Modern towns and surrounding industrial districts need electricity, heat, water and fuels; on the other hand, they reject solid, liquid and gaseous wastes to the environment. The disposal of the solid wastes is a problem and involves consumption of energy and money. It should also be considered that shortage of energy resources and environmental concerns suggest the exploitation of all occasions for a rational use of energy. Therefore, recycling waters, recovering energy and using renewable resources can be an efficient means to improve the energy system of a town