PROJECTS

Total Works upgrade

Chemdose were contracted by Costain Ltd to provide a complete upgrade of the chemical dosing and monitoring equipment of the MOD’s largest water treatment plant. The plant is a river draw and the existing dosing systems were in a very poor state. The site was being run manually 24hrs a day by the client’s operation staff.

Our process chemist worked on site collecting river samples and providing analysis of the site needs, it soon became apparent that the river conditions changed dramatically with colour ranges of 10-750 hazon and turbidity
2-150 NTU. Further investigation found the river to be the flasheist in the UK.

We proposed a fully automated coagulation control system, with a site specific formula.

The water quality analysis also showed that with the varying river conditions the site would require a fully automated pH control, as both Alkali and Acid was required to maintain the optimum coagulation pH set point.
With the help of our Process Chemist, our software engineers developed a fully automated solution to transfer from each from of ph correction chemical, whilst maintaining the pH set point.

New Colour, Turbidity and pH monitors were selected and installed to provide accurate inline readings required by the Coagulation Control.

Bespoke dosing systems were designed and installed to interface with the clients existing bulk storage for Sodium Hydroxide, Aluminium sulphate, Sulphuric Acid and Polymer.
New control panels were installed to interface with the dosing rigs and the new site SCADA system.

The existing chlorination system, was also replaced including new vacuum gas header, chlorinators, injectors and solution dosing lines.

To minimise the risk of cryptosporidium two new UV systems were installed, in a purpose built GRP enclosure. This work included installation of new 450mm ductile iron pipework, valve actuation.

Chemdose also completed site wide replacement of all instrumentation, providing new backboard mounted instruments for:

• Raw Water Oil in Water, pH, Turbidity, Colour
• Clarified Water Turbidity
• 4 No RGF Turbidity, Level, Pressure loss
• Pre contact tank Turbidity, pH, Chlorine residual
• Final Water Turbidity, pH, Aluminium, Colour, Chlorine Residual
• All tanks Ultrasonic Level

The installation of these new instruments also included Duty/Standby sample pumps and interfacing with the site SCADA.

The site is now fully operational and the work undertaken by Chemdose has allowed our client to reduce the operator attendance to a minimum and greatly reducing his chemical usage. The final water quality having dramatically improved.

The client has taken a yearly support contract with our service and maintenance team ensuring continued, uninterrupted reliable plant operation.