Corsehouse Water Treatment Plant was built by Laing Construction and designed by Degremont in 1976 to supply the local population of small villages and industries. The site is situated 4 miles north of Stewarton, Ayrshire, Scotland.

I have operated this plant as relief operator from March 1977 - June 1980.

Water was supplied from Corsehouse Reservoir which is ½ mile from the plant, the reservoir is impounding and consisted of several natural springs and a large catchment area.

Water quality is reasonably good but has a high colour and low acidity due to the peaty catchment source.

Hydrated Lime is dosed at the raw water inlet to increase the Ph value between 6.0 - 6.5 for maximum floc formation.

Two Pulsator clarifiers were used due to their low construction costs, these consisted of a flat bottom with inlet laterals, central vacuum chamber and sludge hoppers built into the side walls.

This design was the first to be tried out in Scotland and because the raw water was low in turbidity there were problems at commissioning with blanket breakup, this was rectified by the addition of a high density polymer being introduced.

There were no moving parts in this design supplementing low maintenance costs and cross circuiting was avoided by pulsing the blanket.

Pulsing was introduced by the vacuum chamber where part of the inlet water was raised ½ meter and released, this resulted in a pulse throughout the blanket which reformed the sludge into a homogeneous stable blanket, the pulses were timed at 1 minute intervals but this could be adjusted depending on raw water quality conditions.

Three Aquazer type 2 rapid gravity filters were used adopting Degremonts own design, consisting of a sand media to a depth of 1.5 meters, combined air scour and backwash and Syphon slow start system.

All backwashes were manually controlled by the operator and initiated when high headloss of between 2.0 - 2.5 meters was reached.

The main coagulant used is Aluminium Sulphate at 22% strength this was dosed to a Flash mixer for rapid mixing prior to the clarifier inlet.

Hydrated Lime used primarily as a Ph correction dosed at the flash mixer.

Polyelectrolyte ( LT24 ) dosed after flash mixer and before clarifier inlet chamber, this was manually batched in the main mixing tank then transferred to a day tank when required, Wallace & Tiernan dosing pumps were used with carrying water to prevent dosing line blockage.

This plant was designed for one man operation and normal duties were performed during daytime hours, if a problem occurred when unmanned a Dial Alarm system would ring round until someone answered, this notified the receiver of the alarm status and called out the person to investigate the problem.

    I enjoyed working at this plant as most of my training in water treatment was assessed here for my college projects in City & Guilds, sadly I have just been informed that Corsehouse was shut down permanately due to the low production of 1.2 MGD maximum output, treated water now feeds this area from a larger treatment plant.