Tag Archives: DEFRA

Is London water drinkable?

27 Oct

There’s nothing terribly bad about London water but researching this made me buy my 12L 6 stage filter…

If you can bring yourself to read this – you’ll note that my writing style is a bit different to the usual. I’ve basically copied, pasted and fiddled with my first hack attempt at an ‘academic’ essay written for an assignment for my diploma of Nutrition. I should also add that despite my findings, which were positive, I have invested in a 6 stage, in-home 12L water filter (something I’ll write about at a later date…).

An average 160L of tap water are consumed by Londoners every day, with roughly 4% drunk from the tap.  Should we be drinking it? After all London is an old, big, busy powerhouse of a city, home to 10million people. It generates 55,000 tonnes of waste and pollutants every day that either pour into the sky, are buried in waste pits or are flushed down our drains. In the Borough of Kensington and Chelsea alone 1,420,000m3/day of treated sewage effluent is permitted into the Thames Tideway every day.   Considering the downside of the solvent nature of water’s magical structure of hydrogen bonds is that polar pollutants are just as easily dissolved into it as the goodness of vital nutrients, it would be a miracle to hear that our tap water is not negatively affected in some way.

What’s in our water before treatment?

Most London water is sourced from the Thames River and the rest is from groundwater sources.  Before treatment, this raw water contains many unwanted pollutants; pesticides and fertilisers from farming run-off, microorganisms such as typhoid and amoeba, hormones from the Pill released into sewerage and even radioactive substances from both man-made and natural sources.  In fact, in Japan, radioactivity is such a problem, Tokyo’s tap water is declared unfit for babies to drink after radiation from Japan’s quake-hit nuclear plant.

All London tap water is recycled

It is interesting to learn that water from an average tap could contain molecules that dinosaurs drank.  However it is horrifying to learn that 63% of our daily water consumption at home originates comes from sewerage.

Fortunately, in Britain, water authorities insist not only on primary and secondary treatment of raw sewage (to remove suspended solids and organic matter, and add disinfectants), but also require tertiary processing (to remove nutrients, biodegradable products and even traces of pharmaceuticals and other organic compounds).

Thames Water thankfully has a long list of the process London water undergoes to rid us of the pollutants, which may or may not come from our own effluent.

  1. A storage reservoir holds water for hundreds of days before it is pumped to the works for treatment so that debris – and solid contaminants settle-out, sunlight breaks down organic material and some bacteria die off
  2. Screening ensures that larger floating substances are removed
  3. Clarification occurs whereby a chemical coagulant is added to bind fine suspended material such as silt and mud particles which are then collected off.
  4. The liquid (water) is sieved to eliminate suspended particles and remove some bacteria
  5. Aeration removes dissolved carbon dioxide, hydrogen sulphide and dissolved metals such as iron.
  6. Granular Activated Carbon (GAC) is a step that passes the liquid through highly porous carbon particles absorb and remove pesticides, organic compounds and unpleasant tastes and odours.
  7. Ammonia is added after chlorination as a further disinfectant to form chloramines, which decay at a slower rate compared to free chlorine, which is useful for longer transportation of the water.
  8. Ozone is injected into the water to breakdown pesticides and organic material.
  9. Chlorine is added to the water supply as a disinfectant to create a slightly acidic bacteria and virus unfriendly environment. As necessary as it is to do this, chlorine in tap water has also been linked to increased cancers. Hot water also vapourises the chlorine creating a toxic mist that can cause skin conditions.

What’s in our water from the tap after treatment?

Even though these processes are in play many trace elements remain dissolved in our tap water that escape into the system thanks to hydrogen bonding . According to the Drinking Water Inspectorate and DEFRA water standards, these trace amounts of even some highly toxic substances are considered acceptable for London tap water:

Figure from DEFRA Drinking Water Standards

How does tap water reach us?

In July 2008, London tap water was voted the best in Britain by scientists from the Drinking Water Inspectorate despite the fact that a problem of lead plumbing was highlighted as a weak point. Replacing ancient lead pipes and dealing with plumbosolvency (lead dissolving into water) is one of the biggest issues facing London tap water.  We can blame Prince Albert.

At the time of Prince Albert’s death in 1861, the Thames was an open sewer, a toxic hot pot of bacteria and the source of the cholera epidemic of 1854.  Grief-stricken Victoria insisted that Albert’s passion for public health be a priority.  Engineer Joseph Bazalgette built six west-to-east interception sewers fed by 450 miles of main sewers and 13,000 miles of local sewers to channel London’s waste into the estuary when water was flowing.  The system became the model for cities worldwide and invented the first recycled water process.

The lead piping works cleverly with the capillary action of water to deliver water upstream to people’s homes above ground but the only problem is that the lead dissolves into the slightly acidic water that passes through it, causing lead poisoning and other serious and harmful impacts on the human body. Since the late 1970s, Thames Water has invested in replacing the lead with copper or plastic pipes. Our water is also hardened by adding lime or phosphate to produce a protective layer of lime scale between the water and the pipes and making the water less acidic, hence less easily dissolving the lead that still exists.

The other problem with London pipes is that when the temperature cools dramatically, water expands as it approaches freezing point and bursts pipes.  London homes suffer from this most Winters, hopefully not this one to come.

So is London Water drinkable?

Despite the fact that London tap water has passed through several pairs of kidneys before it reaches the average mouth, and despite the chemicals and trace elements that are found in it, consumers often can’t tell the difference between bottled water and tap. According to a Which survey in 2006 tap water is cheaper, preferred in a blind taste test, more eco-friendly and safe.

The added good news is that London tap water is also heavily regulated according to strict health based standards for documented by the World Health Organisation in the Guidelines for Drinking Water Quality, DEFRA. 

I drink it over bottled water but have invested in a water filter at home, from which, I have to say, the water tastes absolutely delicious.

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Fruit and veg sales out the window in a crisis reveal statistics

30 Jan

don't expect to see another promo for Macdonalds on this blog anytime soon!!

Newly released figures from DEFRA state that fruit and veg sales are in sharp decline in the UK. Depressing but not surprising. Fruit and veg are simply much more expensive than a £1 burger from Maccas.  But is price alone the cause of such a drop in consumption?  I don’t think so.  Tescos (and the other retailers) drove a 30% price reduction in fruits and vegs  over the last 3 months, Department of Health has spent £75m in 3 years on the change-4-life 5-a-day campaign and still we ate less.

One reason could be the enormous advertising budgets of fast foods and sweets manufacturers, estimated here on DEFRA at £375m a year.  It’s easy to blame price or big food manufacturers for a veggie sales decline but fundamentally I believe our decisions to eat what we eat, when we eat it, are never rational.  My theory is that while price (perception) is important, we humans can only worry about one thing at a time.  And when the health of our finances is in deep doodoo, we let personal nutrition go to hell. ‘Give me comforting, easy to prepare, and cheap food, now!  I’m busy surviving the crisis!’

Fruits and veg are a hassle to prepare, difficult to eat ‘on-the-go’ and to most people, not instantly comforting.  They are seen a personal indulgence of time AND money and add mixed messages about their impact, they are barely worth the trouble. Nutrition is an abstract long term investment for hippies, sadly not an everyday essential for the masses.  One day…

Parliament are debating the issue as we speak.  I’ll keep you posted.

Here’s the article in The Grocer here:

Fruit and veg consumption has continued to fall in the UK, with Brits buying 0.9% less in 2010 than they did the previous year.

Purchases of fruit and veg were 7.5% lower in 2010 than in 2007, new figures from Defra show, and down 8.7% on 2006 levels.

Poor households have cut back the most, with those in the lowest income bracket buying almost a third (30%) less fruit and veg in 2010 than in 2006.

Fruit bore the brunt of the cut, purchases falling by 11.6% between 2007 and 2010, while vegetable sales slipped by less than 3%. But fresh green vegetables also saw significant reductions, with purchases down 4.5% on 2009 and 15% on 2007.

Last week, The Grocer reported that the UK was near the bottom of the pile in a comparative survey of fruit and veg consumption across the European Union.

Nigel Jenney of the Fresh Produce Consortium said it was disappointing to see further confirmation that the UK was not meeting minimum recommendations for a healthy diet.

“The FPC is pressing government to support the industry by doing more to promote fresh produce as the ultimate value-for-money convenience food,” he said.