/tt/file_convert/5fe80e8bc05eaf20d122e9b7/document.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 CouncilC/- Mr Terry MontebelloPartnerPlanning & GovernanceMaddocks140 William StreetMELBOURNE VIC 3000

14 April 2014 1 (electronic)

Peter J Ramsay & Associates Internal Copy 14 April 2014 1 (electronic)

TABLE OF CONTENTS

Page

USE OF REPORT iLIST OF ABBREVIATIONS ii1. INTRODUCTION 12. SCOPE 23. EXPERT EVIDENCE DETAILS 3

3.1 Expert Witness Details 33.2 Expert’s Qualifications and Experience 33.3 Expert’s Area of Expertise 33.4 Statement of Expertise 43.5 Other Significant Contributors to the Report 43.6 Existence of Private or Business Relationship with the Party Requesting this Report 43.7 Instructions that Defined the Scope of the Report 43.8 Facts, Matters and Assumptions Used 43.9 Documents and Other Materials Used to Prepare Report 53.10 Tests or Experiments 53.11 Summary of Opinions 63.12 Provisional Opinions 63.13 Limitation 63.14 Declaration 6

4. FONTERRA OPERATIONS AND SURROUNDS 75. REVIEW OF THE GOLDER ASSOCIATES’ SEPARATION DISTANCE ASSESSMENT 8

5.1 Complaints History 85.2 Odour Criterion 95.3 Meteorological Data used in the Modelling 95.4 Modelling Methodology 105.5 Presentation of Modelling Results 105.6 Interpretation of Modelling Results 115.7 IRAE Separation Distance Assessment 12

5.7.1 Calculation of the Separation Distance 125.7.2 Applicability of Table 4 in EPA Publication 1518 14

6. DETERMINATION OF THE SEPERATION DISTANCE 157. CONCLUSIONS 16

APPENDICES

Appendix A Expert Witness Curriculum Vitae

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.

i

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

ii

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.

1

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.

2

3. EXPERT EVIDENCE DETAILS

3.1 Expert Witness Details

Expert Witness: Ms Alison McRae

Address: Level 10, 222 Kings Way, South Melbourne, Victoria, 3205

Company: Peter J Ramsay & Associates Pty Ltd

3.2 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.

3

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.

4

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.

3.11 Summary of Opinions

My opinions are summarised in the in Section 7 of this report.

5

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.

6

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.

7

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.

8

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.

9

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.

10

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 9 th 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 99.9 th 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 9th 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.

11

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 IRAE Separation Distance Assessment

5.7.1 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.

12

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.

13

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.

14

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.

15

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.

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,

16

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.

17