Category: Water & Utilities

Canterbury WWTW serves a population of 73,394 and has four digester tanks, each with a capacity of 1500m3 sludge, at approx.12.8m dia. x 11.9m. As part of Southern Water’s AMP6 upgrade works, Barhale were contracted to fully refurbish and upgrade two of these digesters.

The works included purging the digesters out of service; draining down and cleaning the digesters; carrying out necessary surveys and ensuing repairs; replacing the old gas mixing system with a new chopper pump system and all associated pipe-work; installing new temperature probes; testing & commissioning and conducting a 28 days reliability test.

The works took place in an extremely challenging working environment that presented some of the highest risks within the industry.

As part of Southern Water’s AMP6 upgrade works, Barhale were
contracted to refurbish the aeration system at Canterbury Waste
Water Treatment Works (WWTW). The works included replacing 7
aeration blowers dating from 1998 with 75kW rotary lobe blowers
which are complementary to new diffusers and the air main. Barhale
also installed new blower and aeration control and instrumentation
systems. These included high and low discharge pressure sensors and
pressure transducer with a visual display or pressure gauge.

The works entailed significant constraints. For example, the blowers
needed to be replaced without stopping the process of the WWTW
and the full works had to stay within consents agreed with the
Environment Agency by Southern Water.