Put in place a sewer system that leads wastewater into a collection basin. The sewer system may be as simple as trenches running along the ground and draining into the basin, or a system of pipes for more discrete transfer. Either way, use the slope of the land so that the water flows freely without the use of a pump.
Decide on a suitable filtering method for the wastewater. The available options include sand filters and screens. Sand filters involve a simple column passageway filled with sand, which sifts out large particle impurities as water passes through it, while filtering screens are designed to prevent particles from passing through. Cross flow filtration methods are also available but require more technology and are more cumbersome to install and use. Connect pipes to lead water from the basin to the filtering system via a pump.
Join the filtration system to a water tank through its outlet. Water reaching this stage is free from solid impurities and only microscopic and dissolved impurities are present. However, if you use cross flow filtration methods, the microorganisms may also be absent at this stage. Use chlorine or its compounds as disinfectants in the tank in proportions outlined by the manufacturer to kill any microorganisms and pathogens present in the water.
Pour and stir dilute acids or bases into the water system to bring the water's pH to the desired levels, depending on its application. Diluted phosphoric acid and di-potassium phosphate are examples of acids and bases used for lowering and raising water pH respectively. Refer to the suitable pH for the plants if the water is for irrigation before deciding on the best pH-altering agent. Most plants highly depend on the soil pH for proper growth, which is easily altered by water used for irrigation.