The water system of my previous van was pretty simple: a 40 liters tank with a submersible pump and a small sink. Unfortunately, I couldn’t keep the water drinkable without some chemical additives. I didn’t like the idea of drinking a chemical cocktail, so I only used the water to wash my body and the dishes. I didn’t like buying portable water in jerrycans, either. Based on my negative experience, I decided to install a professional water filter system that would allow me to treat water, even when obtained from questionable sources.
Installing the fresh water tank
I placed a 90 liters water tank under the raised floor holding the table of the seating area.
I’ll have to regularly clean the tank to avoid contamination. The construction holding the tank can be unlocked and tipped up to easily remove the tank for such maintenance tasks.
I connected the tank with a 38mm hose to a closable nozzle in the very back of the van.
The tank can be easily filled by pouring water into the nozzle.
Installing the wastewater tank
I picked an old 60 Liter tank to collect the wastewater.
There was plenty of space in front of the right back wheel to install the tank without losing chassis clearance.
I connected the wastewater tank with flexible hoses to the drains of the shower and the sinks inside the van.
Installing the pump and the filters
I placed the pump next to the fresh water tank inside the van.
The pump sucks the water out of the tank through a little pre-filter and pushes it into the main filter system that consists of two filter pairs.
The two filter pairs are connected in parallel to increase the throughput. Each pair consists of a ceramic filter cartridge and an activated carbon filter cartridge. The 0,2 micron ceramic filter removes all bugs, bacteria and parasites. The activated carbon filter removes unpleasant tastes, chlorine odors and hazardous chemicals.
Based on the water quality, the filters need to be cleaned and eventually replaced. I installed a little sink below the filter terminal to support these maintenance tasks.
The sink is connected to the wastewater system and allows me to remove the filters without flooding my van.
Installing the boiler
A proper shower requires hot water, does it? After doing some research, I found a German manufacturer building small-sized 12 Volt boilers that can heat up 6 liters to 80 degrees Celsius. The boiler nicely fits under the sink next to the shower.
The (really) hot water can be mixed with cold water to get enough warm water for a pleasant shower.
According to the boiler’s specifications, it was supposed to support a pressure of up to 3bar which seemed to align well with the specifications of the pump. Unfortunately, the safety valve of the boiler opened right before the pump would automatically stop pumping. I installed a pressure regulator in front of the boiler which solved the problem. 
I was finally able to enjoy hot and cold portable water right out of the tap. 
