EIS – Chapter 9 Noise, Dust, Odour and Waste Management

PROPOSED ADELAIDEDESALINATION PLANT

EIS – Chapter 9Noise, Dust, Odour and

Waste Management

Proposed Adelaide Desalination Plant Environmental Impact Statement Chapter 9 – Noise, Dust, Odourand Waste Management

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Contents

9.1 Introduction 3

9.2 Air Quality Assessment 49.2.1 Introduction 49.2.2 Air Quality Guidelines 49.2.3 Existing Air Quality Environment 59.2.3.1 Sensitive Receptors 59.2.3.2 Ambient Air Quality Monitoring 69.2.3.3 Meteorology 79.2.4 Construction Activities 119.2.4.1 Emission Factors 139.2.4.2 Activity Rates 149.2.4.3 Key Assumptions 159.2.5 Assessment of Dust Impacts 169.2.5.1 Particulates of Average Air Dynamic Diameter Less than 10

Micrometers (PM10) 179.2.5.2 Total Suspended Particles (TSP) Compounds 179.2.6 Assessment of Operational Dust Impacts 199.2.7 Management and Mitigation Strategies 19

9.3 Odour Assessment 219.3.1 Introduction 219.3.3 Existing Air Quality in Relation to Odour 229.3.4 Assessment of Odour Impacts 239.3.5 Management and Mitigation Strategies 24

9.4 Noise and Vibration Assessment 259.4.1 Introduction 259.4.2 Noise and Vibration Guidelines 259.4.2.1 Noise and Vibration Assessment Guidelines 259.4.2.2 Construction Noise Emissions Criteria 259.4.2.3 Operational Noise Emissions Criteria 269.4.2.4 World Health Organisation 279.4.3 Existing Noise Environment 279.4.3.1 Sensitive Receptors 279.4.3.2 Existing Noise Conditions 289.4.4 Construction Activities 299.4.4.1 Predicted Noise Levels 299.4.4.2 Predicted Vibration Levels 349.4.5 Operational Activities 359.4.5.1 Predicted Noise Levels 359.4.6 Management of Noise and Vibration 399.4.6.1 Construction 399.4.6.2 Operation 42

9.5 Waste Management 439.5.1 Introduction 43

2 Proposed Adelaide Desalination Plant Environmental Impact Statement Chapter 9 – Noise, Dust, Odourand Waste Management

9.5.2 Excavation 439.5.3 Construction 439.5.4 Operation 439.5.4.1 General 439.5.4.2 Intake Screenings 449.5.4.3 Pre-Treatment Waste 449.4.5.4 Antiscalants 449.5.4.5 Clean-in-Place (CIP) Chemicals 459.5.4.6 Membrane Preservative Solutions 469.5.4.7 Membrane Flushing Solutions 469.5.5 General Waste 46


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9.1 IntroductionThis Chapter reports on the air quality, odour, noise and vibration, and wastemanagement impacts of the proposed Desalination Plant.

The likely air quality and dust emissions arising from construction activities arediscussed and compared with the air quality requirements of the EPA’s EnvironmentalProtection (Air Quality) Policy 1994 guidelines. The results of this analysis are thenconsidered in the context of the dispersion, wind and atmospheric conditions at thesubject site, to assess potential impacts on the local environment.

An assessment of the odour impacts of the proposed development in operation ispresented in the context of existing conditions at the subject site and the likely effect ofconstruction and operational activities.

The potential noise and vibration impacts of the proposal for construction and operationare considered against the EPA Environmental Noise Policy (2007) and the distance tothe nearest sensitive (residential) receptors located to the north of the proposed site.

An account of the waste management regime to be employed during the constructionand operational phases of the proposed Desalination Plant is also provided.

Each section of this Chapter concludes with recommendations on how the identifiedimpacts will be managed and mitigated to minimise local impacts and to ensure that theproposed Desalination Plant complies with EPA and other legislative requirements.

This chapter excludes marine underwater noise and vibration impacts which areincluded in Chapter 7, and impacts of dust and noise on terrestrial ecosystems whichare considered in Chapter 8.

The impacts identified in this Chapter will be managed and monitored through theconstruction and operation stages. Chapter 4 describes the management andmonitoring framework for the overall project.


9.2 Air Quality Assessment9.2.1 IntroductionConstruction works associated with the project have the potential to impact local airquality. The aim of this section is to assess the potential air quality impacts principallyassociated with dust emissions during the construction phase of the Desalination Plant.Dust will principally be generated during the construction period and operationalimpacts associated with dust are expected to be negligible as discussed in Section9.2.6.

The potential air quality impacts associated with the ADP have been assessed by:

Reviewing legislative requirements and ambient air quality goals, and describing theair quality environmental values to be protected;

Describing the existing air quality and dispersion methodology within the proposedADP area;

Identifying the nearest sensitive sites including residential areas;

Estimating air emissions associated with the construction and maintenance activitiesof the project and predicting total suspended particles and particulate matterconcentrations and dust deposition rates using dispersion modelling;

Determining the likelihood for potential air quality impacts through comparison withair quality goals and statutory requirements; and

Identifying impact mitigation measures to assist with the management of the airquality impacts for the ADP.

The primary dust emissions under consideration are particulates of averageaerodynamic diameter less than 10 micrometers (PM10) and Total Suspended Particles(TSP) (Connell Wagner, 2008).

9.2.2 Air Quality GuidelinesAir quality in South Australia is administered under the Environmental Protection (AirQuality) Policy 1994 (Air Quality EPP). The intention of the Air Quality EPP is to supportthe Environmental Protection Act 1993 (SA) by:

Identifying environmental values to be enhanced or protected;

Specifying air quality indicators and goals to protect environmental values; and

Providing a framework for making fair and consistent decisions about themanagement of the air environment.

The South Australian EPA guidelines do not set maximum ground level concentrationsof TSP and the allowable monthly deposition rates. Accordingly, the New South WalesDepartment of Environment and Conservation (NSW DEC) Air Quality Guidelines (NSWDEC 2005) have been used for this assessment. These Guidelines set limits on themaximum annually averaged concentration and the maximum allowable monthlydeposition rates above current background levels as indicated in Table 9.1.


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Table 9.1 New South Wales Air Quality Guidelines

Pollutant Averaging period MaximumConcentration(ug/m3)

Maximum AllowableDeposition(g/m2/month)

Total Suspendedparticulates (TSP)

Annual 90

Deposited Dust 2*4^

Source: NSW DEC 2005 * Maximum increase in deposited dust level ^ Maximum total deposited dust level

In addition to the State legislative requirements, the Commonwealth NationalEnvironment Protection Measures (NEPMs), which outline the agreed nationalobjectives for protecting and managing aspects of the environment have been includedin this assessment. The Ambient Air Quality NEPM includes advisory reportingstandards for fine particles 2.5 micrometres or less in size (PM2.5). These aresummarised in Table 9.2.Table 9.2 Ambient Air Quality National Environmental Protection Measures PM2.5 –

Investigations Level

Pollutant Averaging Period Maximum Concentration (ug/m3) @STP

Fine Particles (PM2.5) 1 day1 year

258

Source: EPHC 2003

9.2.3 Existing Air Quality EnvironmentThis section identifies nearest sensitive receptors, and describes the local environment,including meteorology and ambient air quality in the vicinity of the Desalination Plant.

9.2.3.1 Sensitive ReceptorsThe proposed Desalination Plant site is bound by the ocean to the west, industrial landuses to the east and south and residential dwellings to the north. Part of the vacant landimmediately to the north of the site is within the Onkaparinga Council and a part iswithin the Marion City Council. The land in the Onkaparinga Council area is zoned‘Industrial’ and the land in the Marion Council area is zoned ‘Landscape (Buffer)’. Nofuture residential developments are expected to be constructed on this vacant landgiven its current zoning.

The nearest residential sensitive receptors are located approximately 360 metres to thenorth (Figure 9.1).

360 m


Figure 9.1 Location of nearest sensitive receivers to proposed Desalination Plant site, andChristie Downs air quality monitoring site.

9.2.3.2 Ambient Air Quality MonitoringThe South Australian EPA has established an ambient air quality monitoring site atChristie Downs. Information from the monitoring site was used to develop a cumulativeassessment of baseline air quality. A summary of the ambient air quality results is givenin Table 9.3.

Table 9.3 Christie Downs 2006 Ambient Air Monitoring Results

No of validdays = 268

Average Maximum 2nd Highest 6th Highest 90th

Percentile

PM10 GroundLevelConcentration(GLC) (ug/m3)

16 52 52 42 26

Source: EPA 2007

The results obtained from the Christie Downs air quality monitoring are considered to behighly representative of the likely air quality at the Desalination Plant site. This is due toits close proximity to Port Stanvac, coupled with the fact that the monitoring location ispredominantly in a residential area devoid of significant pollution sources (fugitive orindustrial) (Figure 9.1). The average PM10 ground level concentrations monitored at thesite were used as a basis to quantify the cumulative air quality impact from constructionactivities proposed for the project.


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9.2.3.3 MeteorologyMeteorological conditions are an important consideration when assessing thedispersion of pollutants and potential impacts on air quality. Ground levelconcentrations resulting from pollutant release depend on the meteorological conditionssuch as wind conditions, atmospheric stability, temperature gradients and mixingheights.

Meteorological data recorded by the Bureau of Meteorology (BoM) Automatic WeatherStation (AWS) located at Adelaide Airport (the closest BoM site with full site records)was used to simulate the long term average meteorological conditions to monthlyaverage conditions. These are presented in Table 9.4 with the red figures indicating themaximum and purple figures indicating the minimum.Table 9.4 Long Term Average Meteorological Data for Adelaide Airport

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

Mean MaxTemperature(°C)

27.9 28.0 25.5 22.1 18.5 15.9 14.9 15.9 18.1 20.9 23.8 25.7

Mean MinTemperature(°C)

15.9 16.0 14.3 11.7 9.5 7.6 7.0 7.5 8.9 10.6 12.6 14.4

MeanRainfall(mm)

18.1 18.5 20.8 34.8 54.1 55.9 59.9 49.5 46.5 39.2 25.7 24.1

Mean no. ofCloudy days 7.6 6.4 8.9 11.9 15.3 14.2 15.5 13.3 12.1 11.9 10.8 10.6

Mean 9 amWind speed(km/hr)

13.7 11.6 12.2 12.9 12.6 12.6 14.0 16.1 17.7 18.5 16.4 15.5

Mean 3 pmWind speed(km/hr)

23.0 21.8 20.7 18.7 17.5 17.2 19.0 20.6 21.0 22.1 22.4 23.1

9.2.3.3.1 Wind ConditionsThe magnitude and direction of wind speed on a seasonal and annual basis willinfluence the dispersion of air-bourne pollutants such as dust. In assessing potentialimpacts, ambient seasonal and annual wind conditions at Port Stanvac are shownbelow in wind roses (Figure 9.2). The wind roses indicate that wind blows mainly fromthe north-north-west to the south-west directions. However, there is a strongseasonality in the wind field between summer and winter. During winter, the dominantwind direction is north-north-east. In summer, the wind is mainly east to south with thestrongest winds from the south-east.


BoM Summer BoM Autumn

BoM Winter BoM Spring

BoM Annual

Figure 9.2 Port Stanvac Seasonal and Annual Wind Roses


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9.2.3.3.2 Atmospheric StabilityThe degree of stability in the atmosphere is determined by the vertical temperatureprofile. In stable conditions, vertical movement is limited, whereas in unstable conditionsair parcels tend to move upward or downward. When conditions neither encourage nordiscourage vertical movement they are considered neutral. When conditions areextremely stable, cooler air near the surface is trapped by a layer of warmer air above it,with this condition being an inversion which results in virtually no vertical air motion andinduced dispersion.

The Pasquill Gifford (P-G) stability scheme is normally used to describe atmosphericstability. Stability class under the P-G scheme is designated a letter from A-F (andsometimes G), ranging from highly unstable (A) to extremely stable (F), and outlined inTable 9.5.Table 9.5 Stability Categories

Day-time incoming Solarradiation (mW/cm2)

Night-time Cloud cover(octas)

WindSpeed a

(m/s)>60

30 -60 < 30 Overcast

1 hourbeforesunset oraftersunrise 0-3 4-7 8

< 1.5 A A-B B C D F or G b F D

2.0 – 2.5 A-B B C C D F E D

3.0 – 4.5 B B-C C C D E D D

5.0 – 6.0 C C-D D D D D D D

> 6.0 D D D D D D D D

a Wind speed is measured to the nearest 0.5m/s.b Category G is restricted to night-time with less than 1 octa of cloud and a wind speed less than 0.5m/s.

The atmospheric stability class rose and the frequency distribution of stability class forthe site are shown in Figure 9.3. These figures demonstrate that the proposedDesalination Plant area is dominated largely by neutral and stable conditions withstability class D being predominant. The distribution of unstable and stable conditionsis similar to coastal processes causing high wind speeds. The presence of cloud cover,in the area primarily through the winter months results in low solar radiation and hencereduced heating and cooling of the surface leading to neutral conditions.


Port Stanvac Stability Class Frequency Distribution

0

10

20

30

40

50

60

A B C D E FAtmospheric Stability Class

Freq

uenc

y (%

)

Figure 9.3 Atmospheric Stability Class Frequency Distribution, Port Stanvac


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9.2.3.3.3 Mixing HeightThe mixing height is the height of the turbulent boundary layer of air near the earth’ssurface within which ground level emissions are rapidly mixed. A plume emitted abovethis height will remain isolated from the ground until the mixing height reaches theheight of the plume. A plume emitted below this height will be mixed at a ratedetermined by stability class and wind speed. The height of the mixing layer iscontrolled by convection (resulting from solar heating of the ground during the day) andby mechanically generated turbulence as the wind blows over rough ground.

The mixing height at the Desalination Plant site was estimated using gridded surfaceand upper air meteorological data that was generated by CSIRO Air Pollution Model(TAPM). The estimated mixing height for the Desalination Plant site rises in themorning for just after sunrise until mid afternoon. After this time the mixing heightremains at a relatively constant value until reduced to a lower level in the evening. Thisdiurnal variation of atmospheric structure is consistent with what is expected of siteswith a similar climate to the proposed Desalination Plant site. The diurnal variation isshown in the hourly mixing height profile for the full year in Figure 9.4.

Daily Mixing Height Distribution

0

500

1000

1500

2000

2500

3000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour of Day

Mix

ing

Hei

ght (

m)

Average Maximum Minimum

Figure 9.4 Hourly Mixing Height Profile

9.2.4 Construction ActivitiesConstruction activities for the project have the potential to generate emissions includingdust particulars during ground disturbing activities. This section describes the likelyconstruction activities with the potential to generate emissions and their anticipatedduration. This information has been used to develop emission estimates and dustemission rates associated with each major construction phase as part of theassessment of potential impacts (Appendix F1).


The construction activities associated with the proposed project are likely to involvethose listed in Table 9.6.Table 9.6 Construction Associated Dust Generating Activities Likely to be Employed for the

Desalination Plant

Construction main activities NominalDuration

Likely dust generating activities

Site preparation, bulkearthworks, below-groundstructures (excludingintake/outfall shafts) andunderground services

7 months Clearing, grubbing and stripping of vegetation– mulching and stockpiling using dozers andmulchers;

Excavation for road – haulage of waste;

Construction of roads;

Wheel generated dust from vehicular trafficon unsealed roads;

Stockpile wind erosion; and

Trucks dumping overburden.

Shafts - piling 1.5 months Air emissions from generator activity (fossilfuel fired);

Trucks dumping overburden;

Dozer stockpile work;

Wind erosion from loose surfaces;

Excavation of soil/general earthworks; and

Concrete batching.

Shafts – concrete capping ofpiles

0.5 months Concrete batching;

Loading dump trucks and unloadingoverburden; and

Loading trucks.

Shafts – removal of soil 0.5 months Loading dump trucks and unloadingoverburden;

Excavation/general earthworks;

Stockpile erosion; and

Emissions from diesel fuel combustion –cranes, generator, submersible pump.

Shafts - grouting of rock 0.5 months Concrete batching;

Generator – diesel combustion emissions;

Excavation and general earthworks; and

Stockpile and wind erosion.

Shafts - excavation in rock 1 month Rock Crushing (hydraulic hammer);


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Construction main activities NominalDuration

Likely dust generating activities

Drilling of rock; and

Excavation of rock.

Construction of buildings andabove ground structures

16 months Piling;

Generator – diesel emissions;

Excavator – 30 tonne;

Concrete agitator trucks;

Crane movements; and

Wheel generated dust from vehicular trafficon unsealed roads.

The construction schedule in Table 9.6 is based on an indicative construction programfor the project with consideration given to anticipated construction activities andcomparison with other similar projects including the Gold Coast Desalination Plant(GCD Alliance project). The duration of these activities for the Adelaide DesalinationPlant will be determined by the final design and construction methods adopted by theContractor. The predicted emissions are based on “worst case” assumptions ofindicative construction activity rates based on the Concept Design.

9.2.4.1 Emission FactorsEstimated dust emission rates, from the construction activities listed in Table 9.7, werequantified by Connell Wagner (2008) from the National Pollutant Inventory (NPI)Emissions Handbook for Mining and Processing of Non Metallic Minerals. Foremissions not covered in the NPI handbook the US EPA AP42 document for concretebatching and crushed stone was used. The emission factors for TSP and PM10 as theyapply to the construction activities are listed in the table below.Table 9.7 NPI Predicted Emission Factors for Dust Generating Activity Proposed

Dust Generating Activity TSP PM10 Units*

Wheel generated dust from unpaved roads 3.88 0.96 kg/VKT

Loading stockpiles 0.004 0.0017 kg/t

Wind erosion 0.4 0.2 kg/ha/h

Movement of stockpiles 0.03 0.13 kg/t

Bulldozer on material other than coal 16.7 4.07 kg/h

Trucks (dumping overburden) 0.012 0.0043 kg/t

Excavators/shovels/front end loaders 0.003 0.0014 kg/t

Wind erosion from stockpiles 9937 496 kg/ha/year

Topsoil removal by scraper 1.6 0.5 kg/VKT

Drilling 0.18 0.093 kg/hole


Dust Generating Activity TSP PM10 Units*

Concrete batching 0.0045 0.0024 kg/t

*Units:

kg/VKT – kilograms per Vehicle Kilometres

kg/t – kilograms per tonne

kg/ha/h – kilograms per hectare per hour

kg/h – kilograms per hour

kg/ha/year – kilograms per hectare per year

kg/hole – kilograms per hole

9.2.4.2 Activity RatesThe predicted emission factors are used in conjunction with the assumed activity ratesto determine the modelled emission rates. The tonnage of estimated earthworks andemissions for the Desalination Plant site represents a conservative construction option.

The predicted emission rates are expected to be representative of the “worst case”conditions and hence yield the most conservative air quality assessment at the nearestsensitive receiver.

Table 9.8 Assumed Intensity of Dust Generating Activities for the Construction of theDesalination Plant

Emission Rate (g/s)

Dust Generating Activity Activity Rates Units TSP PM10

Wheel generated dust fromunpaved roads 300 VKT/year* 0.09 0.02

Loading stockpiles 175,000 t/yr 0.05 0.02

Wind erosion 29 ha 3.17 1.58

Unloading from stockpiles 175,000 t/yr 0.40 0.17

Bulldozer on material otherthan coal - 1.13 1.13

Trucks (dumping overburden) 175,000 t/yr 0.16 0.06

Excavators/shovels/front endloaders

175,000t/yr 0.040 0.02

Wind erosion from stockpiles 4.0 ha 1.26 0.63

Topsoil removal by scraper 600 VKT/year* 0.08 0.02

Drilling 2,000 holes/year 0.27 0.01

Concrete batching 20,000 t/yr 0.01 0.004

* Vehicular kilometres , t/yr – tonnes per year, ha – hectares


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9.2.4.3 Key Assumptions

In order to make the above estimations on emissions, several assumptions were madewith regards to the proposed Desalination Plant site activities and the properties of thesoil at the site. These assumptions are summarised in Table 9.9. Although some of theemissions assumptions rely on work hours Monday to Saturday (excluding publicholidays) from 7.00 am to 7.00 pm, the Contractor may seek to gain approval to workoutside of these hours from the EPA in some circumstances. It is unlikely that dustemissions outside of the hours will lead to significant air quality impacts, primarily due tolow air emissions and the lack of high wind speeds that lead to the transportation ofpollutants off site outside of the specified work hours.Table 9.9 Key Assumptions

Subject Assumptions

Wind blown dust Assumed to be a source of emissions 24 hours a day every day of theyear.Although it is reasonable to assume that the bulk of large stockpilesexposed to the wind will be wetted and shielded by a cover and/orbarriers, the conservative assumption of this source being continuousthroughout the year has been made.Such measures will be incorporated into a construction EnvironmentalManagement and Monitoring Plan (CEMMP), including air qualitymanagement measures.

Haulage of wasteand site material

Assumed to be a source for 11 hours a day Monday - Saturday.Wheel generated dust from traffic on sealed roads have been included inthe emissions inventory although they are likely to be negligible.Particulate emissions from diesel exhaust have been assumed to benegligible.Dust control achieved by watering of haulage routes within the proposedDesalination Plant site boundary and on unsealed roads is assumed. 75percent emissions control expected to be achieved by watering at a rate of2 l/m2/hr. These measures will be incorporated into the CEMMP asidentified above.

Soil moisture / Siltcontent

Moisture content of soil in this area assumed to be approximately 2percent for all cases. Silt content is assumed to be approximately 10percent.

Duration ofconstructionactivities

All other emissions expected to be a source 11 hours/day between thehours 7 am – 7 pm, Monday – Saturday for the purposes of thisassessment.

Other Emissions The current construction schedule has provided allowances for the totalcut and fill of earth from this site to level the undulating terrain. Howeverthe expected volumes of excavation have not made allowances for thestripping of topsoil, boxing out of roads, over excavation of serviceinstallations and structures/footings, removal of unsuitable material/rock,excavation of material for construction of site roads / shafts and tunneling.The activity rates for emissions from drilling, topsoil removal (scraper),wind erosion from stockpiles, wheel generated dust (haulage vehicles)from unpaved roads and concrete batching have therefore been assumedfor the purposes of this assessment.


9.2.5 Assessment of Dust ImpactsThe potential dispersion of particulate matter including dust from construction sources isaffected by the ambient meteorological conditions as described earlier in this chapter,including:

Wind speed, profile and turbulence intensity (which are affected by terrain andcoastal fumigation effects);

Atmospheric stability;

Temperature gradient which is determined from atmospheric stability (which is itselfdetermined from wind speed, cloud cover and solar radiation); and

Mixing height and the depth of the atmospheric mixed layer.

Connell Wagner (2008) undertook an assessment of potential dust impacts using theAir Pollution Model (TAPM) to predict the likely dispersion characteristics of any dustemissions generated during construction at the Desalination Plant (Appendix F1).

The assessment considered “worst case” scenarios to conservatively estimate dustconcentrations and deposition rates based on the modelled meteorological conditionsand predicted emission rates.

The assessment of dust impacts included an analysis of the maximum predicted levelsat the nearest sensitive receptors through the modelling of estimated emissions and thegeneration of contours for the daily averaged ground level concentrations of PM10 andannually averaged concentrations of TSP. The contours and predicted concentrationsincluding ambient background concentrations, as monitored at the Christie Downs airmonitoring station, are summarised in Table 9.10 and in the following sections.Table 9.10 Predicted Dust Concentrations and Deposition Rates for Desalination Plant Dust

Assessment

Predicted Level Concentration atNearest SensitiveReceptor

CumulativePredicted Level atNearest SensitiveReceiver

Air Quality Criterion

PM2.5 DailyAveraged (ug/m3)

10.4 - 25#

PM10 Daily Averaged(ug/m3)

20.8 36.8 50*

TSP AnnuallyAveraged (ug/m3)

15.6 - 90^

TSP Deposition(g/m2/month)

0.34 - 2^

# NEPM Advisory Guideline

* Mandatory Commonwealth NEPM Criteria (Goal by 2008 – maximum allowable exceedances – 5 days/year)

^ NSW DEC Approved Methods Guidelines


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9.2.5.1 Particulates of Average Air Dynamic Diameter Less than 10Micrometers (PM10)

The PM10 contours show that the maximum ground level concentrations occur within theconstruction site boundary with the pollutants dispersed most significantly in theeasterly and westerly directions. The nearest sensitive receptors are locatedapproximately 360 meters from the edge of the site boundary. The maximum predictedground level concentration was compliant with the federal NEPM ambient air qualitycriteria. The cumulative level that has been predicted based on the averageconcentrations monitored at Christie Downs also complies with the NEPM criteria(Figure 9.5).

Figure 9.5 PM10 Contours - Daily Average Ground Level Concentration (ug/m3)

9.2.5.2 Total Suspended Particles (TSP) CompoundsThe TSP contours (Figure 9.6 and Figure 9.7) show that emissions were dispersed overthe same regions as the PM10 compounds. As TSP is less buoyant in the air it isdispersed over a shorter distance from the source in comparison to PM10. Themaximum ground level concentrations (Figure 9.7) at the nearest sensitive receiveroccurred west of the site approximately 450 meters from the source. The modelleddeposition rate was well below the guideline levels stipulated by the NSW DEC.


Figure 9.6 TSP Contours – Monthly Deposition (g/m2/mth)

Figure 9.7 TSP Contours – Annually Averaged Ground Level Concentration (ug/m3.)


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The assessment showed that air emissions originating from wind erosion from exposedsurfaces and stockpiles as well as works by earthmovers (e.g. bulldozers) on stockpilesrepresent the greatest potential for air emissions.

The modelling did not predict any exceedences at the residential sensitive receptorsnorth of the Desalination Plant, including consideration of potential cumulative impactsunder the “worst case” scenarios when compared to background concentrations (asmonitored at the EPA established monitoring station at Christie Downs) (Appendix F1).

The construction air quality assessment also gave consideration to emissionsassociated with increased traffic flow particularly form construction vehicles. Theimpact of these emissions will be dependent on the type of fuel used and hours ofoperation with the primary sources likely to be those emissions associated with dieselfuel in heavy vehicles and excavation equipment. Since the air emissions associatedwith these vehicle movements are expected to be of a diffuse, non-concentrated nature,the resulting in increase of air emissions of construction vehicles will have a negligibleimpact on local air quality, providing management and mitigation strategies areaddressed (Connell Wagner, 2008).

9.2.6 Assessment of Operational Dust ImpactsThe primary source of dust emissions relate to ground disturbance and stockpilingduring construction. The dust emissions during operation of the proposed DesalinationPlant are expected to be low due to aspects such as roads being comprised of hardsurfaces. The pre-treatment waste (cake) and waste streams from the desalinationprocess will retain sufficient moisture levels to not pose a dust issue. As such, theimpacts of operational dust are expected to be negligible.

9.2.7 Management and Mitigation StrategiesThe Contractor is required to prepare a CEMMP that includes measures to satisfy theenvironment performance objectives and criteria relating to air quality for the project, aswell as regulatory requirements and conditions of approval. Chapter 4 includes furtherdiscussion of the environmental framework for the project.

The CEMMP will include a Construction Air Quality Management Plan that will providethe flexibility to accommodate changing conditions during construction. It will also allowfor a regime of regular community/stakeholder consultation regarding the matter.

Site works will be undertaken to minimise potential impacts, such as minimising areasdisturbed, progressive rehabilitation and dust suppression management measures. Themanagement measures below provide an overview of typical management measures tobe employed. These will be further refined by the Contractor.

Advising residents/sensitive receptors of any works outside of the hours outlined inEPA Policy;

Develop a Construction Traffic Management Plan and ensure construction vehiclesstay within designated vehicle access routes;

Position frequently trafficked haulage routes as far away from sensitive receptors aspracticable;

Seal heavily trafficked areas to the extent possible;

Restrict vehicle speeds (e.g.20 to 40km/hr) to minimise wheel generated dust onunsealed routes;


Minimise diesel engine idle times and queuing;

Install truck cleaning stations at site boundaries to minimise off-site transport ofmaterial which could cause dust emissions;

Cover all truck loads where there exists the possibility of dust emissions in transport;

Limit truck loads to a vertical height no greater than 0.5 meters above the side wallsof the vehicle;

Maintain all fossil-fuelled plant and equipment to facilitate efficient operation;

Undertake regular watering of exposed surfaces including exposed stockpiles,unsealed roadways, dry/fine material in regions within blasting/drilling areas tosuppress dust generation;

Covering/protection of areas susceptible to significant dust emissions from winderosion;

Locate stockpiles as far away from sensitive receivers as practicable;

Use natural landforms to shield exposed areas and dust generating constructionoperations from prevailing strong winds blowing towards sensitive receptors;

Use water sprays on all conveyor transfer systems and other material transfersystems to control visible dust;

Install emissions control devises (e.g. fabric filters) on concrete batching/crusherplants;

Restrict/cease activities with high dust generating potential (including heavyexcavations and drilling) during periods when strong winds blowing towards sensitivereceptors prevail; and

Damping down of blast areas to suppress dust generation.

The CEMMP will also be required to outline air quality monitoring requirements in orderto ensure that air emissions do not exceed regulatory limits.


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9.3 Odour Assessment9.3.1 IntroductionThe following approach was undertaken to assess the air quality impact of odouremissions from the operations of the Desalination Plant on sensitive receptors:

Identification of South Australian statutory odour requirements applicable to theproject;

Identification of potential emission sources from the proposed Desalination Plantoperations;

Estimating potential odour emissions associated with Desalination Plant operationand the generation of an organic waste stream through an environmental odoursurvey and dispersion air modelling;

Modelling of emission sources;

Assessment of modelled results on sensitive receptors within the study area; and

Identification of necessary odour management and mitigation measures.

9.3.2 Air Quality Guidelines in Relation to OdourThe criteria used to assess the potential impacts from the proposed Desalination Plantare governed by the EPA Guideline 373/07, which provides the criteria for themanagement of odour emissions. The principal legislation dealing with odour in SouthAustralia is the Environment Protection Act 1993. In particular, section 25 imposes ageneral environmental duty on all persons undertaking an activity that may emit odourto take all reasonable and practicable measures to prevent or minimise any resultingenvironmental harm. In addition, causing an odour, which constitutes an environmentalnuisance, is an offence under section 82 of the Environment Protection Act 1993 (SA).The odour criteria are based in principle on compliance with the general environmentalduty to avoid environmental nuisance using ‘best available technology economicallyachievable’ (BATEA).

The odour criteria established by the EPA guidelines are given in Table 9.11.

The EPA guidelines also require the following odour management objectives to be metby the proposed Desalination Plant facility to meet public expectations:

Minimise odour emissions and impact;

Ensure neighbouring sensitive land uses are not exposed to unacceptable levels ofodour from the facility;

Appropriate management strategies are in place to ensure levels of odour atsensitive land uses are within the accepted criteria; and

Application of ongoing risk evaluation and hazard management strategies givendevelopments in odour impact and potential health effects.

Odour criteria are dependent on the number of exposed individuals and are thereforesubject to population density. Odour impact is a subjective assessment and as such anincrease in the number of exposed individuals increases the probability of the presenceof individuals among the population who are sensitive and will be adversely affected.


Table 9.11 Odour Assessment Criteria

Number of People Odour Units (OU)(3 Minute Average, 99.9th Percentile)

2000 or more 2

350 or more 4

60 or more 6

12 or more 8

Single Residence (less than 12) 10

9.3.3 Existing Air Quality in Relation to OdourAn ambient odour survey was conducted by Connell Wagner (Appendix F1) at theproposed Desalination Plant site to determine the background odour concentrations inthe region. This assessment was undertaken by sampling a sufficient quantity of air intoa bag at a height of 2 metres . The odour level was then determined by digitalolfactometry, testing the odour intensity by exposing the air sample to a panel as perAustralian Standard 2542.2.3:1998. The odour intensity (OI) rating was averaged frompanellists’ responses. The assessment locations are given in Figure 9.8.

Figure 9.8 Location of Assessment for Existing Odour at the Site (refer to Table 9.11 forsampling location data)

The results from the olfactometry testing given in Table 9.12 demonstrate that theaverage levels of odour intensity are weak to very weak at all sampling locations.Accordingly, it was considered that there is minimal background odour at present at theproposed Desalination Plant site.


23

Table 9.12 Results of Ambient Odour Sampling and Olfactometry in Terms of Odour Intensity

UTM Location (m) Odour Intensity (OI)SamplingLocation ID X Y 20-Jun 27-Jun 2-Jul 3-Jul

Average

E3 271410 6111859 0 0.5 0.7 0.2 0.35

E4 271279 6112078 0.3 0 0.7 0.5 0.38

N5 271047 6112873 0.4 1 0.5 0.5 0.60

N6 271015 6113679 0 0 0.3 0.3 0.15

9.3.4 Assessment of Odour ImpactsThe primary determinants of the degree of odour impact on sensitive receivers fromsurface borne odour emissions include:

Odour emission rate (concentration);

Meteorology; and

Separation between the source and nearest sensitive receivers.

The primary potential odour emissions associated within the proposed DesalinationPlant would be related to the generation of waste streams during operation. There areconsidered to be few odour issues relating to the construction phase of the DesalinationPlant. Those issues that do occur relate primarily to odour as an artefact of air qualityparticulate issues such as exhaust fumes (generators, traffic, etc.) and as such havebeen considered within the previous air quality section.

The potential odour sources from the operational activities primarily include:

The intake screenings; and

The pre-treatment waste (cake).

These wastes are discussed further in Section 9.5 in this chapter.

The intake screenings will consist of marine organic matter and therefore have thegreatest odour emission potential. The pre-treatment waste (cake) consists primarily ofsediment matter, some salts and very low organic matter and as such have a lowpotential to generate odours.

Accordingly, the assessment of potential odour from the Desalination Plant focussed onthe generation of odour emissions of marine organic matter.

The odour impact assessment was conducted based on a simulated odour emanatingfrom organic marine matter. The aim of the simulation was to assess the impact ofodour from the decomposition of organic marine matter being emitted from a smallsource area, i.e. a waste skip (Appendix F1). The simulation provided a “worst case”odour emissions rate associated with the accumulation of waste and hence odourswithin the waste storage skip. This “worst case” emission rate was modeled using adispersion model to provide a conservative assessment of potential odour impacts asrequired by the EPA Guidelines.

The dispersion model used to analyse the odour dispersion for this project was the USEPA approved Guassian Plume Industrial Source Complex Short Term 3 (ISCST3)model. ISCST3 is considered to be an equivalent to AUSPLUME as they are bothbased on the Guassian plume dispersion principle.


The emissions source (i.e. waste skip) was assumed to be located in the same regionas the cake standing area as indicated in Figure 9.9.

The modelling showed that the predicted odour level at the nearest sensitive receiver isless than 2 Odour Units (OU). Giving consideration to the large buffer distance betweenthe source and the nearest residential sensitive receivers, the modeled resultsdemonstrate that there will be no odour impacts to these receptors and emissions willcomply with the statutory odour criterion of 2 OU (Figure 9.9).

Figure 9.9 Odour Dispersion – 2 OU Contour.

9.3.5 Management and Mitigation StrategiesA detailed Operational Environmental Management and Monitoring Plan (OEMMP) willalso be required for the operation of the proposed Desalination Plant. The OEMMP willinclude management measures to ensure potential impacts associated with odouremissions are addressed. The OEMMP will include mitigation measures such as:

Placement of the waste disposal skip as far from the sensitive regions as practicable;

Avoid conditions that lead to the concentration of odourous emissions within the skip(e.g. leaving the skip closed at all times, to ensure no aeration of the wastematerials); and

Regular disposal of waste material.

The mitigation of odour emissions is best achieved through the regular disposal ofwaste and the avoidance of decomposition of organic matter resulting in the generationof odourous emissions.


25

9.4 Noise and Vibration Assessment9.4.1 IntroductionThis Section provides an assessment of the potential noise and vibration impacts of theproposed Desalination Plant.

The noise and vibration impact assessment includes:

Description of the existing background noise environment of the proposedDesalination Plant site based on baseline noise monitoring results;

Establishing construction and operational noise guidelines for the Desalination Plantusing relevant EPA noise policies and guidelines;

Noise propagation modelling to predict the potential noise impacts at the nearestsensitive receivers during construction and operation of the Desalination Plant; and

Mitigation measures.

Appendix F2 outlines in full the assessment and modellings that were undertaken.

9.4.2 Noise and Vibration Guidelines

9.4.2.1 Noise and Vibration Assessment GuidelinesThe South Australian Environment Protection (Noise) Policy (2007) sets requirementsfor noise emissions from industrial sites based on the land use category of the receiver.Figure 9.10 shows that the closest sensitive residential receivers are to the north of theproposed Desalination Plant site. To the east is an area of industrial developmentincluding car wreckers and similar industry, and to the west is Gulf St Vincent.

9.4.2.2 Construction Noise Emissions CriteriaNoise associated with construction includes all demolition, site preparation andconstruction noise associated with the proposed development. An increased number ofvehicles entering the site (especially heavy vehicles) have the possibility of generatingincreased levels of noise at receivers. Part 23 (1) of the Environment Protection (Noise)Policy 2007 provides recommendations to minimise the impact of construction activityon nearby receivers.

The Policy gives the following allowable noise levels which are to be complied with atpotentially noise affected premises:

Continuous noise (LAeq) 45 dBA

Maximum noise (LAmax) 60 dBA

These allowable noise levels are based on construction activities occurring fromMonday to Saturday (excluding public holidays) and between 7.00am and 7.00pm.

Where measurements of ambient noise at the potentially noise affected premises showthat the ambient noise level (continuous) exceeds 45 dBA, the Policy states that theconstruction noise does not have an adverse effect on amenity unless the source noiselevel (continuous) also exceeds the ambient noise level (continuous).


Similarly, if measurements of the ambient noise at the site show that the ambient noiselevel (maximum) consistently exceeds 60 dBA, the construction does not have anadverse impact on amenity unless the source noise level (maximum) also exceeds theambient noise level (maximum) or the frequency of occurrence of the ambient noiselevel (maximum).

Draft Guidelines for the use of the Environment Protection (Noise) Policy 2007 statethat construction may occur outside of the specified hours, provided that the noiselevels generated do not cause an awakening reaction as defined by the World HealthOrganisation (WHO) (refer to Section 9.4.2.4). Given the large separation distancebetween the construction site and the residential receivers, it is proposed that theallowable hours of construction could potentially be increased, provided that the noiselevels do not cause an awakening reaction to nearby residents (as defined by the WorldHealth Organisation).

9.4.2.3 Operational Noise Emissions CriteriaPart 1 (Section 5) of the Environment Protection (Noise) Policy 2007 addresses thecalculation of indicative noise factors for various planning zones and situations. Theselevels address the operational noise limits, which industrial sites must comply withunder the Environment Protection Act 1993 (SA).

Where the noise source and receiver are both located in the same land use zone, thePolicy sets indicative noise factors for that zone and no further calculation is required.However, when the noise source and the receiver are located in different land usezones, further calculation is required to determine the indicative noise factors.

Section 5 of the Environmental Protection (Noise) Policy 2007 states that where thenoise source and the receiver do not fall into a single land use category, and there is abuffer zone of less than 100 meters between the noise source and receiver, theindicative noise factor for the receiver is the average of the two indicative noise factorsfor the surrounding land use categories.

The EPA also provides guidelines for receivers located in a quiet locality. These valuesare to be used when the averaged indicative noise factors for a mixed use zone sethigher limits than the indicative noise factors for a residential area. A locality is definedas a quiet locality if the principal land use falls within either or both of the following landuse categories:

Residential; and

Rural Living.

Where the limit set by the average of the indicative noise factors is higher than the limitset by the quiet locality, the stricter of the two limits should be used.

Where there exists a buffer zone greater than 100 meters between the source andreceiver, as is the case for the Desalination Plant, the average of the two indicativenoise factors should not be used; rather the residential indicative noise factor should beused.

Based on the local land use planning zones, and the method described above, theindicative noise factors given in the policy are as shown in Table 9.13.


27

Table 9.13 Indicative Noise Factor

Land Use Category Site Indicative Noise

Factor LAeq,15 min dBA(Day)

Indicative Noise

Factor LAeq,15 min dBA(Night)

General Industry 65 65

Residential 52 45

For development assessment, the allowable noise level for the development should notexceed the relevant indicative noise level less 5 dBA. The quiet locality criteria are notsubject to the 5 dBA reduction. Therefore the noise limits that must be achieved at theresidential boundaries are as shown below:

Site allowable limit at residential receiver (LAeq) during the day 47 dBA

Site allowable limit at residential receiver (LAeq) during the night 40 dBA

The proposed Desalination Plant is proposed to operate up to 24 hours per day. Theallowable noise limit for the site is therefore dictated by the night time noise criteria. Formodelling purposes, it has been assumed that all specified equipment is operationalequipment with no stand-by/emergency equipment in operation. In addition to theabove continuous noise level criteria, for quiet localities (residential areas) the predictedmaximum noise level should not exceed a maximum sound pressure level of 60 dBA atthe residential receiver.

9.4.2.4 World Health OrganisationThe WHO Guidelines on Community Noise Part 3.4. Adverse Health Effects of Noisestates that for a ‘good sleep’, the internal noise level in a bedroom should not exceedapproximately 45 dBA more than 10-15 times per night. Based on the assumption thatthe bedroom contains a slightly open window for ventilation, a noise reduction fromoutside to inside of approximately 15 dBA is expected. Accordingly, 10-15 events pernight which cause an Lmax event of 60 dBA at the residence boundary are seen to beacceptable. In addition, the WHO recommends that an internal continuous level of 30dBA should be achieved to avoid sleep disturbance. Based on the same methodologyand assuming a 15 dBA reduction through a slightly open window, a continuous noiselevel of 45 dBA is considered acceptable for the night time period.

These limits correlate with those proposed by the Environment Protection (Noise) Policy2007 for daytime periods.

9.4.3 Existing Noise Environment

9.4.3.1 Sensitive ReceptorsConnell Wagner (Appendix F2) assessed the potential noise and vibration sensitivereceivers for the proposed Desalination Plant as including residential dwellings locatednear the site to the north-east. The nearest noise sensitive receivers were identifiedfrom aerial photography and site visits to the proposed Desalination Plant site asindicated in Figure 9.10. The distance between the proposed site boundary and thenearest sensitive receptor is approximately 360 metres.


9.4.3.2 Existing Noise ConditionsThe noise environment was measured by Connell Wagner (Appendix F2) at a sensitivereceiver near the proposed Desalination Plant site. Un-attended noise measurementswere conducted at this noise monitoring site to determine the existing noiseenvironment and to assist in developing noise emission criteria for the proposedDesalination Plant site. The noise monitoring location was chosen as it represents anindicative residential receiver for the Desalination Plant for both the construction andoperation stages. The location of the noise monitoring site (15 Carlisle Court) can beseen below in Figure 9.10. The monitor was fitted with an approved windshield andfield calibrated prior to and after monitoring.

When measuring noise levels the use of statistical descriptors is necessary tounderstand and describe how variations in the noise environment occur over any givenperiod. A list of common descriptors used in the noise assessment as well as theirmeaning is given below:

LA10 – For a specified time interval, means the A-weighted sound pressure level thatis equalled or exceeded for 10% of the interval;

LA90 – For a specified interval, means the A- weighted sound pressure level that isequalled or exceeded for 90% of the interval;

LAeq – For a specified time interval, means the time average A – Weighted soundpressure level for the interval; and

LAMAX – For a specified time interval, means the highest momentary sound pressurelevel from a single noise event.


29

Figure 9.10 Location of Unattended Noise Logging Site at location typical of nearest residentialsensitive receptor.

A summary of the noise monitoring is given in Table 9.14.

Table 9.14 Summary of Noise Monitoring Data.

Day Night

LAeq dBA L90 dBA LAeq dBA L90 dBA

Carlisle Ct 45 38 39 36

9.4.4 Construction Activities

9.4.4.1 Predicted Noise LevelsConnell Wagner (Appendix F2) undertook noise and vibration modelling to predict andassess construction and operational levels for the proposed Desalination Project.

The construction activities associated with the final design are anticipated to include butnot be limited to those listed in Table 9.15. The construction schedule reflected in thetable is based on an indicative construction program for the project with considerationgiven to anticipated construction activities and comparison with other similar projectsincluding the Gold Coast Desalination Plant (GCD Alliance project). The predictedemissions are based on “worst case” assumptions of indicative construction activityrates based on the Concept Design. It should be noted that the majority of the noisyactivities (piling and hydraulic excavation hammers) are restricted to shaft excavationand plant construction stages.

15CarlisleCourt


The predicted sound power levels associated with the activities are also given in Table9.16 and are based on Australian Standard AS2436.1981: Guide to Noise Control onConstruction, Maintenance and Demolition Sites. The predicted emissions are basedon worst case assumptions of indicative construction activity rates that have beenstated to be a suboptimal solution at this stage. The intensity of the assumedexcavation activities is therefore conservative and based on a single concept solution.Table 9.15 Expected Construction Activity Noise Levels.

Construction mainactivities

NominalDuration

Activity Predictedsoundpower

level (dBA)

Clearing, grubbing and stripping ofvegetation – mulching and stockpilingusing dozers and mulchers

118

Excavation for road – haulage of waste

Excavator (30 tonne)

118

Site preparation, bulkearthworks, below-ground structures(excludingintake/outfall shafts)and undergroundservices

7 months

Construction of roads (grader) 118

Generator 112

Trucks dumping overburden 15 tonne 107

Dozer 118

Excavation of soil / general earthworks

(Excavator (30 tonne))

118

Shafts - piling 1.5months

Concrete batching 112


Trucks dumping overburden 15 tonne 107

Shafts – concretecapping of piles

0.5 month

Loading trucks 15 tonne 107

Loading dump trucks and unloadingoverburden

107

Excavator (30 tonne) / general earthworks 118

Shafts – removal ofsoil

0.5 month

Cranes, generator, submersible pump 120


Generator 112

Shafts - grouting ofrock

0.5 month

Excavator (30 tonne) / general earthworks 118

Shafts - excavation inrock

1 month Rock crushing (hydraulic excavationhammer)

118


31

Construction mainactivities

NominalDuration

Activity Predictedsoundpower

level (dBA)

Drilling of rock 118

Excavation of rock, Excavator (30 tonne) 118

Piling (impact piling rig) 128

Generator 112

Excavator (30 tonne) 118

Concrete agitator trucks 15 tonne 119

Construction ofbuildings and aboveground structures

16months

Crane movements 120

Table 9.16 shows typical sound pressure levels at various distances from the proposedDesalination Plant site. It is expected that the majority of the noisy activities (e.g. pilingand rock crushing) will have impulsive characteristics and so assessment against themaximum noise criterion is appropriate. For activities such as drilling and truckmovements, which have a more continuous characteristic, assessment against thecontinuous noise levels criterion is appropriate. Impact piling is not expected at the sitedue to the close proximity to residents, although it has been included as a reference.Should piling activities be required, a quieter alternative such as screw piling will beconsidered where practical.

Measures for the mitigation and management of noise impacts are described in Section9.4.6.


Table 9.16 Typical Sound Pressure Levels for Construction Activities.

Sound pressure level atdistance dBA

Construction phaseand main activities

Duration Activity Predictedsoundpowerlevel(dBA)

10m

50m

100m

200m

400m

Clearing,grubbing andstripping ofvegetation –mulching andstockpilingusing dozersand mulchers

118 90 76 70 64 58

Excavation forroad –haulage ofwaste

118 90 76 70 64 58

Excavator (30tonne)

118 90 76 70 64 58

Site Preparation –Remediation/earthworks

7 months

Constructionof roads(grater)

118 90 76 70 64 58

Generator 112 84 70 64 58 52

Trucksdumpingoverburden 15tonne

107 79 65 59 53 47

Dozer 118 90 76 70 64 58

Excavation ofsoil. Generalearthworks

118 90 76 70 64 58

Excavator (30tonne)

118 90 76 70 64 58

Diaphragm wall 1.5 months

Concretebatching

112 84 70 64 58 52

From and pour concretecapping

0.5 monthConcretebatching

112 84 70 64 58 52


33




10m

50m

100m

200m

400m

Trucksdumpingoverburden 15tonne

107 79 65 59 53 47

Loadingtrucks 15tonne

107 79 65 59 53 47

Loading dumptrucks andunloadingoverburden

107 79 65 59 53 47

Excavator (30tonne)/generalearthworks

118 90 76 70 64 58Shaft excavation in

sand0.5 months

Cranes,generator,submersiblepump

120 92 78 72 66 60

Concretebatching

112 84 70 64 58 52

Generator 112 84 70 64 58 52Pre-grout rock to bottomof shaft

0.5 months

Excavator (30tonne)/generalearthworks

118 90 76 70 64 58

Rock crushing(hydraulicexcavationhammer)

118 90 76 70 64 58

Drilling of rock 118 90 76 70 64 58Shaft excavation in rock 1 month

Excavation ofrock,Excavator (30tonne)

118 90 76 70 64 58

Plant Construction 16 monthsPiling (impactpiling rig)

128 100 86 80 74 68





10m

50m

100m

200m

400m

Generator 112 84 70 64 58 52

Excavator (30tonne)

118 90 76 70 64 58

Concreteagitator trucks15 tonne

119 91 77 71 65 59

Cranemovements

120 92 78 72 66 60

The allowable noise emissions from construction activities at the noise sensitivereceptors (as based on SA EPA (Noise) Policy) are considered to be:

Continuous (LAeq) – 45 dBA

Maximum noise (LAmax) – 60 dBA

The results of the construction noise modelling demonstrated that the predictedconstruction noise levels will likely be in exceedence of the criteria for some activities atthe site. Generally, controlling noise emissions is the easiest and most effectiveapproach to minimising noise impacts from construction upon sensitive receptors.Careful selection of equipment and hours of operation are normally sufficient to reducenoise levels to reasonable levels.

9.4.4.2 Predicted Vibration LevelsVibration generated by construction activities, if not properly mitigated, has the potentialto cause disruption to residents as well as cosmetic and structural damage to buildings.Vibration transfer from source to receiver is highly dependent on the local soil type (e.g.rock, sand etc). The German DIN 4150 standard gives allowable vibration levels forvarious building types to avoid cosmetic damage to the building. It should be noted thatthese levels are to be measured inside the building.

Historic buildings have stricter requirements for vibration levels due to theirsusceptibility to cosmetic damage from vibration. Due to the distance between theproposed Desalination Plant site and residential areas and buffer zone, vibrationtransfer is not expected to have any significant impact.

During piling activities (should they be required) a site inspection will be conductedduring construction to monitor noise and vibration levels at the nearest residentialpremises. If levels are in excess of the allowable criteria, additional monitoring will beconducted, possible alternative methods and procedures of construction be determined.Management measures will be included in the CEMMP.

Connell Wagner (Appendix F2) undertook an assessment of the likely vibration impactsfrom construction and concluded that the proposed Desalination Plant site is ofsufficient distance from sensitive residential receptors to minimise construction


35

vibration. As such, there are likely to be negligible impacts arising from constructionvibration.

9.4.5 Operational Activities

9.4.5.1 Predicted Noise LevelsA digital model of the proposed Desalination Plant site has been developed by ConnellWagner (Appendix F2) to predict the noise levels generated by the equipment locatedon the site. A perspective view showing the heights of the modelled buildings can beseen in Figures 9.11 and 9.12.

Figure 9.11 Proposed Desalinisation Plant (refer to Table 9.17 for building reference numbers).

The digital model included all major noise sources on the site, all major buildings andpits. A list of the modelled buildings and noise sources can be seen in Table 9.17below.

A

BCD

G

H

I

F


Table 9.17 Modelled Noise Sources

BuildingReference

Name ofBuilding

Height ofBuilding

VolumeofBuilding

Total PredictedBuilding SWLemission(dBA)

PredictedBuilding InternalReverberantSound PressureLevel (dBA)

A Clarification/DAF 8.5 m 93,750m3

78 dBA 71 dBA

B Primary Filtration 5.0 m 57,600m3

85 dBA 76 dBA

C SecondaryFiltration

5.0 m 28,600m3

81 dBA 75 dBA

D Reverse OsmosisPlant

12.0 m 106,000m3

96 dBA 84 dBA

E Centrifuge 11.0 m 15,000m3

90 dBA 88 dBA

Washwaterrecovery pump100 dBA/unit

N/AF

Wash WaterRecovery Tanks 6.2 m PIT N/A

Supernat returnpump 101dBA/unit

N/A

G Transfer PumpingStation

12.5 m 15,000m3

91 dBA 85 dBA

H Intake PumpingStation

12.0 m 18,200m3

91 dBA 84 dBA

I ETSA Substation N/A N/A 80 dBA/unit N/A

When final specification of equipment is conducted, these should be used as maximumallowable sound pressure levels for the equipment. Where a building encloses severalitems of equipment the sound power levels of the individual items of equipment havebeen summed and a reverberant sound pressure level in the building calculated.

In order to predict sound pressure levels at the residential receptors, receiver locationswere included in the model (Appendix F2). The locations are demonstrated in Figure9.12 and represent a distribution of “worst case” receivers.


37

Figure 9.12 Receiver Locations for Desalination Plant Sensitive Receptor Sites (refer toTables 9.19 and 9.19 for receiver information).

A summary of predicted sound pressure levels can be seen in Table 9.18. Themodelling demonstrated that the noise generated by the Reverse Osmosis (RO)Desalination Plant building is the main noise contributor. The site was originallymodelled without acoustic louvres with little attenuation i.e. without screening of somedescription (Table 9.18). Figure 9.13 demonstrates the predicted sound pressure levelcontours as predicted within the modelling.

43

2 1


Figure 9.13 Predicted Sound Pressure Level Contours.

Table 9.18 Predicted Sound Pressure Levels for Modelled Receiver Locations (as specified inFigure 9.12) without acoustic louvres.

ReceiverPredictedSPL (LAeq,

dBA)Allowable Noise

Limit LAeq, 15min dBACompliance with

noise criteria PrimaryContributor(s)

1 32 dBA 40 dBA Yes RO Plant




The site was then remodelled with louvres in order to determine the effect of louvreattenuation. Table 9.19 shows a summary of the results of the simulation with acousticscreening.

Based on results in Table 9.19, it can be seen that a reduction of 1 to 3 dBA is achievedwith the installation of the acoustic louvres. The results from the modelling show that thepredicted operational noise emissions from the Desalination Plant will be within theEnvironment Protection (Noise) Policy 2007 criteria. However, since the predictionshave been based on assumptions and calculations of the sound power levels of theequipment as opposed to manufacturer’s test data, acoustic louvres should be installedwhere louvres are required.


39

Table 9.19 Predicted Sound Pressure levels with acoustic louvres.

Receiver Predicted SPL(LAeq, dBA)

Allowable Noise LimitLAeq, 15min dBA

Compliance with noisecriteria

1 29 dBA 40 dBA Yes

2 31 dBA 40 dBA Yes

3 34 dBA 40 dBA Yes

4 36 dBA 40 dBA Yes

9.4.6 Management of Noise and Vibration

9.4.6.1 ConstructionThe Contractor is required to prepare a CEMMP that includes measures to satisfy theenvironment performance objectives and criteria relating to noise and vibration for theproject, as well as regulatory requirements and conditions of approval. Chapter 4includes further discussion of the environmental framework for the project.

The CEMMP will include a construction noise and vibration management plan thatprovides the flexibility to accommodate changing conditions during construction. It willalso allow for a regime of regular community/stakeholder consultation regarding noiseand vibration management.

Construction activities will be generally be carried out in accordance with theconstruction noise control guidelines as described in AS 2436:1981 Guide to NoiseControl on Construction, Maintenance and Demolition Sites, as set out in Table 9.20.

Where feasible, the construction mitigation plan will:

Control noise at the source, incorporating less noisy construction techniques;

Schedule noisy activities for daytime hours;

Ensure maintenance of equipment and the use of mufflers and silencers, whereappropriate; and

Use of noise barriers (including temporary barriers), where appropriate.

Table 9.20 Construction Noise Management and Mitigation Strategies.

Control Strategy Description

ConstructionHours

As far as practicable, general construction activities will be conducted inaccordance with the timing as set out in South Australian EnvironmentProtection (Noise) Policy 2007.

General Noisemanagementpractices andscheduling ofactivities

In general construction works and consideration of quiet work practiseswould be carried out in accordance with AS 2436:1981 Guide to NoiseControl on Construction, Maintenance and Demolition Sites.

Prior to the commencement of site works, the surrounding communitywould be informed of the upcoming activities and likely duration.

The construction program would continue to be developed in consultationwith the local community to schedule noisier activities during normal



operational hours.

Appropriate selection of construction processes/methodologies andequipment which minimise the generation of noise would be furtherconsidered during development of the project schedule.

Employ respite periods for particularly noisy activities were possible.

Maintain a site activity log, recording the type of activities occurring duringvarious times of the day to assist with retrospective investigation ofcommunity complaints related to noise.

MaximiseShielding anddistance toreceivers

Maximise the offset distance between noisy plant and continuousoperations (generators, crushers etc) and nearby noise sensitive receptorsor ensure that plant is screened using:

Purpose built barriers;

Materials stockpiles;

Site sheds, buildings or other structures; and

Natural topographical barriers.

Where possible, carry out loading and unloading of materials andequipment in areas as far away from noise sensitive areas as possible.

Plant andequipment

Equipment having directional noise characteristics (emits noise strongly ina particular direction) would be orientated such that noise is directed awayfrom sensitive areas.

Avoid the coincidence of noisy plant operating at the same time closetogether adjacent to sensitive receptors.

Acoustic enclosures or localised noise screens could be incorporatedaround fixed plant or over individual pieces of equipment as appropriatebased on acoustic assessment.

All mechanical plant should be silenced by practical means using currentcontrol technology and in accordance with manufacturers specifications,and maintained appropriately.

Plant with the lowest noise rating which meets the requirement of the taskshould be selected.

Where possible for works in close proximity to sensitive receptors, useelectric motors in preference to diesel motors.

Where reversing alarms are to be used, their acoustic range should belimited to the immediate danger area. Traditional “beeper” alarms for mobileequipment could be replaced with:

“Smart alarms” that adjust their volume depending on the ambient levelof noise. These are particularly useful during operations in quieterareas of the site, where other noise on the site is less, or when workstake place during quieter periods such as night time and early morning;and

“Broadband” or “quacker” alarms. These emit a less annoying soundand are more directional (meaning the sound is focused to the area ofconcern); and are less likely to travel to noise sensitive areas. Enclosenoisy equipment as much as possible, depending on the nature of theequipment, access and ventilation requirements.

Where practicable, metal surfaces subject to impacts with heavy objects


41


(such as rock dropping into empty truck trays, or metal grates on roadramps etc) should be lined with rubber impact protection to minimise impactnoise.

Ensure that tailgates on trucks are fitted to avoid noise from the movementof empty trucks.

Where using pneumatic equipment, select silenced compressors or usequieter hydraulic equipment.

Conduct regular inspections and effective maintenance of both stationaryand mobile plant and equipment (including mufflers and enclosures etc).

Equipment not being utilised as part of the work should not be left standingwith engines running for extended periods.

ConstructionTraffic Noise

Establish designated access route/s to the site and inform drivers of theseroutes, parking areas and acceptable delivery times.

Undertake regular site road maintenance (and inspections) to minimiseimpact noises from trucks travelling over irregularities in the road surface(pot holes, washouts or ruts).

Limit vehicle speeds in critical areas both on and off site.

Allow one way traffic flow through the site to minimise the use of reversingalarms as much as possible and minimise traffic delays.

Ensure vehicles within compounds do not queue outside the worksite closeto residential areas. This particularly applies in the commencement of shiftduring morning hours, where sleep disturbance issues may arise.

Entry and departure of heavy vehicles to and from the site are restricted tothe standard daylight construction times.

Noise Monitoring Due to the varying nature of the construction activities to be undertakenthroughout the project the effectiveness of the construction noise mitigationmeasures and management procedures would be reviewed regularly.Ongoing monitoring and review of the site noise management practiceswould be undertaken:

At the commencement of construction activities;

In response to a valid community complaint regarding constructionnoise; or

Where review of upcoming construction schedule indicates a highlikelihood for impact at a sensitive receptor location;

The purpose of monitoring is a proactive management tool to assist with:

Investigating the likely sources of construction noise impact;

Quantifying the extent of likely impact (through comparison with theproject noise level goals);

Identifying the need for further controls or modified site noisemanagement practises; and

Establishing the effectiveness of noise mitigation measuresimplemented.


9.4.6.2 OperationThe Contractor is required to prepare an OEMMP that includes measures to satisfy theenvironment performance objectives and criteria relating to noise and vibration for theproject, as well as regulatory requirements and conditions of approval.

The operational noise assessment has identified the potential noise impacts associatedwith the operation of the Desalination Plant are largely connected with the RODesalination Plant. Nuisance noise during operation is unlikely to be significant withcareful design of mechanical plant for noise control such as louvres which weredemonstrated during the modelling (Appendix F2) as reducing the noise by 1 – 3 dBA.A summary of recommended measures to be considered in the detailed design andoperational management stages are listed in Table 9.21.Table 9.21 Operational Noise Management and Mitigation Strategies.

Noise Source Options for Mitigation

Pump Facilities Motors associated with pump stations would be designed with considerationto noise emissions. Mitigation options may include:

Enclosures and/or louvre attenuation;

Acoustic line plant rooms;

Barriers; and

Locating plant in areas which maximise shielding provided bytopography, buildings or structures associated with the project.

Further studies Perform further investigation into the potential for noise impact (includingsleep disturbance) during the detailed design stage and incorporateacoustic treatment as required to maintain appropriate noise levels atnearest sensitive receivers.


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9.5 Waste Management9.5.1 IntroductionThe wastes produced during excavation, construction and as part of operation of theproposed Desalination Plant are outlined in this section and where possible theexpected final point of disposal has been included. The Concept Design was used toprovide the basis for all waste streams and the estimated quantities of waste produced.The final design will need to be in accordance with the environmental performanceobjectives and criteria for the project including for the management of waste.

9.5.2 ExcavationDuring the excavation phase considerable quantities of rock, sand and soil will beproduced. Excavation wastes are principally associated with construction of the intakesystem (intake shaft, intake conduit and intake pumping station) and cutting andlevelling of the site prior to construction of tanks and structures.

The performance criteria require that where possible the design should be balanced cutto fill to minimise the need to dispose of material off site.

Topsoils will, where possible be re-used as landscaping materials while rock and soilwill be used as base material during levelling of the site in preparation for theconstruction of tanks and structures. All excess materials will be taken off site fordisposal in an approved manner as grade 1 landfill.

The excavation activities require careful planning and management to ensure that theimpact on the local community and environment is minimised.

9.5.3 ConstructionQuantities of waste generated during construction phase activities will be subjected tothe site environmental management system particularly through the CEMMP. Wherepossible waste materials will be reduced in quantity or re-used and segregation ofwaste materials will be required prior to off site disposal to allow the capture ofrecyclable materials (oils, metals, glass, plastics, paper, and wood products).

Careful planning and management of the construction phase will be essential tominimise the potential waste impact on the local community and environment. Thespecifications for the project will incorporate provisions for environmental managementand mitigation measures.

9.5.4 Operation

9.5.4.1 GeneralThe Desalination Plant will generate a number of waste streams from the treatmentprocess which will require appropriate management. Wastes arising from operation ofthe plant and the management arrangements proposed are discussed below.


9.5.4.2 Intake ScreeningsThe intake screenings comprise material such as marine debris (e.g. shells and grit)and marina biota that may enter the intake and accumulate on the fine screens at theintake pumping station. The likely quantity of the marine debris captured by the screenswill be a function of the intake velocity, prevailing weather conditions (e.g. storm events)and seasonal factors.

The potential for entrainment is minimised by measures outlined in Chapter 3 and 7.

The Concept Design allows for the intake screenings to be collected in a waste skip(s)and disposed off-site to an approved waste management facility at intervals as required.

9.5.4.3 Pre-Treatment WasteThe dissolved air floatation (DAF) tanks in the Concept Design would generate frequentdischarges of the floated sludge which is delivered to the sludge thickeners.

The pre-treatment filters will be routinely cleaned to remove the floc and colloidalmaterial captured during the filtration process. The Concept Design includesbackwashing with filtered seawater and air scouring. Each primary filter is anticipatedto require cleaning once per day and secondary filters at a lower frequency with actualrequirements controlled by feed water quality and process operating conditions, whichmay vary from time to time. Dirty washwater generated during filter backwashing will bedelivered to recovery tanks where the particulate material will be settled out. In order tominimise raw seawater pumping, clarified washwater will be recycled to the inlet of thepre-treatment plant.

The solid or settled material removed during the washwater clarification process wouldbe thickened and dewatered to form waste sludge or ‘cake’. The Concept Design allowsfor thickening using a centrifuge system.

The final waste sludge would be stored for off-site disposal to an EPA approved wastemanagement facility. The sludge material would be salty and predominantly containiron hydroxide and organo-silicates from the marine environment. Based on theConcept Design, the 50 GL per annum plant would produce approximately 50 tonnes ofsludge (20% w/v dry solids) per annum. This quantity would depend on the coagulantdose, type of pre-treatment selected, and the suspended solids concentration of thescreened seawater entering the proposed Desalination Plant.

Identification of potential beneficial re-uses of pre-treatment waste forms part of thescope for the successful Contractor.

9.4.5.4 AntiscalantsProprietary antiscalants are added to the filtered seawater before it enters the reverseosmosis process to protect the membranes and enhance their performance viaprevention or minimisation of inorganic scale build-up on the membrane surface. Thereis a wide range of antiscalants on the market, with the most common chemistriesinvolving polycarboxylic acid, polymaleic acid, dendrimers or organo-phosphatepolymers. Most products are tailored for specific types of waters and sparingly solublesalts. Some products work by preventing crystal nucleation, others by retarding thegrowth of formed crystals, while others employ both antiscaling and dispersingproperties. Antiscalant doses in the feed water to the reverse osmosis system arenormally in the range of 0.5 to 6 mg/L, depending upon the product and processoperating conditions (e.g. pH, temperature, recovery rate).


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The antiscalant compounds are rejected entirely (100%) by the reverse osmosismembranes and subsequently form part of the saline concentrate stream. The conceptdesign assumes one type of ‘broad spectrum’ antiscalant is to be used for both the firstpass and second pass RO systems. However, the use of different antiscalants may beconsidered in the detailed design phase, provided compliance with the ecotoxicologicalassessment as discussed in this EIS.

9.5.4.5 Clean-in-Place (CIP) ChemicalsThe RO membranes require periodic chemical cleaning to remove accumulated foulantmaterial (i.e. salts, biofilm) over several months and maintain efficient performance, withrespect to energy consumption and permeate quality. The cleaning frequency can varyand is dependent upon the filtered seawater quality. In general, membranes arecleaned in-situ, commonly referred to as ‘Clean-In-Place’ (CIP). CIP chemicals areselected on the basis of the known or anticipated foulants. Both acid and alkalinesolutions may be employed, the selection and use of which is normally recommendedby the membrane manufacturer, based on the process operating conditions. CIPsolutions are circulated through the membrane elements at elevated temperatures (30-35o C) to dissolve the foulant material, while minimising damage to the reverse osmosismembranes.

Typical CIP chemicals may include the following:

Alkaline solutions

Sodium hydroxide;

Dodecyl sodium sulphate;

Sodium lauryl-sulphate;

Tri-sodium phosphate;

Tri-sodium polyphosphate;

Di-sodium phosphate; and

Acidic Solutions

Citric acid;

Hydrochloric acid; and

EDTA-Na (ethylene diamine tetraacetic acid- sodium salt).

Proprietary chemical blends for both acid and alkaline CIP are available. Thesechemicals reduce the need for storage and handling of multiple chemicals.

The volume of spent CIP solutions will depend on the cleaning frequency for each of thefirst pass and second pass RO systems. The first pass will require significantly morechemical cleaning then the second pass ‘polishing’ RO system. Depending upon thefiltered seawater quality, chemical cleaning of the first pass membranes may berequired once every 6 months or longer depending on operational use. The ConceptDesign has allowed for spent CIP solutions to be discharged to a collection tank forneutralisation and off-site disposal to a trade waste collection point. A variation to thisapproach could include neutralisation and disposal via the outfall. Neutralised CIPwaste could be blended with the saline concentrate. Such an approach has been


adopted for other large-scale desalination plants in Australia and overseas. This wouldnonetheless be subject to assessment against the environmental criteria andperformance objectives set for the Desalination Plant and be subject to EPA approval.

9.5.4.6 Membrane Preservative SolutionsIf the proposed Desalination Plant is taken out of service for prolonged periods, the ROmembranes will require preservation to minimise biological growth and degradation oftheir active desalination capability, in accordance with manufacturer recommendations.Sodium metabisulphite (SMBS) is the most commonly used preservative agent for ROmembrane systems. Alternative biocides are available, but are often more expensiveand toxic than SMBS, with systems requiring more significant flushing to removeresidues prior to restarting the desalination system. When the Desalination Plantrestarts, the preservative solution will need to be flushed with RO permeate (notsubjected to post-treatment) from the membranes and associated pipe-work. For theConcept Design, the spent preservative solution and associated flushing waste wouldbe collected in tanks to be neutralised and disposed off-site to a licensed trade wastedisposal point. A variation to this approach would be controlled discharge to the outfall,allowing blending of the low salinity solution with saline concentrate. This would besubject to assessment against the environmental criteria and performance objectives.

The Concept Design has assumed that the volume of preservative solution requiredwould be in the order of 25 to 40 cubic metres.

9.5.4.7 Membrane Flushing SolutionsFor short-term shutdowns (typically less than 3 days), the RO membranes are typicallystored in low salinity permeate (not subject to post-treatment or any other chemicaladdition). Upon Desalination Plant restart, the membranes would be flushed, with theflushing waste directed to either the Washwater Treatment System or the outfall.

9.5.5 General WasteThe Contractor will be required to manage waste in accordance with the environmentalperformance criteria for the project including that, where possible, waste production isminimised.

General materials arising from operation activities that are no longer required will bemanaged in accordance with industry best practice. Where practical, materials will bemade available for re-use or recycling either on site or off site by others.

Refuse produced on a daily basis during the excavation, construction and operationphases will be collected and centralised in a manner that will prevent fouling of the siteand working areas or attract vermin. All refuse will be segregated for safe disposal andsubject to the site environmental management plan and reduced, re-used or recycledwhere possible.

Where possible, design excavation works should balance cut to fill to minimise therequirement for offsite disposal. Where waste is disposed of it will be done so inaccordance with EPA requirements.

EIS – Chapter 9 Noise, Dust, Odour and Waste Management

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