Is It Safe To Drink Water From A Motorhome Tank

One of the benefits of a motorhome is having pretty much most of your home luxuries but one of the things that can often be very different is the use of the water and taps for drinking water. Not every country is the same and so this can be dangerous without taking some precautions first.

It is not advised to drink water from a motorhome water tank, this is due to a number of reasons including the water tank can have remaining chemicals that are harmful to the body. It is also due to not every country has safe drinking water straight from the tap.

In this article we are going to talk about whether you can drink water from a motorhome tank, is it safe to and how you can make the water drinkable in your motorhome.

Is It Safe To Drink Water From A Motorhome Tank

Broadly speaking it is rarely safe to drink water from a motorhome tank. This is due to a number of factors, all of which add up to a situation in which you don’t really want to be drinking water from the tap in a motorhome. There are exceptions that will be covered.

The main reason why it is not recommended that you drink water from the tap in a motorhome is that water does not like standing still. If water has been left to sit in a water tank for over 24 hours the quality of the water will have already significantly been reduced, both in terms of taste and the presence of microbiological nasties.

Drinking water that has been contained in a motorhome water tank for a length of time is broadly similar to drinking water from the hot water tank in most homes; both should definitely be avoided due to the potential health risks.

Most UK water companies suggest that water treated by them in water treatment plants will generally be fine for up to 24 hours, after which it should be assumed the quality has reduced.

A second reason why drinking water from a motorhome water tank will probably not be safe is the way that you obtain water and move it around the motorhome. To bring water on from an external source you will almost certainly have to use a length of connecting hose. Water hoses are prone to harbouring harmful bacteria, which can end up in your water tank.

Whilst water in a hose is fast flowing it leaves behind a wet film in a cold dark tube, which is an ideal environment for bacteria growth, potentially including mould growth.

Similarly, motorhomes use a series of pipes to bring water from the water tank to taps, showerheads and other water devices. These pipes are also prone to bacteria growth resulting from water being left in them. 

The third reason that drinking water from a motorhome water tank is generally a bad idea is the source of the water itself. Most touring sites use mains water supplies with the water being carried from the main pipeline through a series of smaller pipes around the site. The problem with this is that you don’t know what state these pipes are in.

Furthermore, if the site is not a particularly busy one, or you are the first to pitch there after the down season, the water going into your motorhome water tank has probably been sat still in the pipes for a long time. This can result in all sorts of microbiological issues, including diseases like Legionnaires lingering in the pipes.

This can also be a feature in lesser-used hotel rooms but is even more of an issue when using a pipe system that is buried underground, like in a campsite.

Does It Need Filtering Before It Is Safe To Drink?

One of the main exceptions to the rule that water from a motorhome tank is unsafe is when a suitable filtration system is used. There are three main types of filtration system, all of which improve the quality of a water supply, but only one of which makes water safe to drink.

Activated Carbon Filters

Activated carbon filters are very good at removing bad smells and tastes from water. It generally filters out chemicals such as zinc, chlorine, copper and mercury. It does not, however, remove bacteria from a water supply. An example of an activated carbon filter system is the typical fridge filter jugs, such as Brita filters.

Whilst these filters will improve most water supplies, particularly in terms of quality and taste, they will not make dangerous water safe for drinking. In fact, they can add to the problem if filters aren’t changed regularly, as they can harbour harmful bacteria themselves.

Grit Filters

Grit filters do exactly what it sounds like they do. They tend to be fine metal meshes designed to block grit and other large debris from getting into a tank. These tend to be on the point where the water enters a motorhome water tank to prevent material from actually entering the system.

These are particularly useful if you are planning to use a lot of water supplies that you are unsure about, as they will help to prevent things like grit from ending up in your shower or washing up. However, like activated carbon filters these do not make dangerous water safe to drink. 

Microbiological Filters

Microbiological filters are the only filter type that makes dangerous water safe to drink. There a few different types of microbiological filters that work in different ways, but they all achieve the same result.

Most use a combination of filtration materials, such as activated carbon, fine sediment layers, and sand. The result is that fine particles, or microbes, are removed from the water.

They can actually kill off almost all harmful bacteria, including cryptosporidium microbes that can cause a lot of damage to the body. Another emerging form of microbiological filter involves subjecting potentially harmful water to UV light.

UV light, when used properly, is highly effective at killing off bacteria. However, it must be from a system designed for the specific function; waving around a UV keyring torch in a glass of water simply won’t cut it. They also don’t remove physical sediment, so are generally used as part of a combined filtration system. 

If you are looking for a more prosaic solution, you could always look at expeditionary and trekking water filters.

Systems such as the Lifestraw and squeeze-bag filters designed to allow people to drink from streams (and even in some cases puddles) will make your water safe to drink, but they are fiddly to use. It depends on the type of motorhome experience you are looking for.

Most microbiological filter systems will cost between £100-£300 unfitted, so that is a cost factor that must be borne in mind.

What Do I Need To Do Before I Drink The Water From The Water Tank?

If you are determined to drink water from a motorhome water tank then there are some things you can do to improve the chance of the supply being safe, but most will not guarantee safety. Fitting a filter, as discussed above, is one potential solution and arguably the safest.

Other than that you will have to be very conscious of maintaining your water tank, hose, and internal pipework if you are feeling nihilistic and simply wish to stick your head and mouth under a motorhome tap. 

Cleaning and sterilisation are absolutely essential if you wish to drink water straight from a motorhome water tank. You can use cheap chlorine-based sterilisation solutions to work on the tank itself, but under no circumstances allow the chlorine solution to be pulled through the internal piping between the tank and taps or showerhead.

While the solution is working do not turn on any water pumps, and dump the water afterwards. If you wish to sterilise the whole system then make sure you use a sterilisation product designed for the purpose. Most leisure stores sell solutions that are safe to use on internal pipework.

As much as it sounds like a lot of effort and work you really should carry out this process every time you start a camping trip.

If you don’t do this between every trip you risk the build up of harmful bacteria in water left standing in the tank. Even if you think the tank is empty, there will still be a wet film around the edges. 

Descaling is another option to prepare a water tank for use if you are intending to drink water straight from it. You can use a specifically designed descaling solution, or a simple citric acid based solution (make sure it is food grade and safe for accidental ingestion). Normally a descaling solution will need to be pulled through the pipework using the pump to ensure it is all removed.

Descaling has the benefit of removing any rough areas of limescale that can be a great environment for growing bacteria, and will also improve the taste of your water. If using a descaling product make sure to follow the manufacturer’s instructions for your own safety.

It is best practice to combine descaling with sterilisation; first remove the limescale then sterilise the surface for best effect.

Descaling should be carried out every few months, depending on how often you use your motorhome. 

Water treatment is another option you can take in the form of using additives. Water purification tablets, sometimes chlorine-based, perform a role similar to the treatment used in water treatment plants, only less thoroughly and on a smaller scale. Using additives in some cases can make water safe for over a week.

It can either be added in tablet or liquid form to your tank to treat the water and as long as you are using a genuine water treatment product harmful water can be made safe. One downside is that the water may have a slight taste to it, and might smell a little bit like a swimming pool; this does not necessarily mean it is unsafe.

Purification treatments also won’t remove any physical sediment, so should be combined with other filters if you are concerned about that. A word of caution: if you are planning to use water purification additives make sure you follow the instructions and don’t over treat the water. At best this will make the water taste horrendous, and at worst it can cause damage to your health.