Council archive · source document
Appendix 6. Odour Buffer Assessment [As Published] · 132007.2399
REPORT ODOUR BUFFER ASSESSMENT NOOSA SEWAGE TREATMENT PLANT NOOSA SPRINGS DEVELOPMENT PRECINCT J StarCo Developments Limited 22 October 2007 Job 1898b
See the original
The page text is free to read. Viewing or downloading an original file needs an account.
Log in to see the originalFull text of the other 63 pages
Page 2
PROJECT TITLE: Odour Buffer Assessment Noosa Springs Development
Precinct J
JOB NUMBER: 1898b
PREPARED FOR: Phil Starkey, StarCo Developments Pty Ltd
STATUS: Draft
PREPARED BY: Robin Ormerod
QA PROCEDURES CHECKED BY: N/A
APPROVED FOR RELEASE BY: Robin Ormerod
COPYRIGHT: This report is subject to the copyright statement
located at www.pae.net.au
© Pacific Air & Environment Pty Ltd 2007
ABN 23 887 350 026
REVISIONS:
VERSION DATE DESCRIPTION PREPARED BY REVIEWED BY
V1 15.10.07 DRAFT R ORMEROD G. GALVIN
FINAL 22.10.07 REPORT R. ORMEROD CLIENT
Pacific Air & Environment Pty Ltd ABN 23 887 350 026
BRISBANE:
Level 1, La Melba, 59 Melbourne Street South Brisbane Qld 4101
PO Box 3306 South Brisbane Qld 4101
Ph: +61 7 3004 6400
Fax: +61 7 3844 5858
SYDNEY:
3 Spring Street Sydney NSW 2000
PO Box 4216 Sydney NSW 2001
Ph: +61 2 8249 4464
Fax: +61 2 8249 4001
Email: [email protected]
Website: www.pae.net.au
1898b Report.doc i
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 3
DISCLAIMER Pacific Air & Environment Pty Ltd (PAE) acts in all professional matters as a faithful advisor to the Client and exercises all reasonable skill and care in the provision of its professional services. Reports are commissioned by and prepared for the exclusive use of the Client. They are subject to and issued in accordance with the agreement between the Client and PAE. PAE is not responsible for any liability and accepts no responsibility whatsoever arising from the misapplication or misinterpretation by third parties of the contents of its reports. Except where expressly stated, PAE does not attempt to verify the accuracy, validity or comprehensiveness of any information supplied to PAE for its reports. Reports cannot be copied or reproduced in whole or part for any purpose without the prior written agreement of PAE. Where site inspections, testing or fieldwork have taken place, the report is based on the information made available by the client or their nominees during the visit, visual observations and any subsequent discussions with regulatory authorities. The validity and comprehensiveness of supplied information has not been independently verified and, for the purposes of this report, it is assumed that the information provided to PAE is both complete and accurate. It is further assumed that normal activities were being undertaken at the site on the day of the site visit(s), unless explicitly stated otherwise. 1898b Report.doc ii Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 4
ES1 EXECUTIVE SUMMARY The proposed development of Precinct J at Noosa Springs will occur within a 600 metre buffer that has been established around the Noosa Sewage Treatment Plant (STP). An assessment of odour impacts is required to determine whether development within the buffer would be adversely affected by odour emissions from the STP. A similar issue arose for previous residential development within part of Precinct G (associated with the recently approved development application for resort residential uses in Precinct F), and StarCo commissioned PAE to prepare a detailed odour assessment based on a combination of advanced modelling, source odour measurements, field observations and a small community survey. The same modelling has been used to show the predicted impact of the STP on odour levels in Precinct J. The results show that the predicted odour levels in Precinct J are within the 2.5 odour unit guideline set by the Queensland EPA. This result in conjunction with the other information gathered for the Precinct G assessment leads us to conclude that the odour impacts in Precinct J are acceptable. 1898b Report.doc iii Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 5
TABLE OF CONTENTS
1 INTRODUCTION 1
2 PROJECT DESCRIPTION 2
2.1 The Site and Proposed Development 2
2.2 Odour Complaints 3
3 ODOUR ASSESSMENT CRITERIA 4
3.1 Factors Affecting Odour Response 4
3.2 Quantitative Odour Descriptors 4
3.3 Queensland Odour Guideline 5
4 ODOUR ASSESSMENT 6
4.1 Precinct G Odour Assessment Report 6
4.1.1 Dispersion Modelling 6
4.1.2 Community Odour Survey 7
4.1.3 Field Odour Intensity Surveys 7
4.1.4 Assessment and Conclusions 7
4.2 Precinct J Assessment 7
5 CONCLUSIONS 9
6 REFERENCES 10
APPENDIX A Odour Buffer Assessment: Noosa Sewage Treatment Plant
List of Figures
Figure 2.1: Location of Noosa STP and Noosa Springs Development, showing
location of Precinct J ................................................................................. 2
Figure 2.2: Location of Proposed Precinct J Development Relative to 600 m STP
Buffer ..................................................................................................... 3
Figure 4.1: Predicted Odour Concentrations Associated with Noosa STP, with Noosa
Springs Precinct J highlighted..................................................................... 8
1898b Report.doc iv
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 6
1 INTRODUCTION StarCo Developments Pty Ltd (StarCo) commissioned Pacific Air & Environment (PAE) to conduct an odour assessment to assess the potential for development within the current 600 m buffer zone around the Noosa Sewage Treatment Plant (STP). The proposed development within the existing buffer represents a small section of the Noosa Springs development, specifically, proposed Precinct J. The existing 600 m buffer area is shown on the Plan of Development and pre-dates the upgrading of the Noosa STP. The upgrading of the facility has resulted in a decrease in odour emissions through strict licensing requirements and enclosure of the inlet works. StarCo seeks approval for the development of 27 residential lots within the 600 m zone. 1898b Report.doc 1 Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 7
2 PROJECT DESCRIPTION
2.1 The Site and Proposed Development
The Noosa STP and Noosa Springs development are situated on Noosa Springs
Drive, Noosa Heads. Figure 2.1 shows the location of the STP and Noosa Springs
Development, with Precinct J highlighted. Figure 2.2 shows Precinct J in more
detail, and also shows the location of the 600 m buffer line (dashed curve) around
the STP, set by Noosa Shire Council for planning purposes. A 35 m high ridgeline
runs between the Noosa STP and Noosa Springs.
StarCo wishes to develop inside the existing buffer in Precinct J.
Figure 2.1: Location of Noosa STP and Noosa Springs Development,
showing location of Precinct J
1898b Report.doc 2
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 8
Figure 2.2: Location of Proposed Precinct J Development Relative to 600 m
STP Buffer
2.2 Odour Complaints
Historically the Noosa STP was the cause of numerous odour complaints. However,
a major upgrade of the treatment plant several years ago resulted in a dramatic
reduction in the number of complaints. Since 2000 the plant has received only rare
odour complaints, all associated with abnormal activity on site (e.g. equipment
failure).
For its earlier stages, the Noosa Springs development noted and investigated any
odour events that may be attributed to the STP over a period of at least 18 months.
During that period only one event (one of the three previously mentioned) was
sourced to the STP.
1898b Report.doc 3
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 9
3 ODOUR ASSESSMENT CRITERIA
The Queensland EPA Guideline on „Odour Impact Assessment from Developments‟
contains a detailed discussion of issues associated with odour response and
assessment. This section briefly describes the basic factors associated with odour
response, known as the FIDOL factors, and then identifies assessment criteria.
3.1 Factors Affecting Odour Response
Analysis of community odour exposure has identified five factors that are important
in determining the potential for annoyance and complaint:
Frequency (how often odour occurs);
Intensity (how strong the odours are);
Duration (how long odour events last);
Offensiveness (the degree of unpleasantness); and
Location (is the location „sensitive‟?).
These are together called the FIDOL factors (NZ Ministry for Environment, 1995).
Generally, the greater the frequency, intensity, duration and offensiveness of an
odour the more likely it is to cause annoyance and lead to complaints.
3.2 Quantitative Odour Descriptors
Key elements of quantitative odour criteria that are used for planning purposes are:
Concentration
Averaging time and
Percentile value
Concentration is the odour strength (in odour units) as determined by dynamic
olfactometry.
Averaging times for odour criteria are generally either 1 hour or 3 minutes, or in
the case of NSW the „nose response time‟, taken to be approximately 1 second.
Dispersion models that are used for predicting or simulating odour concentrations
utilise a basic time interval of one hour for individual calculations. For smaller
averaging times, the 1-hour result is converted using a statistical relationship
between concentration and averaging time.
The percentile value refers to the percentage of time (usually over a full year)
during which the actual odour concentration must be within the criterion
concentration.
The shorthand notation incorporating these parameters is written in the form C p,t
where C is the concentration and the subscripts p and t refer to the percentile value
and the averaging time, respectively. For example, C99.5 1-hr refers to the 99.5th
percentile 1-hour average concentration.
1898b Report.doc 4
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 10
3.3 Queensland Odour Guideline
In July 2004, the Queensland EPA released the final form of its Guideline on „Odour
Impact Assessment from Developments‟. This document had been in development
for some years, a fact reflecting the challenges in developing a comprehensive
odour policy.
For the assessment of odours caused by complex mixtures of odorous compounds,
such as odours from wastewater treatment plants or intensive livestock operations,
the Guideline sets out three possible approaches to establishing criteria for
assessing acceptable levels of impact based on odour dispersion modelling:
Odour annoyance threshold (concentration) guidelines;
Odour intensity guideline; and
Alternative assessment tools for odour assessment for the expansion of
existing activities.
For this study, the „default‟ odour concentration guideline approach is adopted,
since there is insufficient information to justify an alternative approach. The
Guideline sets out the following advice in relation to odour concentration guidelines:
Proponents of new facilities may undertake an impact assessment with
relevant inputs of emissions and local meteorology to an air dispersion
model to provide estimates of the likely odour impacts in the surrounding
environment. The inputs should be as detailed as possible, reflecting any
variation of emissions with time and including at least a full year of
representative hourly meteorological data. The modelled odour
concentrations at the “most exposed existing or likely future off-site
sensitive receptors” should be compared with the following guideline
values.
0.5 ou, 1-hour average, 99.5th percentile for tall stacks
2.5 ou, 1-hour average, 99.5th percentile for ground-level sources
and down-washed plumes from short stacks, and
for facilities that do not operate continuously, the 99.5th percentile
must be applied to the actual hours of operation.
Further details are contained in section 5.1 of the Guideline.
In the application of this type of guideline, the appropriate criterion for the Noosa
STP is C99.5 1hr = 2.5 ou, since it is not a „tall stack‟ source type.
1898b Report.doc 5
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 11
4 ODOUR ASSESSMENT
This section explains the approach taken to predict odour levels associated with the
proposed development. The information in this report is based on the data and
methods used for the 2005 assessment of STP odour for the residential
development within a small part of Precinct G associated with the recently approved
development application for resort / residential uses in Precinct F (Holmes, 2005). A
copy of the 2005 report is attached as Appendix A.
4.1 Precinct G Odour Assessment Report
In early 2005, PAE conducted an odour assessment for the Precinct G development
which is approximately 650 m south east of precinct J and also within the 600 m
STP buffer.
This study included dispersion modelling of odour emissions from the STP using
measured emission rates in the CALPUFF dispersion model. The study also included
the results of a small community survey covering existing residential areas to the
northwest of the STP, and some field observations of odour near the STP against
which comparisons were made with the model. The combined weight of these
approaches led to the conclusion that odour impacts in Precinct G would be
acceptable, with the predicted C99.5 1hr odour level below the EPA default guideline
of 2.5 ou.
4.1.1 Dispersion Modelling
Prediction of odour dispersion from the STP was based on the CALPUFF model,
which is a widely recognised USEPA regulatory model. As with any model CALPUFF
requires inputs in three major areas:
Emission rates and source details,
Meteorology, and
Terrain and surface details, as well as specification of specific receptor
locations.
Staff from PAE made an inspection of the Noosa STP in August 2004 to identify the
key sources of odour. The STP underwent a major upgrade in 1997, enclosing
many of the major odour-producing processes. The inlet works and fermenter are
both totally enclosed and the vapour treated in a biofilter. The primary clarifiers
are also totally enclosed and the vapours treated in activated carbon scrubbers.
The site inspection by PAE identified three dominant sources of odour within the
facility:
Biofilter;
Activated Carbon Scrubbers (2); and
Bioreactor.
Airlabs Pty Ltd was commissioned to conduct odour sampling on these three
sources to determine suitable odour emission rates (OER) for dispersion modelling.
The Airlabs sampling report is included as Appendix B of Holmes (2005).
1898b Report.doc 6
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 12
No long term on-site weather data are available, but local conditions were modelled using the recognised meteorological models (TAPM) a and CALMET. 4.1.2 Community Odour Survey A small community odour survey conducted by PAE in existing residential areas to the northwest of the STP) indicated that the majority of people surveyed could not detect odour from the STP. Indeed many were unaware of the existence of the STP. From a total of 15 respondents, one could regularly detect odour while another two said that they could smell the STP but only about once per year. 4.1.3 Field Odour Intensity Surveys 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. Taking into account the small number of samples and the inherent uncertainty in the data, the field observations were broadly consistent with the model predictions of odour at the times of the observations. 4.1.4 Assessment and Conclusions Dispersion modelling of the significant odour sources within the Noosa STP using CAPLUFF indicated that odour impact in the area of interest within the Precinct G development was below the Queensland odour guideline level of 2.5 ou. After assessing the combined results of dispersion modelling, odour complaints records and a small community survey we concluded that the odour impacts at the area of interest within the Precinct G development were not expected to result in significant annoyance to future residents. Any odour impacts were predicted to occur at night and would be infrequent. 4.2 Precinct J Assessment For the current assessment, the modelling performed for the Precinct G development has been adopted. The predicted C99.5 1hr odour impact is shown in Figure 4.1. a The EPA Guideline on Odour Impact Assessment from Developments (July 2004), section 6.4, states: “The CSIRO‟s air quality model TAPM can be used to generate hourly one-year meteorological data required for the dispersion models. This is a prognostic meteorological model, which eliminates the need to have site-specific meteorological observations. The model can predict airflow important to local scale air pollution such as sea breezes and terrain induced flows. For sites where observed meteorological data is not available and the site is subject to the sea and land breeze effects, it is preferable to use TAPM model for the generation of meteorological data.” 1898b Report.doc 7 Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 13
Species: Location: Scenario: Percentile: Averaging Time:
Odour Noosa STP Normal Operation 99.5th 1-Hour
Springs
Model Units: Guideline: Met Data: Plot:
Used: Odour units 2.5 ou (Qld EPA) 2000 CALMET- E Castillo
CALPUFF (ou) Generated
v5.7
Figure 4.1: Predicted Odour Concentrations Associated with Noosa STP,
with Noosa Springs Precinct J highlighted
1898b Report.doc 8
Noosa Springs Precinct J Development StarCo Developments Limited
PAE Job 1898b
Page 14
5 CONCLUSIONS An evaluation of the potential for development of Noosa Springs within the current buffer zone around the Noosa STP has been undertaken using a combination of assessment techniques. The current buffer zone was established some years ago and the Noosa STP has since had a major upgrade that includes a high level of odour control. After assessing the combined results of dispersion modelling, odour complaints records and a small community survey conducted for the earlier Precinct G development (Holmes, 2005) we conclude that the odour impacts onPthe Precinct J development are not expected to result in significant annoyance to future residents. The predicted odour levels in this area are below the 2.5 ou EPA guideline level. As with the Precinct G results, the odour impacts occur at night and are infrequent. We conclude that the proposed Precinct J development within the existing 600 m buffer should not be refused on the grounds of possible adverse odour impacts. 1898b Report.doc 9 Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 15
6 REFERENCES Frechen, F. (1997) Odour Measurement and Odour Policy in Germany. Proc. National Workshop on Odour Measurement Standardisation, UNSW, Sydney 20-22 August 1997. Frechen, F. (2002) Odour Emission Inventory of German Wastewater Treatment Plants – Odour Flow Rates and Odour Emission Capacity. Proc. Enviro 2002, Melbourne 7–12 April 2002 2002. Hibberd, M. F., Physick, W. L., and Park, G. (2003). Verification of several aspects of TAPM against multi-year monitoring data at Collie. In: National Clean Air Conference: linking air pollution science, policy and management: CASNO3, Newcastle City Hall. [Newcastle, NSW]: Clean Air Society of Australia and New Zealand. p. 71 (printed abstract). 6 p. Holmes, G (2005) Odour Buffer Assessment Noosa Sewage Treatment Plant. Consultancy report by Pacific Air & Environment for StarCo Developments, Brisbane. Hurley, P. J. (2002a). The Air Pollution Model (TAPM) Version 2: user manual. Aspendale: CSIRO Atmospheric Research. (CSIRO Atmospheric Research internal paper; 25). 38 p. Hurley, P. J. (2002b). The Air Pollution Model (TAPM) Version 2. part 1: technical description. Aspendale: CSIRO Atmospheric Research. (CSIRO Atmospheric Research technical paper; no.55). 49 p. Hurley, P. J., Manins, P. C., Lee, S. H., Boyle, R., Ng, Y. L., and Dewundege, P. (2002a). Year-long urban airshed modelling in Melbourne: verification of TAPM for photochemical smog and particles. In: Conference proceedings: 16th International Clean Air & Environment Conference, Christchurch, N.Z. [Christchurch, N.Z.]: Clean Air Society of Australia and New Zealand. p. 347-353. Hurley, P. J., Physick, W. L., and Luhar, A. K. (2002b). The Air Pollution Model (TAPM) Version 2. part 2: summary of some verification studies. Aspendale: CSIRO Atmospheric Research. (CSIRO Atmospheric Research technical paper; no.57). 46 p. Lorimer G.D. (1998). The AUSPLUME Gaussian Plume Dispersion Model Environmental Protection Authority of Victoria. Luhar, A. K., and Hurley, P. J. (2003). Evaluation of TAPM, a prognostic meteorological and air pollution model, using urban and rural point-source data. Atmospheric Environment, 37 (20): 795- 2810. NSW DEC 2005, Approved Methods for Modelling and Assessment of Air Pollutants in NSW, August 2005. New Zealand Ministry for the Environment (1995) Odour Management under the Resource Management Act. Ormerod, R.J., P.C. D‟Abreton & S.C. Grocott (2002a) Development of Site-Specific Odour Criteria and Compliance Assessments Using Odour Intensity Observations 1898b Report.doc 10 Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 16
and Modelling. Proc. 2002 Biennial Conference of the Clean Air Society of Australia & New Zealand, Christchurch, August 2002. Ormerod, R.J., S.C. Grocott & P. D‟Abreton (2002b) Development of Site-Specific Odour Criteria for Industrial Facilities Using a Variety of Tools. Proceedings, Enviro 2002 Odour Conference, 7-12 April 2002, Melbourne. Ormerod, R.J. & S.C. Grocott (2002) Development and Application of State-of-the- Science Techniques for Odour Monitoring, Modelling and Assessment: A Case Study from Queensland. Proceedings, 4th Annual Conference of the Environmental Engineering Society of Queensland, Brisbane, May 2002. Pasquill, F. (1974) Atmospheric Diffusion. The Dispersion of Windborne Material from Industrial and other Sources. 2nd edition. Ellis Horwood Limited, Chichester, UK. Queensland Environmental Protection Agency (2004) Odour Assessment from Developments Scire, J.S., D.G. Strimaitis and R.J. Yamartino (2000a) A User‟s Guide for the CALPUFF Dispersion Model (Version 5), Earth Tech, Inc., Concord, MA. 1898b Report.doc 11 Noosa Springs Precinct J Development StarCo Developments Limited PAE Job 1898b
Page 17
APPENDIX A ODOUR ASSESSMENT FOR PRECINCT G [OCR of page images] APPENDIX A ODOUR ASSESSMENT FOR PRECINCT G
Page 18
ODOUR BUFFER ASSESSMENT
NOOSA SEWAGE TREATMENT PLANT
StarCo Developments Pty Ltd
Job No 1898a
4-April-2005
Page 19
[i]
Odour Buffer Assessment
StarCo Developments
Project Title: Odour Buffer Assessment – Noosa Sewage Treatment Plant
Job Number: 1898a
Prepared for: StarCo Developments Pty Ltd
Status: Final Report
Date of release: 4 April 2005
Prepared by: Glen Holmes
Approved for release by: Robin Ormerod
REVISIONS
Version Date Description Prepared by Reviewed by
1 2/3/05 Draft released for client comment Glen Holmes Robin Ormerod
2 22/3/05 Draft released for client comment Glen Holmes
3 04/4/05 Final released to client Glen Holmes
QUALITY CHECKPOINTS
Project Phase Prepared by Approved by
Methodology Glen Holmes Robin Ormerod
Assumptions and raw data sources Glen Holmes Robin Ormerod
Internal review of manipulated data Glen Holmes Robin Ormerod
Raw data approved by client (if appropriate) - -
Report outline Glen Holmes Robin Ormerod
DISCLAIMER and COPYRIGHT
This report is to be read subject to the report disclaimer and copyright statement located at
www.pae.net.au
CITATION
This report should be cited as follows:
Holmes, G (2004), Odour Buffer Assessment Noosa Sewage Treatment Plant, Consultancy report for StarCo
Developments, Brisbane.
© Pacific Air & Environment Pty Ltd 04 April 2005
ABN 23 887 350 026
www.pae.net.au
Brisbane Sydney
Level 1, La Melba 3 Spring Street
59 Melbourne Street Sydney
PO Box 3306 NSW 2000
South Brisbane Qld 4101
Ph +61 7 3004 6400 Ph +61 2 8249 4464
Fax +61 7 3844 5858 Fax +61 2 8249 4001
1898a report final.doc PAE Job Number 1898a
Page 20
[ii]
Odour Buffer Assessment
StarCo Developments
Table of Contents
1 INTRODUCTION ....................................................................................................... 1
2 SITE DESCRIPTION .................................................................................................. 1
2.1 LOCATION .................................................................................................................. 1
2.2 PROPOSED DEVELOPMENT ................................................................................................ 2
2.3 COMPLAINTS ............................................................................................................... 3
3 ODOUR ASSESSMENT CRITERIA ............................................................................... 3
3.1 FACTORS AFFECTING ODOUR RESPONSE ............................................................................... 4
3.1.1 Frequency.......................................................................................................... 4
3.1.2 Intensity............................................................................................................ 4
3.1.3 Duration ............................................................................................................ 5
3.1.4 Offensiveness..................................................................................................... 5
3.1.5 Location ............................................................................................................ 5
3.2 QUANTITATIVE ODOUR DESCRIPTORS ................................................................................... 5
3.3 QUEENSLAND ODOUR GUIDELINE ....................................................................................... 6
3.3.1 Odour Annoyance Threshold (Concentration) Guidelines .......................................... 7
3.3.2 Odour Intensity Guideline .................................................................................... 7
3.3.3 Alternative Assessment Tools for Odour Assessment – Expansion of Existing Activities 8
3.4 SUMMARY OF CRITERIA BASED ON EPA GUIDELINE .................................................................. 8
4 MODELLING METHODOLOGY .................................................................................... 8
4.1 STATUS OF MODELS ...................................................................................................... 9
4.2 SELECTED MODELS AND METHODOLOGY ..............................................................................10
4.3 TAPM .....................................................................................................................10
4.4 CALMET .................................................................................................................11
4.5 CALPUFF ................................................................................................................12
5 MODEL INPUTS ...................................................................................................... 13
5.1 SOURCE DETAILS ........................................................................................................13
5.2 METEOROLOGY ...........................................................................................................13
5.3 STABILITY .................................................................................................................15
5.4 METEOROLOGICAL DATA VALIDATION .................................................................................16
6 MODELLING RESULTS............................................................................................. 16
7 COMMUNITY ODOUR SURVEY................................................................................. 18
8 FIELD ODOUR INTENSITY SURVEYS ....................................................................... 19
9 ASSESSMENT.......................................................................................................... 22
10 CONCLUSION ......................................................................................................... 23
11 REFERENCES .......................................................................................................... 24
1898a report final.doc PAE Job Number 1898a
Page 21
[iii]
Odour Buffer Assessment
StarCo Developments
List of Figures
FIGURE 2.1: LOCATION OF NOOSA STP AND NOOSA SPRINGS DEVELOPMENT 2
FIGURE 2.2: LOCATION OF PROPOSED DEVELOPMENT 3
FIGURE 4.1: MODELLING METHODOLOGY UTILISED IN THE STUDY. 10
FIGURE 4.2: EXAMPLE OF LOCAL WIND FIELD FOR ONE HOUR PREDICTED BY CALMET 12
FIGURE 5.1: WIND ROSES FOR THE STUDY AREA, 2003 14
FIGURE 5.2: FREQUENCY OF PASQUILL-GIFFORD STABILITY CLASSES FOR THE SUBJECT SITE
DERIVED FROM TAPM 16
FIGURE 6.1: PREDICTED (C99.5 1-HR) ODOUR CONCENTRATION (OU) - CALPUFF 17
FIGURE 6.2: PREDICTED ODOUR CONCENTRATIONS BY HOUR OF DAY FOR THE PROPOSED
PRECINCT G DEVELOPMENT 18
FIGURE 7.1: ODOUR SURVEY AREAS 19
FIGURE 8.1: FIELD OBSERVATION LOCATIONS 21
1898a report final.doc PAE Job Number 1898a
Page 22
[1]
Odour Buffer Assessment
StarCo Developments
1 INTRODUCTION
StarCo Developments Pty Ltd (StarCo) commissioned Pacific Air & Environment (PAE) to conduct
an odour assessment to assess the potential for development within the current 600 m buffer zone
around the Noosa Sewage Treatment Plant (STP). The proposed development within the existing
buffer represents a small section of the Noosa Springs development, specifically, a small portion of
Precinct G within the approved Plan of Development.
The existing 600 m buffer area is a condition of the Rezoning Deed and imposed prior to the
upgrading of the Noosa STP. The upgrading of the facility has resulted in a decrease in odour
emissions through strict licensing requirements and enclosure of the inlet works. As such, StarCo
seeks allow the development of residential dwelling units within the 600 m zone.
This report represents the findings of the odour assessment conducted by PAE.
2 SITE DESCRIPTION
2.1 Location
The Noosa STP and Noosa Springs development are situated on Noosa Springs Drive, Noosa Heads.
Figure 2.1 shows the location of the STP and Noosa Springs Development. Noosa Shire Council
currently maintains a 600 m buffer around the STP for planning purposes. (The buffer is
represented by the yellow dashed line.) There exists a 35 m high ridgeline running between the
Noosa STP and Noosa Springs.
1898a report final.doc PAE Job Number 1898a
Page 23
[2]
Odour Buffer Assessment
StarCo Developments
STP
Noosa
Springs Area of
Interest
Figure 2.1: Location of Noosa STP and Noosa Springs Development
2.2 Proposed Development
StarCo wishes to develop inside the existing buffer in a small area within Precinct G south of Resort
Drive. The development within the area of interest is for the purposes of residential dwellings
(refer to Figure 2.2).
1898a report final.doc PAE Job Number 1898a
Page 24
[3]
Odour Buffer Assessment
StarCo Developments
STP
Noosa Springs
Development
Offices
Area of
Interest
Approximate
Location of
Current Buffer
Figure 2.2: Location of Proposed Development
2.3 Complaints
Historically the Noosa STP has been the cause of numerous odour complaints. However, a recent
major upgrade of the treatment plant has resulted in a dramatic reduction in the number of
complaints. Since the beginning of 2000 the plant has received only three odour complaints, all
associated with abnormal activity on site (e.g. equipment failure).
The Noosa Springs development has also been noting and investigating any odour events that may
be attributed to the STP for the previous 18 months. During that period only one event (one of the
three previously mentioned) was sourced to the STP. Of particular note is the location of the
Noosa Springs development offices, to the east of the existing tennis courts.
3 ODOUR ASSESSMENT CRITERIA
The recently released Queensland EPA Guideline on ‘Odour Impact Assessment from Developments’
contains a detailed discussion of issues associated with odour response and assessment. This
section of the Guideline briefly describes the basic factors associated with odour response, known
as the FIDOL factors, and then identifies assessment criteria.
1898a report final.doc PAE Job Number 1898a
Page 25
[4]
Odour Buffer Assessment
StarCo Developments
3.1 Factors Affecting Odour Response
Analysis of community odour exposure has identified five factors that are important in determining
the potential for annoyance and complaint:
Frequency;
Intensity;
Duration;
Offensiveness; and
Location.
These are together called the FIDOL factors (NZ Ministry for Environment, 1995). Generally, the
greater the frequency, intensity, duration and offensiveness of an odour the more likely it is to
cause annoyance and lead to complaints.
3.1.1 Frequency
The frequency of odour exposure simply refers to how often odour events occur. It is a function of
the variations of odour emissions over time, and of the meteorological conditions in the area
around an odour source. The frequency of odour events is generally greatest in areas that are
most often downwind of the source.
3.1.2 Intensity
The intensity is the perceived strength of an odour and it is related to the odour concentration, or
the mass concentration of the compounds involved. However, the relationship is not direct.
For simple odours associated with single compounds, such as hydrogen sulphide, the relationship
between the intensity and the mass concentration of the compound (µg/m3) or its odour
concentration (ou), has the general form of a power law or a logarithmic relationship. Thus, as the
odour concentration increases, the perceived strength or intensity increases by a much smaller
amount. The relationship between odour intensity and odorant concentration may be described by
the Weber-Fechner law (Frechen, 1997), which is written as:
I = kw log(COD)
where
I = intensity level
kw = Weber-Fechner coefficient
cOD = odorant concentration
What this means, for example, is that a doubling of the odour concentration leads to a
proportionally much smaller increase in odour intensity, the parameter detected by human noses.
An important implication of this relationship is that in order to reduce the impact of an odour that
1898a report final.doc PAE Job Number 1898a
Page 26
[5]
Odour Buffer Assessment
StarCo Developments
causes annoyance, a reduction of say 50% may lead to only a marginal change in perceived
strength or intensity.
3.1.3 Duration
The duration of odour events is controlled mainly by meteorological conditions, although variations
in odour emissions may also be important for sources that vary in strength over short time periods.
Longer duration odour events are likely to be associated with more stable meteorological
conditions, which tend to be common at night and around sunrise and sunset. Somewhat
persistent odour events appear to be generally more likely to cause annoyance than very brief
single exposures, although this may simply reflect the general distribution of types of odour
sources (which have different types of impacts). Desensitisation or habituation can occur during a
substantial period of continuous exposure.
3.1.4 Offensiveness
Offensiveness is a subjective or qualitative aspect of an odour, relating to its intrinsic
pleasantness/unpleasantness or underlying quality. The offensiveness of an odour generally
increases as its strength increases.
3.1.5 Location
Location is an essential consideration when assessing the likelihood of odour nuisance. Greatest
emphasis is placed on ‘sensitive’ locations such as residences, schools, hospitals, recreation areas
and so on. People working within industrial environments are generally expected to be less
sensitive to odours than people within their home environment, but this assumption is increasingly
being challenged by practical examples of workers offended by odours from other enterprises. For
example, a person working in an office with no odour-generating activities will probably expect to
work in a low-odour environment. There are some less straightforward situations: for example,
people travelling past odorous activities may consider the odour to be unacceptable, even though it
is not impinging upon their residential property or workspace. This is an area that is not well
resolved in terms of assessing the validity of complaints about odorous activities, but odour
assessment generally places greatest emphasis and importance on odours at residential and other
sensitive sites.
3.2 Quantitative odour descriptors
Key elements of quantitative odour criteria that are used for planning purposes are:
Concentration
Averaging time and
Percentile value
Concentration is the odour strength (in odour units) as determined by dynamic olfactometry.
1898a report final.doc PAE Job Number 1898a
Page 27
[6]
Odour Buffer Assessment
StarCo Developments
Averaging times for odour criteria are generally either 1 hour or 3 minutes, or in the case of NSW
the ‘nose response time’, taken to be approximately 1 second. Dispersion models that are used for
predicting or simulating odour concentrations utilise a basic time interval of one hour for individual
calculations. For smaller averaging times, the 1-hour result is converted using a statistical
relationship between concentration and averaging time.
The percentile value refers to the percentage of time (usually over a full year) during which the
actual odour concentration must be within the criterion concentration.
The shorthand notation incorporating these parameters is written in the form Cp,t where C is the
concentration and the subscripts p and t refer to the percentile value and the averaging time,
respectively. For example, C99.5 1-hr refers to the 99.5th percentile 1-hour average concentration.
3.3 Queensland Odour Guideline
In July 2004, the Queensland EPA released the final form of its Guideline on ‘Odour Impact
Assessment from Developments’. This document had been in development for some years, a fact
reflecting the challenges in developing a comprehensive odour policy.
For the modification or expansion of existing facilities, relevant to this application, the Guideline
states:
“For proposed modifications to an existing facility, proponents should review its complaints
data to assist in determining the likely impacts of the modifications on complaint
frequency. The experience of industries with similar discharges should also be drawn upon
to identify proven odour management practices. Proponents are also encouraged to
consult with local community members to ascertain if there are any chronic odour impacts
in the community. Techniques such as odour annoyance surveys and odour diaries may
also be of assistance in determining likely impacts from the modifications. Further details
are provided in Appendix A [of the Guideline].
“Atmospheric dispersion modelling may assist in predicting potential impacts from
modifications to an existing facility, however community feedback on existing operations
should be given greater weight than modelling estimates of the same. In particular
modelling should not be used to explain away adverse community feedback. Dispersion
modelling may be used to identify sources of odours at a facility and to estimate relevant
contributions of the sources. This information may be used to develop cost effective odour
source control strategies.”
For the assessment of odours caused by complex mixtures of odorous compounds, such as odours
from wastewater treatment plants or intensive livestock operations, the Guideline sets out three
possible approaches to establishing criteria for assessing acceptable levels of impact based on
odour dispersion modelling:
Odour annoyance threshold (concentration) guidelines;
Odour intensity guideline; and
Alternative assessment tools for odour assessment for the expansion of existing activities.
These are explained below.
1898a report final.doc PAE Job Number 1898a
Page 28
[7]
Odour Buffer Assessment
StarCo Developments
3.3.1 Odour Annoyance Threshold (Concentration) Guidelines
The Guideline sets out the following advice in relation to odour concentration guidelines:
Proponents of new facilities may undertake an impact assessment with relevant inputs of
emissions and local meteorology to an air dispersion model to provide estimates of the
likely odour impacts in the surrounding environment. The inputs should be as detailed as
possible, reflecting any variation of emissions with time and including at least a full year of
representative hourly meteorological data. The modelled odour concentrations at the
“most exposed existing or likely future off-site sensitive receptors” should be compared
with the following guideline values.
0.5 ou, 1-hour average, 99.5th percentile for tall stacks
2.5 ou, 1-hour average, 99.5th percentile for ground-level sources and down-
washed plumes from short stacks, and
for facilities that do not operate continuously, the 99.5th percentile must be applied
to the actual hours of operation.
Further details are contained in section 5.1 of the Guideline.
In the application of this type of guideline, the appropriate criterion for the Noosa STP would be
C99.5 1hr = 2.5 ou, since it is not a ‘tall stack’ source type.
3.3.2 Odour Intensity Guideline
The Guideline states:
EPA will accept an assessment of odour impacts from the sources using an odour intensity
guideline value. This approach recognises the fact that the same concentration (stimulus)
of different odorants does not elicit the same perception of intensity (response) in human
observers..., and
…the proponent should conduct computer modelling and compare the results with the
following criterion:
odour concentration equivalent to an intensity level of “weak” multiplied by
the relevant default peak to mean factor, averaged over 1-hour, 99.5th
percentile, applicable at the “most exposed existing or likely future off-site
sensitive receptors”, and
for facilities that do not operate continuously, the 99.5th percentile must be
applied to the actual hours of operation.
The application of this criterion requires an odour intensity relationship to be determined for the
odour sources under investigation. No such relationship has been determined for this study.
However, based on our knowledge of unpublished data from various interstate STP sources it is
likely that this approach would yield a value slightly higher than the 2.5 ou criterion noted above.
1898a report final.doc PAE Job Number 1898a
Page 29
[8]
Odour Buffer Assessment
StarCo Developments
3.3.3 Alternative Assessment Tools for Odour Assessment – Expansion of Existing
Activities
Alternatively, EPA will accept an assessment of odour impacts using the tools discussed in
Appendix A of the Guideline document. These tools are:
Community odour surveys;
Odour diaries;
Odour complaints;
Field observations of odour intensity, character and offensiveness; and
Compliance history.
The guideline states
These tools can be used for assessing the current status of odour impacts from
existing industries that may wish to expand. Impact from an existing facility can be
more realistically assessed using these tools in preference to relying solely on
dispersion modelling. Once the survey is conducted to establish the current odour
status of an existing facility, a site-specific odour assessment criterion can be
developed for the expansion of this facility. Odour dispersion modelling should not
be used to try to prove the absence of an adverse effect from an existing facility
when community data, such as complaint records, are already available to
demonstrate the current level of effect.
Some of these methods, for example, community odour surveys, have been incorporated into this
study for Noosa Springs
3.4 Summary of Criteria Based on EPA Guideline
In this case for defining a suitable buffer around the Noosa STP, a default odour criterion based on
the Guideline would be C99.5 1hr = 2.5 ou (see section 3.3.1). However, the results of the small
community survey and the complaints record collected by both Noosa Springs and the Noosa STP
must also be taken into consideration.
Actual experience of a community with a specific odour source is potentially far more meaningful
than default assessment criteria that do not take into account site specific factors or the important
influence of the modelling inputs and methods on predicted odour levels.
4 MODELLING METHODOLOGY
This section explains the approach taken to predict odour levels associated with the proposed
development. The prediction relies on odour dispersion modelling using the CALPUFF dispersion
model. As with any model CALPUFF requires inputs in three major areas:
Emission rates and source details,
Meteorology, and
Terrain and surface details, as well as specification of specific receptor locations.
1898a report final.doc PAE Job Number 1898a
Page 30
[9]
Odour Buffer Assessment
StarCo Developments
4.1 Status of Models
Plume dispersion modelling has undergone significant refinement in recent years. Steady state
Gaussian plume air dispersion models such as AUSPLUME and the USEPA's ISC3, which formed the
basis of air dispersion assessment for many years, are now being replaced by a generation of
three-dimensional models, such as CSIRO's TAPM and CALPUFF, which is endorsed by the US EPA.
These new models incorporate many additional algorithms that simulate influences ignored by the
steady state Gaussian models but which are known to significantly impact upon plume dispersion in
many situations.
The steady state Gaussian plume models adopt a relatively simple methodology. They assume that
for each hour all meteorological conditions, most notably wind speed and direction, are fixed for
that hour. They also assume that meteorological conditions do not vary from location to location
i.e. the wind field is assumed to be constant over the modelling domain. During any particular
hour under consideration, the plume from the source is assumed to travel in the direction of the
wind, and disperse at a rate determined by the current meteorological conditions. In the next
modelled hour, the model assumes that the plume instantly changes direction to align itself with
the new wind direction and the plume from the previous hour ceases to exist. In other words, all
information pertaining to the previous hour of modelling is discarded. Variable plume trajectories
or variable rates of plume diffusion therefore cannot be simulated with such an approach.
The key assumptions inherent in the steady state Gaussian plume dispersion models may be
summarised as follows:
Meteorological parameters remain constant for the period of one hour.
Meteorological parameters remain fixed over the entire modelling domain, which often
includes all regions within 10 km or more of the source.
In the vertical, most meteorological parameters either remain constant (e.g., wind
direction) or vary according to generic formulae (e.g., wind speed, temperature) that are
seldom, if ever, validated for the site.
The height of the mixing layer remains constant for the entire region.
Almost always there is deviation from these assumptions. In situations where terrain is relatively
variable in height, for example, the assumptions can be so strongly violated that they are no longer
a useful basis for prediction of plume behaviour for much of the time.
The main sets of conditions under which AUSPLUME and similar models tend to perform poorly are:
Very light winds;
Stable conditions, associated with surface temperature inversions and often drainage flows
along valleys and gullies; and
Highly convective (unstable) conditions.
The first two of these conditions often occur together, and are generally the critical conditions
associated with maximum odour impacts from poultry farms and other odour sources that release
odours at or near ground level.
1898a report final.doc PAE Job Number 1898a
Page 31
[10]
Odour Buffer Assessment
StarCo Developments
4.2 Selected Models and Methodology
The CALMET and CALPUFF models substantially overcome the basic limitations of the steady-state
Gaussian plume models. CALMET, the meteorological pre-processor for the dispersion model
CALPUFF, calculates three-dimensional meteorological data based upon observed ground and upper
level meteorological data, as well as modelled data generated for example by TAPM. CALPUFF then
calculates the dispersion of plumes within this three-dimensional meteorological field (Figure 4.1).
The air dispersion modelling conducted for this assessment has been based on the modelling
approach outlined above, which utilises the TAPM and CALMET/CALPUFF models. The following
sections describe these models.
Gridded mesoscale
Meteorological data meteorological data
generation (gridded)
TAPM
Land use and topography
Downscaled meteorological Land use and topography
data generation (gridded)
CALMET Observational meteorological
data (upper air and surface)
Emission rates
Puff dispersion model to simulate hourly
dispersion of pollutants Source characteristics
CALPUFF Complex terrain
(e.g. hills close to the source)
Gridded pollution concentration
data over modelled
domain for different
averaging times
Figure 4.1: Modelling methodology utilised in the study.
4.3 TAPM
The Air Pollution Model, or TAPM, is a three dimensional meteorological and air pollution model
developed by the CSIRO Division of Atmospheric Research. Detailed description of the TAPM model
and its performance is provided elsewhere, (Hurley, 2002a, 2002b; Hurley et al., 2002a, 2002b;
Hibberd et al., 2003; Luhar & Hurley, 2003).
1898a report final.doc PAE Job Number 1898a
Page 32
[11]
Odour Buffer Assessment
StarCo Developments
TAPM solves the fundamental fluid dynamics and scalar transport equations to predict meteorology
and (optionally) pollutant concentrations. It consists of coupled prognostic meteorological and air
pollution concentration components. The model predicts airflow important to local scale air
pollution dispersion, such as sea breezes and terrain induced flows, against a background of larger
scale meteorology provided by synoptic analyses.
Upper air data were generated over the study region using TAPM. The TAPM-generated data and
observed meteorological data were entered into the CALMET diagnostic meteorological model,
which is discussed below.
TAPM is also capable of extracting a two dimensional meteorological data set for use in AUSPLUME
modelling.
4.4 CALMET
CALMET is a meteorological pre-processor that includes a wind field generator containing objective
analysis and parameterised treatments of slope flows, terrain effects and terrain blocking effects.
The pre-processor produces fields of wind components, air temperature, relative humidity, mixing
height and other micro-meteorological variables to produce the three-dimensional meteorological
fields that are utilised in the CALPUFF dispersion model.
The hourly TAPM-generated data for the period of analysis, from January 2003 to December 2003,
were used as input to the CALMET pre-processor together with observation data from the Bureau of
Meteorology site at Tewantin to create a fine resolution, three-dimensional meteorological field for
input into the dispersion model.
CALMET uses the meteorological inputs in combination with land use and geophysical information
(input at a 50 m resolution) for the modelling domain to predict gridded meteorological fields for
the region. Figure 4.2 shows an example of the non-steady-state wind fields predicted by CALMET.
1898a report final.doc PAE Job Number 1898a
Page 33
[12]
Odour Buffer Assessment
StarCo Developments
Figure 4.2: Example of Local Wind Field for One Hour Predicted by CALMET
4.5 CALPUFF
CALPUFF (Scire et al., 2000a) is a multi-layer, multi-species non-steady state puff dispersion model
that can simulate the effects of time and space varying meteorological conditions on pollutant
transport, transformation and removal. The model contains algorithms for near-source effects
such as building downwash, partial plume penetration, sub-grid scale interactions as well as
longer-range effects such as pollutant removal, chemical transformation, vertical wind shear and
coastal interaction effects. The model employs dispersion equations based on a Gaussian
distribution of pollutants across the puff and takes into account the complex arrangement of
emissions from point, area, volume, and line sources.
CALPUFF is endorsed by the US EPA, and has been used in many studies in Queensland and other
parts of Australia.
1898a report final.doc PAE Job Number 1898a
Page 34
[13]
Odour Buffer Assessment
StarCo Developments
5 MODEL INPUTS
5.1 Source Details
Staff from PAE made an inspection of the Noosa STP in August 2004 to identify the key sources of
odour. The Noosa STP underwent a major upgrade in 1997, enclosing many of the major odour-
producing processes. The inlet works and fermenter are both totally enclosed and the vapour
treated in a biofilter. The primary clarifiers are also totally enclosed and the vapours treated in
activated carbon scrubbers. The site inspection by PAE identified three dominant sources of odour
within the facility:
Biofilter;
Activated Carbon Scrubbers (2); and
Bioreactor.
Airlabs Pty Ltd was commissioned to conduct odour sampling on these three sources to determine
suitable odour emission rates (OER) for dispersion modelling. The Airlabs sampling report is
included as Appendix B. Based on the odour sampling, the following odour source parameters
were defined:
Table 5.1: Modelling Source Parameters
Diameter/Surface Release Flux Rate Total OER
Source Type
Area Height (ou.m/s) (ou.m³/s)
Biofilter b Area 64 m² 1.0 m 1.35 86.4
Scrubber 1 a Point 8.8 m 0.5 m --- 50
Scrubber 2 a Point 7.4 m 0.5 m --- 50
Bioreactor b c Area 1 348 m² 1.5 m 10 13 480
Notes: a. The scrubbers vent horizontally and so were modelled as low exit velocity (0.01 m/s) with large
equivalent diameters, maintaining volumetric flow rates. A nominal exhaust temperature of 25°C was used.
b. The initial vertical spread was assumed to be 0.5 m.
c. Odour emissions from the aerobic half of the bioreactor are assumed to be approximately 70% of
the anaerobic half (based on data in Frechen 2002).
5.2 Meteorology
No long term on-site weather data are available, but local conditions have been modelled using the
recognised meteorological models (TAPM)1 and CALMET. A wind rose diagram for the study site,
taken from data generated by TAPM and CALMET (see section 4.3 and 4.4 for a description) is
1
The EPA Guideline on Odour Impact Assessment from Developments (July 2004), section 6.4, states: “The
CSIRO’s air quality model TAPM can be used to generate hourly one-year meteorological data required for the
dispersion models. This is a prognostic meteorological model, which eliminates the need to have site-specific
meteorological observations. The model can predict airflow important to local scale air pollution such as sea
breezes and terrain induced flows. For sites where observed meteorological data is not available and the site is
subject to the sea and land breeze effects, it is preferable to use TAPM model for the generation of
meteorological data.”
1898a report final.doc PAE Job Number 1898a
Page 35
[14]
Odour Buffer Assessment
StarCo Developments
shown in Figure 5.1. Note that the wind rose data are extracted from a model, and therefore
represent an estimate of the local conditions.
The wind roses show the frequency of occurrence of winds by direction and strength. The bars
correspond to the 16 compass points – N, NNE, NE, etc. The bar at the top of each wind rose
diagram represents winds blowing from the north (i.e., northerly winds), and so on. The length of
the bar represents the frequency of occurrence of winds from that direction, and the widths of the
bar sections correspond to wind speed categories, the narrowest representing the lightest winds.
Thus it is possible to visualize how often winds of a certain direction and strength occur over a long
period, either for all hours of the day, or for particular periods during the day.
46.2 % 14.5 % 6.7 %
CALM CALM CALM
No. of Records :- 2184 No. of Records :- 2184 No. of Records :- 2184
0:01 - 6:00 6:01 - 12:00 12:01 - 18:00
.1 2.1 4.1 6.1 8.1 >10
TO TO TO TO TO
N
2 4 6 8 10
WIND SPEED m/s
0 10 20 30 40
38.1 % 26.4 % % FREQUENCY
CALM CALM
WIND ROSES
Noosa Springs
E:\Ajobs 1800-1899\1898 Noosa Springs Odour Buffer\1898a\modelling\calm WD randomised.m
Period: 1/ 3 to 12/ 3
JOB NO.1898a
No. of Records :- 2184
PACIFIC AIR
18:01 - 24:00 No. of Records :- 8736 & ENVIRONMENT
ALL HOURS
Figure 5.1: Wind Roses for the Study Area, 2003
Figure 5.1 shows that in the early morning (rose at top left) winds occur most frequently from the
south, but occasionally from other directions. By afternoon (rose at top right), winds are stronger
and most frequently from directions between southeast and northeast representing both common
synoptic scale influences and the seabreeze effect. The wind roses also indicate a significant
amount of calm conditions. Calm conditions, in this instance, are defined as winds as less than 2
km/hr.
1898a report final.doc PAE Job Number 1898a
Page 36
[15]
Odour Buffer Assessment
StarCo Developments
5.3 Stability
An important aspect of plume dispersion is the level of turbulence in the atmosphere near the
ground. Turbulence acts to dilute or diffuse a plume by increasing the cross-sectional area of the
plume due to random motions. As turbulence increases, the rate of plume dilution or diffusion
increases. Weak turbulence limits plume diffusion and is a critical factor in causing high plume
concentrations downwind of a source, particularly when combined with very low wind speed.
Turbulence is related to the vertical temperature gradient, which determines the condition known
as stability, or thermal stability. For traditional dispersion modelling using Gaussian plume models,
categories of atmospheric stability are used in conjunction with other meteorological data to
describe the dispersion conditions in the atmosphere.
The most well-known stability classification is the Pasquill-Gifford scheme (Pasquill, 1974), which
denotes stability classes from A to F. Class A is described as highly unstable and occurs in
association with strong surface heating and light winds, leading to intense convective turbulence
and much enhanced plume dilution. At the other extreme, class F denotes very stable conditions
associated with strong temperature inversions and light winds, such as commonly occur under
clear skies at night and in the early morning. Under these conditions plumes can remain relatively
undiluted for considerable distances downwind. Intermediate stability classes grade from
moderately unstable (B), through neutral (D) to slightly stable (E). Whilst classes A and F are
strongly associated with clear skies, class D is linked to windy and/or cloudy weather, and short
periods around sunset and sunrise when surface heating or cooling is small.
As a general rule, unstable (or convective) conditions dominate during the daytime and stable
flows are dominant at night. This diurnal pattern is most pronounced when there is relatively little
cloud cover and light to moderate winds.
The frequency distribution of estimated stability classes in the meteorological file is presented in
Figure 5.2. The data show a high proportion of class F conditions (38% of hours), and a total of
47% of hours with either E or F class This is consistent with the expected occurrence of stable
conditions at such a location.
Given the location of the areas of interest to the southwest of the STP, the critical conditions are
associated with northeast winds, which occur predominantly during the afternoon and early
evening, when stability classes C and D are expected to dominate. The intervening ridge between
the STP and the areas of interest also precludes an important role of stable conditions, when air
movement over obstacles is impeded.
1898a report final.doc PAE Job Number 1898a
Page 37
[16]
Odour Buffer Assessment
StarCo Developments
40%
35%
30%
25%
20%
15%
10%
5%
0%
A B C D E F
A B C D E F
Figure 5.2: Frequency of Pasquill-Gifford stability classes for the subject site derived from TAPM
5.4 Meteorological Data Validation
The meteorological data set used in dispersion modelling is dominated by the observations made
by the Bureau of Meteorology (BOM) site at Tewantin. The validity of this data set has been tested
through comparisons with onsite data collected between December 2004 and February 2005.
A data set of surface meteorology extracted for the Noosa Springs site from the 2003 modelling
year, indicated very little variation from that recorded by the BOM at Tewantin. Similarly, data
recorded by PAE between December and February showed good comparison between wind
directions and temperatures at the two sites. Some variations were observed with wind speeds but
these can be attributed to siting conditions of the two weather stations.
Overall, comparisons of the two data sets indicate that the dispersion modelling CALMET data set
provides a good representation of meteorology in the Noosa Springs area.
6 MODELLING RESULTS
The predicted odour concentrations resulting from the Noosa STP based on the estimation
techniques discussed in the previous section are shown below in Figure 6.1 for CALPUFF modelling.
1898a report final.doc PAE Job Number 1898a
Page 38
[17]
Odour Buffer Assessment
StarCo Developments
Figure 6.1: Predicted (C99.5 1-hr) Odour Concentration (ou) - CALPUFF
The modelling predicts an C99.5 1-hr odour concentration of 2.48 at the area of interest within
Precinct G. An analysis of predicted odour concentrations (as predicted by CALPUFF) for various
hours of the day is shown below in Figure 6.2. The analyses show that daytime levels are low, and
that higher levels occur at night.
1898a report final.doc PAE Job Number 1898a
Page 39
[18]
Odour Buffer Assessment
StarCo Developments
5
4.5
4
3.5
Odour Concentration (ou)
3
2.5
2
1.5
1
0.5
0
0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400
Hour of Day
Figure 6.2: Predicted Odour Concentrations by Hour of Day for the Proposed Precinct G
Development
7 COMMUNITY ODOUR SURVEY
A small community odour survey conducted by PAE in the areas shown in Figure 7.1
(approximately 500 m from the centre of the STP) indicated that the majority of people surveyed
could not detect odour from the STP. Indeed many were unaware of the existence of the STP.
From a total of 15 respondents, one could regularly detect odour while another two said that they
could smell the STP but only about once per year. A summary of the survey and responses is
included in Appendix A.
1898a report final.doc PAE Job Number 1898a
Page 40
[19]
Odour Buffer Assessment
StarCo Developments
Survey
Areas
STP
Figure 7.1: Odour Survey Areas
8 FIELD ODOUR INTENSITY SURVEYS
Odour intensity has been adopted as the basis for recording semi-quantitative odour data in the
field. This can assist in evaluating model performance. The method developed for the project
permits quantification of ambient odour levels at concentrations at least 100 times lower than is
possible using dynamic olfactometry. This allows validation of odour dispersion models, a process
previously not possible.
Odour intensity is a subjective concept. However, to standardise the odour logging and analysis
approach as far as possible, two major steps have been taken:
Adoption of a standard scale for describing odour intensity, as detailed in the German
Standard VDI 3882 (I) which relates to odour measurement; and
1898a report final.doc PAE Job Number 1898a
Page 41
[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
Page 42
[21]
Odour Buffer Assessment
StarCo Developments
Figure 8.1: Field Observation Locations
Table 8.2: Odour Intensity Observations – Details
Observation 2 MGA 1 Time Duration of Site Description
Observation
1 – Dec 21 508458. 7078519. 16:00 Observation aborted – odour not detected
2 – Jan 11 508521. 7078477. 10:20 15 mins Northwest of STP
3 – Jan 11 508507. 7078502 11:15 Observation aborted – odour not detected
4 – Jan 11 508459. 7078462. 11:24 15 mins Northwest of STP
5 – Jan 11 508458. 7078519. 11:50 15 mins Northwest of STP
1. Australian Geodetic Datum (1966)
2. Observations 2-5 corresponded to odour sampling by Airlabs
Analysis of the odour intensity data detailed in Appendix B allows estimation of mean odour
concentration, which can be compared to odour modelling predictions. The observations also allow
estimation of the maximum odour concentration during each observation period, and the peak-to-
mean ratio. The results are contained in Table 8.3.
Table 8.3: Estimated odour concentrations from observed odour intensity observations 1
Mean odour Maximum odour
Peak:Mean
concentration (ou) concentration (ou)
Observation
Max. Min. Median Average Average
Estimate Estimate Estimate Estimate Estimate
2 0.91 0.75 0.84 2.9 3.5
4 0.63 0.47 0.54 1.8 3.3
5 0.48 0.32 0.39 1.2 3.1
1. Average of paired observations. The relationship between odour and intensity as determined by
Airlabs is expressed as: I = 2.07 Ln(Conc) + 1
A comparison between the predicted model results and field odour observations can be made in
order to validate the results of odour dispersion modelling. This requires comparing the observed
(estimated) and modelled odour concentrations at the observation location under the specific
weather conditions at the time of the observations.
Any comparison of modelled and observed concentrations must take into account the uncertainty
inherent in both sets of data. The uncertainty in the estimated odour concentrations based on
intensity observations can be expressed simply by the range of estimated mean concentrations.
Models predict so-called ensemble mean concentrations. For a given set of meteorological
conditions, averaged over 1 hour, the resulting ground level concentration predicted by the model
is the average that would occur under those conditions (assuming the model is accurate). In any
specific hour, however, turbulence in the atmosphere will cause variations in actual concentrations,
so that even a “perfect” model will not capture these random variations. Hence, when the model
predicts a certain result, the actual concentrations in the field under the same conditions may differ
significantly from the model result, purely by this chance or random factor. Only by gathering data
from many similar situations will the model result and the average results from the real world be
certain to coincide (provided that all of the data are accurate). Whether an individual observation
(e.g., of 30-minute averaged odour concentrations) matches the model prediction for that single
event is strongly influenced by random factors. Any individual real-world result may differ from the
model by at least a factor of two due to turbulence-based variability (Stein and Wyngaard, 2001).
Hence, a factor of two around the model prediction is a fair indication of the range of values one
might expect when comparing the model result with an actual measurement. Furthermore, the
results of the model prediction are dependent on the observer’s location relative to the direct
1898a report final.doc PAE Job Number 1898a
Page 43
[22]
Odour Buffer Assessment
StarCo Developments
downwind line from the source. Errors in location caused, for example, by a shift in the mean wind
direction, can lead to larger differences between measured and observed concentrations. Taking
these factors into account, if the ranges of possible observed and modelled values do not coincide,
it is likely that there are errors in model inputs, particularly emission rates
A comparison of the odour concentrations predicted through filed intensity observations and those
predicted using the CALPUFF dispersion model under the same meteorological conditions is
presented below in
Table 8.4: Comparison of Modelled to Observed Odour Concentrations
Observation Observed Concentration CALPUFF Prediction
2 0.75 - 0.91 <0.1 – 1.0
4 0.47 - 0.63 <0.1 – 0.3
5 0.32 - 0.48 <0.1 – 2.0
Notes: Model comparisons were made with CALPUFF run in 2-D mode to simplify the analysis due to the
proximity of the observation locations to the STP.
9 ASSESSMENT
Dispersion modelling of the significant odour sources within the Noosa STP using CAPLUFF has
indicated that the area of interest within the Precinct G development is marginally below the
Queensland odour guideline level of 2.5 ou. However, there are several other factors that must be
considered in assessing the potential for development within the current buffer zone.
First and foremost of these is that a temporal analysis of the predicted odour concentrations at
various times of the day indicates that it is predominantly in the early hours of the morning and
late in the evening that the predicted odour levels approach the guideline criteria. This
corresponds to the times of day when people are usually indoors and less likely to be affected by
any adverse odour events. As can be seen in Figure 6.2 odour concentrations are not expected to
exceed 0.5 ou during the day at the proposed development site.
The second is the fact that the 2.5 ou guideline is designed to be applied to new developments or
expansion of existing facilities only. For assessment of the impact of existing facilities other
assessment techniques such as complaints records and community surveys should be given greater
weight than dispersion modelling (refer to section 3.3).
The record of odour complaints maintained by the Noosa STP indicates that since the upgrade of
the facility odour has only been problematic as a result of abnormal activity at the STP. The
CALPUFF modelling results agree with this level of complaint with the nearest residents to the STP
predicted to experience a C99.5 1-hr level of less than 1 ou under normal operating conditions. This
complaint level is also validated by the records from Noosa Springs where only one odour event
has been noted in the last 18 months (one of the three noted by the STP).
The small community survey conducted by PAE also indicates that the dispersion modelling results
reflect the impacts of odour from the STP, with only one respondent regularly noticing odours from
the STP. Both areas surveyed are approximately equidistant from the STP as the proposed
development, although the predicted odour levels are lower.
With these points in mind, together with the validation of the meteorological data used with the
data collected on site between December 2004 and February 2005, dispersion modelling appears to
provide a good assessment for the potential odour impacts on the Noosa Springs site. Of particular
1898a report final.doc PAE Job Number 1898a
Page 44
[23]
Odour Buffer Assessment
StarCo Developments
interest is the model’s ability to provide an assessment of the times of day when potential odour
issues may occur. Figure 6.2 shows that the highest impacts of odour from the STP can be
expected to occur at night (i.e. during times of the most stable atmospheric conditions). The time
series analysis for the Precinct G development indicates that the highest odour impacts (being at or
below the guideline level) can be expected to occur between the hours of 8 pm and 6 am when
people are most often indoors where odour levels are less noticeable, especially in cooler weather
when windows and doors are less likely to be open.
Finally, comparison of the modelled and observed odour levels shown in Table 8.4 is significant.
The upper end of the range of predicted odour levels for each observation is indicative of the
‘plume centreline’ concentration’, which is predicted to occur somewhere in the vicinity of the
observation site. In field situations where odour is being observed, it is difficult to ensure that the
observation set is performed at the plume centreline, because this needs to be estimated prior to
the observations being made under conditions of (almost invariably) fluctuating wind direction.
Taking observation ’2’ in Table 8.4 as an example, the estimated concentration from observation is
approximately 0.8 ou (in the range 0.75 - 0.91 ou). The corresponding CALPUFF prediction is in the
range <0.1 to 1.0 ou, where 1.0 ou is the model prediction of the centreline concentration. In
other words, CALPUFF predicts that somewhere near the observation point the odour concentration
was as high as 1.0 ou. This is therefore consistent with the observed odour levels, since we cannot
be sure where the centreline was in relation to the observation point.
The other two observations indicate that the model may have somewhat underpredicted in the case
of observation ‘4’ and overpredicted in the case of ‘5’. Overall, given the small data set it is
apparent that there is a general, broad agreement between the observed and modelled results.
10 CONCLUSION
An evaluation of the potential for development of Noosa Springs within the current buffer zone
around the Noosa STP has been undertaken using a combination of assessment techniques. The
current buffer zone was established some years ago and the Noosa STP has since had a major
upgrade that includes a high level of odour control.
After assessing the combined results of dispersion modelling, odour complaints records and a small
community survey we conclude that the odour impacts at the area of interest within the Precinct G
development are not expected to result in significant annoyance to future residents. Any odour
impacts are predicted to occur at night and would be infrequent. As such, PAE concludes that the
limited development within the existing 600 m buffer proposed by StarCo should not be refused on
the grounds of possible adverse odour impacts.
1898a report final.doc PAE Job Number 1898a
Page 45
[24]
Odour Buffer Assessment
StarCo Developments
11 REFERENCES
Frechen, F. (1997) Odour Measurement and Odour Policy in Germany. Proc. National Workshop on
Odour Measurement Standardisation, UNSW, Sydney 20-22 August 1997.
Frechen, F. (2002) Odour Emission Inventory of German Wastewater Treatment Plants – Odour
Flow Rates and Odour Emission Capacity. Proc. Enviro 2002, Melbourne 7–12 April 2002 2002.
Hibberd, M. F., Physick, W. L., and Park, G. (2003). Verification of several aspects of TAPM against
multi-year monitoring data at Collie. In: National Clean Air Conference: linking air pollution
science, policy and management: CASNO3, Newcastle City Hall. [Newcastle, NSW]: Clean Air
Society of Australia and New Zealand. p. 71 (printed abstract). 6 p.
Hurley, P. J. (2002a). The Air Pollution Model (TAPM) Version 2: user manual. Aspendale: CSIRO
Atmospheric Research. (CSIRO Atmospheric Research internal paper; 25). 38 p.
Hurley, P. J. (2002b). The Air Pollution Model (TAPM) Version 2. part 1: technical description.
Aspendale: CSIRO Atmospheric Research. (CSIRO Atmospheric Research technical paper; no.55).
49 p.
Hurley, P. J., Manins, P. C., Lee, S. H., Boyle, R., Ng, Y. L., and Dewundege, P. (2002a). Year-long
urban airshed modelling in Melbourne: verification of TAPM for photochemical smog and particles.
In: Conference proceedings: 16th International Clean Air & Environment Conference, Christchurch,
N.Z. [Christchurch, N.Z.]: Clean Air Society of Australia and New Zealand. p. 347-353.
Hurley, P. J., Physick, W. L., and Luhar, A. K. (2002b). The Air Pollution Model (TAPM) Version 2.
part 2: summary of some verification studies. Aspendale: CSIRO Atmospheric Research. (CSIRO
Atmospheric Research technical paper; no.57). 46 p.
Lorimer G.D. (1998). The AUSPLUME Gaussian Plume Dispersion Model Environmental Protection
Authority of Victoria. Luhar, A. K., and Hurley, P. J. (2003). Evaluation of TAPM, a prognostic
meteorological and air pollution model, using urban and rural point-source data. Atmospheric
Environment, 37 (20): 795-2810.
New Zealand Ministry for the Environment (1995) Odour Management under the Resource
Management Act.
Ormerod, R.J., P.C. D’Abreton & S.C. Grocott (2002a) Development of Site-Specific Odour Criteria
and Compliance Assessments Using Odour Intensity Observations and Modelling. Proc. 2002
Biennial Conference of the Clean Air Society of Australia & New Zealand, Christchurch, August 2002.
Ormerod, R.J., S.C. Grocott & P. D’Abreton (2002b) Development of Site-Specific Odour Criteria for
Industrial Facilities Using a Variety of Tools. Proceedings, Enviro 2002 Odour Conference, 7-12
April 2002, Melbourne.
Ormerod, R.J. & S.C. Grocott (2002) Development and Application of State-of-the-Science
Techniques for Odour Monitoring, Modelling and Assessment: A Case Study from Queensland.
1898a report final.doc PAE Job Number 1898a
Page 46
[25]
Odour Buffer Assessment
StarCo Developments
Proceedings, 4th Annual Conference of the Environmental Engineering Society of Queensland,
Brisbane, May 2002.
Pasquill, F. (1974) Atmospheric Diffusion. The Dispersion of Windborne Material from Industrial and
other Sources. 2nd edition. Ellis Horwood Limited, Chichester, UK.
Scire, J.S., D.G. Strimaitis and R.J. Yamartino (2000a) A User’s Guide for the CALPUFF Dispersion
Model (Version 5), Earth Tech, Inc., Concord, MA.
1898a report final.doc PAE Job Number 1898a
Page 47
[26]
Odour Buffer Assessment
StarCo Developments
Appendix A
Example Community Questionnaire
1898a report final.doc PAE Job Number 1898a
Page 48
[27]
Odour Buffer Assessment
StarCo Developments
QUESTION SCALE ANSWER AND NOTES
1. How often do you 1-10 12 x 1;
notice odour from 1=never 10=always 3 x 2; and
the STP? 1x4
2. Where do you Outside
notice the odour?
3. What time of day (morning, night, etc) No specific time
do you notice this
odour most?
4. What time of year (summer, winter, specific 2 x summer
do you notice this months, etc) 2 x winter
odour the most?
5. Any common (still, windy, hot, dry etc) 2 x gusty wind
weather conditions? 1 x warm weather
6. How long does the 1= <=1 min 2 x 1;
odour typically last? 2= 1-30 min 1 x 4; and
3= 30-60 min 1 x 5.
4= 1-2 hr
5= 2-6 hr
6= 6-12 hr
7= 12-24 hr
7. How intense is the 1= hardly noticeable, 10= 2 x 1;
odour? nearly died 1 x 4; and
1 x 5.
8. Can you describe Sewer (all positive respondants)
the smell?
9. Can you assess 0= No odour 2 x 1;
your own DEGREE 1= not annoying 1 x 2; and
OF ANNOYANCE due 2= a little annoying 1x3
to odour in the 3= annoying
environment over 4= very annoying
the last year? 5= extremely annoying
10. Do you think the Y/N 2 x yes
odour from the STP 2 x no
has been acceptable?
11. Any other things none
you want to tell us?
Note: Repsonses for Questions 2 – 11 are only from those that answered Question 1 with a score
of 2 or more (i.e. 4 respondents).
1898a report final.doc PAE Job Number 1898a
Page 49
[28]
Odour Buffer Assessment
StarCo Developments
Appendix B
Analysis of Odour Intensity Field Observations
BACKGROUND INFORMATION
1898a report final.doc PAE Job Number 1898a
Page 50
[29]
Odour Buffer Assessment
StarCo Developments
Odour intensity observations have been used in line with the method described by Ormerod et al.
(2002). The method permits approximations of odour concentration to be derived from a series of
odour intensity observations made in the field, following an adaptation of standard German
methods VDI 3882 and VDI 3940.
VDI 3940 describes a procedure for logging odour in the field, involving noting the odour intensity
every 10 seconds over a 10 minute period. The method is employed over a grid of points on the
ground at various times throughout a year, in order to determine the number of ‘odour hours’,
which form the basis of determining acceptability. An odour hour occurs when the specific odour in
question is clearly recognisable for at least 10% of the sample period, i.e., at least 6 of the 60
observations over a 10-minute period. Over a year, the odour is considered to be unacceptable if
odour hours occur for more than 10% of the time, i.e., more than 876 hours in a year. Where
observations are not possible to prove this, a modelling procedure is also allowed, and it involves
the routine application of a factor of 10 to modelled 1-hour odour concentrations to account for
odour fluctuations (Frechen, 1997). Effectively, the odour hour approach equates to a nose-
response-time averaged odour concentration equivalent to the intensity of weak or distinct odour
on the VDI scale, occurring at a frequency of at least 1% of the time over the whole year. (A
clearly recognisable odour is assumed to equate to either weak or distinct on the VDI scale).
Observations of odour intensity in the field for this study are only loosely based on the German
approach because the objectives are not identical. Observations are made at various locations
downwind of the odour source. However, rather than defining ‘odour hours’, the procedure is
based on using the observed odour intensity measurements as a basis for estimating mean and
peak odour concentrations and peak-to-mean ratios, and for relating the field observations to
odour complaints and other reports. The observations also provide a basis for ground-truthing of
model simulations of odour concentration.
Most observing periods are of 30 minutes or greater in order to obtain a more representative
sample of the fluctuations in odour intensity than is required in the German odour hour approach.
The odour intensity observations are made every 10 seconds (within a margin of error estimated to
be typically ±10%), but the actual sampling of odour occurs only during inhalation, which typically
has a duration of 2-3 seconds. Thus, the odour data represent 2- to 3-second average samples
once every 10 seconds.
Analysis of odour intensity field observations
An important aim of the odour intensity observations is to provide data from the field that might
assist in odour dispersion model evaluation. The method of analysing the data for this purpose is
described in Ormerod et al. (2002). Briefly, it involves use of a Monte Carlo simulation method
based on the initial observations, to convert odour intensity to odour concentration and to generate
a cluster of estimates of the odour concentration averaged over the sampling period. The cluster of
results reflects the uncertainty involved in the conversion from intensity to concentration. A total of
100 Monte Carlo simulations are made for each 30-minute field observation..
The results of the analysis are plotted as time series and as scatter plots showing the results of the
mean vs. peak concentrations and of the mean vs. peak-to-mean ratios for each of the 100
simulations. These scatter plots visually display the uncertainty inherent in the estimated
concentration data.
Plotting of the field results as time series provides a convenient format to illustrate the fluctuations
of odour over time. Plots have been prepared for the original odour intensity time series and for
1898a report final.doc PAE Job Number 1898a
Page 51
[30]
Odour Buffer Assessment
StarCo Developments
the estimated odour concentrations corresponding to these series. Odour concentration (ou) is
estimated from the respective odour intensity field observations and the theory described in
Appendix B. This work has been published and presented in recent conferences (e.g., Ormerod et
al. (2002a, 2002b) and Ormerod & Grocott (2002)).
Examples of the time series of odour intensity as observed and the corresponding calculated odour
concentration time series, are presented in the following series of plots.
Odour Observations - Observer FT
11 Jamuary 2005, 1020 - 1035 EST
Noosa STP (508521, 7078477)
6
5
Odour intensity (VDI 3882)
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time (minutes)
Figure B1.1: Odour Intensity Time Series, Observation #2
1898a report final.doc PAE Job Number 1898a
Page 52
[31]
Odour Buffer Assessment
StarCo Developments
Odour Observations - Observer FT
11 Jamuary 2005, 1020 - 1035 EST
Noosa STP (508521, 7078477)
4
3.5
Odour Concentration (ou)
3
2.5
2
1.5
1
0.5
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Time (minutes)
Figure B1.2: Multiple Calculated Time Series of Odour Concentration (ou) based on
Odour Intensity Field Observations, Observation #2
Mean vs P:M ratio from 100 Realisations
4.0
3.5
3.0
Peak-to-Mean Ratio
2.5
2.0
1.5
1.0
0.5
0.0
0.9 0.9 1.0 1.0 1.0 1.0 1.0 1.1 1.1
Mean Odour Concentration (ou)
Figure B1.3: Mean Odour Concentration vs Peak to Mean Ratio, Observation #2
1898a report final.doc PAE Job Number 1898a
Page 53
Appendix C Airlabs Odour Sampling Reports [OCR of page images] Appendix C Airlabs Odour Sampling Reports
Page 54
13 October 2004 Pacific Air and Environment P.O. Box 3306 South Brisbane Qld 4101 Attention: Mr Glen Holmes REPORT No. SEP04176 ODOUR SAMPLING & ANALYSIS CONDUCTED FROM THE NOOSA WASTE WATER TREATMENT PLANT SAMPLES FOR PAE 30™ SEPTEMBER 2004 Authorised by / Mr. D Arbuckle BE Env.Eng. (Hons) SENIOR TESTING OFFICER
Page 55
Report to Pacific Air & Environment TABLE OF CONTENTS INTRODUCTION TEST METHODS Odour Velocity DEFINITIONS OLFACTOMETRY TEST CONDITIONS RESULTS List of Tables Table 1: Biofilter Physical Conditions Table 2: Biofilter Sampling and Analysis Times. Table 3: Biofilter Test Conditions... Table 4: Biofilter Test Results......... Table 5: Bioreactor (Cell 5) Physical Conditions... Table 6: Bioreactor (Cell 5) Sampling and Analysis Times Table 7: Bioreactor (Cell 5) Test Conditions Table 8: Bioreactor (Cell 5) Test Results Table 9: Activated Carbon Scrubber Conditions... Table 10: Activated Carbon Scrubber Sampling and Analysis Times... Table 11: Activated Carbon Scrubber Test Conditions... Table 12: Activated Carbon Scrubber Test Results...... Report No. SEP04176 Page 3
Page 56
Report to Pacific Air & Environment Report No. SEPO04176 INTRODUCTION AirLabs was commissioned by Pacific Air and Environment to sample and analyse duplicate odour samples from the following sources at the Noosa Wastewater Treatment Plant: ° Biofilter e Bioreactor e Activated carbon scrubber (attached to the primary clarifiers) All sampling and analysis was conducted by AirLabs on the 30" September 2004. TEST METHODS Odour Odour sampling and analysis was conducted in accordance with the Australian/New Zealand Standard 4323.3 ‘Stationary Source Emissions — Part 3: Determination of Odour Concentration by Dynamic Olfactometry’. Sample Collection Point source samples (carbon scrubber) were collected using the “lung-in-the-box” technique. The sample was drawn through a Teflon® tube that fed into a Nalophan® sample bag. Approximately 40 litres of sample was collected. Area samples (Biofilter and Bioreactor) were collected using an emissions isolation flux hood. All samples were analysed within 30 hours of sample collection. Sample Analysis The odour concentration of each sample was determined using a dynamic olfactometer operating in the forced choice mode utilising a step factor of 1.5. Two ports were available to each panel member; one presenting the odorous gas and one presenting a neutral reference gas. Individual threshold estimates for each panel member were determined and the corresponding odour concentrations were calculated. The odour panellists were all familiar with the procedure and specially selected in accordance with the Australian Standard criteria. The total number of dilutions of the sample at which 50 percent of all responses of the panellists confirmed odour detection is reported as the panel threshold, and is expressed in odour units (OU). The precision of results obtained by these techniques lies statistically within the 95% confidence interval. Odour Emission Rate For those samples collected using the flux hood, the odour emission rate (OER) was calculated by multiplying the odour concentration by a function of the residence time of the odourous air flow and the flux hood’s vertical footprint. airlabs Page 3 of 7
Page 57
Report to Pacific Air & Environment Report No. SEP04176 Velocity Velocity profiles were obtained across the activated carbon scrubber outlet ducts using a calibrated hot wire anemometer. The estimated accuracy of this method is +10%. DEFINITIONS OU &/or (OU/m3) Measured odour concentration Nm$ Gas volume in wet cubic metres at a temperature of O°C and an absolute pressure of 101.325 kPa. OU/m2/s Odour units emitted per square meter of surface area per second (fluxhood) N/A Not applicable K Temperature in Kelvin (°C + 273) OLFACTOMETRY TEST CONDITIONS Olfactometer Calibration Status Last accuracy calibration: 11-03 Last repeatability calibration: 11-03 Sampling Conditions N/A for plant equipment. Dilution Equipment OdourLab Version 2. Location AirLabs Office 149 Bryants Road Loganholme, Qld 4129. Reference Odourant 43.5-ppm n-butanol
Page 58
Report to Pacific Air & Environment RESULTS = Biofilter Table 1: Biofilter Physical Conditions Report No. SEP04176 Odour Source Sampling Position Sampling Plane &ID Dimensions (m) Biofilter - 1 Surface Flux hood Biofilter - 2 Surface Flux hood Table 2: Biofilter Sampling and Analysis Times Sample ID Sample Date Sample Time Analysis Date Biofilter - 1 30/09/2004 13:20 30/9/2004 Biofilter - 2 30/09/2004 13:30 30/9/2004 Table 3: Biofilter Test Conditions Sample ID Temperature (K) Biofilter - 1 309 Biofilter - 2 308 Table 4: Biofilter Test Results Odour Sample ID Emission Rate (OU/m2/sec) Biofilter - 1 72 Biofilter - 2 ilies}
Page 59
Report to Pacific Air & Environ ment RESULTS — Bioreactor (Cell 5) Table 5: Bioreactor (Cell 5) Physical Conditions Report No. SEP04176 Odour Source Sampling Sampling Plane & ID Position Dimensions (m) Bioreactor (Cell 5) - 1 Surface Flux hood Bioreactor (Cell 5) - 2 Surface Flux hood Table 6: Bioreactor (Cell 5 ) Sampling and Analysis Times Sample ID Sample Date Sample Time Analysis Date Bioreactor (Cell 5) - 1 30/09/2004 14:10 30/9/2004 Bioreactor (Cell 5) - 2 30/09/2004 14:00 30/9/2004 Table 7: Bioreactor (Cell 5 ) Test Conditions Sample ID Temperature (K) Bioreactor (Cell 5) - 1 38 Bioreactor (Cell 5) - 2 39 Table 8: Bioreactor (Cell 5 ) Test Results Odour Sample ID Emission Rate (OU/m2/sec) Bioreactor (Cell 5) - 1 9.8 Bioreactor (Cell 5) - 2 10
Page 60
Report to Pacific Air & Environment RESULTS — Acti in Scrubbers Table 9: Activated Carbon Scrubber Conditions Report No. SEPO4176 - 1,5002 Odour Source Sampling Sampling Plane Dimensions &ID Position (m) Activated Carbon Scrubber i outlet 0.300 — 1,800 Activated Carbon Scrubber: ivated Carbon Scrubber iia 0300 Table 10: Activated Carbon Scrubber Sampling and Analysis Times Sample ID Sample Date Sample Time Analysis Date eS Scrubber 30/09/2004 13:39 30/9/2004 salen Scrubber 30/09/2004 13:42 30/9/2004 Table 11: Activated Carbon Scrubber Test Conditions Temperature Velocity Actual Flow Wet Flow Sample le (k) (m/s) (m?/s) (Nmn?/s) Activated Carbon Scrubber 300 8.69 0.61 0.56 — 1,800 Activated Carbon Scrubber 300 6.12 0.43 0.39 - 1,500 Table 12: Activated Carbon Scrubber Test Results Panel Source Sample ID ated a ie Threshold Emission Rate Eee (OU/m?) (OU/s) Activated Carbon Scrubber ~ 1,800 0.56 90 50 Activated Carbon Scrubber 1,500 0.39 120 47 1 1,000kg carbon charge 2 600kg carbon charge airlabs Page 7 of 7
Page 61
ay) (1) @ 14% February 2005 L Qa b Ss Pacific Air and Environment P.O. Box 3306 South Brisbane Qld 4101 Attention: Mr Glen Holmes Report No. JANO5003 ODOUR SAMPLING & ANALYSIS CONDUCTED FROM THE NOOSA WASTE WATER TREATMENT PLANT SAMPLES FOR PAE 117 JANUARY 2005 Authorised by: Mr. D Arbuckle BE Env.Eng. (Hons) SENIOR TESTING OFFICER
Page 62
Report to Pacific Air & Environment TABLE OF CONTENTS INTRODUCTION TEST METHODS Odour Intensity DEFINITIONS OLFACTOMETRY TEST CONDITIONS RESULTS List of Tables Table 1: Physical Conditions Table 2: Sampling and Analysis Times Table 3: Test Results Report No. JAN05003 Page an
Page 63
Report to Pacific Air & Environment Report No. JANO5003 INTRODUCTION AirLabs was commissioned by Pacific Air and Environment to sample and analyse duplicate odour samples from cells 2 and 5 of the Noosa Wastewater Treatment Plant bioreactor. All sampling and analysis was conducted by AirLabs on the 11" January 2005. TEST METHODS Odour Odour sampling and analysis was conducted in accordance with the Australian/New Zealand Standard 4323.3 ‘Stationary Source Emissions — Part 3: Determination of Odour Concentration by Dynamic Olfactometry’. Sample Collection Point source samples (carbon scrubber) were collected using the “lung-in-the-box” technique. The sample was drawn through a Teflon® tube that fed into a Nalophan® sample bag. Approximately 40 litres of sample was collected. Area samples (Biofilter and Bioreactor) were collected using an emissions isolation flux hood. All samples were analysed within 30 hours of sample collection. Sample Analysis The odour concentration of each sample was determined using a dynamic olfactometer operating in the forced choice mode utilising a step factor of 1.5. Two ports were available to each panel member; one presenting the odorous gas and one presenting a neutral reference gas. Individual threshold estimates for each panel member were determined and the corresponding odour concentrations were calculated. The odour panellists were all familiar with the procedure and specially selected in accordance with the Australian Standard criteria. The total number of dilutions of the sample at which 50 percent of all responses of the panellists confirmed odour detection is reported as the panel threshold, and is expressed in odour units (OU). The precision of results obtained by these techniques lies statistically within the 95% confidence interval. Odour Emission Rate For those samples collected using the flux hood, the odour emission rate (OER) was calculated by multiplying the odour concentration by a function of the residence time of the odourous air flow and the flux hood’s vertical footprint. Odour Intensity Method: Olfactometry Determination of Odour Intensity VDI Guideline 3882 part 1 (1 992) Deviations: Odourants were not presented randomly 4 panel members were used airlabs Page 3 of 5
Page 64
Report to Pacific Air & Environment Report No. JAN05003 DEFINITIONS OU Measured odour concentration/threshold OU.m3 /m?.min Odour units emitted per square meter of surface area per minute N/A Not applicable OLFACTOMETRY TEST CONDITIONS Olfactometer Calibration Status Last accuracy calibration: 11-04 Last repeatability calibration: 11-04 Sampling Conditions N/A for plant equipment. Dilution Equipment OdourLab Version 2. Location AirLabs Office 149 Bryants Road Loganholme, Qld 4129. Reference Odourant 43.5-ppm n-butanol
Used in these records
Appendix 6. Odour Buffer Assessment [As Published]Related documentApplication case desk ↗
About this file
- File size
- 2.8 MB (large file)
- File type
No other editions are linked here.
Original file
Log in to download the original file
The download may take up to a minute.