Great Gaddeson Water Tower - June 2103

[Yorrick]

Quicklime and calcium hydroxide (hydrated lime) have been used to treat biological organic waste for more than 100 years.

How Lime Treatment Works

Lime treatment controls the environment needed for the growth of pathogens in bio-solids and converts sludge into a usable product.
Treatment of biological wastes with lime is based on several chemical reactions.
Bio-solids treatment by Lime Stabilisation can be achieved by applying a controlled dose of liquid lime, hydrated lime or quicklime to sewage sludge.
This is considered the best method of treatment to produce a valuable end product for land based recycling, both simply and efficiently.
Calcium hydroxide is an alkaline compound that can create pH levels as high as 12.4.
At pH levels greater than 12 and increased temperatures, cell membranes of harmful pathogens are destroyed.
The high pH also provides a vector attraction barrier, preventing flies and other insects from infecting treated biological waste.
Because lime has low solubility in water, lime molecules persist in bio-solids to prevent re-growth of pathogens.
When quicklime (CaO) is used with water, an exothermic reaction occurs.
As heat is released, the temperature of the biological waste can increase to 70ºC, which provides effective pasteurization.
The high pH also will precipitate most metals present in the waste and reduce their solubility and mobility.
Lime will also react with phosphorus compounds to prevent eutrophication.
The solubility of calcium hydroxide provides free calcium ions, which react and form complexes with odorous sulphur species such as hydrogen sulphide and organic mercaptans.
As a result of this reaction, the biological waste doors are actually destroyed, not just “covered over.â€
In general, lime stabilization is a non-proprietary process, although patented processes are available.

I won’t pretend to understand all of that, but I do know that lime is mixed with water and then mixed with sewage and then used as fertilizer.

I think that’s what this contraption is for.

It looks like water comes into the top tank then flows into the middle tank at a controlled rate.
The weight of water causes the middle tank to swing back and forth.

The swinging waggles a paddle in the third tank, stirring the lime to help it dissolve.
It looks like the solution then just overflows into the big tank underneath.
From the scale formed around all but the top tank, I would guess the lime is added to the middle one.

A metal box and the unused lime.

It sits on top of a 1,000 gallon water tank, just below the main tank at the top of this Victorian water tower.

On the ground floor is this bench saw

The tree canopy is higher than the tower, giving most of the lower area inside an interesting green tinge.

A crows nest made a change from pigeon shit and the crows were sensible enough to piss off when I came up the ladder.

A couple of miles away stands this. I haven’t found any history specific to either tower. My best guess would be the Victorian one was built around the 1880s and the new one replaced it in the 1970s.

That was all guess work so if anyone’s got any other ideas I’d love to hear them.​