Appendix 6. Odour Buffer Assessment [As Published] · 132007.2399

                                                                                           [20]
             Odour Buffer Assessment
             StarCo Developments


       Assessment of the odour intensity-concentration relationship for odour emitted from the
       main stack, as an adjunct to the normal dynamic olfactometry procedure.

The odour intensity scale is summarised in Table 8.1.

                        Table 8.1: German VDI 3882 Odour Intensity Scale
                  Odour intensity                            Intensity level I
                   Extremely strong                                    6
                      Very strong                                      5
                        Strong                                         4
                        Distinct                                       3
                         Weak                                          2
                      Very weak                                        1
                    Not perceptible                                    0



Observations of odour intensity in the field for this project are based on the approach detailed in
The German VDI 3940 (“Determination of Odorants in Ambient Air by Field Inspection”).
Observations were made at various locations downwind of the plant. The observed odour intensity
measurements were used as a basis for estimating mean odour concentrations and peak-to-mean
ratios. Further information can be found in Appendix B and in Ormerod et al. (2002a, 2002b) and
Ormerod & Grocott (2002).

Paired odour intensity observations were made on 21 December 2004 and 11 January 2005 by PAE
staff at four locations in the area adjacent to the sewage treatment plant. These observations were
made primarily to assist in verifying model predictions of ambient odour levels. Figure 8.1 shows
the positions of the observation locations. On both days winds were gusty with clear skies and
temperatures about 28°C. Table 8.2 outlines observation site details. Details of the observations
are contained in Appendix B.




                                                         Intensity
                                                        Observations




                                                               STP




1898a report final.doc                                                     PAE Job Number 1898a