Grey Water Treatment for Residential Building

In many urban and semi-urban areas, shortage of fresh water has become a regular issue. Residential buildings consume a large quantity of water every day for bathing, washing clothes, cleaning utensils and other domestic activities. Most of this water, except water from toilets, is known as grey water. If this grey water is mixed with black water, it becomes sewage and its reuse becomes difficult and costly. However, if it is collected separately at the source, it can be treated with relatively simple and low-cost methods and reused for non-potable purposes such as toilet flushing, gardening and floor washing. This paper presents a conceptual framework for grey water management at residential building level developed as part of an academic project in civil engineering. At present, the work is in conceptual stage. The physical model, laboratory testing and actual performance evaluation are planned for the next phase of the project. Therefore, this paper does not claim any experimental results or removal efficiencies. Instead, it focuses on need for grey water management, characteristics of grey water, principles of treatment, proposed system arrangement, methodology for future experimental work, possible reuse options, benefits, limitations and safety aspects.