Systems and the future
Wastewater treatment
housinggated communityhotelschoolrural community
A system that cleans a building’s black water and gray water before returning it to the ground or a river, or reusing it. It ranges from the septic tank to compact plants and constructed wetlands.
What it solves
It protects rivers, wells and beaches from pollution. In Costa Rica more than 75% of the population depends on septic tanks and less than 15% is connected to sewers with a treatment plant.
Today
Choose the system according to the soil, the slope and the groundwater level. Separate gray water to reuse it for irrigation or toilets with the right treatment.
Common mistake
Placing a septic tank in saturated soil or near a well and forgetting to empty it.
Tomorrow
Constructed wetlands treat gray water with plants and can be a garden and habitat for birds. Treated water goes back to irrigation and toilets, which eases the demand on drinking water during longer droughts.
Fact A vertical-flow constructed wetland requires about 3 m² per person. In warm climates it can go down to 1.5 m².
Where it comes from
- 1Indus civilization Mohenjo-daro, present-day Pakistan, Mature Harappan period
Its covered drains had settling pools that held back sediment and were cleaned from time to time. - 2Domestic sanitation France, 1860
Work began on a buried tank for a house’s wastewater, a forerunner of the septic tank.
Masters
- Kongjian Yu Houtan Park, Shanghai, China, 2010
He designed a 1.7-kilometer linear wetland with terraces and cascades where plants clean the water of the Huangpu River. He teaches that treating water can also be a park for the city.
Appears in the routes
See also
Also in Systems and the future
Diagrams and texts by LDB Arquitectura. They are shared under the CC BY 4.0 license, which allows them to be used and adapted with credit to the source.