A planning inspector has determined that a lightweight expandable clay aggregates (LECA) cover on a biogas plant’s tanks would adequately protect the living conditions of local residents.
Biogen won planning consent in 2016 for the construction of the facility, but the plant was not built in line with the approved plans which showed the two liquid digestate tanks covered by a roof. The tanks were roofless but employed a floating cover of LECA, comprising a full covering of clay balls to a depth of 20 centimetres that floated on the liquid, rising and falling with the digestate level.
Since the biogas plant was commissioned there had been a history of malodour complaints from local residents, particularly downwind of the facility. Biogen argued that this was likely to be due to the spreading of digestate and organic fertiliser on farmland and that the LECA covering was more effective in reducing odour than the roof originally proposed.
An independent review of air dispersion modelling indicated that if the digestate temperature was 20°C the odour concentration would be negligible at the nearest residential properties.
The inspector, at a hearing held earlier this month, allowed the appeal and quashed the enforcement notice subject to a condition requiring the installation and operation of a suitable digestate cooling system.