Low cost and sanitary efficient method for providing a large water body suitable for direct contact recreational purposes, the large water body water having a surface of at least 3,000 m2, the method comprising:
- designating a sedimentation zone 1 and a dissipation zone 2 in the large water body, both having different configurations and treatment methods, wherein:
- the sedimentation zone 1 and the dissipation zone 2 are located within the same water body 3, and are not separated by a physical barrier, wherein a ratio between a volume of water contained within the dissipation zone 2 and a volume of water contained within the sedimentation zone 1 is from 1:2 to 1:40;
- the sedimentation zone 1 has an aesthetic purpose and is used mainly for secondary non-direct recreational contact purposes, wherein the sedimentation zone 1 is designed to have a density of bathers lower than the dissipation zone 2, wherein as a daily average no more than 20% of the total number of bathers within the large water body 3 are present in the sedimentation zone 1;
- the dissipation zone 2 is used for direct contact purposes, such as swimming and bathing, and is designed to have a high density of bathers, wherein as a daily average, at least 80% of the total number of bathers within the large water body 3 are present in the dissipation zone 2 with a maximum density of one bather per two square meters;
- applying a disinfection method based on a CT index into the volume of water contained within the sedimentation zone 1, wherein the CT index requires that the sedimentation zone 1 is treated by adding disinfectant agents to achieve a specific concentration “C” of the disinfectant agents during a minimum contact time of “T” in the volume of water contained within the sedimentation zone 1, and wherein the disinfection method is performed such that the disinfectant agents are applied to the volume of water contained in the sedimentation zone 1 so that the CT index is at least 42 every 72 hours;
- applying an efficient amount of a flocculant composition into the sedimentation zone 1 that aids in the settling of different microorganisms and/or contaminants that are present in the sedimentation zone 1, and wherein water flows and water circulation within the sedimentation zone 1 are maintained to allow sedimentation;
- maintaining a permanent chlorine residual in the volume of water contained in dissipation zone 2 by adding an efficient amount of chlorine so that at least a 0.5 mg/L free chlorine level is maintained in the water volume contained within the dissipation zone 2;
- injecting water to the dissipation zone 2 by means of one or more inlet nozzles 26 that along with natural currents produced by winds and/or water temperature differences, has the capacity of generating a water dissipation pattern of the volume of water contained in dissipation zone 2 into the sedimentation zone 1, and
- wherein the dissipation zone 2 is arranged and configured to allow a Contamination Reduction Index (CRI) of up to 30 minutes.