On-site sanitation systems are options which help treat the waste at source, rather than dealing with it several miles away in a centralized manner. In the absence of sewerage systems and piped supplies, communities have to devise decentralized ways to deal with their shit. Some of the most common on-site sanitation systems include septic tanks and pit latrines.
Flash cards developed by the Urban Management Centre and CEPT University’s Performance Assessment System classify different on-site sanitations available, encompassing all four aspects in the value chain: Collection/storage, conveyance, semi-centralized treatment and disposal/use.
Visually appealing and easily comprehendible graphics from Eawag’s ‘Online Compendium of Sanitation Systems and Technologies’ help better illustrate the entire value chain of various types of on-site sanitation systems that are currently in use.
These systems deal with collecting and storing black water from latrines. It can also include partial anaerobic treatment of solids that settle down in tanks and pits. The following three collection systems find a place in the flash cards.
Sewage from the point of origin is conveyed using one of the following means to certain centralized or semi-centralized areas for further treatment.
Semi centralized treatment options cater to the needs of a larger area like entire neighbourhoods or even the entire city. These can be broadly classified into two types: One, to deal with the black or grey water from the latrines and bathrooms and, systems to manage the sludge.
Once partially treated or otherwise, the sludge can be injected into the soil either as fertilizers for plants or be disposed off in a form that is not harmful to the environment. Some of the most commonly followed practices are listed here.
You can download the flashcards as a PDF document from the link below.