Sewage PollutionWe’ve come a long way since the days of bedpans and pots being emptied out of windows directly into the streets below, but reading some of the statistics on sewage pollution incidents, maybe it’s not quite far enough.

The Sewers

In the ‘Great Stink’ summer of 1858, sewage was literally piling up in the streets of London with 30,000 people dying from an epidemic of cholera as a result. The poor sanitation of the city even caused Parliament to be suspended as the stench from the Thames was deemed too awful to continue.

However, thanks to the pioneering response of engineer Joseph Bazalgette, who set about designing and building a massive system of underground sewers across the city, the problem was solved and we still reap the benefits of his original pipes in keeping the city free of effluent.

In the years that followed, Bazalgette’s ideas were rolled out across the land and today 380,000km of sewers connect our toilets to treatment plants run by 11 water and sewerage companies.

Where Does Sewage Go?

Each day we flush 11 million tons of raw sewage down our toilets and that is probably the last we wish to think about it.

If our own waste and a little toilet paper is all we flush, then perhaps we don’t need to worry; however, if we flush anything else at all, then we are causing grave problems further down the line and personally contributing to the amount of raw sewage with contaminates out waterways on a regular basis.

Sewerage Treatment Works

The UK’s water companies are responsible for running sewerage treatment plants where human and industrial waste is treated via a number of processes. They are overseen by the government’s Environment Agency in England and Wales and by the Environment Protection Agency in Scotland as well as being monitored by the relevant industry watchdogs.

What causes Sewage Pollution?

There are many causes for sewage pollution but some of the more common ones are down to lack of repairs at critical times, by the water companies. Thus, broken water mains and leaking pipes have accounted for many incidences in the past. However other common reasons include, low-level treatment discharges, blockages in the sewer system from sanitary waste products and overflows from flooding.

Low Level Sewage Treatment

To re-attain high quality, clean water from the sewage, it should undergo 4 different treatment processes culminating in ‘tertiary’ treatment which disinfects the water. However, water is discharged in many parts of the UK which is only subject to either preliminary or primary treatment levels and which means water will still contain pathogenic bacteria and viruses.

Non-Flushable Sanitary Items

Each day, people flush down the toilet products which were never designed to be carried through the sewers or treated at sewerage plants. Items such as tampons, cotton buds, condoms, and panty liners regularly block drains, filters and cause overflow problems. Environmental groups such as Surfers Against Sewage (SAS) have been lobbying for years for people to put these sorts of products in a bag and into the bin rather than into the toilet where they can eventually end up polluting our waterways and littering our beaches.

Combined Sewer Overflow

There are 27,000 outlets which intermittently discharge untreated waste water into our waterways from sewers which carry a combination of both storm water and sewage. At times of heavy or persistent rain, sewage will use these overflow systems, causing potential pollution. This is called a combined sewer overflow or CSO.

CSO is not a rare problem and it is estimated to occur at least once a week in the River Thames, for instance. Also, during unseasonably bad weather, as with the past two summers, water quality at beaches fell drastically due to the discharges and run-off from adjacent outlets.

Effects Of Sewage Pollution On Health

If raw or untreated sewage is found at sea, it poses a serious health hazard to humans.

Sickness and diarrhoea as well as ear, nose and throat infections are common results but it is also possible to contract acute febrile respiratory illness, Hepatitis A, and typhoid.

You can also become ill if eating shellfish which has been grown in polluted water.

Effects Of Sewage Pollution On The Environment

The effects of sewage pollution in the marine environment are also devastating to the fish and organisms that live there. Fish can be poisoned and their growth and general health greatly impaired.

Old Equipment And Lack Of Investment

A lack of investment in water treatment works, and in upgrading sewers has meant that in past years, targets for high quality water have been missed. However, in line with the government’s improvement scheme, introduced in 1998, plans are in place to continue with improvements and keep ourselves and our marine environment healthy.