Have you ever wondered how we decide what type of water project to build in which country? Why do we typically dig wells in Northern Uganda, but build rainwater harvesting tanks in Mexico? There are many factors that determine the cost, location, and type of water source we construct. Some of these factors include in which country the project is being constructed (and what materials are available in their local markets), the landscape of the project site (is it possible to get a drilling rig there?), the geology (whether there is a lot of bedrock), and whether there are any latrines or rubbish piles located close to the proposed project site (any contamination site should be located at least 30 feet away). Here, we break down each type of water source, and why we use (or don’t use) them in certain locations.
There are two kinds of wells – deep wells and shallow wells. Shallow wells are under 30 metres in depth, and are typically installed in soft ground, such as sand, gravel, or clay. However, we no longer build shallow wells, as the Ugandan government has phased them out, and the bedrock is too hard in Ghana for shallow wells. Climate change has also made shallow wells less reliable, as there is not as much rainwater to replenish them. Instead, we have replaced shallow wells with more reliable technology, such as deep wells. Although deep wells are more expensive than shallow wells, they access more water, and serve more people. Construction of deep wells (also known as boreholes) requires a large, flat terrain, so that a drilling rig is able to make it to the area; this is why we don’t build deep wells in areas that are too mountainous. They are over 30 metres deep, and typically reach 100 metres in Uganda and Ghana. Deep wells access groundwater reserves, known as ‘aquifers,’ which are collections of water deep in the ground. The well must be at least 10 metres away from any contamination site (such as a latrine or garbage pile), and contamination sites cannot be uphill from a water source.
Water from a deep well is considered to be safer than water from shallow wells because there are fewer risks of contamination. However, there are still specific measures that must take place in order for water from the deep well to be considered potable. For one, the well must be at least 10 metres away from any source of contamination (such as a latrine or buried garbage pile). Due to the lack of sunshine, water from a deep well will not develop algae or bacterial growth. The surface water that refills these groundwater reserves also must pass through a natural filtrations system, which includes layers of soil, sand, and gravel or rocks. However, there is still the risk of debris, such as gravel, getting into the well. For this reason, our local partners install multiple screens throughout the piping of the well to filter out and ground debris. To be considered clean and potable, all our wells must pass a water quality test (which tests for pH level, total dissolved solids, calcium hardness and calcium nitrate, iron fluoride, chloride levels, e-coli, salmonella, etc.), and results must fit within the World Health Organization and country guidelines. After the results of the test come back, and the water is deemed safe, the community can enjoy clean water for generations (with proper maintenance, of course)!
We build protected springs in areas which are hard to reach with well drilling equipment, as they may be very mountainous, such as Western Uganda. Protected springs collect water from existing streams or springs flowing downhill using PVC piping, which then directs the water through a natural filtration system, consisting of rocks, gravel, and sand. This filtered water is collected in a cement storage tank, and accessed by the community using a tap. While this water will still need to be boiled or filtered through a cloth in order to be safe, it eliminates the numerous threats from stagnant, sun-exposed water, such as bacteria, algae, and insects.
Rainwater harvesting tanks are a very simple technology, and are extremely effective for use in remote locations, since they only require a truck to deliver the materials. Rainwater harvesting tanks collect rain water from the roofs of nearby homes, churches, or schools, using PVC piping as gutters, and direct it to big cement holding tanks, which can then be accessed by the community with a tap. Rainwater harvesting tanks also have cleaning valves (a pipe at the bottom of the tank to empty the water when the tank needs to be cleaned), and a square manhole with a cover at the top of the tank, which allows the caretaker to go inside and clean the tank every two months. The rainwater is collected before it touches the ground, so it is cleaner than surface water from contaminated ponds or hand-dug wells. While we advise communities to boil the water before drinking it, many of the tanks we complete in Mexico come with filters, so that, when the community drinks from the tank, they know it’s safe! There are a few criteria for the communities in which we build rainwater harvesting tanks: they must have a wet or rainy season for three to four months of the year (or have consistent rainfall throughout the year), and there must be aluminum or tin roofs somewhere in the community, in order to catch the rainfall. Because of the climate of these regions, rainwater harvesting tanks work very well in Mexico and parts of Africa.
There you have it! Hopefully, you’ve learned a little more about all of the different water sources we and our partners complete here at Ryan’s Well Foundation. We consult directly with our on-the-ground partners (who conduct rigorous research), and take pride in ensuring that we have matched the community with the source that best suits their needs. If you have any other questions – whether big or small – about our water sources or our project work (even if it’s just out of curiosity), please don’t hesitate to contact our Project Coordinator, Keely, at firstname.lastname@example.org. She would love to hear from you!