Efficient wastewater treatment protects the Baltic Sea

​HSY treats wastewater already better than is required at minimum by the authority regulations. When we meet the goals, nutrients contained in our wastewater strain the Gulf of Finland increasingly less.

If wastewater would flow to the Gulf of Finland as is, the rich phosphorus and nitrogen nutrients contained in it would make our coastal waters strongly eutrophic. At the moment, wastewater is treated at the Suomenoja wastewater treatment plant but its operational limits will soon be reached as the nutrient loads and population increase. Therefore, increased treatment output and capacity are needed in order to secure efficient wastewater treatment also in the future.

The goal of the Blominmäki treatment plant is to treat wastewater better than ever before. The goal is to remove from wastewater over 96% of the phosphorus and organic matter as well as over 90% of the nitrogen it contains. Even if the population and volume of wastewater to be treated increase, the resident-specific nutrient load on the Baltic Sea will decrease from the current level.

The large-scale construction project cannot be unnoticeable. In time, it will, however, transform into a wastewater treatment plant that blends in with the surroundings and is capable of excellent treatment results. With the help of the new treatment plant, we can protect our coastal waters and the Gulf of Finland far into the future.