What happens to our shit and pee after we flush the toilet? That is exactly what visitors to the sewage treatment in Assen could see today during the open day. From the stinking beginning to the clean end.
“People here become really aware of the large installation. It takes a lot of energy and they also see how much waste is in the water,” said John Oude Velthuis of the sewage treatment.
Because we all rinse enough because of what does not belong in the sewer. Toilet blocks, dentures or sanitary napkins and wipes for example. Especially to make people aware, the reception is provided by toilet ladies Mientje and Manon.
There are several things on their clothesline that should not be flushed. “A huge amount of damp toilet paper is used. Wheat wipes, but also supposedly biodegradable. The problem is: that can really take weeks or months before it dissolves.”
To illustrate the problem, they let children stir in a bucket of water. First there is a damp cloth in it and then a toilet paper. The result: the toilet paper dissolves, but nothing happens with the damp cloth. “This makes the pumps clog. All those wipes become white sheep,” say the toilet ladies.
Oude Velthuis also comes across crazy things. “I was sometimes called by a woman who asked if I had seen a hamster. He had fallen in a street vessel, but I did not come across it. Or you get a phone call that the gold ring had been washed away from someone who was angry. You get that kind of questions.”
The water takes about twelve hours on a dry day to get through the entire installation. From the filters in the beginning, to a basin with bacteria and finally to the last tank before the water flows into the Noord-Willemskanaal.
“People often think that we make drinking water here, but of course the WMD does that for us. We make surface water,” says Oude Velthuis. Water is not the only thing that comes from the sewage treatment. Five trucks full of sludge are removed every day. Biogas is made and a lot of sand remains after cleaning.
The waste is automatically filtered at the start of the process and is drained to waste incineration. So there is little hope for lost rings and the hamster did not encounter old Velthuis either.
Although the toilet ladies have told a lot about what should not be flushed, their most important message is something that is allowed. “We actually say everything that comes out of the butt or the toilet roll, but have also added the mouth to it, because we’d rather not clean that up,” they laugh.
The doors were open especially because of the 25th anniversary of the Hunze and AAs Water Board, which manages the installation. In the coming months there will be a few events, including the opening of the Laboratory in Veendam on October 18.