Clean water
One of our most important tasks is to treat wastewater. We do this with the help of 15 sewage treatment plants, 1 sludge drying plant, 300 sewage pumping stations and 610 kilometers of pressure pipes. These plants process over one hundred million cubic meters of water each year. Part of this water comes from households and businesses connected to the sewer system. The other part is rainwater that ends up in the sewer system.
Purifying water
That we have clean water seems quite normal. But purifying wastewater from the sewers is a big job. Every day the 1.4 million inhabitants in Hollands Noorderkwartier produce over 120 liters of wastewater per person. In addition, another 30,000 companies discharge their wastewater into the sewer. So every year we collect one hundred million cubic meters of wastewater and purify it in sewage treatment plants. We return the treated water to the surface water.
The Water Chain Department is constantly looking for innovative and individual solutions to sustainably purify wastewater into clean (surface) water. But at the lowest possible social cost for our residents.
How clean is clean?
Purified wastewater must meet strict, legal requirements. For example, it must not contain too much phosphate. Too much phosphorus creates too much algae and plants. When those algae and plants die, bacteria break down the dead material. To do this, they use oxygen. So too much dead algae and plants can cause a lack of oxygen. The living plants and animals can also die at an accelerated rate as a result. And then we are eventually left with dead water. Also, the amount of copper, mercury, lead and zinc in the water should be minimal. High concentrations of heavy metals are highly toxic. To check whether the surface water meets the legal requirements, we regularly analyze the treated water.
What can you do yourself?
It's nice when the water in our lakes, ditches, waterways and canals is clean. Then swimming and boating is a lot more fun! And it is good for nature. At our pumping stations we remove a lot of litter from the water. That is why we support the silent rapers, people who clean up litter so that it does not end up in the ditch. You can help us prevent water pollution. Use water sparingly: don't waste or pollute it. And Health ensure that wipes, grease, paint residue, chemicals and medicines don't end up in the sewer. Find more tips on the Water Bosses page.
