Sewage treatment - what you should know

Cath Hassell

Cath Hassell of ech2o consultants ltd
links water poverty, surfers against sewage and
decoupling stormwater from the sewers.

(this article was first published in Green Building Magazine, Summer 2012)

In January I was in Brighton delivering a series of training sessions on sustainable water in the UK. It was cold but sunny, and for three days the sun bounced off a fabulously blue sea into the training room. It was too cold to swim, but that was probably a good thing. Because, 12 years after the European Union's Urban Wastewater Treatment Directive banned the dumping of raw sewage to sea, the 225,000 residents of Brighton and Hove are still doing precisely that! In Brighton, the contents of every person's toilet is coarsely screened and discharged directly into the sea. This rudimentary “treatment” removes disposable nappies, sanitary towels and most toilet paper but none of the poo (nor the tampons, condoms, and ear buds that are commonly found in waste water). The discharge is via a 1.8 km long sea outfall off the nearby cliffs, which may seem a long way out but currents and tides have the potential to bring this sewage back nearer the coastline. As well as being unsightly when tampons and condoms are washed up onto beaches, the greater concern is for swimmers. Surfers against Sewage (www.sas.org.uk) was formed in 1990 by a group of surfers in Cornwall who were fed up of swimming among poo and falling ill as a result. The most common diseases caught from surfing or swimming in sewage-polluted water are gastroenteritis and ear, nose and throat infections, whilst pathogens such as Hepatitis A and E. coli 0157 can cause more serious illnesses.

Dumping raw sewage to sea
As an island nation the UK has always used the sea as a dustbin. Even when this practice was outlawed by the EU it took many years for the UK to comply. Devon and Cornwall with their long coastlines, large influx of tourists in the summer months that put extra pressure on the water and sewage system, and unscreened sewage outfalls from almost every bay, was a particular problem. The situation was compounded by the fact that the area has a relatively low number of households, (3% of the UK's population) but 30% of the UK's coastlines and rerouting sewers to centralised treatment plants would result in a heavy premium per customer. In 1990 (when the water industry was privatised) 40% of the sewage in these two counties was discharged into the sea with no treatment at all and just 3% of beaches passed the Good Beach Guide recommendations for water quality. Since that time South West Water has invested £2 billion to improve sewage treatment standards; 250 crude sewage outfalls have been closed and 247 million litres of waste water is now treated daily in over 600 treatment works. By 2006, when the bulk of the work was completed, the 144 main bathing sites in the south west all complied with the EU mandatory standard and in 2011, 29 beaches were awarded the Blue flag for exceptional water quality1.

Water poverty
But all this has come at a cost to South West Water's customers, who now pay the highest water rates across the UK; the average bill is £517 which is 43% higher than the UK average. In the Autumn budget, the Government announced a £50 subsidy for all 700,000 households in the south west to be paid from April 2013. With water currently at £4.62/m3, a family of four on a meter in Plymouth, using the average 150 litres/person/day, will pay a staggering £1012 a year for 219m3 of water, putting the £50 reduction into perspective2. In fact, for families in the south west living in a small house or flat the water bill can easily exceed their heating bill3, and water poverty is becoming an increasing concern in many areas of the UK4. 23% of households spend more than 3% of their income on water bills and 11% pay more than 5%5. In households that are on benefits the figures are 50% and 20% respectively, and the Government is so concerned that the Water White Paper, released in December 2011, gives water companies the power to introduce a social tariff for households on low incomes.

Combined Sewer Overflows (CSOs)
It is important to realise that our seas are still not immune from being contaminated with raw sewage even with modern sewage treatment plants. Poorly designed and operated CSOs, of which there are 22,000 in the UK, discharge untreated sewage into the sea (or rivers) when storm water in combined sewers overloads the system and the drains are filled to capacity, a situation that occurs all too regularly. Surfers against sewage, having campaigned tirelessly for many years to get sewage treatment plants installed across the UK, are now turning their attention to CSOs. They run an on-line warning system, where anyone can post a message to alert swimmers or surfers that a sewage spill has occurred6.

Ensuring that as much storm water as possible is removed from the drainage system is therefore vitally important on any development whether large or small, new build or existing. Consideration should always be given to SUDS, and installing rainwater harvesting in non domestic buildings. Meanwhile, back in Brighton (now the only area in the UK, and among the last in Europe, that does not meet European Union standards on wastewater treatment) the wait for an end to this frankly embarrassing situation is almost over. In 2013 a new £300 million sewage treatment plant, treating 95 million litres of waste water a day, will finally be completed. About time too.

1 All from Clean Sweep Report Published 2008 Accessed on line at http://www.southwestwater.co.uk/media/pdf/6/c/SWW_Edelman_final.pdf
2 As opposed to the same family in the Thames Water region who would pay £388
3 16,000 kWh of gas at 5p per kWh £800
4 When a household spends more than 3% of their income, after housing costs on water and sewage bills, as defined by the Joseph Rowntree Trust
5 This is 2.4 million households in England alone. Data from Water for Life, Water White Paper, Dec 2011
6 In the summer of 2011 there were 48 sewage spills across Devon and Cornwall alone due to heavy rainfall.

 

 

 

 



Cath Hassell is an expert in sustainable water strategies and low-carbon and zero-carbon technologies, formed from a background of 17 years experience in the conventional plumbing industry and 11 years in environmental building. From 1998 - 2004 she worked at Construction Resources, designing and implementing rainwater harvesting, greywater recycling and solar technologies for domestic, commercial and industrial sites. She set up ech2o consultants ltd in 2004. She was a founder member of the UK Rainwater Harvesting Association (UKRHA) and a director of the AECB (the Sustainable Building Association) for 7 years. Fascinated by how we use water across different age-ranges, cultures and genders, Cath talks (and writes) about technological and behaviour-change solutions to water shortages to a wide range of audiences, in the UK and abroad, including over 6000 school pupils in 2009/10

 

 

 

 

 

 

 

Share with: