The accumulation of non-recyclable and non-recoverable materials, known as “common refuse”, within the community (such as various plastics, metals, and broken glass) led us to search for the most responsible manner to dispose of them. Ciudad Saludable, our Parent Organization, proposed the development of a “sanitary trench” under the guidance of their sanitary engineer, Luis Sáenz.
Non-recoverable materials that will go into the landfill.
- Synthetic cloths
- Regionally non-recyclable plastics – 3,4,5,6, and 7
- Plastic bags
- Plastic packaging from food and cleaning supplies
- Laminated paper
- Broken glass
- Undesired metals
Non-recoverable materials that will NOT go into the landfill.
- Used motor oil and other petroleum products
- Used batteries
- Hazardous materials will be dealt with on a case by case basis.
Please send us any suggestions you have for dealing with these problematic materials.
While we do not view this landfill as the final solution for our refuse, we do concede to the fact that as long as these useless materials are generated in the community we will need to manage them in a safe and responsible manner. We are however working hard through education and innovating thinking to reduce the amount of these materials that enter the community and find creative ways to renew their value. Already by separating out all organic and recyclable materials we are reducing the amount, by weight, of refuse going into the landfill by 87%. Through our continued efforts we hope to someday see the remaining 13% be reduced to 0% waste, following the example set forth by Zero Waste South Australia. For the present we will be testing the landfill designed by the Sanitary Engineer, Luis Sáenz of Ciudad Saludable.
The pilot landfill that we are making in San Francisco is essentially a trench 1 meter deep, 3 meters wide and 5 meters long. Each side of the trench has a 45º slope to the bottom, which measures 1m x 3m, giving the trench a total volume of 9 cubic meters. Our original plan was to cover the sides and base of the trench with 10cm of compacted clay to create an impermeable layer of protection, but Ciudad Saludable’s sanitary engineer, Luis Sáenz, assured us that the dense clay parent material, characteristic of Amazonian soils, would be sufficiently impermeable. As such, we are not adding any extra protection.
As a pilot study, we will keep track of the volume of non-recoverable waste that enters the trench and the amount of time it takes to fill. The information we gather will give us a good idea of the expected lifespan of the total area of the terrain that we have allocated for the landfill. The following steps outline how the trench will be managed.
- Each weekly deposit will be weighed and we will measure both the uncompacted and compacted volumes.
- The deposit will be compacted in the trench and then be covered with a thin clay layer that will also be compacted, thus creating an impermeable layer between each deposit. This will also help to keep the waste from blowing away in the wind, a problem that many informal dumps in the region encounter.
- When the trench has been filled it will be covered with a 45cm thick layer of compacted impermeable clay and then with 20cm of fertile topsoil to be planted with various useful plants. We still don’t know what plants (flowers, timber-yielding trees?) would be optimal so please send us your ideas.
- Once the trench has been filled, we will then dig another one adjacent to the wide side of the previous trench, following the natural slope of the land.
The pilot trench was dug in the period of three days with the help of the whole SFS team and one community volunteer. Here is how we did it.
- We began by measuring the area of the trench, 3m x 5m, exactly 1.5m from the unkempt road and 1m from the neighboring terrain that is currently unused.
- Next we measured an area of 1m x 3m in the center of the trench.
- We proceeded to dig the central area 1m deep with pick-axes and shovels, separating the topsoil so it may be used for agricultural purposes later on in the project.
- We then dug down all four sides at 45º angles to complete the trench.
- From there we dug a canal 40cm wide and 30cm deep along the high sides of the trench to direct the flow of water down the natural slope.
- The final step is the construction of a movable 6m x 6m roof with a 5º slope to keep the rain out while we are filling the trench.