Emptying a motorhome: where and how to dispose of grey and black water

Emptying your tanks is part of everyday life in a motorhome. Done properly, it takes a few minutes. Poorly planned, it can ruin a day: a full tank, a cassette filled to the brim and no service point nearby. Here is how to go about it and where you can empty legally.

Grey water, black water: what are we talking about?

• Grey water comes from the sink and shower. It is stored in a tank under the vehicle and emptied through a valve.
• Black water comes from the toilet. In most motorhomes and campervans, it is collected in a removable cassette, reached through a hatch on the outside.
• Fresh water is the water in the tank you fill up at the service point.

The two types of waste water are not emptied in the same place and are never emptied into nature, a ditch or a storm drain. It is illegal and polluting, not least because of the chemicals used in cassettes.

Where to empty?

Service points at aires de services

This is the most common option. A service point (borne) usually combines a drain for grey water, a disposal point for the cassette and a drinking water tap. It may be free or paid. The differences between aires are explained in our guide service area, aire or campsite.

Campsites

Almost all campsites have a waste disposal platform, in principle reserved for their guests. Some open it to passing travellers for a small fee: ask at reception.

Some petrol stations

A few stations, mainly on major routes, have a service point. They are handy on a long journey but remain rare: don't rely on them alone.

Emptying step by step

1. Position the vehicle so that the grey water valve is above the drain.
2. Open the valve and let it drain completely, then close it.
3. Take out the cassette, empty it into the dedicated disposal point and rinse it with the tap provided for that purpose (never the drinking water tap).
4. Add a suitable chemical to the cassette if you use one, then put it back.
5. Fill up with fresh water using a hose kept just for that purpose.
6. Leave the service point clean for the next person.

Disposable gloves and a hose kept just for drinking water are the two accessories that make life so much easier.

How often should you empty?

It all depends on the size of your tanks, the number of travellers and how much you use the onboard shower. For two people, a cassette usually fills up in a few days. The safest approach is to use every service point you pass rather than waiting until you are full, especially in winter or on poorly equipped roads. In cold weather, some service points turn off the water and tanks can freeze: see our guide to motorhomes in winter.

No more last-minute hunting for a service point

With Pakvia, what is known about each overnight stop is shown, including whether it has waste disposal. When your evening stop doesn't, a waste disposal point is suggested every day along your route. From the outset, you know where to empty, where to fill up and where to sleep.

Want to take your preparation further? Read our guide to planning a campervan road trip, then plan your route for free.