Today we had review. The way they ran that was a number of the crew stood at the front of the class and asked us questions about things we should know. It was an interesting way to do it, and it worked pretty well. I’ll be doing more studying tonight for the test tomorrow. They did say that only two people have ever failed it since they started the academy, so it should be pretty straightforward.
We also had a talk about organizing and planning our independent study project, which is the third requirement needed to graduate from the academy. The second part is going out and participating on a full build from start to finish. I don’t think I’ll be able to fit that in this year, so hopefully next year I can work on that.
In the afternoon, my group went over to a different site to work on some botanical cells. These are big planters that are used to process grey water. This is what we started with: a big hole in the ground. You can see a little tunnel hole at the bottom. That’s the spot where we run the pipe that connects to the adjacent cell. My first job was to finish digging that out so we could fit the pipe through.
Once that was completed, we lined the cell with EPDM rubber. If you want to know what EPDM is, it’s ethylene propylene diene monomer. Look it up on Wikipedia if you want to know the details.
Once the cell is lined, we had to cut the hole for the pipe, stretch the EPDM over the pipe, add a gasket over that and then clamp the whole thing so it’s sealed. Here is a picture of Sangeeta (the G is pronounced like it is in the word Great) doing that detail.
Once that was all sealed up, we attached the observation pipe to the end of the stem pipe. This will stick out of the cell so you can open the cap and see what your water level is. It basically allows you to keep an eye on things. Once you attach that, you surround it with large rocks. The observation pipe has a tonne of holes drilled into it so the water will leave the pipe, go through the rocks and into the cell.
After the big rocks are in place, you start dumping gravel into the cell to fill it up. We won’t be filling it all the way with gravel, obviously. Only up to about 16 inches (40cm) below the top.
After the gravel, we’ll put about 2 inches (5cm) of sand as a buffer, then fill the rest with soil. That will finish off the cell and then we can start planting things in it once we have all of the water flowing. We didn’t get as far as that. Just to the point of filling it with gravel. Here is a gravel action shot.
Meanwhile, over at the main build site, they were working on adobe packout. Remember yesterday I mentioned about packing out the spaces between the tires to bring it out flush? Well, this is a picture of the guys working on that.
They are packing out with adobe, which is a mix of 2 parts sand, 1 part clay and two hand fulls of chopped straw. It works really well and as you work up the layers, you’ll do more sifting on the sand and clay to finer versions. You’ll also want finer straw. In the end, you can make it super smooth for a nice finish.