Odour Risk Assessment

For new Methane Stripping Plants (MSPs) which will be located close to property, or where the planning authority or Environment Agency request an odour risk assessment, an odour risk assessment should be carried out.

In order to carry out a site specific odour risk assessment it is necessary to mimic as closely as possible the conditions under which the full scale plant will produce a potentially odorous off-gas from the aeration process.
Bubling methane stripping tank

“The offgas vented from a methane stripping plant may give rise to complaints about odours from some leachates unless suitable odour control is provided.”

To do this we use our a trial plant equipment, is set up (as described elsewhere) and run for up to 4 hours.

“The offgas vented from a methane stripping plant may give rise to complaints about odours from some leachates, unless suitable odour control is provided. However, for most leachates there is no significant odour produced during the process.”

The trial MSP is fed with fresh site leachate, until the off-gas from the plant reaches full strength and steady-state conditions have been accomplished. At this time the air being expelled from the trial will contain a characteristic odour which will be representative of that experienced from the full scale plant.

An air sample is taken which is sent to an odour panel. The odour panel records the test panel’s views on the severity of the odour.

The consultant incorporates the report from the test panel on the impact of the odour, obtained from the odour panel, into an odour risk assessment, based upon the predicted impact of the full scale plant on the sensitive receptors which will have been identified at that site.

The report will include a conclusion which will either demonstrate that no significant odour impact will occur, or if an impact is identified, it will propose ameliorative measures, such as the provision of a suitable odour removing bio-filter.