The more observant amongst you will have spotted that 16th May was also the day of the Cup Final. But, for some people, this was too good an opportunity to miss (besides the right team won - sorry to all you Rangers fans).
We met at the Heigham water treatment works, just off the Norwich
Ring Road. The old pump house 
dates from Victorian times. It is now used as a museum. From there
we left for the new treatment works. On such a hot day the reservoir
on site 
(which holds a single day's supply) looked very inviting.
Most of the interior of the treatment works is kept dark - to
prevent the growth of algae in the treated water and to deter
insects from dropping in. Here you can see the flocculation tanks,
where water from the river, after filtering and ozonation is aerated,
causing much of the organic material to flocculate and cause a
scum on the surface 
which is then scraped off.
Treatment of the water with ozone has many advantages (it reduces
the amount of chlorine that needs to be added to the final product).
But there is a safety problem - ozone is not good to breathe).
There are ozone sensors throughout the area, and an alarm went
off while we were there. But we calmly left by the nearest exit
and waited until it was all clear.
After a jolly good lunch back at the Pump House we headed off
to see the other side of the water treatment story.
Some people seemed surprised that areas of a sewage treatment
works semlt a bit. And I must admit I was as nervous as Janet
whilst walking within a couple of feet 
of the aeration tanks. By
this time the 'product' had already been screened, the grit removed
and passed through the anaerobic treatment area. To remove remaining
organics that contribute to the Biological Oxygen Demand (BOD)
aerobic bateria are used - and the more oxygen present, the better.
The sight of 6m deep tanks being churned by giant agitators is
a spectacular sight from afar - from 2m away it's awesome. 
All-in-all it was a fun and educational day out.
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