Waterfilter system

Because we want to live as independently as possible and utilize a resource on our land, we decided to build our own filtration system to filter this water into drinking water. We came across a design by Josh Kern, who tested this system twice a month for over 3 years to observe its effects. The results showed that this system, with very little maintenance, delivers excellent results in filtering water.

For the filtration system, we used four 300-liter barrels. These barrels were originally used for food storage. If you want to build a similar system, make sure that the barrels are made of HDPE (High-Density Polyethylene). Since it’s for drinking water, it’s important to choose the right kind of plastic.

We started by leveling the ground. The barrels are placed on four concrete blocks in the ground. Then, we made all the connections to the barrels and filled them one by one with the required materials. This might sound like a straightforward process, but in reality, it took months to complete the entire process. It all starts with gathering all the materials, which takes a lot of time because there are many things needed—barrels, connections, pipes, various types and sizes of stones and sand, making Biochar, preparing the site, cleaning all the materials before they go into the barrels, moving everything to the highest point, etc.

Because the construction of the entire project took so much time during an already busy period, unfortunately, there are few process photos taken.

For those who also want to build a similar system, or just to show where potential problems might arise in this process, here are some issues we encountered while building this water filtration system.

1. Spare Barrel
After everything was filled and we were ready to test the system, we discovered a crack had formed in the first barrel (with stones). This was likely due to dropping the stones into the barrel and the pressure from the weight. We had to replace this barrel, but this meant removing everything and reconnecting the fittings entirely. Fortunately, we had a spare barrel, so this is definitely recommended (just in case…).

2. Amount of Water Needed for Cleaning Materials
Cleaning the materials is necessary to ensure that the water is properly filtered. Depending on how clean the products are initially, you may need to clean them thoroughly. This required much more water than we initially expected, especially cleaning the sand of small twigs and organic material, as well as the stones.

3. Clean Water Needed to Make Clean Water
It might sound ironic, but to properly clean the materials, you actually need clean water. Where will you get this from? In our case, we were fortunate to have access to filtered water from the village, as the water from the stream is quite murky. However, if you don’t have this, the process can be challenging. Cleaning materials with dirty water is essentially not an option.

4. Cost of Connections
Most materials are relatively inexpensive or can be found in nature. By far, the largest cost was all the fittings. Especially the taps are very expensive. This ended up costing significantly more than expected. Another cost is the special drinking water pipes needed from the filter. Due to the size of our project, these are rather long pipes.

5. Use plastic valves, not metal
The taps we used are metal. Initially, this seemed more robust, and they are also smaller/handier, making them easier to implement. In hindsight, we might need to replace them with plastic taps. In winter, it can freeze here, and there is a chance the taps could freeze and break. Plastic taps are somewhat more forgiving and less prone to this. Ultimately, we’ll need to insulate them well in the winter.

6. Warm Water
The barrels are positioned somewhat under the trees. Still, they are in the sun for part of the day, and it can get over 40 degrees here. The water in the barrels can, therefore, become quite warm. If anything is a good breeding ground for bacteria, it’s lukewarm/warm water. It’s important to properly insulate the barrels, but how do you do this in a way that still allows you to maintain the system?

7. Location
Since we want to rely as much as possible on gravity and not be dependent on a pump, we built the system at the highest possible location on the property. It’s a one-time effort if done correctly, but ultimately, hundreds of kilos of material need to be hauled up to fill the barrels. This is certainly something to keep in mind.

8. Float and Connections
One of the most challenging things to get right is the float. Ultimately, you want the lid on the barrel to keep out pests. The float ball must be able to move freely and not hit the lid. This requires some careful adjustments. It’s especially important not to make the connection from the first to the second barrel too high. We want to get as much water yield as possible, but it can become difficult if this connection is too high. Also, make sure the check valve at the bottom can move freely and isn’t blocked by stones. This can take some fiddling.

9. Making Biochar
Making biochar is quite simple to do yourself, but in terms of planning, you need to consider the time of year. We were just in time, but in summer, we’re not allowed to make fires. This means the project would have stalled for months. Luckily, we were able to make one more batch of biochar at the last minute using our fire permit to fill the barrel.

So, we encountered quite a few things before this project was a success, but in the end, it worked out, and we’re happy with the result.