Design, Construction & Commissioning of a reliable wash water treatment, sludge thickening and sludge dewatering system. Hardham Water Supply Works (WSW) provides water to over 200,000 customers in the North of West Sussex. The existing processing plant had suffered from a number of deficiencies which led to breaches of the existing discharge consent for the site. The project brief was to provide adequate and robust capacity for the site to ensure compliance with the new EA discharge consent, and to meet the statutory undertaking date.
Design Solution – Wash Water Treatment
In order to reinforce the existing wash water treatment system a new flocculation and lamella solids separation system were designed and installed to provide an additional 100% wash water treatment capacity. This additional treatment system was completed with the associated polymer preparation, polymer dosing, sludge removal and supernatant transfer equipment together with the necessary instrumentation, quality sampling and control.
An additional MCC complete with PLC/HMI designed and manufactured by our Automation Control & Technology was provided to control the additional wash water treatment equipment.
Design Solution – Sludge Treatment
New sludge balancing and thickening facilities have been designed and installed comprising a 180 m³ pre-thickened sludge balancing tank, pumped tank mixing, thickener feed pumping, WRc thickeners and thickened sludge transfer pumping. The additional thickening facilities were completed with the associated polymer preparation and polymer dosing equipment together with the necessary instrumentation and local control.
The two existing picket fence thickeners have been converted into thickened sludge holding tanks with the removal of the existing picket fence mechanisms and the installation of external “low shear” mixing pumps. The two existing 1500mm x 1500mm plate presses have been fully refurbished with replacement polypropylene filter plates, filter cloths and controls. A single new additional 1500mm x 2000mm plate press has been installed complete with controls in order to provide a combined total press volume of 14,658 litres. The three existing hydraulic ram pumps and high pressure cloth wash pump have been refurbished together with the provision of a new service water break tank, air compressors, air receivers and extensions to existing press sludge feed, press liquor drainage and cloth wash systems to connect the new additional plate press.
The existing sludge treatment MCC has been replaced with a new MCC complete with PLC/HMI designed and manufactured by our in-house controls division.