Unsolicited Additional Information - Re Planning - Part 2 - EPA

Report Number 2008A72(1)RME Environmental Ltd2.2 Conversion factors from I-hour ground level concentrations to 8 and 24 hourand Annual average ground level concentrationScreen 3 outputs maximum I-hour ground level concentrations utilising worst-casemeteorological dispersion estimates. In order to allow comparison with SI 271 of 2002 forCarbon monoxide, Oxides of nitrogen and Sulphur dioxide, conversion from I-hour groundlevel concentrations to 8 and 24 hour and Annual averages must occur. This is performedusing established conversion factors published by the USEPA and Environment agency, UK.The U.S. EPA recommends a maximum I-hour to maximum annual conversion factor of 0.08for both point and area sources within its procedures for assessing risks. This value issupported by recent studies, researching the dispersion from point sources that undergo initialmixing, which have reported values within the range of 0.06 - 0.20. A conversion factor of0.20 was used in this study - being on the upper end of the range of the values published, itproduces the most conservative results (Ontario Regulation 346).The Environment agency recommends a maximum I-hour to maximum 8 hour and 24 hourconversion factors of 0.70 and 0.59 for point sources (EA, 2002; Turner 1994).These conversion factors were utilised to allow for comparison of maximum I-hour groundlevel concentrations with averaging period contained in SI 271 of 2002.2.3 lnputdataTable 2.7 illustrates the input data utilised within the Screen 3 dispersion model for Scenarios1 and 2. This was utilised in conjunction with the Screen 3 dispersion model to estimate themaximum ground level concentration at down wind receptors in the vicinity of the site.Emission concentration data was provided by Eurofarm foods Ltd and used in conjunctionwith source and building characteristics. A worst case meteorological screening file containedwithin Screen 3 model was utilised to determine worst-case ground level concentration. Aworst-case detected emission concentration was utilised within the dispersion model.For inspection purposes only.Consent of copyright owner required for any other use.3EPA Export 26-07-2013:17:03:31