L:\825 -849\842\842.1 - Expert Evidence Report, Warrnambool City Council.docx
WARRNAMBOOL CITY COUNCIL
STATEMENT OF EXPERT EVIDENCE
Planning Panel Hearing
Amendment C90 to the Warrnambool Planning Scheme –
Separation Distance for Fonterra Australia Pty Ltd, Dennington
April 2014
Author:
Primary Author:
Ms Alison McRae, Associate
Distribution Record:
Recipient
Date Issued
Number of Copies
Warrnambool City Council
C/- Mr Terry Montebello
Partner
Planning & Governance
Maddocks
140 William Street
MELBOURNE VIC 3000
Peter J Ramsay & Associates Internal Copy
14 April 2014
1 (electronic)
14 April 2014
1 (electronic)
TABLE OF CONTENTS
Page
USE OF REPORT
LIST OF ABBREVIATIONS
1. INTRODUCTION
2. SCOPE
3. EXPERT EVIDENCE DETAILS
3.1
Expert Witness Details
3.2
Expert’s Qualifications and Experience
3.3
Expert’s Area of Expertise
3.4
Statement of Expertise
3.5
Other Significant Contributors to the Report
3.6
Existence of Private or Business Relationship with the Party Requesting this Report
3.7
Instructions that Defined the Scope of the Report
3.8
Facts, Matters and Assumptions Used
3.9
Documents and Other Materials Used to Prepare Report
3.10
Tests or Experiments
3.11
Summary of Opinions
3.12
Provisional Opinions
3.13
Limitation
3.14
Declaration
4. FONTERRA OPERATIONS AND SURROUNDS
5. REVIEW OF THE GOLDER ASSOCIATES’ SEPARATION DISTANCE ASSESSMENT
5.1
Complaints History
5.2
Odour Criterion
5.3
Meteorological Data used in the Modelling
5.4
Modelling Methodology
5.5
Presentation of Modelling Results
5.6
Interpretation of Modelling Results
5.7
IRAE Separation Distance Assessment
5.7.1 Calculation of the Separation Distance
5.7.2 Applicability of Table 4 in EPA Publication 1518
6. DETERMINATION OF THE SEPERATION DISTANCE
7. CONCLUSIONS
APPENDICES
Appendix A
Expert Witness Curriculum Vitae
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i
USE OF REPORT
The preparation of this report has been undertaken for the purpose of providing expert evidence to
the Planning Panel Hearing regarding Amendment C90 to the Warrnambool Planning Scheme, and
the separation distance provided in this for the Fonterra Australia Pty Ltd milk processing wastewater
treatment plant in Dennington, Victoria, and it is not intended that this report should be used for any
other purpose.
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LIST OF ABBREVIATIONS
kg
Kilograms
mg/L
Milligrams per Litre
OU
Odour Unit
SEPP (AQM)
State Environment Protection Policy (Air Quality Management)
WWTP
Wastewater Treatment Plant
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1.
INTRODUCTION
I was engaged by Warrnambool City Council (Council) to provide expert evidence to the Planning
Panel Hearing in relation to Amendment C90 to the Warrnambool Planning Scheme, and specifically
the separation distance provided in this Amendment for the Fonterra Australia Pty Ltd (Fonterra) milk
processing wastewater treatment plant (WWTP) in Dennington, Victoria.
Amendment C90 to the Warrnambool Planning Scheme makes changes to allow development of
land in the North Dennington area for residential use. The changes are made via incorporation of the
North Dennington Structure Plan (NDSP) and associated Development Contributions Plan into the
Planning Scheme. As part of the Amendment, Council seek to rezone Farming Zone land to a
General Residential Zone.
The Amendment also provides a 300 m separation distance from the WWTP at the Fonterra plant to
the new residential zone. However, based on a Separation Distance Assessment undertaken by
Golder Associates in March 2014 (the Golder report), Fonterra are claiming that a 500 m separation
distance should be provided.
This report provides my opinion on the Golder report and outlines what I consider an appropriate
separation distance from the WWTP would be.
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2.
SCOPE
I have been requested to:

Review the Golder report and consider the appropriateness of the approach taken by Golder to
determine a separation distance of 500 m;

Considering the North Dennington Structure Plan and other available information, examine
what an appropriate separation distance would be between the proposed General Residential
Zone and the Fonterra WWTP; and

Prepare a report on my findings and present evidence to the panel.
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3.
EXPERT EVIDENCE DETAILS
3.1
Expert Witness Details
3.2
Expert Witness:
Ms Alison McRae
Address:
Level 10, 222 Kings Way, South Melbourne, Victoria, 3205
Company:
Peter J Ramsay & Associates Pty Ltd
Expert’s Qualifications and Experience
I am an Associate of Peter J Ramsay & Associates Pty Ltd, based at our head office in Melbourne,
Victoria. I am an Environmental Engineer with over fifteen years experience in industrial facility
permitting, air quality assessments, Environmental Management Systems (EMSs), environmental
auditing, cleaner production technologies and site assessments. In my role with Peter Ramsay &
Associates I have been responsible for managing an extensive range of projects on a variety of
existing, former and proposed industrial sites, dealing with environmental issues including air
emissions, water, waste management and land contamination.
I hold a Bachelor of Engineering (Environmental) (Hons) and a Bachelor of Commerce from The
University of Melbourne. I am a member of Engineers Australia (MIEAust) and a member of the
Clean Air Society of Australia & New Zealand.
My curriculum vitae is provided in Appendix A.
3.3
Expert’s Area of Expertise
My professional career has focused on identifying and resolving environmental issues at industrial
and commercial facilities. I possess expertise in the area of air quality, including assessments of
odorous emissions and air dispersion modelling. I have performed numerous air quality assessments
and undertaken modelling for a variety of industrial industries to consider the potential impacts of the
operations on the surrounding community.
I have previously acted as an expert witness at the Victorian Civil and Administrative Tribunal (VCAT)
and have provided assistance to Mr Peter Ramsay of Peter J Ramsay & Associates in relation to
various expert witness cases at VCAT and panel hearings.
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3.4
Statement of Expertise
In view of my professional qualifications and expertise, I believe I am well qualified to prepare and
present this evidence to the panel.
3.5
Other Significant Contributors to the Report
There were no other significant contributors to this report.
3.6
Existence of Private or Business Relationship with the Party Requesting this Report
There is no relationship between myself and Council, beyond the commercial arrangement to prepare
this expert evidence report.
3.7
Instructions that Defined the Scope of the Report
Written instructions were received from Maddocks on behalf of the Council to provide an expert
evidence report in relation to the Golder report and the appropriate separation distance between the
proposed General Residential Zone and the Fonterra WWTP.
3.8
Facts, Matters and Assumptions Used
The following facts, matters and assumptions were used in the preparation of this report:

The Golder report and documents relating to Amendment C90 to the Warrnambool Planning
Scheme, provided by Maddocks;

The outcomes of the expert conclave held on 9 April 2014, and attended by Mr Frank Fleer of
Golder, Tracy Freeman of Air Quality Professionals Pty Ltd (participation by phone), Ms Eve
Graham of EPA (observer) and me,

Regulatory guidelines and other literature; and

My experience in air assessments, air quality and dispersion modelling, and odour-emitting
facilities.
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3.9
Documents and Other Materials Used to Prepare Report
The documentation and materials used to prepare this report included:
Reports and Documents

Report prepared by Golder titled: Fonterra Australia Pty Ltd, Separation Distance Assessment Fonterra Dennington WWTP, 25 March 2014, Report Number: 147618007-002-R-Rev0.

Amendment C90 to the Warrnambool Planning Scheme, which includes the North Dennington
Structure Plan.

Letter of 14 January 2014 from EPA to Council regarding: Amendment C90, North Dennington
Growth Area, Our Ref 5004111.

Email of 20 March 2014 from EPA to Council regarding the calculation of the separation
distance outlined in the letter of 14 January 2014.

Letter of 28 March 2014 from EPA to Council regarding: Amendment C90, North Dennington
Growth Area, Our Ref 5004111.

Fonterra Licence 74313, issued 28 November 2008.
Legislation and Guidelines

Victorian Government 2001, State Environment Protection Policy (Air Quality Management),
Government Printer, Melbourne (SEPP (AQM)).

EPA Publication 500, Code of Practice for Small Wastewater Treatment Plants, June 1997.

EPA Publication 891.3, Code of Practice Onsite Wastewater Management, February 2013.

EPA Publication 1518, Recommended separation distances for industrial residual air
emissions, March 2013.

EPA draft Publication 1550, Construction of input meteorological data files for EPA Victoria’s
regulatory air pollution model (AERMOD), October 2013.

EPA draft Publication 1551, Guidance notes for using the regulatory air pollution model
AERMOD in Victoria, October 2013.

British Water, Code of Practice: Flows and Loads – 4, Sizing Criteria, Treatment Capacity for
Sewage Treatment Systems, Southbank House, London, BW COP: 18.11/1, revised 2013.
3.10 Tests or Experiments
No tests or experiments were performed to assist in the preparation of this report.
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3.11 Summary of Opinions
My opinions are summarised in the in Section 7 of this report.
3.12 Provisional Opinions
The opinions expressed are not considered to be provisional.
3.13 Limitation
I consider myself qualified to prepare and present the report. I have not addressed questions falling
outside my area of expertise, and do not consider it incomplete or inaccurate in any respect.
3.14 Declaration
I have made all the enquiries that I believe are desirable and appropriate and that no matters of
significance which I regard as relevant have to my knowledge been withheld from the Panel.
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4.
FONTERRA OPERATIONS AND SURROUNDS
The Fonterra milk processing facility consists of the production plant and the WWTP. It is understood
that the plant produces milk powders and liquid concentrates. The WWTP is located to the north of
the main plant. Based on the description provided in the Golder report, the WWTP consists of a
balance tank, four mechanically aerated tanks, a digester and a clarifier. The plant and WWTP
operate 24 hours a day, seven days a week.
The Farming zoned land to the north of the WWTP is occupied by a number of residential properties,
situated within a distance of 500 m. The nearest residence appears to be situated approximately
160 m to the north-east. Residential 1 Zones are present within 500 m of the WWTP to the south and
east; specifically, approximately 300 m to the south and 450 m to the east. It is noted that this
includes a primary school at 263 Russell St.
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5.
REVIEW OF THE GOLDER ASSOCIATES’ SEPARATION DISTANCE ASSESSMENT
The Golder report comprised measurements of odour emissions from the WWTP and air dispersion
modelling using the AERMOD model (under normal operating conditions), as well as an Industrial
Residual Air Emissions (IRAE) separation distance assessment. My findings from a review of this
report are as summarised in the following sections.
5.1
Complaints History
The assessment approach adopted in the Golder report does not include an evaluation of the
complaints history of the Fonterra operations. Whilst I consider that complaints data are rarely directly
correlated with actual pollutant concentrations, these data would provide a ‘real world’ indication of
whether or not the present site activities are actually impacting on the amenity of the nearby sensitive
receptors (the residents), and for this reason should be the first consideration in an evaluation of
separation distance for an existing facility. Air dispersion modelling is a predictive tool whereas
complaints data provide real life community feedback on the performance of an industrial facility.
At this time, I understand that no complaints have been received by Council or EPA in the last five
years regarding offensive or annoying odours from the Fonterra WWTP. However, EPA did advise at
the expert conclave that they are confirming their information as complaint records are contained in
two databases and therefore not easily reconciled.
Golder stated at the expert conclave that the information logged by Fonterra in regard to complaints
received is limited and frequently does not include the name or location of the complainant. As an
outcome of the conclave, Golder agreed to include an evaluation of the Fonterra complaint data in an
amended report that is being prepared.
As noted in Section 4, residential zones are located approximately 300 m to the south of the Fonterra
WWTP and approximately 450 m to the east, with individual residential properties present well within
500 m to the north-east. The Golder report indicates the prevailing winds to be northerlies in
autumn/winter and southerlies during summer. Therefore residences appear to be present in areas
that are frequently down-wind of the present facility.
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5.2
Odour Criterion
Golder has adopted a criterion of 5 OU for the Fonterra WWTP in the assessment, rather than the
1 OU design criterion at ground level for new or expanded facilities stated in the SEPP (AQM). I note
that the 1 OU criterion equates to the odour threshold, and is defined as the odour concentration that
is just detectable by 50% of screened panellists. According to the SEPP (AQM), the design criterion
applies at and beyond the boundary of the premises from which odorous emissions are discharged.
As the WWTP is an existing facility, it is agreed that the 1 OU criterion is not appropriate. Whilst I
agree with using a 5 OU criterion, being defined as the concentration where beneficial uses are
compromised (i.e. the level above which odorous emissions may be considered offensive), I consider
that criterion should be applied at and beyond the boundary of the premises. In other words, 5 OU
becomes the compliance criterion to ensure that there is no discharge of offensive odours beyond the
boundaries of the premises, which is a requirement of Fonterra’s EPA Licence.
Golder noted at the expert conclave that EPA and consultants had routinely applied the criterion at
the nearest sensitive receptor, not the boundary. This has not been my experience. Further, I note
that if Golder had followed this approach they should have applied the 5 OU criterion at the nearest
residence, which is approximately 160 m to the north-east.
5.3
Meteorological Data used in the Modelling
Golder has used a synthetic meteorological data set for use in the dispersion model AERMOD. The
data was generated using the CSIRO prognostic model The Air Pollution Model (TAPM). Hourly data
from the Bureau of Meteorology (BOM) Automatic Weather Station (AWS) at Warrnambool Airport,
6.6 km north of the Fonterra site, was assimilated into the model as observational data.
I note that when measured meteorological data of sufficient quality are available, these are always
preferable to synthetic data generated by a prognostic model. However, EPA Draft Publication 1550
Construction of input meteorological data files for EPA Victoria’s regulatory air pollution model
(AERMOD), states that when data is not available within a 5 km radius of the site, synthetic data,
such as data generated by TAPM, can be used.
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A Victorian EPA air monitoring station, located in Albert Park at Coulstock Street, Warrnambool,
provided measured meteorological data between November 2006 – November 2007. This monitoring
station was located 1.5 km from the coast and 5.7 km south east of the Fonterra site. Although the
monitoring station was not within 5 km of the site, I believe that the meteorological data from the EPA
met station should at least have been used to validate the TAPM generated data itself. This is
particularly since the Warrnambool Airport AWS data assimilated into the model is located
approximately 8.5 km from the coast, whilst the Fonterra site is located approximately 2.3 km from
the coast. However, Golder validated the synthetic data against observational data at the Port Fairy
AWS which is relatively far from the Fonterra site (15 km west), and directly on the coast.
Golder agreed at the expert conclave to include a comparison between TAPM generated 2007
meteorological data and the EPA Warrnambool 2006 – 2007 in their amended report. It is also
understood that they are re-running the AERMOD model with the TAPM generated 2007 data.
5.4
Modelling Methodology
Golder used AERMOD to predict the ground level concentrations of odour resulting from the odorous
emissions from the Fonterra WWTP. According to the report, the TAPM output files were converted
into files suitable for inclusion into AERMOD. However, no details have been given as to how the files
were prepared. Input and output files have also not been included in the report, making it impossible
to check and comment on the efficacy and accuracy of the model.
Golder agreed at the expert conclave to provide information on the conversion of the TAPM files into
suitable AERMOD files, and AERMOD summary files, in their amended report. Golder also advised
that the parameters outlined in EPA draft Publication 1550 for a low density residential land use were
used and it was agreed at the conclave that this was appropriate.
5.5
Presentation of Modelling Results
The EPA draft Publication 1551 Guidance notes for using the regulatory air pollution model AERMOD
in Victoria, states that to assess the impact of emissions to air as specified in Schedule C (Part C) of
SEPP (AQM), the following should be selected as output options in AERMOD:

Top 100 table of the model results;

9th highest (99.9th percentile) concentration files (plot files) for pollutants having an averaging time
of 1 hour or less (with post-processing undertaken to produce 3-minute average predictions); and

Highest (100th percentile) concentration files (plot files) for pollutants having an averaging time of
greater than 1 hour.
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Whilst this guideline is draft, I note that EPA has referred to the above in their advice to Council of
28 March 2014.
Golder has plotted both the highest (rank 1) and 9th highest (rank 9) concentrations at each receptor
in the model domain and has relied upon the rank 1 plot. The top 100 table of model results is not
provided nor is the 9th highest (99.9th percentile) concentration mentioned in the report. Golder has
referenced Publication 1551 in their report but makes no mention of this aspect of the guidelines.
It was discussed at the expert conclave that Golder considered the top 100 table and 99.9th percentile
concentration at or beyond the boundary to not be relevant in the context of a separation distance
assessment, as opposed to a compliance assessment, and therefore did not present this data. It was
agreed in the conclave that this was reasonable.
However, agreement was not reached on the matter of the use of the rank 1 rather than rank 9 plot. I
agree that the SEPP (AQM) provides no guidance on the plots to be presented as an output to model
simulations, and only references that the predicated maximum concentration should be the 9 th
highest (99.9th percentile) for averaging times of 1 hour or less. This is because the plots are of little
concern in a compliance assessment where the focus is on the maximum predicted concentration.
But, it is generally understood that model predications of the 99.9th percentile value are more reliable
predictions of the maximum expected concentrations than the highest values, particularly in modelling
shorter averaging times. This is because the peak results are likely to be overestimations as an
artefact of the predicative nature of the model. I assume that this is the reason for the guidance given
by EPA in Publication 1551 to use the rank 9 plot.
Therefore, if isopleth plots are to be used to interpret the model results, the rank 9, and therefore plot
of the 9th highest concentration at each receptor in the model domain should be used.
5.6
Interpretation of Modelling Results
A review of the rank 1 and rank 9 plots shows that the 5 OU isopleths in each plot extend beyond the
boundaries of the facility. This suggests that under normal operating conditions there is the potential
for offensive odours to be experienced off-site.
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The rank 1 isopleth presented by Golder indicates that exceedances of the adopted 5 OU criterion
extend well into the residential zone to the south. The exact concentrations are unknown as only the
5 OU contour is shown. However, when considering the rank 9 plot, the 5 OU isopleth does not
extend into the residential zone to the south, but does extend off-site to the north where some
scattered residential properties are present, as well as to the east. The 5 OU isopleth for rank 9 is
situated approximately 350 m from the WWTP. This means that offensive odours may be
experienced by residents within this 350 m zone.
It must be remembered however that these are plots of emissions during normal operations (i.e.
routine emissions) and not the unintended emissions that may result from upset or abnormal
conditions, which are what separation distances are intended to be protective of. Therefore while the
modelling plots indicate impact areas for normal operations, it is inappropriate to use these to derive a
separation distance intended to be protective of non-routine emissions in upset conditions.
5.7
5.7.1
IRAE Separation Distance Assessment
Calculation of the Separation Distance
I agree that the recommended separation distance in EPA Publication 1518 Recommended
separation distances for industrial residual air emissions for the Fonterra milk processing plant is
100 m. The application of the separation distances for sewage treatment plants (using the formula in
Table 6 of the guidelines), in absence of any other suitable industry activity for the Fonterra WWTP,
also seems a reasonable approach.
Golder used the equation for mechanical/biological wastewater plants in Table 6 of Publication 1518
to calculate the separation distance for the Fonterra WWTP. This equation requires an equivalent
population served value, since sewage treatment plants are, as stated in Publication 1518, linked to
the size of the population that they serve. To determine the equivalent population, Golder reviewed
the flowrate and COD data for the WWTP for the period 1 January 2013 to 11 January 2014. Data for
periods where the WWTP or milk processing plant was shutdown, or where the COD load was less
than 500 kg/day (which Golder states suggests low production activity or low WWTP flow conditions)
was excluded. Golder then calculated the COD and BOD load statistics, selected the 95th percentile
value, and using a COD/BOD5 ratio of 1.6 and BOD/person/day load of 50 g, calculated an equivalent
population of 75,500. This gives a separation distance of 420 m.
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I have the following concerns with the approach taken by Golder:

I see no reason to exclude the WWTP load data for days when the Fonterra plant was known to
be shutdown or where COD loads were less than 500 kg/day. This presumably contributes to the
skewed distribution of the data, as shown in Figure 9 in the Golder report. However, my review of
the raw data has shown that there does not appear to be a significant number of days excluded,
and therefore it is unlikely to substantially alter the statistics.

The 50 g BOD/person/day value used by Golder is sourced from EPA Publication 500 Code of
Practice for Small Wastewater Treatment Plants. My review has shown that the more recent
EPA Publication 891.3, Code of Practice Onsite Wastewater Management outlines in Table 4
an organic material loading rate of 60 g BOD/person/day. I note that this value is stated to be
based on two reference sources, one being Publication 500. A review of the British Water Code
of Practice: Flows and Loads – 4, Sizing Criteria, Treatment Capacity for Sewage Treatment
Systems also shows a recommended loading for a standard residential dwelling of
60 g BOD/person/day. I note also that the website of the Scottish Environment Protection
Agency indicates that this British Water value is an average BOD load value. I note that if
Golder has used this value then a separation distance of 400 m would have been calculated.

The use of the 95th percentile load value is not sufficiently justified. I consider that a measure of
central tendency such as a mean or a median value should have been used, in view of the fact
that the BOD/person/day loading rate appears to be an average value. Furthermore, I consider
that it makes logical sense to use the average load value in this case, due to the fact that the
BOD/person/day being used to calculate the population size is also expressed as an average.
I note that in their letter of 28 March 2014 to Council, EPA used the mean COD load value
(2,800 kg/day) to calculate an equivalent population load (28,000 people) for the purpose of applying
the same separation distance formula. EPA calculated a recommended separation distance of
300 m. I note that EPA do not state what COD (or BOD) per person value they use for the
conversion, but the calculation suggests a per person COD of 100 g/day was used. I understand from
the expert conclave that EPA used the mean COD value as they consider that an industrial facility
should be able to better control their wastewater quality than a sewage treatment plant. Golder noted
at the conclave that this was not reflected in the variability in organic load recorded at the Fonterra
WWTP.
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5.7.2
Applicability of Table 4 in EPA Publication 1518
EPA commented in their letter of 28 March 2014 that in accordance with Publication 1518, any
proposal to either increase or reduce a recommended separation distance needs to be justified.
Publication 1518 outlines in Table 4 the criteria that must be considered during the assessment of a
site-specific variation to the recommended distance. Whilst this is generally used in situations where
a reduction is sought, I concur with EPA that there is no reason why this should not be applied in
cases where an increase to the separation distance is sought. This is not considered in the Golder
report.
It was acknowledged by all parties at the expert conclave that Table 4 in Publication 1518 is not
directly applicable to the type of impact assessment being undertaken for the Fonterra WWTP (i.e. an
existing facility which is requesting a greater separation distance than Publication 1518
recommends). However, Golder agreed to consider the relevant aspects of Table 4 in their amended
report.
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6.
DETERMINATION OF THE SEPERATION DISTANCE
Based on the information in my possession, the NDSP and my experience and expertise in
separation distances, I have considered what an appropriate distance between the Fonterra WWTP
and the proposed General Residential zone should be.
As stated earlier, I agree that, in the absence of a better approach, the use of the equation for the
calculation of a separation distance for a sewage treatment plant is reasonable. Therefore, using the
EPA Publication 891.3 BOD loading rate of 60 g BOD/person/day, and an average COD load of
2,840 kg/day (BOD of 1,770 kg/day) I calculate an equivalent population of 29,500. Using the
equation 10n1/3 (where n is the equivalent population) this produces a separation distance of 310 m.
This is essentially what has been calculated by EPA and what is allowed for in the NDSP.
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7.
CONCLUSIONS
Based on my consideration of the issues in relation to odour, I conclude that:

My review has shown that Golder has not, to date, undertaken a review of historical complaints
details to consider if adverse amenity impacts on residents (or other sensitive receptors)
already located within a 500 m radius of the plant are occurring. Whilst they have agreed to do
this in their revised report, there is presently no evidence from EPA, Council or Fonterra that
odour-related amenity issues exist with the present separation distance to sensitive receptors. I
note that there is an existing residential zone present 300 m to the south of the WWTP.

Golder have not applied the selected 5 OU criterion, defined as the concentration where
beneficial uses are expected to be compromised (i.e. the level above which odorous emissions
may be considered offensive), at and beyond the boundary of the premises. Golder noted at
the expert conclave that EPA and consultants had routinely applied the criterion at the nearest
sensitive receptor, not the boundary; however this has not been my experience. Further, I note
that if Golder had followed this approach they should have applied the 5 OU criterion at the
nearest residence, which is approximately 160 m to the north-east.

Model predictions of the 99.9th percentile value are more reliable predictions of the maximum
expected concentrations than the highest values, particularly in modelling shorter averaging
times. This is because the peak results are likely to be overestimations as an artefact of the
predictive nature of the model. Therefore, if isopleth plots are to be used to interpret the results
of the Golder AERMOD modelling, the rank 9, and therefore plot of the 9 th highest
concentration at each receptor in the model domain should be used.

Golder has inappropriately used the results of air dispersion modelling for normal operations to
suggest a separation distance from the sensitive uses. The isopleth plots produced are of
emissions during normal operations and not upset conditions, which are what separation
distances are intended to be protective of.

I do not agree with the IRAE separation distance calculated by Golder. I consider that a BOD
loading of 60 g/person/day, which I understand to be an average, should have been used,
along with the mean or at least median COD load.
17

Using the EPA Publication 891.3 BOD loading rate of 60 g BOD/person/day, and an average
COD load of 2,840 kg/day (BOD of 1,770 kg/day) I calculate an equivalent population of
29,500, and a corresponding separation distance of 310 m from the equation in EPA
Publication 1518. This is essentially what has been calculated by EPA and what is allowed for
in the NDSP.

Overall, on the basis of my review, there is considered to be little reason that the separation
distance for the Fonterra WWTP would need to extend to greater than 300 m.