The motorhome waste water we generate in our van from washing ourselves, cleaning our teeth, washing vegetables, and doing the dishes etc, is known as “Grey Water”
Gravity ensures this water travels in pipes to a holding tank. Your sink, hand basin and shower are all connected to the same tank, located at a low point in our motorhome.
This motorhome waste water tank might be under the chassis exposed to the elements, or in a warm and cosy space insidea double floor cavity. (Handy if you holiday in winter or visit ski resorts) The tank will have a tap accessed from the outside, and usually, but not always, on the opposite side to your habitation door.
If you don’t empty it, It will come back up to see you​
New motorhomers don’t give grey water a moment’s thought. At home they are used forgetting about any water once it has disappeared down the plug hole, never to be seen again. Unfortunately, most if not all of the waste we generate in our van we get to see again!
Keeping an eye on your motorhome waste water tank level is a good idea, but very often it won’t help, because most grey tank level display gauges are probably wrong. Sludge and greasy deposits attach themselves to the tanks sensors and they lie.
A newbies first indication of this lie, is often a scream from a partner when they see this awful coloured, foul smelling water in the shower tray!
Remember those connected pipes? Well when your tank is full, there is no overflow, so the pipes will fill, the shower being lower than the kitchen sink and wash basin will begin to fill with this filth.
Grey water can smell bad, very bad. So bad, that many people new to motorhomes confuse it with Black Water (poo and pee), they smell it and are convinced that the smell is coming from the loo.
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Why can this concoction smell so bad?​
I’m not sure why, and while I’m sure scientists could explain why this harmless few gallons of water with a bit of toothpaste, soap scum and washing up grease can smell so bad, just know that it can.
So how can we get rid of motorhome waste water.​
Just like your grey water at home, the grey water from your van should end up in a the mains sewage system for proper treatment to make it safe. Not that it is particularly dangerous, especially so if you have not used any harsh chemicals but that is the best place for it.
At almost all campsites you will see signs for grey water, or waste water disposal, this might be a separate receptacle/drain or a purpose built drive over drain. If there are no signs about disposal of Grey then ask.
Most use a bowl, bucket or purpose made waste hog to empty their tank into. On some vans the taps are low making this very awkward.
Never empty grey in the vicinity of fresh water taps, the drain cover at the base of the fresh water tap might look ideal place to dump some grey, but it will NOT be the right place.
If the smell occurs when you are on the road, putting the plugs in the sinks will help.
Don’t Do It.​
A few decades ago, drink driving did not carry the social stigma that it does today, admitting you drove home after a couple of beers back then would not earn you the condemnation by everyone that you would get today. It’s the same for dumping grey waste. Before social media, no one batted an eyelid if someone ignorant of the issues emptied in a drain at a lay-by. These days if someone sees you doing this, the resultant video could make you an internet sensation.
We have no ideas if drains lead to sewers or streams, so this practice is just just not on and I believe illegal. One can argue that it does no harm, you might be sure you have zero chemicals in it but unless you want to be the star of a viral video on YouTube, Forums and Facebook. always empty your grey in a proper place. There is no excuse not to! Apart from the thousands of CL‘s and Campsites. Look at this map of stopovers.
On small sites you might well be asked to throw your grey water at the base of trees or into hedgerows. If you are on a site like this ensure you don’t use any harsh chemicals. Using the Ecover range of products in the van will ensure that you’ll not harm the environment.
Juicy Blackberries​
If you don’t uses harsh chemicals, your grey waste won’t do any harm. 25 years ago we lived in 10 acres in a very rural part of Wales. For years we emptied tanks, no chemicals at all, into an isolated corner of some scrubland. Maybe 5 or 6 empties a year at 100 gallons a go. (We had an RV with big holding tanks) The only effect to the habitat was that particular bit of hedgerow grew the biggest blackberries you’ve ever seen. My mother in law would visit and had no idea why the blackberries in that corner tasted so good, and I never told her.
There is a lot you can do to keep your grey tank clean. There are dedicated grey tank cleaning materials. If you search the forums for grey tank cleaning you’ll get a lot of hits. Some will swear that half a dozen bottles of full fat Lidl coke placed in the tank and then sloshed around as you take it for a bumpy ride will keep the tank clean, some swear by dissolved dishwasher tabs, and others use diluted bleach.
Personally, I rarely bother to clean our motorhome waste water tanks, but we are fastidious about what we put in it. We never use harsh chemicals, using Eco washing up liquid and natural shower gels and soaps. Before we wash dishes we will wipe the plates and cutlery clean so very little gunk goes into our tank. Scraping plates, or pouring coffee grinds into the sink are a guaranteed way to gunk up your tank and start growing that smell.
Use your Loo​
It might seem strange at first, but use your loo for things like coffee grinds and similar kitchen waste. This really saves a lot of gunk going into your motorhome waste water tank. While your grey tank is hard to get at and almost impossible to clean thoroughly. Your toilet waste tank will cope with all sorts of waste, it is easily cleaned and rinsed and you are likely to be emptying and rinsing everyday anyway.
Emptying often and leaving the tank tap open when not in use will help dry out the tank and hopefully keep the smells away.
This article is being discussed here