TAILORED SOLUTIONS TO MEET WATER QUALITY DRIVERS WITHIN YORKSHIRE
Brenda Franklin1, Ian Farmery 2, Norman Johnson1, Paul Hulbert1
1Earth Tech Engineering Limited, UK
2Arup, UK
(free)
In late 2004 and as part of their AMP4 Large Schemes Programme, Yorkshire Water Services (YWS) were faced with meeting DWI undertakings for quality schemes at four major treatment works by 31 December 2006. This represented a major challenge in meeting the tight deadlines.
This paper considers two of the schemes at Langsett and Loftsome Bridge and describes how YWS, their framework consultants (Arup and Turner and Townsend) and the Large Scheme Contractors Earth Tech Morrison (ETM) combined to provide tailored and ultimately successful solutions to meet their quality drivers.
At both sites raw water quality had deteriorated over recent years leading to periodic exceedances of the Prescribed Concentrations and Values (PCVs) of Trihalomethanes (THMs) in their respective distribution systems. Loftsome Bridge also had a second associated DWI undertaking relating to exceedance of the PCV for pesticides. The chosen solution at each site was the provision of an additional treatment stage, with Dissolved Air Flotation (DAF) and new filters being constructed at Loftsome Bridge and a separate manganese removal stage at Langsett.
The key to success was good teamwork with excellent cooperation within the Core Team (YWS, ETM and Arup). Both schemes were delivered on time and within budget.
KEY WORDS Combined Lamella Thickener, Dissolved Air Flotation, Fast Track, GAC Adsorbers, Pesticides, Rapid Gravity Filtration, Manganese Removal, Sludge Drying, THM.
