Wastewater treatment

You are at the Garmerwolde Wastewater Treatment Plant

At Noorderzijlvest Water Authority, in addition to providing safe and sufficient water, we also ensure clean water in Groningen, north and central Drenthe, and a small part of Friesland. We do this by treating municipal wastewater. Take Garmerwolde, for example. Here, we treat all the wastewater that ends up in the sewer system from households, businesses, and rainfall. Think of the water you use when you take a shower, or when you flush the toilet at school or work.

In Garmerwolde, we treat 98,544 cubic metres of wastewater every day. That’s equivalent to a daily load of 960 lorries!

How does it work?

In Garmerwolde, the wastewater goes through several stages before it is finally discharged into the Eems canal. First, the mechanical treatment process removes large debris and sand from the water. The water then flows into tanks. Here, various bacteria feed on the contaminants in the water. This occurs in different “environments” where these small organisms can thrive. That is why the water passes through different zones with high, low, or no oxygen levels.

The bacteria then slowly sink to the bottom, where they can be separated from the treated water. We reuse the sludge containing the bacteria to treat even more water. Finally, the water is returned to the natural environment via the Eems canal.

We recently conducted research on removing pharmaceutical residues from wastewater. Noorderzijlvest plans to implement this technology within three years to prevent pharmaceutical residues from entering the environment.