Otterbourne Water Supply Works (WSW)

Orthophosphoric Acid and Sodium Hypochlorite Chemical Dosing works package for Southern Water with Main Contractor GTBV Joint Venture. M&E Contractor Colloide will supply, delivery, install and commission 2 dosing systems. The Orthophosphoric Dosing Package comprises a kiosk housing dosing pump arrangement, instrumentation and control panel for the new pumps. The Sodium Hypochlorite Dosing Package comprises a kiosk housing with storage tanks, fill point cabinet, dosing pump arrangement, instrumentation and control panel.

Colloides Chemical Dosing expertise will ensure that these packaged dosing systems have been designed and constructed with a view to reducing time on site. Following offloading, setting in place and installation, Colloide will complete SAT’s on all equipment.

The work forms part of a scheme to upgrade the water treatment quality and capacity of Otterbourne Water Supply Works (WSW).

Otterbourne WSW is situated at Otterbourne, near Winchester. Otterbourne WSW abstracts water from two sources. Surface water is abstracted from the River Itchen, the water passes through a culvert to the clarifiers. The raw water is dosed with ferric chloride, powdered activated carbon (PAC) and polyelectrolyte (poly) to aid flocculation and eventually passes through ten Rapid Gravity Filters. Groundwater is abstracted from a series of boreholes and wells and is treated by a membrane filtration plant.

Under the proposed development, the filtered water from the surface and groundwater streams will be combined, pumped through UV disinfection equipment, and dosed with orthophosphoric acid and sodium hypochlorite before passing through a new set of Chlorine Contact Tanks. The treated water will then be pumped to the primary reservoirs by nine new High Lift Pump.

This project is part of Southern Water’s £10 million AMP7 framework contract, which covers the provision of plant, materials and services for the design, supply, installation and commissioning of packaged chemical dosing units for approximately 78 sites in the South East of England. These sites include both water and wastewater sites using an assortment of chemicals, but mainly focusing on ferric.

 

Presteigne Wastewater Treatment Works (WwTW)

The design, supply, installation and commission of a new Ferric Dosing system at Presteigne WwTW for Welsh Water with Main Contractor Morgan Sindall Construction and Infrastructure. Presteigne WwTW is located to the East of the town Presteigne in Powys, Wales. This project is part of a Welsh Water Framework which Colloide successfully bid on.

The driver for this scheme is to meet compliance for a new phosphorus consent and for growth within the catchment up to 2040. Welsh Water is investing more than £8 million to improve the wastewater system in both Norton and Presteigne. Find out more about the Norton and Presteigne investment projects schedule.

The Ferric Sulphate Dosing Package will include, but not be limited to the following: 1 No. chemical storage tank and bund, 2 No. chemical dosing pumps, 1 No. weatherproof kiosk, associated pipework and valves, 1 No. chemical delivery lockable fill point and control panel, 1 No. complex package plant Control Panel to DCWW standards, testing, commissioning, offloading, M&E installation, training and O&M Manuals.

 

Mercia Park STW

Severn Trent alongside NOV Completion & Production Solutions has tasked M&E Contractor Colloide Engineering to design, supply, install and commission a new chemical dosing system. This system will be part of NOV’s pump station and is required due to the length of the rising main and the time that the sewage may sit within it. This project is part of a Severn Trent Framework.

The dosing system is to meet the following requirements:

• Dosing Chemical = Calcium Nitrate (as per Severn Trent current standard).
• Dosed Media = Raw Sewage
• Sewage Pumping system Flowrate = 12 to 18 l/s (Normally 12 l/s, increasing to 18 l/s to accommodate for any peaks).
• Rising Main length = 9450m
• Rising Main Pipe Spec = Variable
• Expected Rising Main Pressure = Approx 8 bar, (max 18 bar)
• Dosing to be done into the pump, prior to Progressive cavity pumps.
• Electricity supply = 400V/3ph /50Hz