A&J saves largest to last with Yorkshire Water AMP4 contract
The largest contract carried out by A&J Fabtech under the AMP4 5 year framework agreement with Yorkshire Water was completed at the end of 2009 with the installation of the final 8 x 40 metre diameter scrapers at the Yorkshire water Knostrop treatment works.

Knostrop is Yorkshire Water’s largest wastewater treatment works, treating waste generated by the equivalent population of around one million. The plant deals with flows from the domestic and industrial areas of Leeds before discharging them into the River Aire. As part of a £43million upgrade new activated sludge treatment tanks and settlement tanks, incorporating scraper bridges designed and manufactured by A&J, were built to improve the plant’s efficiency as well as improving the quality of the final effluent.

The total contract placed with A&J for the Knostrop upgrade included the design and manufacture of 3 x 40m diameter tank scrapers plus the refurbishment of 4 x 45m scrapers in phase one of work on the site. Phase two saw the design, manufacture and installation of a further 8 x 40m diameter scraper bridges, arms and ancillary equipment, the whole contract scheduled over a total of 18 months.

The AMP4 framework agreement, covering the design, manufacture, supply and installation of water treatment scraper bridges over 25m in size was originally secured by the company in 2003 and covered the AMP4 period 2004-2009.

Throughout the framework agreement period, A&J has worked in partnerhsip with Yorkshire water and other framework suppliers to develop and improve plant designs, aiming to improve efficiency, longevity and performance of specified equipment. This work has led to a number of innovations from A&J, which will now be carried over into the next investment period (AMP5) and incorporated into all future designs.

One key innovation has been the development of a scum concentrating and removal system which significantly improves the removal of floating material from foul water settlement and treatment tanks. This new design has produced sufficient performance improvement to warrant becoming an integral element of future designs.