Eating sewage in Trowbridge
Wessex Water have been given permission for a new "sludge digestion facility" at their Trowbridge works, subject to their producing an improved landscaping scheme.
The facility incorporates:
• Two anaerobic digester tanks each at 23.6 metres in height and 15.6 metres in diameter. The tanks will be of Glass Reinforced Plastic (GRP), a non-reflective grey in colour with access stairs and hand railings of galvanised steel;
• A boiler house - 10.1 metres x 8.1 metres and 4.7 metres in height, with a stack at 14.5 metres in height. Steel frame and corrugated aluminium cladding construction, grey in colour;
• Combined Heat and Power (CHP) Plant - 12.2 metres x 3 metres and 5.4 metres in height with a stack at 10 metres in height. Steel container, grey in colour;
• A generator enclosure. Steel container, grey in colour; and 5 control kiosks - one kiosk measuring 9 metres x 4 metres at 5 metres in height and the
other four kiosks each measuring 7 metres x 3 metres at 3.5 metres in height. Each of GRP, grey in colour.
The scheme represents a huge economic and environmental improvement. The sludge is currently dosed with lime and removed from the site to be disposed of in landfill. The new development will offer a more advanced system by using anaerobic digestion vessels to speed up the sludge decomposition process. The digested sludge will produce methane which will be harnessed to generate heat and electricity. The heat generated will be fed back into the anaerobic digestion process and the electricity produced will meet the energy needs of the works, with surplus energy being fed into the national grid. The end product from the digested sludge will be used as an agricultural fertiliser.
Nearby residents and the town council had objected, saying there would be visual intrusion and an adverse traffic impact, but the plans were approved by Wiltshire Council's Strategic Planning Committee in February with conditions, and with the requirement for better landscaping involving bigger trees to hide the works from public view as much as possible.