1.5.2 Alternative to Effluent Reuse: Safe Infiltration
Safe infiltration refers to allowing treated effluent to seep into the ground without posing any risks to human health or the environment. When considering safe infiltration, a variety of conditions must be met, including:
Groundwater Depth: The groundwater level should be at least 1.5 meters below the infiltration area. In cases where infiltration trenches or rocks with fissures are present, a greater distance between the groundwater level and the infiltration area may be necessary to prevent contamination.
Distance from Water Sources: The closest water source should be more than 30 meters from the infiltration point. This ensures a sufficient buffer to prevent any potential water source contamination.
Soil Infiltration: Infiltration refers to the controlled and gradual percolation, both horizontally and vertically, of treated effluent into the subsurface soil. The infiltration rate can be determined with a percolation test and is recommended to be at least 4 l/m2/h. This helps ensure that the treated wastewater can effectively percolate through the soil layers without causing pooling or runoff.
We will learn more about the safe handling of effluent with regard to infiltration in module 8.
