Wednesday - Final Immersion

So, the whole point of this trip was to make a survey of the latrine situation here in Sasle. The four us, Juan Carlos, Francisca, Racquel and me, made a start of it at best. My estimate is that over 4 hours we covered about 15 km making a large loop with a considerable number of side digressions to see various home both with, and without, latrines. For sake of brevity I will post a bunch of the latrine photos as I know that that is the only reason you are probably following this. so for all of you have been patient, here is your reward.

 

This house is equipped with a simple latrine that discharges into an underground septic pit. It is a rare exception in this area as, for the most part, the soil is too rocky to excavate. Think about it - you need more than just a toilet - the stuff has to go somewhere. The solution that is currently being implemented is the development of latrines with above ground biodigesters. The waste stream leaves the latrine itself and is piped by gravity into a small building that houses a large plastic bag in which the waste natually degrades by bacterial action. This is basically what happens below ground in a septic tank. One of the byproducts of this process is the production of methane which can be used as a source of energy for cooking and heating. The next slides show examples of these structures. I know, I know...too much fun.

Latrine Building

Biodigester Building

View of Latrine from Biodigester Building

Effluent Connection Between Latrine and Biodigester

One of the biggest hurdles to getting this done is the excavation. Neither the phtos nor words adequately describe how difficult this terrain is to excavate. There is no heavy equipment available - it is done strictly by hand with shovel and prybar. Even if heavy equipment was available it would be virtually impossible to get it into the positions needed for placement of the biodigesters. As one can see, the biodigester must be lower than the latrine itself since there is no water for flushing other than a can poured down the drain after use. Which brings us to our next shots.

 

Simple. But effective. That's all I will say. You do the rest.

The biodigestion process occurs spontaneously within the bag. Solid waste settles to the bottom, excess fluid flows out through an overflow valve and the bacteria go to work digesting the solids and producing methane.

The PVC pipe fitting seen is the exit pipe for the methane. For some reason the locals refer to is "butana" or butane, but it is predominantly methane (single carbon) with lesser amount of ethane, propane and butane mixed in. It's all combustible anyways. The plastic bottle is full of water and serves as a water trap (just like the U-pipe in a kitchen drain or toilet) and prevents backleakage and loss of gas. The average daily rate of gas production for a family of four yields approximately 40 minutes of flame on a single burner stove. For many of these people it is a significant improvement. Obviously, though, it does not eliminate their need for wood or other fuel for cooking. It just helps out.

Lastly, here are a couple of shots of a new installation going in, courtesy of Bridges To Community. The supervising hand on this is one of the BTC volunteers Jorge Valdivia who lives in the community.

The most time consuming aspect of the whole process is the excavation. Once this is done by the homeowner, Jorge and his crew and get the unit built in two days.

So, how can you top that, huh? You can't. Really. But, if you are interested in doing something to help me and my group of stout engineers, please consider checking out the EWB online fundraiser:

Here's the link: https://support.ewb-usa.org/fundraise/team?ftid=91356

Anything you can do would be greatly appreciated.