy it is to bring a little planting spade onboard and dig our human waste deep down into the soil on an island. Boom – the problem is basically solved. Human waste is considered valuable nutrition up on land, but an accelerating problem when dumped/poured into the seawater. The paradox is obvious: In Scandinavia, the basic four-week summer vacation in July is the time of the year when most people want to take baths. It is also the same four weeks when most people dump or pour their human waste into the same water. And the same time when the warm water temperature creates the best conditions for the growth of algae.
10 different liquids to clean a Porta-Totty? Come on...!
This is how marketing makes us buy plastic bottles filled with mostly water and toxic detergents we don't actually need. We do not doubt that the products are effective, but we do not trust them at all for their content.
Wtf...ten special products including specially made toilet paper...
We have tested one homemade liquid for years and it works great – lemon leftovers soaked in white vinegar, mixed with baking soda and essential oils for the scent. Voila.
We have no toilet tank that can be pumped at the pump stations, but we still store the hmhm, so planning is key.
When the containers are full, the need for land is crucial, so planning a little in advance is quite important. Of course, we missed that once and ended up in a pretty critical situation. We just had to find somewhere to empty our containers. We were sailing south from Kalmar and the waters were very shallow so there were not many islands reachable for us. And it was too far from any marinas. However, we found one island pretty along our way and we almost reached all the way into it. With no dingy onboard swimming was the solution. Swimming with black water containers...just gotta get done.
The only island close enough, with deep enough water close enough.
The Black Water pilot is ready to launch.
Floating containers waiting. Emptied into the soil.
Dug deep holes to speed up the biological degradation.
Covered with soil. Cleaned containers with non-toxic soap.
Process intensively supervised from the mother ship:-)
Containers were pulled back and made ready for docking again.
An easy mission in July. Possibly tougher in November.
