A DISPERSION MODELLING A A SSESSMENT OF IR ...proposed peaking plants ( temperature, stack velocity,...

For the Attention of: Prepared by: Mr Gerry Kelly, Mr Sean Creedon Senior Consultant Senior Environmental Consultant ESBI Engineering & Facility Management Ltd Reviewed by: Ms. Lisa Blyth Technical Manager Ref: ECS2763– November 07

A DISPERSION MODELLING

ASSESSMENT OF AIR EMISSIONS

FROM THE PROPOSED PEAKING

PLANTS AT THE EDENDERRY

POWER FACILITY AS PART OF AN

ENVIRONMENTAL IMPACT

STATEMENT

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31

ESBI Engineering & Facility Management Ltd. ECS2763

Bord na Móna Technical Services November, 07

Executive Summary Bord na Móna Technical Services (TS) was commissioned by ESBI to carry out an Air Dispersion Modelling impact assessment of the proposed installation of two Pratt and Whitney TwinPacs peaking plants at the Edenderry Power facility, Ballykilleen, Edenderry, County Offaly as part of an Environmental Impact statement. The purpose of this assessment was to establish the potential air quality impact of the operation of the plants on the ambient air levels of Nitrogen Dioxide and Sulphur Dioxide. This report outlines the air quality impact of these sources on the surrounding area, sensitive receptors and at the boundary. Each Pratt and Whitney TwinPacs peaking plant have two air emission points. These consist of 20m high stacks located at each end of the plant structure. All plant infrastructural information was supplied ESBI. The emission rates for the existing on-site Main Boiler stack (A1-1) was taken from the IPPC licence for the facility (IPPC P0482-02). The emission characteristics of the proposed peaking plants ( temperature, stack velocity, volumetric discharge , emission rate) were taken from a previous report on the same type of plant carried out by URS Ireland ( ‘Air Dispersion Modelling for an IPC Licence Application, Rhode, Co. Offaly. URS Ireland 2004). These rates were then inputted into the AERMOD dispersion model and the worst case odour impact was determined at the boundary and sensitive receptors based on the worst case meteorological year (1994). The air dispersion modelling demonstrates that the ground level impact of the combination of the existing A1-1 emissions and the proposed peaking plant emissions exceed the Air Quality Standards ( AQS) for both nitrogen dioxide and sulphur dioxide. The worst case levels occur at the north east boundary the facility. The worst case impact at the boundary is predicted to be 156.7% and 169.48%of the 1hr and annual NO2 limit values respectively and 114.6%, 244.5% and 226.4% of the 1hr, daily and annual average SO2 limit values respectively. A number of sensitive receptors located outside the boundary of the facility were examined. The dispersion modelling assessment indicates that the predicted impact at these locations is not significant. The worst case impact at the sensitive receptors are predicted to be 38.9% and 26.8%of the 1hr and annual NO2 limit values respectively and 54.9%, 49.6% and 35.5% of the 1hr, daily and annual average SO2 limit values respectively. Respectively Submitted ___________________ __________________________ Mr. Sean Creedon Ms. Lisa Blyth Senior Environmental Consultant Technical Manager

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



TABLE OF CONTENTS

1.0 INTRODUCTION 2.0 SCOPE

2.1 Scope of Project

3.0 POLLUTANTS/AIR QUALITY GUIDELINES

3.1 Pollutants 3.2 Qxides of Nitrogen 3.3 Sulphur Dioxide

4.0 DISPERSION MODEL DESCRIPTION

4.1 Introduction 4.2 Aermod

5.0 DISPERSION MODELLING ASSESSMENT

5.1 Emission parameters 5.2 Modelled Domain/Receptors 5.3 Meteorology/Surface Characteristics 5.4 Treatment of Terrain 5.5 Treatment of Buildings and site plan 5.6 Sensitivity Analysis 5.7 Conversion ratios for NOx/NO2 5.8 Background Pollutant concentrations

6.0 ASSESSMENT OF IMPACTS

6.1 Maximum Ground Level Impacts 6.2 Discussion Of Results 6.3 Sensitivity Analysis 6.4 Conclusions

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



1.0 INTRODUCTION Bord na Móna, Technical Services was commissioned by ESBI Engineering & Facility Management Ltd to undertake a desk based dispersion modelling assessment of selected air emissions from a proposed peaking plant to be located within the grounds of the Edenderry Power facility, Edenderry Co. Offaly. The equipment will consist of two Pratt and Whitney TwinPacs, each comprising of two gas turbines installed back to back. Each unit will have two emission stacks with a rectangular cross section of 3.07 x 2.47m and 20m high. The units will burn gasoil with 0.1% Sulphur content and produce an electrical output of 52MW. It is estimated that the units will typically run between 0 and 500 hours annually. The equipment is proposed to be installed on a concrete pad with corresponding construction of required liquid fuel storage tanks and a demineralised water storage tank. The aim of this assessment was to determine if the potential emission from the proposed plant combined with the existing emission from the main stack of the power plant had the potential to significantly impact on ambient air quality.

The dispersion modelling assessment allows for the estimation of the predicted air quality impact on the surrounding environment.

The impact assessments are presented in the form of concentration contours/isopleths produced using US EPA approved and recommended Irish EPA dispersion modelling techniques (AERMOD v 6.1.37- issued 18th September 2007). Concentration contours are superimposed on an aerial photograph of the locality indicating percentile pollutant concentrations (using a worst case year of hourly meteorological data).

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



2.0 SCOPE 2.1 Scope of Project

The scope of the project is to establish the potential worst case impact on ambient air quality of the operation of the proposed peaking plants. The location of the existing power station is outlined in Figure 2.1 below.

Figure 2.1 Location of Existing Power station

Figure 2.2 overleaf indicates the proposed location of the peaking plants within the boundary of the facility.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



Figure 2.2 Location of Peaking plants

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



3.0 POLLUTANTS/AIR QUALITY GUIDELINES 3.1 Pollutants

ESBI staff indicated via e-mail correspondence that the two most significant air pollutants emitted during the operation of the proposed peaking plants would be oxides of Nitrogen (NOx) and Sulphur Dioxide (SO2). A number of previously determined odour emission rates are used in this dispersion modelling exercise.

3.2 Oxides of Nitrogen

Nitrogen Dioxide is classed as both a primary and a secondary pollutant, and it is one of a number of important oxides of nitrogen present in the atmosphere. Nitric Oxide (NO) and Nitrogen Dioxide (NO2) are the most abundant man-made oxides of nitrogen in urban areas. These are formed in all high temperature combustion processes, although NO predominates. Around 90% of the emissions from combustion sources are of NO rather than NO2. However, since the NO can all potentially be converted to NO2 it is usual to express all of the NOx as NO2 when making mass emissions estimates.

As a primary pollutant NO2 is emitted from all combustion processes (such as a gas/oil fired boiler or a car engine). The main sources of primary NO2 from the facility will be from air emission stacks (4 in total) from the proposed peaking plant and the main emission stack from the existing facility. As a secondary pollutant NO2 is derived from the oxidation of primary NO. Secondary pollution is usually derived from regional sources and may be used as an indicator of general air quality in the region.

Overall NOx levels in Ireland may be regarded as moderate by international standards (reference: “Ireland’s Environment 2004”, EPA April 2004).

Nitric oxide is not generally considered to be harmful to health at the concentrations found in ambient atmosphere. Once NO is mixed with air containing ozone, it quickly combines with oxygen forming NO2. In significant concentrations nitrogen dioxide can be highly toxic, causing serious lung damage with a delayed effect. Other health effects of exposure to nitrogen dioxide include shortness of breath and chest pains. It is also involved in the production of ground-level ozone, acid rain and smog.

The ambient air quality guidelines for Nitrogen Oxides are outlined in S.I. Air Quality Standards Regulations 2002 (S.I. No. 271 of 2002). The Air Quality Standards 2002 transposes the First and Second Daughter Directives relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



in ambient air, benzene and carbon monoxide in ambient air. The older air quality standards regulations (S.I. 244 of 1987) will be fully revoked by these regulations in 2009. These Air Quality Standards Regulations 2002 also transposed part of the Air Framework Directive not covered by the EPA Act 1992 Regulations 1999. Table 3.1 below describes the Air Quality Standards for this parameter.

TABLE 3.1: AIR QUALITY STANDARDS FOR NITROGEN OXIDES

Pollutant Regulation Limit Type

Margin of Tolerance

‘Limit Value’

‘Alert Threshold’

‘Upper Assessmen

t Threshold’

‘Lower Assessmen

t Threshold’

Hourly limit value

NO2 for the

Protection of Human

Health.

Averaging period = 1

hour

50% on the entry into force

of this Directive, reducing on 1 Jan

2001 linearly to reach 0% by 1 Jan

2010

200 µg/m³

NO2, not to be

exceeded more

than 18 times a

calendar year

70% of limit value (i.e. 140

µg/m³), not to be

exceeded more than 18 times in

any calendar

year)

50% of limit value (i.e. 100

µg/m³), not to be

exceeded more than 18 times in

any calendar

year)

Annual limit value

NO2 for the

Protection of Human

Health.

Averaging period = Calendar

year

50% on the entry into force

of Directive, reducing

on 1 January

2001 linearly to reach 0%

by Jan 2010

40 µg/m³ NO2

80% of limit value

(i.e. 32 µg/m³)

65% of limit value

(i.e. 26 µg/m³)

Nitrogen Dioxide

1999/30/EC

Annex II Annex V

Annual limit value

for the Protection

of Vegetation (for NOx)

Averaging period = Calendar

year

None 30 µg/m³ NOx

400 µg/m³ measured over

three consecutive

hours at locations

representative of air quality over at least

100 km² or an entire zone or agglomeration, whichever is the smaller.

80% of limit value (24 µg/m³)

65% of limit value (i.e. 19.5 µg/m³)

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



3.3 Sulphur Dioxide

SO2 is produced when fuels containing sulphur are burned. SO2 is a corrosive acid gas and when mixed with moisture in the atmosphere creates sulphuric acid, which falls as acid rain. Both wet and dry deposition has been implicated in the damage and destruction of vegetation and in the degradation of soils, building materials and watercourses. The major sources of SO2 in Ireland are from energy generation (electricity stations) and commercial & residential heating units. Transport’s contribution is less significant since the introduction of sulphur less fuels but vehicles do emit some SO2. The trend in SO2 emissions over the period 1990 to 2002 has shown a decrease of almost 50%. Power stations remain the principal source of this type of emission with combustion sources in the industrial and residential/commercial sectors largely accounting for the remainder of emissions. (Reference: “Ireland’s Environment 2004”, EPA April 2004). As is the case for Nitrogen Oxides the ambient air quality guidelines for Sulphur Dioxide are outlined in S.I. Air Quality Standards Regulations 2002 (S.I. No. 271 of 2002). Table 3.2 overleaf outlines the applicable Air Quality Standards.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



TABLE 3.2: AIR QUALITY STANDARDS FOR SULPHUR DIOXIDE

Pollutant Regulation Limit Type

Margin of

Tolerance

‘Limit Value’

‘Alert Threshold’

‘Upper Assessmen

t Threshold’

‘Lower Assessmen

t Threshold’

Hourly limit value for

the Protection of Human

Health.


hour

150 µg/m³ (43%) on the entry into force

of this Directive, reducing

on 1 January

2001 linearly to reach 0%

by 1 January

2005

350 µg/m³,

not to be exceeded more than 24 times a

calendar year

- -

Daily limit value for

the Protection of Human

Health.


hours

None

125 µg/m³,

not to be exceeded more than 3 times a

calendar year

60% of 24-hour limit value (i.e. 75 µg/m³, not to be exceeded

more than 3 times in any

calendar year)

40% of 24-hour limit value (i.e. 50 µg/m³, not to be exceeded

more than 3 times in any

calendar year)

Sulphur Dioxide

1999/30/EC

Annex I Annex V

Limit value for the

Protection of

Ecosystems.

Averaging period = Calendar year; and winter (1 Oct to 31 March)

None 20 µg/m³

500 µg/m³ measured over

three consecutive

hours at locations

representative of air quality over at least

100 km² or an entire zone or agglomeration, whichever is the smaller.

60% of winter limit value (12

µg/m³)

40% of winter limit

value (8 µg/m³)

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



4.0 DISPERSION MODELLING DESCRIPTION 4.1 Introduction

Any material discharged into the atmosphere is carried along by the wind and diluted by wind turbulence which is always present in the atmosphere. This process has the effect of producing a plume of polluted air that is roughly cone shaped with the apex towards the source and can be mathematically described by the Gaussian equation. Atmospheric dispersion modelling has been applied to the assessment and control of odour for many years, originally using Gaussian form ISCST 3 and more recently utilising advanced boundary layer physics models such as ADMS and AERMOD. Once the emission rate from the source is known (g/s), the impact on the surrounding vicinity can be estimated. These models can effectively be used in three different ways. Firstly, to assess the dispersion of pollutants and to compare with the appropriate Air Quality Standards (AQS), secondly, in a “reverse” mode, to estimate the maximum pollutant emissions which can be permitted from a site in order to prevent significant air quality impact occurring and thirdly, to determine which process is contributing greatest to the ambient air quality impact and estimate the amount of required abatement to reduce this impact to within acceptable levels. In this latter mode, models have been employed for imposing emission limits on industrial processes, odour control systems and intensive agricultural processes.

4.2 AERMOD AERMOD is a new generation air modelling system used to support regulatory and non-

regulatory modelling requirements worldwide. The application is used to assess the impact of air emissions from industrial sources, and can predict pollutant concentrations from point, line, area, volume, and flare sources with variable emissions in all terrain regimes. AERMOD simulates essential atmospheric physical processes and provides refined concentration estimates over a wide range of meteorological conditions and modelling scenarios. The state-of-the-science dispersion modelling system includes:

• An advanced meteorological pre-processor to compute site-specific planetary boundary layer (PBL) parameters;

• Highly developed dispersion formulations that incorporate current PBL understanding and variables for both convective and stable boundary inversions

• Enhanced treatment of plume rise and plume penetration for elevated inversions allowing for effects of strong updrafts and downdrafts that occur in unstable conditions;

• Improved computation of vertical profiles of wind, turbulence, and temperature; • Sustained treatment of receptors in terrain ranging from flat to complex; • In homogeneity of the atmosphere by calculating dispersion as a function of

height; and • A”dividing streamline” approach for computations in complex terrain.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



Percentile analysis for pollutant emissions are calculated for the maximum 1-hour averages and 24hr averages using the Analyst 3D post-processing utility. This utility determines the maximum concentration of a pollutant from all receptors at a specific percentile, for a specific averaging period. Employing the percentile facilitates the omission of unusual short term meteorological events that may cause elevated pollutant concentrations and hence a more accurate representation of the likely average pollutant concentrations over an averaging period.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



5.0 DISPERSION MODELLING ASSESSMENT 5.1 Emission Parameters

The existing significant pollutant source at the facility is the main boiler stack. The proposed installation of the peaking plants will result in an additional four stacks at the facility. The emission parameters of the existing and proposed stacks are outlined below and overleaf.

TABLE 5.1 INPUT DATA FOR A1-1 ( MAIN BOILER STACK) Parameter Nitrogen Oxides Sulphur Dioxide

X-Co-ordinate 261071.1 261071.1 Y-Co-ordinate 227011.7 227011.7

Base Elevation (m) 69.2 69.2 Release Height (m) 70 70 Volume Flow (m3/s) 216 216

Stack Temperture 165 165 Stack Diameter 3.8 3.8

Emission rate(g/s)Note2 43.78 80.83 Periods of Operation 24 hours a day –7 days a week 24 hours a day –7 days a week

Note 1: Emission rates taken from Schedule B Table B.1.1 IPPC Licence P0482-02

The above emission rates refer to burning of Peat and a mixture of Peat and Biomass. The licence also has a provision to allow the facility to use a mixture of Peat and MBM. The emission limit values for this fuel type are considerable lower. Therefore the above emission rates represent the worst case emission levels from the existing boiler stack.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



TABLE 5.2 EMISSION PARAMETERS OF PEAKING PLANT STACKSNOTE1

Peaking Plant 1 ( Stack 1) Peaking Plant 1 ( Stack 2) Peaking Plant 2 ( Stack 1) Peaking Plant 2 ( Stack 2)

Parameter Nitrogen Oxides Sulphur Dioxide

Nitrogen Oxides Sulphur Dioxide

Nitrogen Oxides Sulphur Dioxide

Nitrogen OxidesSulphur Dioxide

X-Co-ordinate 260914 260914 260923 260923 260921 260921 260930 260930 Y-Co-ordinate 227106 227106 227109 227109 227081 227081 227084 227084 Base Elevation

(m) 69.2 69.2 69.2 69.2 69.2 69.2 69.2 69.2

Release Height (m)

20 20 20 20 20 20 20 20

Volume Flow (m3/s)

199.4 199.4 199.4 199.4 199.4 199.4 199.4 199.4

Stack Temperture

350 350 350 350 350 350 350 350

Stack Dimensions

3.07 x 2.47 3.07 x 2.47 3.07 x 2.47 3.07 x 2.47 3.07 x 2.47 3.07 x 2.47 3.07 x 2.47 3.07 x 2.47

Emission rate(g/s) 7.5 3.5Note 3 7.5 3.5Note 3 7.5 3.5Note 3 7.5 3.5Note 3

Periods of Operation Note 2

24 hours a day –7 days a week








Note 1: All input data taken from ‘Air Dispersion Modelling for an IPC Licence Application, Rhode, Co. Offaly’ URS Ireland January 2004 Note 2: This period of operation is worst case. It is projected that the plants will operate between 0 and 500 hours per year. Note 3: This emission rate was quoted in the URS report as 7g/s using 0.2% sulphur containing fuel. It is proposed to use 0.1% sulphur containing fuel in the proposed plants therefore the emission rate was adjusted accordingly.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



5.2 Modelled Domain/Receptors

A Cartesian receptor grid was constructed of 24 x 25 receptor points (total of 600 receptors) spaced 100 metres apart. The co-ordinates of these receptor grid corners are given below:

NE Corner (262200, 228500) [Easting, Northing] NW Corner (259900, 228500) [Easting, Northing] SW Corner (259900, 226100) [Easting, Northing] SE Corner (262200, 226100) [Easting, Northing]

In addition, receptors were located at selected locations on the boundary of the site. These are indicated in Figure 5.1 as a series of blue flags. A set of seven specific sensitive receptors were selected. These consisted of dwelling houses identified from an aerial photograph of the site and surrounding area as well dwelling houses noted in vicinity during previous site visits. The sensitive receptors are indicated in Figure 5.1 below and outlined in Table 5.3 overleaf.

Figure 5.1 Location of sensitive receptors

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



TABLE 5.3 LOCATION OF SENSITIVE RECEPTORS Sensitive Receptor X Co-ordinate Y Co-ordinate Elevation (m)

SR1 261161.2 226822.7 70 SR2 261341.9 226682.7 71 SR3 261301.4 226496.6 71.5 SR4 261306.9 226365.8 71.5 SR5 260984.5 227716.2 71.5 SR6 261362.2 228206.3 72 SR7 260621.5 228320.5 79

5.3 Meteorology/Surface characteristics

The meteorological data for three years, from 1993 to 1995, for Claremorris Meteorological Station was used in the dispersion modelling assessment. This meteorological station is approximatley135km from the Edenderry facility location. A graphical depiction of the frequency of wind speed and wind direction for 1993, 1994 and 1995 is highlighted in Figures 5.2 to 5.4 below.

Figure 5.2 Windrose for Claremorris meteorological station 1993

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31





For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:31



The surface characteristics in the surrounding area of the facility are relatively uniform with cut and developed bog predominating as well as significant areas of grassland. Also, there are a number of sections of forestry in the surrounding area. These characteristics were incorporated into the meteorological data using the AERMET program. Using this program the data was processed from Stage 2 to Stage 3 using the site specific surface characteristics. The three surface characteristics for each type of land use (bog, grassland and forestry) were inputted into the AERMET program prior to processing to the Stage 3 phase. The three characteristics are surface roughness {zo}, the Albedo { r } and the Bowen ratio { Bo}.

5.4 Treatment of Terrain

The terrain grid was constructed based on the ordnance survey maps of the surrounding

area. Grid references of know elevations were collated and using the SURFER 8 Contouring and Surface Mapping Program a terrain grid corresponding to the receptor grid was created.

The elevations of the receptor locations were obtained from an aerial photograph of the

area obtained from the Ordnance Survey. Elevations and heights of the surrounding terrain were obtained from a 1:50,000 scale discovery series ordnance survey map. . Elevations were taken from map contours and bench marks throughout the area of the receptor grid. Terrain heights were taken into account for all of the modelling undertaken. For the purpose of this modelling assessment elevated terrain data was used. The terrain heights ranged from 70 meters to 90 meters.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



5.5 Treatment of Buildings and Site Plan

A number of significant buildings were included in the dispersion model. These buildings were chosen on the basis that the height of each structure was 40% of the lowest stack height. In this case that eliminated any structures that were less than 8 metres in height (peaking plant stacks are 20m in height). Table 5.4 below outlines the description, location and dimensions of each of the buildings inputted into the model. TABLE 5.4 CHARACTERISTICS OF SIGNIFICANT ON-SITE BUILDINGS

Building ID Description x co-

ordinate y co-

ordinate Elevation Height Length Width Radius

1 Main building 260982 227001 69 50 Polygon 2 Peat Storage 260926.9 227156.4 69 21.4 80.4 30.6 N/A 3 Cooling towers 261005.9 227013 69 14.6 127 17 4 Day Tank 260949 227061 69 9 N/A N/A 5.35

5 Untreated Fuel tank one 260955 227041 69 9 N/A N/A 4.75

6 Untreated Fuel Tank 2 260958 227028 69 9 N/A N/A 4.75

7 Air intake inlet 260905 227104 69 9.755 3.7 3.3 N/A 8 Air intake inlet 260929 227112 69 9.755 3.7 3.3 N/A 9 Air intake inlet 260912 227079 69 9.755 3.7 3.3 N/A 10 Air intake inlet 260939 227089 69 9.755 3.7 3.3 N/A

11 Demineralising tanks 1 261024.5 227040.7 69 13.7 N/A N/A 5.35

12 Demineralising tanks 2 261032.8 227049.7 69 13.7 N/A N/A 5.35

The site boundary and location of each building within the site was obtained from a site layout drawing supplied by ESBI.

5.6 Sensitivity Analysis Sensitivity analysis is required to be carried out in order to determine the variability in

predicted concentrations due to changes in the model input data. The sensitivity of the model was determined for variation in meteorological data and the presence and absence of on-site buildings.

5.7 Conversion Ratios for NOx/NO2

In determining the impact of Nitrogen Dioxide from combustion sources it is important to note that of the Nitrogen Oxides, Nitric oxide is the most significant form emitted

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



(typically more than 90%). Conversion of Nitric oxide takes place in ambient air and the conversion rate is dependent on a number of factors such as ambient Ozone concentration, presence of daylight and the presence of organic compounds and radicals. The Environment Agency (Air Quality Modelling and Assessment Unit) have produced guidance on how to estimate the level of Nitrogen Dioxide impact in ‘Air Dispersion Modelling Report Requirements’ EA 2004. The guidance on the conversion ratios is as follows:

The guidance recommends a phased approach for assessment. This includes:

1. Screening/worst case scenario

50% and 100% of the modelled values should be used for short term and long term average concentration respectively. If PEC (process contribution + “relevant background concentration”) exceeds the relevant air quality objective then proceed to step 2 Long-term: “Relevant background concentration” = background annual means: Short-term: “Relevant background concentration” = 2 x background annual means

2 Worse case scenario

35% for short-term and 70% for long-term average concentration should be considered. If PEC exceeds the relevant air quality objective, then proceed to step 3.

3. Case specific scenario

Operators are asked to justify their use of percentages lower than 35% for short term and 70% for long term in their application reports.

• The validity of“ozone –limiting “procedure for assessment of likely maximum conversion of NOx to NO2 should be assessed on a case-by-case basis.

• In some models, ozone photochemistry algorithms may have been used in the prediction of NO2 concentrations. Because of doubts on the validation of these modules and uncertainties in the values used for input parameters such as ozone concentrations, sunlight, etc it is advised that uncertainties be quantified and justified before modelled predictions are accepted.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



5.8 Background Pollutant Concentrations

The Irish EPA carries out ambient air quality monitoring under the specific requirements of the Air Quality Standards Regulations 2002. These regulations require that the EPA provide the public with information on ambient air quality. This information must be up to date and available on a widespread basis. These regulations are a result of the Air Framework Directive 96/62/EC. This directive requires that member states divide their territory into zones for the assessment and management of air quality. In Irelands case there are four zones ranging from Zone A to Zone D. The extent of monitoring and assessment in each zone is determined by population size and air quality status. The facility location fails within Zone D (the predominantly rural zone). Therefore the average air quality levels recorded by the EPA for this zone will be used as the background concentrations for this assessment. Table 5.5 below outlines the background level applied in the assessment.

TABLE 5.5 BACKGROUND LEVELSNOTE 1 OF NO2AND SO2

Nitrogen Dioxide Location Concentration (µg/m3)

Killkitt, Co. Monaghan 2 Glashaboy, Co. Cork 9 Mountrath, Co. Laois 12

Average 7.7 Sulphur Dioxide

Shannon Estuary 3 Mountrath 4

Killkitt 3 Average 3.3

Note 1: Background levels were taken from ‘Air Quality in Ireland 2005- key indicators of Ambient Air Quality’EPA

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



6.0 ASSESSMENT OF IMPACTS 6.1 Maximum Ground Level Impacts

Outlined in Table 6.1 are the predicted worst case pollutant impacts. These impacts have been adjusted to include the reference background concentrations.

TABLE 6.1 WORST CASE GROUND LEVEL PREDICTED IMPACTS FROM AERMOD DISPERSION MODELLING ( BACKGROUND ADJUSTED)

Nitrogen Dioxide Note 2 Sulphur Dioxide

Year 1hr average as a 99.8

percentile

Annual Average

1hr average as a 99.7

percentile

Daily average as a

99.2 percentile

Annual Average

1993 300.8 45.0 381.0 232.8 29.3 1994 313.4 67.8 400.9 305.6 45.3 1995 309.1 62.9 395.3 254.1 42.0

Limit Values Note 1 200.0 40.0 350.0 125.0 20.0

Note 1: Limit values taken from S.I. 271 of 2002 Note 2: These levels are predicted using the worse case scenario (2) conversion ratiosof NOx to NO2

All of the above maximum ground level impacts occur at a location to the north east of the proposed location of the peaking plants. The distance from the nearest peaking plant stack to the maximum impact location is 84m (Grid ref 260988E, 277168N). This grid reference is on the boundary of the facility. Table 6.2 overleaf outlines the impact at the nearest sensitive receptors during the worst case meteorological condition that occurred in the 1994 data set from Claremorris meteorological station.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



TABLE 6.2 WORST CASE GROUND LEVEL IMPACT AT SENSITIVE RECEPTORS USING CLAREMORRIS METEORLOGICAL DATA SET 1994 (BACKGROUND ADJUSTED)

Nitrogen Dioxide Sulphur Dioxide Sensitive receptor

X Co -ordinate Y Co-ordinate 1hr average as a 99.8

percentile

Annual Average

1hr average as a 99.7

percentile

Daily average as a 99.2

percentile

Annual Average

SR1 261161.2 226822.7 77.8 10.7 192.2 62.0 7.1 SR2 261341.9 226682.7 72.6 10.5 196.2 64.3 7.5 SR3 261301.4 226496.6 63.5 9.5 179.7 74.9 6.4 SR4 261306.9 226365.8 58.5 9.3 159.8 58.3 6.0 SR5 260984.5 227716.2 50.6 10.6 153.4 61.4 8.6 SR6 261362.2 228206.3 40.0 9.9 107.9 35.0 7.6 SR7 260621.5 228320.5 47.7 9.2 107.2 31.7 6.3

Limit Values Note 1 200.0 40.0 350.0 125.0 20.0 Note 1: Limit values taken from S.I. 271 of 2002

A number of air quality concentrations are plotted as isopleths in appendix 1. These contour plots displayed in Figures 1.1 to 1.5. They show the worst case ground level impacts for the Claremorris meteorological data 1994 as a series of percentiles and annual maximum plots. The 1hr hourly average NO2 concentrations are displayed as 99.8 percentiles. The NO2 annual average contour plot is displayed as a maximum. The 1hr hourly average and daily average SO2 concentrations are displayed as 99.7 and 99.2 percentiles respectively.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



6.2 Discussion of Results

Comparison of the maximum ground level prediction in Table 6.1 with the appropriate ambient Air Quality Standards (AQS) indicates that the operation of the proposed peaking plants will result in exccedence of the limit values at the north east boundary of the facility. Examination of the predicted impacts when the model is run without any buildings indicates that the existing building would have a significant impact on the plume dispersion from the proposed plants and cause significant building downwash of the emission plume. Comparison of the maximum ground level impacts at the nearest sensitive receptors in Table 6.2 with the appropriate ambient Air Quality Standards (AQS) indicates that the operation of the proposed peaking plants will not result in a significant impact at these locations. In general the maximum predicted impacts are estimated at Sensitive receptor location SR1. At this location the impacts are predicted to be 38.9% and 26.8%of the 1hr and annual NO2 limit values respectively and 54.9%, 49.6% and 35.5% of the 1hr, daily and annual average SO2 limit values respectively.

6.3 Sensitivity Analysis

The results of the examination of the variation between the 1993 to 1995 meteorological data sets from the Claremorris metrological station are outlined in Table 6.3 below;

TABLE 6.3 PERCENTAGE VARIATION IN METEORLOGICAL DATA SETS ( BACKGROUND ADJUSTED)

Nitrogen Dioxide Sulphur Dioxide 1hr average as a 99.8 percentile Annual Average 1hr average as a

99.7 percentile Daily average as a 99.2 percentile Annual Average

2.3 23.2 2.9 15.6 24.7

The above table indicates that there is low sensitivity to meteorological data in the short term predicted concentrations with a higher sensitivity been displayed for the longer term predicted concentrations. Table 6.4 overleaf outlines the significant impact that the on-site buildings have on the dispersion of proposed emissions from the facility

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



TABLE 6.4 PERCENTAGE REDUCTION IN MAXIMUM GROUND LEVEL IMPACT ( ALL SIGNIFICANT SITE BUILIDIGNS REMOVED)

Nitrogen Dioxide Sulphur Dioxide 1hr average as a 99.8 percentile Annual Average 1hr average as a

99.7 percentile Daily average as a 99.2 percentile Annual Average

91.7 96.6 85.6 91.6 92.6 The percentage reduction outlined in Table 6.4 indicate the significant impact of the on site buildings on the dispersion of the pollutants.

6.4 Conclusions

A number of conservative assumptions were made during the assessment of the potential impact on air quality of the installation of the proposed peaking plants. These are as follows:

• Existing boiler stack is operating at maximum capacity and maximum emission rates

• Peaking plant operates 24hr a day , 7 days a week ( proposal is for 0 to 500 hours per year)

The dispersion modelling assessment indicates that the emission from the proposed peaking plants will have a significant impact on ambient air quality at the boundary of the facility. This impact is predicted to be located at the north eastern boundary of the facility which reflects the prevailing wind direction of the meteorological data set. The assessment also indicates that the emissions from the proposed plants will not have a significant impact on the nearest sensitive receptors.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



Appendix 1 Isopleths

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



Figure 1.1 Maximum ground level 1 hr average NO2 levels as a 99.8 percentile

Figure 1.2 Maximum ground level Annual average NO2 levels

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



Figure 1.3 Maximum ground level 1 hr average SO2 levels as a 99.7 percentile

Figure 1.4 Maximum ground level Daily average SO2 levels as a 99.2 percentile

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



Figure 1.5 Maximum ground level Annual average SO2 levels

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32

ESB International - Dublin 011660-22-RP-0001 Issue Number A Edenderry Noise Modelling 05 December 2007

C:\Program Files\Neevia.Com\Document Converter\temp\011660-22-RP-0001_A_01.doc Page 2 of 8

CONTENTS

1. INTRODUCTION 3

2. NOISE MODELLING 3

2.1 Noise Model 3

2.2 Brief Description of ISO 9613-2:1996 3

2.3 Noise Model Input Data 5

3. NOISE MODEL RESULTS 7

3.1 Noise Model 7

3.2 Cumulative Impact 7

4. DISCUSSION OF RESULTS 8

APPENDIX A

Equipment and Associated Sound Power Levels Input to The Model

APPENDIX B Locations of the Proposed Principal Noise Sources and Modelled Receptor Points

APPENDIX C Diagrams of Site Outlay and Noise Iso-contours

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



1. INTRODUCTION

Project Management Group (PM) was requested by ESB International (ESBI) to carry out a Noise Modelling study for the Edenderry Power Plant, Edenderry, Co. Offaly. The purpose of the modelling is to assess the contribution of proposed generators to noise levels at the nearest noise sensitive location to the site. This report details the findings of the study.

2. NOISE MODELLING

2.1 Noise Model

The Bruel & Kjaer Predictor Type 7810 software package was used to model the noise levels to be emitted to the surrounding environment from the proposed generators.

Predictor Type 7810 is a proprietary noise calculation package for computing noise levels in the vicinity of industrial sites. Calculations are based on the International Standard ISO 9613-2: 1996 “Acoustics – Attenuation of Sound Outdoors – Part 2: General Method of Calculation.” This method has the scope to take into account a range of factors affecting the attenuation of sound including:

• Magnitude of the noise source in terms of sound power;

• Distance between the source and the receiver;

• Presence of obstacles such as screens or barriers in the propagation path;

• Presence of reflecting surfaces;

• Hardness of the ground between the source and receiver;

• Attenuation due to atmospheric adsorption;

• Meteorological effects such as wind gradient, temperature gradient and humidity.

Calculations are performed over octave bands from 63 Hz to 8 kHz and results are reported in overall A-weighted decibels (dBA).

2.2 Brief Description of ISO 9613-2:1996

ISO9613-2:1996 calculates the noise level based on each of the factors discussed above. However, the effect of meteorological conditions is significantly simplified by calculating the average downwind sound pressure level, LAT(DW), for the following conditions:

• Wind direction at an angle of ±45° to the direction connecting the centre of the specified receiver region with the wind blowing from source to receiver, and;

• Wind speed between approximately 1ms-1 and 5ms-1, measured at a height of 3m to 11m above the ground.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



The equations and calculations also hold for average propagation under a well developed moderate ground based temperature inversion, which commonly occurs on clear calm nights.

The average downwind sound pressure level from any point source at a receiver location, LAT(DW), is determined by calculating LfT(DW) which is the equivalent continuous downwind octave-sound pressure level at the receiver location. This is calculated for each point source, and its image sources, and for the eight octave bands with nominal midband frequencies from 63Hz to 8 kHz. The equation for calculating this parameter is given below:

ADLDWL cWfT −+=)(

where:

Lw is the octave band sound power level produced by the point source;

Dc is the directivity correction for the point source;

A is the octave band attenuation that occurs during propagation, namely attenuation due to geometric divergence, atmospheric absorption, ground effect, barriers and miscellaneous other effects.

The agreement between calculated and measured values of LAT (DW) support the estimated accuracy shown in Table 2.1.

Table 2.1 Estimated accuracy for broadband noise of LAT (DW)

Distance, d† Height, h*

0<d<100m 100m<d<1000m

0<h<5m ±3dB ±3dB

5m<h<30m ±1dB ±3dB

* h Mean height of the source and receiver.

† d Mean distance between the source and receiver.

Note These estimates have been made from situations where there are no effects due to reflections or attenuation due to screening.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



2.3 Noise Model Input Data

The model was run to determine the impact of two proposed generators on noise levels at the nearest noise sensitive location to the site.

ESBI provided un-weighted sound pressure data for the generators between frequencies 63 – 8000 Hz (see Appendix A for datasheet). The estimated major source @ 400ft data (the black curve) was taken to represent the overall sound pressure level experienced at a distance of 400 ft from each generator. However as the Predictor model requires source noise to be input as A-weighted sound power levels the provided data was converted. The first step was conversion from un-weighted sound pressure (dB) to A-weighted sound pressure dB(A). The A-weighted sound pressure levels were then converted to A-weighted sound power levels using the following equation.

Lw = Lp + 20log r + 8

where Lp is the sound pressure level at a distance of r metres from the source (r = 122m; 400ft)

and Lw is the sound power of the source

and 8 is a correction factor that takes into account the reflection of sound from the predominately paved surface between the sources (proposed generators) and the receiver (noise sensitive locations).

The sound power levels for input to the model, resulting from the above calculations are documented in Table 1 in Appendix A. The generators sound data was input to the model as two point sources. Although the generators units are very large (approx. 37m in length) each was modelled as a point source since the distance from the source to the receiver is greater than 3 times the length of the source.

The locations of the proposed generator sources and the noise sensitive receptor point are shown on the site layout plan in Appendix B.

The input data for each noise source included:

• The source positions – the proposed location on the site of each principal equipment item/noise source.

• The source elevation (metres) – the height at which noise is emitted from each noise source. Information provided by ESBI indicated that height of noise output is 5m above ground level.

• Directivity – emission direction

• Source Noise Emissions – The A weighted sound power levels for each source between frequencies 63Hz and 8kHz. In accordance with ISO 9613-2, the sound power levels at 31 Hz were not input into the model.

• Working Hours – The model allows the user to define daytime and night-time periods, so that noise levels can be predicted for each period e.g. daytime/night-time. For the purposes of this assessment, in order

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



to predict the maximum possible noise levels, all of the noise sources were assumed to run continuously during the day.

• The Receptor Positions – Receptor NSL1 is the closest noise sensitive locations to the site. NSL1 represents a single story dwelling adjacent to the southeast corner of the site (see layout in Appendix B).

• Receptor Elevation – Input into the model as 1.5m to represent average head height.

• Ground Conditions - Ground conditions between the noise sources and the receptor points were also included in the model. A background map of the proposed site was included in the model for reference purposes.

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



3. NOISE MODEL RESULTS

3.1 Noise Model

Table 3.1 details the predicted maximum noise levels (dBA) at the closest noise sensitive location due to the addition of 2 No. TwinPac generators at the site.

Table 3.1: Noise Modelling Results

Receiver Point

Predicted Noise Level (dBA)

NSL 37

Noise level predictions were made for a grid of receiver points around the site and coloured iso-contours of the noise levels thereby generated to give an overall picture of the spatial distribution of noise levels within the grid. The iso-contour of predicted noise levels is contained in Appendix C.

3.2 Cumulative Impact

The cumulative effect on the nearest NSL of existing site noise levels and the predicted noise levels due to the proposed generator noise source has been calculated by the Predictor software. The results are detailed in Table 3.3.

Baseline monitoring was undertaken at the nearest noise sensitive location to the site in November 2007. As can be seen from Table 3.2 the LAeq result for the daytime monitoring period is 48dB(A). The LAeq result for the night-time monitoring period is 47dB(A). The LA90 represents the sound pressure level exceeded for 90% of the monitoring period and is a good indicator of the background noise level excluding peak noise events. Since the facility operations are relatively constant it is considered that the LA90 value (46dBA for daytime and 45dBA for night time) is a reasonable representation of facility noise contribution at this monitoring location.

Therefore the ambient LA90 values were used to represent the existing level contribution of the site at the noise sensitive location for the purpose of cumulative impact analysis.

Table 3.2: Noise Monitoring Results from 27th November 2007

Receiver Point

LAeq

dB(A)

LAMAX

dB(A)

LA10

dB(A)

LA90

dB(A)

NSL

Daytime Ambient Noise 48 59 49 47

NSL

Night time Ambient Noise

47 67 48 45

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32



Table 3.3: Cumulative Effect of Ambient Noise as LA90 and Predicted Noise from the proposed generator

Receiver Point Existing Site Contribution (Monitored LA90)

Predicted Noise Level Contribution of Generators (dBA)

Predicted Cumulative Noise Level Contribution of site + Generators (dBA)

NSL

Daytime Ambient Noise

47 37 47

NSL

Night time Ambient Noise

45 37 46

4. DISCUSSION OF RESULTS

The results of the cumulative noise modelling (Table 3.3) show that the noise contribution from the proposed generators has a minimal affect on the current noise levels at the nearest NSL as a result of the site. It should be noted that the human ear cannot perceive changes in sound level of less than 3 dBA (Bies, David A. and Hansen, Colin H. Engineering Noise Control Theory and Practice 3rd Edition, 2003).

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32


C:\Program Files\Neevia.Com\Document Converter\temp\011660-22-RP-0001_A_01.doc

APPENDIX A

EQUIPMENT AND ASSOCIATED SOUND POWER LEVELS INPUT TO

THE MODEL

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32


011660-22-RP-0001_A_01.DOC

Table 1: Sound Power Levels For Equipment Input To Noise Model

Source Description & Ref. No. Octave Bands Hertz (Hz)

Sound Levels per band

63 125 250 500 1K 2K 4K 8K Total

Un-weighted Sound Pressure Level @ 400 ft (122m) – Provided (dB)

64 58 53 46 46 47 43 32 68.7

A weighted calculated Sound Pressure Level @ 400 ft (122m) – Provided (dBA)

38 42 44.5 43 46 48 44 31 53.0

Sound Power calculated for a TwinPac Generator

87.7 91.7 94.2 92.7 95.7 97.7 93.7 80.7 102.7

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:32


011660-22-RP-0001_A_01.DOC

APPENDIX B

LOCATIONS OF THE PROPOSED PRINCIPAL NOISE SOURCES AND

MODELLED RECEPTOR POINTS

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:33


C:\Program Files\Neevia.Com\Document Converter\temp\011660-22-RP-0001_A_01.doc

Site Layout – Edenderry Power Plant

Nearest Noise Sensitive Location

Locations of the Proposed Principal

Noise Sources

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:33


011660-22-RP-0001_A_01.DOC

APPENDIX C

DIAGRAMS OF SITE OUTLAY AND NOISE ISO-CONTOURS

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:33

NSL

Industrial Noise - ISO 9613.1/2, Final New Area - version of Final New Area - MODELLING NOV 2007 [K:\Projects\011319~1\22ENVI~1\110NOI~1\FINALE~1] , Predictor Type 7810 V4.00

-227000

261000

LEGEND

Building

Ground regionHousing regionIndustrial siteFoliage regionPoint sourceGridGrid pointSurface contourLine sourceGPS calibration pointReceiver

20.0 - 30.0 dB(A)

30.0 - 40.0 dB(A)40.0 - 45.0 dB(A)45.0 - 50.0 dB(A)50.0 - 55.0 dB(A)55.0 - 70.0 dB(A)70.0 - 100.0 dB(A)

period: Day period

MODELLING NOV 2007

0 m 100 m

scale = 1 : 4000origin = -227400, 260800

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 26-07-2013:00:59:33

A DISPERSION MODELLING A A SSESSMENT OF IR ...proposed peaking plants ( temperature, stack velocity,...

Documents

Transcript of A DISPERSION MODELLING A A SSESSMENT OF IR ...proposed peaking plants ( temperature, stack velocity,...