Caravans have come a long way over the years, and a lot of them now come factory fitted with grey water tanks. What is a caravan grey water tank for for, and do you actually need one?
Australia is going through a fair bit of change when it comes to dealing with grey water from caravanning and camping, and its important that you do the right thing for the environment, other people and to avoid a nasty fine or being turned away from a camp site.
A Grey water tank allows you to comply with the fully self contained arrangement that some places are now asking for in order to camp there. I say some, because the reality is the large majority of Australia does not require you to contain your grey water.
What is grey water?
In terms of camping, grey water is the water you consume that comes from doing your dishes, having a shower, washing clothes and washing your hands. This means its usually got soap, food scraps, oil and other bits and pieces in it. It does not include anything that goes down your toilet; this is known as Black Water and is a whole different kettle of fish.
Storing grey water
As mentioned above, grey water tanks are becoming quite common, and popular on caravans and hybrids, and are generally 60 – 150 litres. Any water that goes down the sink or shower, ends up in the grey water tank, and then the idea is that you empty it prior to arriving at the next camp.
Often your grey water tank is no where near the capacity of your fresh water tanks, so there’s some juggling to be had, or you need to empty it mid way in a responsible way. Alternatively, you let it run out in a responsible way (if you are allowed to).
Grey water changes to black water
Grey water is virtually harmless when it first leaves your sink, or washing machine, or shower. If it goes onto a piece of land in the sun, you’ve used environmentally friendly chemicals and it soaks away without upsetting anyone its probably the best way of dealing with it.
However, if you store it for more than 12 hours, it slowly turns to black water and this process is hugely accelerated with heat. If you are camping in the northern parts of Australia where it is warm, expect your grey water to turn to black water faster.
Whilst grey water straight from your dishes is probably not something you’d want to play with too much, its generally fairly clean, has no odour and when your kids jump in the puddle it creates when you let it go its not the end of the world. Store it in some heat though, and when you release it the grey water will reek and you don’t want to go anywhere near it. This is because bugs and bacteria grow, and its turned into a form of black water.
Black water is not something you want to play with, which is where the collection and holding of grey water becomes an issue.
Why fit a caravan grey water tank?
Grey water tanks are fitted primarily to comply with the regulations of specific camp site regulations. Collection and disposal of grey water has been an international norm in motorhomes and campervans for many years, and its slowly rolling out in Australia.
That said, I honestly feel its a giant snowball that has occurred without people really thinking about it, because you now have dump points that are being filled with grey water that they were never designed for, and people making a far bigger deal about grey water than is actually necessary.
It seems like some councils have all copied each other and made grey water collection mandatory (in some areas, not the whole of Australia). That’s great, except you now have a huge number of people with 50 – 150 litres of grey water every couple of days that need places to dispose of it.
When they do the right thing and go to a toilet dump spot, and find that it is full because they are being hammered so much more, then what?
Is the dumping of well managed grey water as its created, in a suitable place better for the environment than having to empty toilet dump points far more often, and the environmental issues that go with it?
Do you actually need a grey water tank?
In Western Australia, there are only a handful of places that require you to collect your grey water, and its most certainly not the national parks. There are a couple of shires that have mandated it at a few sites, but in the hundreds of different camp sites we’ve been to all over WA, only one has required that we collect our grey water, and that was at Cossack.
I simply took a 20L water container, and modified our sink outlet to go into it. The caretaker did come, and even checked and photographed the setup, but in my mind its all a bit of overkill. If people got rid of their grey water in an environmentally sensible and respectful way there would be far less issues than containing it, carting it to a dump point and getting rid of it.
As we had an outdoor shower it meant we couldn’t use it for that night, but we were OK with that. If it were a longer stay, it’d be a bit more annoying.
In other states, its a different story, and grey water tanks are needed more often, but its almost exclusively in council provided RV stops. I know plenty of people travelling around this great land that don’t have tanks, and have only been turned away from a tiny, tiny number of camp sites.
Will that change in the future? Maybe. Is the environmental benefit of taking grey water to a toilet dump point any better? I’m not really sure, and I hope the rule changes and those who adopt them are sensible in their thoughts.
What changes are made as time goes on will be fascinating to see; its a lot of work for people to contain their grey water and dispose of it correctly in national parks, and other remote camping areas. This is especially the case when you are camping, and don’t have access to a caravan or camper trailer with in built tanks.
Its important that you read the signage properly too, as self contained does not necessarily mean you aren’t allowed to let grey water out, onto the floor.
Fitting your own caravan grey water tank
Like water tanks, its not too hard to install a grey water tank on your camper trailer or caravan. It’s a fairly uncomplicated DIY project, providing you take your time and do it well.
Carefully consider its position and size
When you install a grey water tank, there will be times when it will be full, and very heavy. This can hugely affect your weight distribution, and dramatically increase or decrease your tow ball weight, which can be a big problem.
Second to this is that if you take the van off road, it can be subject to getting hit, which is another major issue. The last thing you want to happen is to come down a rock step and have the grey water tank get ripped off, potentially damaging other gear under your trailer.
The size of the grey water tank is hugely important too; if you have 300L of fresh water, and a 50L grey water tank, its going to cause you some issues along the way. That’s not to say you need the same capacity as your drinking water, but you need a way of dealing with the difference.
Grey water tank mounting
Water is heavy. Even if you go for a 40L tank (which is on the smaller size for a grey water tank), that’s at least 40kg of weight bouncing around, and if it comes off and hits another vehicle, its going to be a serious accident.
Not only do the straps need to be well and truly suitable to take the weight, but where you attach it to does as well. This means using proper bolts (not screws) and ensuring the structure will take the weight. Ideally you tuck it out of the way, support it well and it never moves.
Protect the grey water tank
If you do much gravel driving, you’ll find that parts of the trailer can be hugely subject to gravel rash. If its a plastic tank generally they are super thick and will take this for years without any damage. However, if its going to cop a flogging you may need to look at a light weight guard, and installing some protection for the pipework too.
If it gets hit and breaks its not as serious as losing your water tanks, but its still an inconvenience.
Consider a bypass
I would seriously consider fitting a bypass to the tank, so when you don’t need to use it, you can close a couple of ball valves and let the grey water run out onto the floor (where allowed) or into a designated drain. The less you use your grey water tank the better, as they are smelly things!
Check your weights
Lastly, make sure that any changes you make keep you well within the weight spectrum. Its so easy for people to be overweight today, especially with vans that only come with 400kg of payload, or that are incorrectly labelled on their nameplate.
When you install a grey water tank, you are going to be moving weights, which will upset your tow ball weight and change things as you consume water. If your water tanks are up the front, and your grey water tank is down the back, you will be losing tow ball weight at a rapid rate by reducing the weight in front of the axles, and increasing it at the rear.
Make sure the drain empties everything
If you have a choice in where the drain is, and how its going to sit, make sure the drain allows every last drop out of the grey water tank. This will reduce the chance of it smelling, and means you can keep it empty, and ready to go at all times.
Can you use a portable grey water tank?
A lot of people don’t want a fixed grey water tank, and they opt to purchase or build a portable grey water tank. These are available off the shelf with wheels so you can walk them around, or you can easily build your own. The issue with portable tanks is stopping them from overflowing, and their limited capacity.
When you have several hundred litres of fresh water on board and only a 20 – 40 litre portable grey water tank its easy to fill it up and have no way of disposing it.
How to stop your grey water tank smelling
Grey water that is released straight onto the ground is generally fairly clean, and non toxic. I mean, you wouldn’t want to drink it, but if it was to come in contact with your skin its not going to do you any harm. However, once its been stored for some time it becomes hazardous, and will get quite a smell.
My folks have a grey water tank in their caravan and it absolutely reeks, even after being cleaned. The drain is not located right at the bottom of the tank, which means you can never fully open it. Beyond this, they have no bypass, so even in a caravan park where you should be just draining straight from your shower and sink into their drain, it still has to go through the grey water tank.
How to clean your grey water tank
Grey water tanks can smell pretty bad (like as bad a sewage!), and you need to clean them out from time to time. There’s a lot of chemicals that people will recommend, or you can buy dedicated tank cleaner and put it down the drain with the tank closed, and some water inside. A drive around ensures that the tank gets a good sloshing around, and then you can drain it all out.
Where can you empty grey water?
Grey water tanks can be emptied at designated grey water dump points in caravan parks (usually drains near where you camp, or a larger, designated grey water dump point), along with toilet dump points if its been sitting for some time.
It’s bad practice to let the grey water out onto the road as you drive out of a camp, or to dump it anywhere near water sources. If its more than 12 hours old, you should be taking it to a black water dump site.
Let it out if you are allowed
If you are allowed, and you are using environmentally friendly chemicals, I firmly believe you are better off releasing your fresh grey water in a slow, respectful and careful manner than storing it and putting it into a caravan dump point.
I’m sure I’ll get disagreements about this, but I don’t feel we are at the level where everyone can be containing grey water and disposing of it at a dump site. The infrastructure and logistics just don’t add up, and the cost (environmentally and financially) of processing the extra grey water created from camping is never considered.
Some dump points have signs saying no grey water allowed, and then you have the logistical issues where the drain of your grey water tank is often not higher than the lip of the dump point meaning it wont flow out under gravity even if you wanted it to.
That said, you should try and use biodegradable detergents, clean your dishes properly before washing them (removal of food scraps)and let the water out somewhere that its going to drain away without upsetting others.
Don’t be the fool who does two loads of washing and leaves 40L of soap and water on the floor in the middle of a big campground where it takes days to drain away.
What do we do?
We don’t have a grey water tank, and have no plans to fit one. I mentioned above that we’ve only had one instance where we needed a tank, and we just knocked a portable grey water tank up in a couple of minutes. We carry a couple of different grey water hoses which allows us to get rid of it in a smart way, and we are responsible with our grey water. I don’t think you need to go any further than this.
What do you do with your grey water? Do you have a grey water tank? Has it restricted you at all when travelling Australia?