AWN Consulting was appointed to assess the potential odour and air quality impacts associated with the Drehid Mechanical & Biological Treatment (MBT) facility in County Kildare. The facility will divert 250,000 tonnes of residual waste from landfilling and will create up to 50,000 of compost-like material.

The impact of the proposed facility on ambient concentrations of odour, bioaerosols, nitrogen dioxide (NO2), particulate matter with a size less than 10 μm (PM10) and 2.5 μm (PM2.5) was assessed.

The receiving environment in terms of air quality was assessed by means of a review of long-term EPA ambient air monitoring data representative of the region. In addition, a baseline survey for NO2 and SO2 was conducted at locations close to the proposed facility. The results of the baseline air quality review showed that the air quality experienced in Drehid was similar to that in other rural areas, with pollutant concentrations well below the National and EU limit values.

The impact of odour and other emissions from the facility was assessed using the US EPA regulated AERMOD air dispersion model with appropriate stack heights derived to ensure that all odour and ambient air quality standards and guidance levels were complied with at the nearest residential receptors.

A detailed odour management plan was also formulated to ensure that odour is given the highest priority on an on-going basis at the facility.