At Project Maji, our mission is to ensure access to clean and safe drinking water. We achieve this by rehabilitating borewells and installing solar-powered water solutions to provide sustainable water access. Addressing common physio-chemical and bacteriological contaminants in groundwater is a primary challenge, especially in regions where iron, manganese, and fluoride are prevalent.
Each borewell we rehabilitate undergoes a hydrogeological survey whereby we perform a yield test, and a water quality test. Based on the outcomes, we plan the suitable treatment of the water.
Treatment of Physio-chemical Contamination
We apply three core treatments that are efficient and cost-effective and select the relevant method depending on the water quality results. The filtration methods can also be combined if necessary.
Iron and Manganese Removal: We use activated manganese dioxide? Potassium permanganate? as an oxidizing agent to solidify and coagulate and trap these dissolved contaminants. The water then passes through activated carbon, which removes any odor or bad taste while trapping the left-over oxidized particles. Oxidation of iron and manganese is also achieved by using chlorine as the oxidizing agent, and is a secondary effect of our chlorination disinfection process when employed
Sand Filtration: The first step in our multi-media filtration process removes physically suspended contaminants such as sand and mud, preparing the water for further treatment. This filtration technique is integrated into our River Solution and deployed for communities at the bank of the Volta River. It filters out harmful larvae from the river while eliminating direct contact with the bilharzia infested river.
Polypropylene Filtration: Finally, water is passed through polypropylene filter cartridges to remove any sediment particles down to 0.5 microns, ensuring the water is free from physical impurities and safe for consumption.
To ensure the filters are kept clean, we have strict backwashing protocols in place. In this process we flush the coagulated contaminants, trapped in the filtration media, ensuring the filtration system remains effective and unclogged.
Treatment of Bacteriological Contamination
When we rehabilitate a borewell, we treat the well with chlorine also known as ‘well shock chlorination treatment 'This is done by adding a calcium hypochlorite solution to achieve a chlorine concentration of 50-200ppm in the well water. It disinfects boreholes and the water it contains to eliminate bacteria, viruses, and other pathogens.
Chlorine is automatically lethal to most bacteria when the right amount is used. Therefore, most of the initial contaminants in the water are eradicated through exposure to this treatment.
Next, depending on the required treatment, we use in-line chlorination dosing to treat bacteriological contamination like coliform and E. coli, we expose the water to controlled amounts of chlorine. This method is reliable and cost-effective for disinfecting water. Chlorine dosing technologies are used to treat water, which is then distributed to standpipes, kiosks, and households. Over time, chlorine concentration decreases due to reactions and time, posing a challenge in maintaining effective levels. Dosing concentration adjustments are made based on water sampling at different points to ensure safety and taste are balanced. For example, dosing at 1 ppm might result in 0.5 ppm at standpipes, 0.3 ppm at fast turnover tanks, and nearly 0 ppm at slow turnover tanks and household taps, with stabilization taking several days.
Alternative treatments
Occasionally, we offer alternative, more costly treatments that tackle complex water safety concerns. For example, upon donor request, we have integrated nano filters in our kiosks. As an alternative to chlorination, nanofiltration uses filters with perforation levels of 1 nanometer to trap and eliminate bacteria virus?. However, due to its higher cost, Project Maji primarily utilizes chlorination.
We have also experimented with Reverse Osmosis: a technique that treats salt contamination, including arsenic, chlorides, fluorides, and sodium. However, due to its high setup, maintenance cost, power requirements, and water wastage, it is less suitable for our sustainable water solutions and is not used in our operations.
Lastly, we have piloted electrocoagulation in Ghana. The details of this solution can be found in this dedicated website blog. Executed in partnership with African Water Corridor, TU Delft, Witteveen+Bos, and SARI, it is Africa's largest electrocoagulation pilot plant that purifies 1,000 liters (about the volume of a large refrigerator) of water per hour.
Our commitment to providing clean and safe drinking water drives us to continually improve our water treatment processes. By addressing the unique challenges of physio-chemical and bacteriological contamination, we ensure that communities in Ghana and beyond have access to the vital resources they need for a healthier future.
To join our mission, make a donation now and provide sustainable access to safe water.
