This blog, and the websites associated with it are an ongoing study of slow sand water filtration, which is a sustainable technology. In view of current events and the general decline of the quality of our environment on a local and global scale; access to safe clean water through locally sustainable technology should be a top priority.
A slow sand water filter can be built from mostly recycled materials, and does not need electricity or petroleum produced energy to operate. Slow sand filters do not need chemicals added to enable their functionality. Slow sand filters last years and are readily repaired and maintained without the need of non-sustainable resources. Slow sand water filtration uses naturally occurring biological, and mechanical processes to remove harmful substances from water.
Sustainability is very well described here. Read about sustainability, read about slow sand water filtration; and then make your own decision about how “sustainable” rapid sand filtration, membrane filtration, or distillation really is after reading about those processes also. Look at the component parts used, energy used, and chemicals used and figure out what kind of resources are necessary in each situation.
When deciding if a water filter is sustainable technology, carefully consider:
The renewable, or non-renewable energy source required to produce the device and the pollution created when producing the device. Is the device recyclable? What resources are used to produce the device? Are those resources renewable? Are people exploited in order to produce the device? How long will the device last? Can the device be repaired locally?Also, consider the same things when investigating the operation of the device. Water is needed by people all the time. If non-sustainable energy is needed always to run the filter, then is it really sustainable technology – even if it is produced in a sustainable manner?
What if there was a water filter that required some energy input to produce (energy that could be renewable energy), but required no resources to operate other than sunlight, gravity and some manual labor (adding water occasionally by hand). And what if this filter was totally reusable, non polluting, locally repairable, and did not wear out? That describes a small slow sand water filter. Think about it.