A Sustainable Solution to Safe Water Access
Energy-free Storage: Rainwater catchment systems provide water storage above ground level with zero energy requirements for pumping. Almost all groundwater and surface water require energy to raise the water above ground level, which is needed to store water in a tank system that is separated from the environment. Having an elevated water source also allows individuals to access the water solely through the use of gravity, reducing the need for manual or electrical pumping. Since the water is falling into the tank, gravity is the only force required to fill the tank.
Long-term Water Storage: Storing rainwater allows people to utilize rain events to provide a clean water source for extended periods, lasting anywhere from months to whole seasons. Many areas around the world, such as the tropics, undergo year-round to seasonal rainfall patterns. The tropics and sub-tropics make up 85% of the global population that lacks access to clean drinking water. In addition to the tropics, almost all other climates have a period of rainfall throughout the year, except for desert climates, which receive very low precipitation, and commonly rely on deep groundwater or external sources for their water supply. Providing a way to store water for extended periods allows communities access to localized water throughout seasonal change, reducing the threat of physical water scarcity throughout the year.
Increased Adaptive Capacity to Climate Change: According to studies conducted by the Intergovernmental Panel on Climate Change, “extreme precipitation events over most of the mid-latitude land masses and over wet tropical regions will very likely become more intense and more frequent by the end of this century…”. Extreme precipitation events will increase erosion and surface runoff into water bodies, contributing to water pollution. Relying on surface water as the primary source of drinking water increases the risk of water-related diseases. On the flip side, precipitation events can increase the potential volume of rainwater storage and prevents it from facing the risk of pollution from increased erosion and runoff.
Culturally Assimilative: Many developing countries throughout the world are currently using water tanks for storage, yet this is most commonly used to store groundwater or surface water through pump systems. Unfortunately, many communities don’t practice rainwater catchment on a large basis. This could be for many reasons, including a lack of resources to create a new system or a lack of access to individual rooftops. However, introducing rainwater catchment systems, that are provided for to the communities, will be culturally adaptable for communities using water tanks, since it is only introducing an augmentation in the process instead of a whole new system.
Obtaining Safe Water Quality
Starting with Safer Water: Using rainwater, as opposed to surface water or groundwater, provides many benefits. Since Gravity Water’s Clean Water Systems use a manual “flush” technique that diverts the initial rainwater that hits the catchment surface from entering the system, very little sediment ever enters the water system. Using water that is virtually free of sediment reduces the likelihood of bacteria concentrations in the water, since fecal bacteria, which host the majority of the viruses associated with water-related illnesses, commonly bind to sediment during transport. Lower sediment levels also mean a longer lifespan for water filters and overall less maintenance for water tank system. Since the majority of water-related illnesses are associated with human-based fecal contaminations, a high percentage of the sources for the water-related illnesses are eliminated, even before filtration takes place.
Filtration Methodology: The Gravity Water tank system uses a three-tier filtration system. Pre-filtration takes place using a 5-micron sediment filter to remove particulates that enter the water tank system. After pre-filtration, a granulated carbon filter is used to remove lead, heavy metals, and all odor and taste associated with the rainwater. The last filter used is a 0.1-micron hollow-membrane water filter, which is used to remove 99.99999% of all bacteria, such as Salmonella, cholera and E. coli and 99.9999% of all protozoa, such as Giardia and Cryptosporidium.