The purpose of this Decree is to guarantee potable water for homes, for institutions (hospitals, schools, etc.), for social uses in factories (kitchen, toilets, bathrooms, etc.), and finally for industrial uses where it is necessary (pharmaceutical and food industry, etc.). Other uses of potable water must be authorized. This Decree contains measures for the sustainable use of potable water and measures aiming to ensure a best use of potable water resources. Mining companies must deliver up potable water extracted during their operations and exceeding their own demand. Protection of quantity and quality of extracted water is the duty of the mining company. In the interest of sparing water use, the system of water charges must be worked out in a way to interest industrial water users in the reduction of potable water use. This Decree regulates those works, constructions and other activities which may change the natural course and flow of waters, and which may cause harm to the quantity, the quality and the utilization of water resources in the area of work. The Decree sets out rules regarding the prevention of contamination and pollution of waters as well, and rules regarding the treatment of waste water and the sewerage system. Polluters of surface water and underground water must pay a waste water penalty; those who pollute the sewerage system must pay a sewerage system penalty. This Decree sets out the administrative proceedings for the determination of the amount of the penalty. The amount incoming from waste water penalties must be used for works of modernisation according to the decision of the Ministry of Environmental Protection and Town-planning. While sewerage system penalties remain at the water companies and may be used for development and reconstruction works, and to cover operational and maintenance costs. The Decree deals also with the servitude enabling the work of water authorities. If these works limit the use or make unusable the property on which the servitude lays, the proprietor may request the compensation of damages or the expropriation of the property. Appropriate works preventing and reducing soil erosion shall accompany agricultural and forestry works. Finally, this Decree determines the duties of the water authority. The keeping of a water book and the register of water resources are foreseen by this Decree as well.