On Friday, June 18, we visited the closest place related to ecology. We decided to go for a walk to the sewage treatment plant to bring closer our knowledge of natural processes. The lady who checks the composition and level of water pollution took us to the laboratory and showed us the activities that she performs during her work. After the introduction, the man controlling the proper operation of the sewage treatment plant briefly introduced us to his work and what the sewage treatment plant consists of. Then it was time to see all the biological processes. We visited the sewage treatment plants with a man who in an interesting and funny way made our time pleasant and helped us acquire knowledge. We learned that we purify water by providing bacteria and oxygen. We saw what it all looks like and what we can have thanks to such processes. The incoming sewage is cleaned of unnecessary pollutants several times until clean water is obtained, which then goes to the river. At the end, we were led to the top of the reservoir to admire the panorama of our city. Beautiful weather accompanied us all day.