After chemical and biological analyses of water, The water in our client well has a high rate of these parameters: TDS: 763 mg/L. Conductivity: 1525µS/cm hardness: 452mg/L as CaCO3. Turbidity: 22.4 FTU Chloride: 266 mg/L as Cl- In addition, the water is contaminated by bacteria (total coliform ˃80 cfu in 100 ml). The plan used is: Reduce the values of all these parameters (elimination of all impurities, organic matter, suspended solids, pesticide, sand, seaweed, chlorine, sodium, calcium, sulphate...) so that the water becomes usable, healthy and sterile for the 3 villas, and for each villa are using reverse osmosis under the tap so that the water becomes potable. This plan is the best and cheapest and has been approved by the French company.