In this paper we will study water as one of the most valuable resources on Earth, the way in which water pollution affects drinking water, rivers, lakes and oceans and how to prevent or reduce it. Before the releasement of wastewater into lakes, rivers and oceans, it is necessary to go through a number of chemical processes to reduce it's amount and toxicity. Pollution from pulp and paper production is a serious problem. Pulp and paper mills pollute our water, air and soil. It is believed that the pulp and paper industry are the largest and most polluting industries in the world and, later in this study, we are attempted to present the processes for primary, secondary and tertiary treatment and pretreatment of wastewater from the production process of pulp and paper. Here described are the Best Available Techniques or BAT, defined by the EU directives, for specific procedures of processing from the production of pulp and paper from various mills that use certain techniques to reduce emissions and impact on the environment as a whole. People need paper products and we need sustainable, environmentally safe production.