For years, Waternet has been fighting a fierce battle against a hard mass of congealed fat containing countless wet wipes. This greasy ‘wipe cake’ causes persistent blockages in the Amsterdam sewer. And the sewage pumping stations also regularly become clogged. At the R3 final pumping station in Diemen they are fed up with the greasy muck.
Despondent, operators Michel Blom and Raymon Sanou open the shutters to the reception cellar of the pumping station. All Diemen’s wastewater ends up here before it is pumped to water purification. What they find does not surprise the operators. Almost no waste water can be seen in the meters-deep pit. All you see is one big thick gray mass.
“It is a floating layer of up to one and a half meters thick, one compact lump of cloths and grease,” explains operator Michel Blom. Every year, Amsterdam residents dump thousands of wet wipes in the sewer. “It’s time to create again. The well is shoveled twice a year. And that has to be done with the tap, because suction won’t do anything, the mass is too thick for that. And then about 30 to 40 tons of grease and wipes come out. That costs a lot of money,” says Blom.
Creating the floating layer is not the only problem. The pumps that have to pump the water also become clogged by the wipes. “When the water in the well is low, the wipes shoot into the pumps and then you get pump failures. This also happens at night, so there is a chance that we will be unclogging pumps at night,” says Blom.
It could be worse. In the building next to the well, two powerful pumps are making noise. They pump the water to the water treatment plant. A third pump is standing still. “Yes, it is broken and the cause is wipes. These wipes form a tangle and twist into the pump’s impeller and damage the ‘seals’, shortening the lifespan of the pumps. That also costs a lot of money,” says Blom.
Bathtubs full of frying oil and cooking fat
In addition to the thousands of wet wipes, the people of Amsterdam also discharge four tons of grease into the sewer through the sink every day. That’s twenty full bathtubs with frying oil, cooking fat and food scraps. The costs for cleaning the sewers and purifying the water run into the millions every year. Money for which Amsterdam residents ultimately pay the bill through the water board tax and waste tax.
Things can be different and better. It would make a big difference if everyone took the frying fat to a collection point. But not in every neighborhood. There are 2,500 collection points for frying fat throughout the Netherlands. In Amsterdam there are only 42. The supermarkets in particular are failing here. For example, there is no Albert Heijn in Amsterdam where you can hand in frying fat. But there is hope, because supermarket chain Jumbo now has 4 branches where you can return frying fat.
Biofuel from frying oil
According to Frans Claassen, director of MVO, the chain organization for oils and fats, many more collection points are needed. Since 2010, MVO has been working with fat recycling companies on the ‘Fritory Fat Recycle It!’ campaign. The campaign aims to inform and encourage consumers and retailers to collect used frying fat or used cooking oil separately for recycling into biofuel.
Claassen doesn’t know exactly why there are so few supermarkets in Amsterdam where you can hand in your frying fat. “It may have to do with ignorance on the part of the supermarkets that they can request such a collection point,” he speculates. Supermarkets that want to become a collection point can register at frituurvetrecyclehet.nl.
What is allowed in the sewer?
You can dump the so-called 3 P’s in the sewer, namely: poop, pee and (toilet) paper.
But what do you do with…?
Frying fat – you pour it back into the packaging and hand it in at a collection point. Or if necessary, pour it into an old milk carton and throw it in the trash.
Cooking fat – grease residues from margarine and oil should be wiped from the pan with paper towels or old newspaper and thrown in the trash.
Dispose of damp wipes such as cleaning wipes, baby wipes, make-up wipes and damp toilet paper in the rubbish bin.
You hand in paint and other chemicals at the waste separation station.