How to avoid a blocked drain? Southern Water answer your questions

A drain

Hair-clogged plugs and slow draining water may not be the sexiest of subjects, but it really does matter – as anyone who has ever suffered from the foul stench of a blocked drain will attest. Southern Water lift the lid on how to safely dispose of wet wipes, cooking fat, and much, much, more. Read their answers and be in with a chance of winning £400 worth of vouchers

Pre-child your water and waste disposal needs may have been fairly simple – but the introduction of baby wipes, nappies, and various child-rearing accoutrements can leave you drowning in stuff to dispose of. Mumsnetters put their questions on the subject to Southern Water's drain expert Sharon Holdstock to answer.

In the kitchen

man and daughter in kitchen

Q: In the old days, food cans used to be binned, but now we are asked to rinse them and recycle. Does this rinsing cause sewer problems?

Yes, it can do. Anything that’s got a fat or grease content, or even bits of food, can contribute to causing a build-up of debris, fat and other unflushable items that cause blockages, which can subsequently lead to sewage flooding in your home or garden. You can wipe out all your jars and tins with kitchen paper and then pop that into the rubbish before putting them in the recycling bin. That way, it’s a win all ways round – clear sewers and you’re still doing your recycling duty!
We've got some great hints and tips on how to dispose of items on our website.

Q: Can things like off milk or liquid food be flushed? Obviously liquids can't go into recycling, but it seems like asking for trouble to pour them down the sink.

Things like that really shouldn’t be poured down the sink, as the fat and the calcium in any dairy products can build up and combine with other unflushable items in the sewers. This all sets into a concrete-like substance and stops the normal sewer flow, leading to sewage backing up the pipes and into your home. So, as with any other liquid – cooking oils or leftover soup, for instance – make sure they’re in a container or bottle with a lid and put the whole thing in the bin

Q: Can you put coffee grounds down the sink?

No. If you have a garden, used coffee grounds can be used as a fertiliser as they’re slightly acidic and full of nitrogen, a mineral that aids vegetable and plant growth. Coffee grounds are particularly good for tomato plants, which thrive on nitrogen. But if you don’t have a garden….put them in the bin!

Q: What about cooking fat? Should we be scraping any fat out of pans, and are some types of fat worse than others?

Yes, you should always dispose of cooking fat by throwing it in the bin rather than washing it down the drain. You can scrape more solid fats into something like an empty yoghurt pot or margarine container and then throw it in the bin. If you have any liquid fat – for example, olive or sunflower oil or even meat juices – simply pour it into an empty bottle and then throw it in the bin. And there is no one fat that’s better or worse than any others….they’re all a menace to our sewers!
There's plenty of information on our website about the impact of fat, oil and grease.


woman bathing son

Q: If you have shared drains, is there anything you can do to reduce the chances of a blockage from things your neighbours flush?

We work very hard to explain to people that their actions can not only affect them but their neighbours as well, but unfortunately there's not much we can do if someone is flushing the wrong thing down the loo. That’s why it’s really important to spread the message that you should only flush the 3Ps – pee, poo and (toilet) paper – because what you flush affects you and your neighbours. That's why we've joined forces with the Consumer Council for Water (CCWater) to get animated in our efforts to end the scourge of our sewers.

Q: I roll my eyes, but my husband keeps buying the posher loo roll that has added oils, like aloe and coconut. Are these worse environmentally? When the tissues break down does the oil wreck the water? Sometimes he even buys the ridiculous quilted stuff. I'd love to give him a better reason to not pick them up – other than me being a tight-arse, of course!

In the industry, it’s a well-known fact that ‘posh’ toilet paper takes a lot longer to break down in the sewers than ‘normal’ loo paper, so we'd always recommend buying thinner makes. This not only helps our sewers, but also costs you less – it's a win-win!

Q: But what about moist toilet tissue (the pre-packed sort) or tissues (the nose-blowing sort)? Especially if they're greasy because you've used them to wipe off excess face cream or sunscreen.

They should all go in the bin! Moist toilet paper and tissues are stronger than toilet paper, as they’re designed to stay together when wet, unlike toilet paper, which is designed to break down in water. Our sewers aren’t designed to take anything other than the 3Ps – pee, poo and paper – and putting anything else into the sewage system risks a build-up of fat and unflushable items, which can cause a blockage and may result in sewage flooding your home.

Q: We blocked up all our plumbing recently with just toothpaste spit. Is this a common thing? Is there something toothpaste manufacturers could do about this?

To be honest, we’ve never heard of a blockage due to this before! Unfortunately, we can’t tell manufacturers what they do and don’t put in their products and usually your spit, combined with the little bit of water you use to brush your teeth, is enough to dilute it. I think it’s quite unlikely that a singular, or very small number of incidents, is likely to persuade toothpaste manufacturers that this is much of a problem.

Q: I worry about the chemicals used to clean sinks and toilets. Should I be?

Any cleaning products can cause issues with gases in the sewer network if they’re either very strong, or a lot is used. However, we all like a nice clean loo, and as long as the products are diluted (which will happen during flushing normally) and used in the recommended dosages, you’ll be safe to use them, and unlikely to cause blockages.

Q: Bit niche, but my friend says she picks all the hair from her hairbrush and shoves that down the loo. Is this a bad idea?

Hair should always go in the bin. Everyone will know how easily hair can get caught up and tangled – how often does it clog up your shower tray? Putting hair down the loo risks it doing that with other unflushable items, which can cause a blockage. Besides, if your friend is picking it off her brush anyway, it won’t take her any more effort to put it in the bin rather than down the toilet!

Q: I saw a tip on here the other day about flushing uneaten 'sloppy' foods down the loo. It made sense, but still sounded a bit iffy. By this logic, is vomit okay?

Soup, stews or any other ‘sloppy’ food hasn’t been digested, and so has all the fat and grease content still intact (as well as the calcium in any dairy products). That fat and grease combines with any other unflushable items in the sewer to create a concrete-like substance that can cause a blockage, which then backs the sewage up in the sewer and it finds the easiest path out – which is usually back up your toilet – or anything with a wastewater pipe – and into your house.

Any uneaten sloppy foods should be put in a lidded container and thrown in the bin.
But we all get ill sometimes, and we all need somewhere to be sick – and the toilet is, of course, the ideal place. As the food’s been in your stomach – even for just a little while – it will have been digested to a certain extent and so the fat and grease shouldn’t cause as much of a problem as foods that haven’t been anywhere near your digestive system!

Q: In a loo roll crisis, we have been known to put kitchen roll in the bathroom and use it for toilet paper until the shops open. According to the adverts, it is really strong. Will it break down in the sewer system, or cause blockages?

It can most definitely cause a blockage. As you’ve rightly identified, kitchen roll is stronger than toilet paper and is actually designed to absorb moisture and stay together when wet, unlike toilet paper, which is designed to break down in water. This means it could cause a blockage and, ultimately, a sewage flood.

Q: What can you do to unblock a toilet without causing damage?

You can always try using a plunger to see if that will free the blockage, which shouldn’t cause any damage to your toilet.

Q: What is the most common item that gets flushed down the toilet that causes a serious sewer problem?

The most common items that get flushed down toilets are wipes (whether cleaning, make-up, baby or moist toilet tissue), sanitary items (sanitary pads and tampons) and condoms. None of these should ever be flushed down the toilet – just pop them in a bag and put them in the bin!

Q: I think that lots of people flush anything just for convenience. Also lots of toilets in public places don't have rubbish bins in them, so what is the best thing to do with the rubbish, if not put it down the toilet?

All public places – restaurants, leisure centres, pubs, offices, and so on – should have bins for the disposal of sanitary items, hygienic wipes etc. We also work hard to encourage our customers – and everyone else! – to throw their unflushable items in the bin. All parents should have nappy bags, so please put the spoiled nappy in one and wait until you find a bin!

The rest of the house

Q: Is there such a thing as a flushable wet wipe? I'm sure I saw some advertising about some wet wipes that could 'be flushed down the pan – is this a myth?

Unfortunately, there are no wipes that should be flushed down the toilet – regardless of what manufacturers say on their packaging. It’s not because they won’t flush away – of course they do – but the problem is that they don’t break-up during their journey through the sewers like toilet paper does. When combined with other unflushable items and fat, oil and grease, they create blockages which can cause sewage to back up and flood homes, gardens and businesses. That’s why the industry is lobbying the Government, to make manufacturers change the misleading information on their packaging, to make the message much clearer for customers: nothing except the 3Ps should be flushed down the toilet. The Consumer Council for Water has a really interesting blog about it.

Q: Which of the most common unflushables can be recycled or disposed of in an environmentally friendly way, rather than general waste or incineration?

Even though kitchen rolls, blue rolls and tissues are made of paper they are made to be strong and won't break down as rapidly as toilet tissue, so it's recommended they're composted instead. Another thing that can be safely composted is hair (it’s a good source of nitrogen!).

Q: Decidedly un-glam, but what about animal shit? I've been removing cat shit from the litter tray – with gloves – and flushing it, as apparently it's not supposed to go in the bins either. Which is more appropriate, bin or loo?

Always put pet poo in the bin! The wastewater treatment process is only designed to treat human waste and animal poo has much higher levels of bacteria, as well as a higher nitrate content. So the safest thing is to bag it and put it in the bin!

So there you have it! Everything you've ever wanted to know about keeping your pipes clear (not a fallopian tubes joke) and running smoothly.