Every river in England is contaminated by a 'chemical cocktail' of sewage, agriculture and road pollution, according to a parliamentary report from the Environmental Audit Committee. Microplastics, slurry, car tyre particles, oils and wet wipes are also part of the problem, putting human health and the natural environment at risk of harm.
Some of this pollution comes from runoff from agricultural land, roads and businesses, but some of it comes directly from our homes, and is caused by the products we use every day in our kitchens and bathrooms.
What we put down our drains really matters. Although it’s not the only cause, in more than half (55%) of all the English and Welsh rivers failing to meet good ecological status, wastewater pollution is a contributing factor.
Choosing less polluting, more sustainable products, and disposing of them safely, can help reduce sewer blockages and water contamination.
The water we use at home for things like showering, flushing the loo and washing clothes and dishes heads down the drain. Many of us don't think too much about what happens next - but it's the start of a long journey.
In many cases, surface water (ie. rain water that's fallen into gutters and drains) also mixes with the sewage, in combined sewers, as it travels through the pipe network and end up at a sewage treatment plant.
As wastewater contains a wide range of contaminants including faeces, urine, food waste and chemicals from household cleaning products, soaps and shampoos, it must be cleaned thoroughly before it can be returned to natural watercourses.
First, it's filtered to remove larger items such as wet wipes and sanitary products, leaves and grit. It then goes into settlement tanks where suspended solids, oils and fats are separated out. After further treatment to remove suspended and dissolved organic matter, the cleaned water is returned to local rivers and streams. Some sewage works also apply a higher level of treatment to remove nitrogen and phosphorous, or disinfect water to remove viruses and bacteria.
This system of wastewater treatment should mean that only clean water is released into watercourses; however, it is frequently bypassed by combined sewer overflows, which allow untreated sewage to flow directly into seas and rivers.
There are more than 21,000 combined sewer overflows (CSOs) in the UK. They're a vital part of the network and provide a ‘safety valve’ to divert excess water and prevent homes and streets being flooded with sewage in case of emergency.
Water companies are permitted to discharge untreated wastewater through CSOs when the system is overloaded, typically during periods of unusually heavy rainfall or when sewers are blocked. However, although this system is designed for use in emergencies, it is being used with increasing regularity.
In 2020, water companies emptied untreated sewage into our seas and rivers in this way more than 400,000 times. Not only does this make conditions extremely unpleasant for swimming and other water-based activities, it also threatens ecosystems and affects human health, causing everything from ear infections to severe gastroenteritis.
While the water that's filtered from the sewage treatment plant is sent to rivers and seas, there's also the small matter of the residue left behind – called sewage sludge.
Farmland is the ultimate destination for the majority of the UK’s sewage sludge. According to the water industry, around 78% of the country’s treated sludge – 3.6m tonnes – is spread as fertiliser on hundreds of farms each year.
Investigators commissioned by the Environment Agency found sewage waste destined for English crops to be contaminated with dangerous 'persistent organic pollutants' including dioxins, furans and polycyclic aromatic hydrocarbons at levels that may present a risk to human health, as well as the antimicrobial triclosan, which scientists believe may cause antibiotic resistance.
They also found these sludges to be widely contaminated with microplastics that could ultimately leave soil unsuitable for agriculture. Microplastics enter the sewage system from washing synthetic clothes, tyre crumb washing off the roads and other sources.
Sewage treatment works can remove 99% of these microplastic fibres from wastewater; however, having carefully removed them from wastewater, they are then spread across the land where they either accumulate in the soil where crops are grown or wash off the soil back into rivers.
Some substances cannot be removed easily by conventional sewage treatment methods. Both prescription and over-the-counter medications find their way into wastewater. Unused drugs should never be disposed of down the drain; however, medications also enter the sewerage system in urine.
Antibiotics and synthetic hormones (such as contraceptive drugs) have been found in rivers and lakes, and in the fish living there. Increasing levels of synthetic oestrogen in water can trigger a condition known as intersex in freshwater fish, which has caused population decline in some species.
Other chemicals found in sewage include caffeine and ibuprofen. Their effects are not routinely monitored and the full impacts are unknown; however, studies suggest they are harmful to wildlife. There’s evidence to show that just under half of UK rivers could contain ibuprofen at levels that pose a risk to fish.
An increasing cause of sewer flooding is so-called 'fatbergs' and other blockages. These are the result of the wrong things – usually non-degradable solids – being put down the toilet, such as wet wipes, sanitary products and other disposable items. These mix with solid fats to create large sewer blockages.
To keep sewers flowing, you should only ever flush three things down the toilet. These can helpfully be summed up as the three Ps - poo, pee and paper (toilet paper, that is).
While some wipes are labelled as 'flushable', they don't all break down quickly when they enter the sewer system, and may still cause blockages. 'Fine to Flush' is the official standard identifying which wet wipes can be safely flushed down toilets. Manufacturers can have their wipes tested for flushability by independent technical experts. If they pass the tests, they can display the ‘Fine to Flush’ symbol.
Many of these are incredibly widespread, and therefore difficult to avoid. But if you're keen to clean up your water pollution, these are the chemicals to avoid where possible.
Check the ingredients lists of cleaning products, laundry detergent, dishwasher tablets, bath and shower products, and any other products that are likely to end up down the drain.
Parabens are a group of compounds widely used as an antifungal agent, preservative and antimicrobial in a variety of everyday products, including cosmetics, deodorant, face cream, shampoo and toothpaste. An estimated 90% of cosmetic products include parabens and, for many years, they have been considered safe as they are virtually non-toxic.
Studies have, however, linked parabens to hormone disruption, reproductive toxicity, immunotoxicity, neurotoxicity and skin irritation. Despite treatments that eliminate them relatively well from wastewater, parabens are frequently detected in surface water, fish and sediments. Choose paraben-free shampoos and beauty products where possible.
Triclosan is an antibacterial agent which is added to a wide range of household and personal care products (eg. toothpastes, mouthwashes, soaps and deodorants) to offer long-lasting protection against bacteria, moulds and yeasts. Triclosan can affect the body’s hormone systems – especially thyroid hormones, which regulate metabolism – and may disrupt normal breast development.
The EU classifies triclosan as irritating to the skin and eyes, and as very toxic to aquatic organisms, noting that it may cause long-term adverse effects in the aquatic environment. Widespread use of triclosan may also contribute to antibiotic resistance.
Phthalates are a group of chemicals that are most commonly used to make PVC soft and flexible. They are also used in synthetic fragrances, in everything from shampoo to deodorant and laundry detergent.
Unfortunately, they are also hormone-disruptors, and phthalate exposure has been linked to early puberty in girls, a risk factor for later-life breast cancer. Phthalates can be dangerous to both ecosystems and humans, and many are not completely removed during conventional wastewater treatment processes.
PFAS (perfluoroalkyl and polyfluoroalkyl substances) are a type of man-made microplastic that have been generating concern due to their extreme persistence, mobility and potential to build up inside living organisms. Some have been linked to a range of health problems when found in high doses.
They have been termed ‘forever chemicals’ as they do not biodegrade in the environment. They've been manufactured since the 1940s, and are now estimated to be in almost every living organism on the planet, including in the bloodstream of nearly every human being. They are useful for their non-stick, stain-resistant properties, which means they can be found in a huge variety of consumer products, from clothes and home furnishings to food packaging and cleaning products.
They're relatively unknown in the UK, but a household name in the USA, where they were the focus of a very lengthy lawsuit on behalf of people who had become sick after ingesting PFAS in water contaminated by a nearby manufacturing plant. Recent detection of PFAS in UK waters have highlighted the poor removal of PFAS by wastewater treatment.
Synthetic fragrances are commonly used in a wide array of everyday products and often contain as many as 200 ingredients. The word ‘fragrance’ or ‘parfum’ on a label represents an undisclosed mixture of various scent chemicals and ingredients, potentially including hormone-disrupting phthalates, synthetic musks and ethylene oxide. Fragrances enter the aquatic environment via wastewater, have been found to be toxic to aquatic life and can accumulate in the food chain.
Other potentially harmful chemicals include stilbenes, used as optical whiteners in laundry products; non-biodegradable surfactants derived from crude oil; and liquid polymers, which are poorly biodegradable and may remain in ecosystems for many years.
Look for plant-based formulations with ingredients that are readily biodegradable, and choose fragrance-free products or those scented with essential oils. If your local shops don't stock them, online retailers such as Ethical Superstore have a wide range of environmentally friendly laundry, dishwashing and household cleaning products, as well as personal hygiene and beauty products.
Check our reviews to that can match the best for cleaning power – but remember that eco products often don't use optical whiteners, so they may not achieve top marks in tests designed to measure whiteness.
Beware of greenwashing. Some manufacturers make unsubstantiated claims about their cleaning products or toiletries, so find out exactly what's in them, and what makes them eco-friendly, before handing over your cash.
While refillable products and those with plastic-free or recyclable packaging may be more sustainable in some ways, check the ingredients to be sure they're not creating pollution in another way. Ideally, neither the product nor the packaging should harm the environment.
Soap nuts contain a natural surfactant called saponin, and have been used for centuries to wash both people and clothes. Also known as soap berries, they are the fruit of the Sapindus tree, and are entirely natural and biodegradable.
Wash balls or laundry eggs, also known as ecoeggs and ecoballs, use natural mineral or plant-based pellets encased in a refillable plastic ball. Refillable dryer eggs are also available, which can reduce drying time and contain natural essential-oil fragrance sticks.
A washing bag, such as the Guppyfriend, captures plastic microfibres from your washing and prevents them from entering the marine ecosystem.
Instead of chemical fabric conditioners and synthetic fragrances, try naturally scented bags or sachets in drawers and wardrobes to keep clothes and linen smelling fresh. Many plant ingredients including lavender, peppermint and eucalyptus are also moth deterrents.
Washing-up soap bars combine plastic-free packaging with biodegradable, non-polluting ingredients to make a sustainable alternative to regular bottles of washing-up liquid. They may take a little getting used to, but can still clean your dishes effectively.
Try making your own natural cleaning products. You can bulk-buy ingredients such as citric acid (useful for descaling), bicarbonate of soda (which can neutralise acid, scrub shiny materials without scratching, deodorise, and remove certain stains) and borax substitute (an all-purpose cleaner and scourer).