Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
9.
Air quality
9.1
Overview of air quality issues
Local air quality and wind data collected by the Bureau of Meteorology at
Amberley and the Environmental Protection Agency (EPA) at Flinders View was
used for this study. Key existing activities affecting ambient air quality in the
region include the Swanbank Power Station, coal and clay mining and a solid
waste disposal facility. The pollutants relevant to this study are nitrogen dioxide,
sulfur dioxide, PM10 total suspended particulates and ozone. As a result of the
transport mode remaining undefined at this stage, reference is made to possible
pollutants emanating from both bus and rail modes.
The REF found that nitrogen dioxide was the most important pollutant for bus
emissions, and for sensitive receptors a separation distance of 20 m was
recommended from a bus station with 150 buses per hour and 20 m for a railway
station. In respect to electric trains, air pollutant emissions will be minimal.
During construction there is however the potential for elevated levels of dust.
Based on these findings, air quality impacts would be determined by virtue of
buffering the alignment and identifying sensitive receptors within this buffer.
Considering prevailing wind direction and wind speeds, impact areas are
identified and discussed.
9.2
Air quality standards and goals
National standards and goals for air quality are set by agreement between the
Commonwealth and state governments through the National Environment
Protection Council (NEPC) and published in the National Environment Protection
Measure (NEPM) for Ambient Air Quality. They deal with exposure of the general
population to air pollutants and protect against adverse health effects due to
carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3)
and particulate matter with aerodynamic diameter less than 10 μm (PM10). In
2003, the NEPM was revised to include an advisory reporting standard for PM2.5
(particulate matter with aerodynamic diameter less than 2.5 μm). These are only
applicable to residential areas well away from major industries and roadways.
The Queensland state guidelines are indicators and goals contained in Schedule
1 of the Environmental Protection (Air) Policy 1997 (EPP (Air)), which is
subordinate legislation made under the EP Act. These indicators and goals are
applied to the assessment of industrial sources of pollutants. The EPP (Air)
covers a wider range of pollutants than the NEPM guideline. The pollutants that
are relevant to this study are nitrogen dioxide, sulfur dioxide, PM10 and total
suspended particulates, as presented in Table 9-1. Ozone is also included
because it is an important air pollutant that can form in the atmosphere due to
the interaction of sunlight and other air pollutants including nitrogen dioxide.
These pollutants are relevant because they commonly occur in urban areas due
to direct emissions from traffic and are generally used as indicators of urban air
pollution. There are many other air pollutants that are identified for their odorous
PB
2134204A-RPT020-D:br
Page 95
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
or toxic properties. Ambient air quality standards are defined for some in the
Victorian State Environment Protection Policy (2001) and some in the air toxics
NEPM. These pollutants are less common, and tend to be considered on a site
specific basis.
Deposition of particulate matter can result in dust nuisance and reduced public
amenity, for example due to soiling of clothes, plants and building surfaces. This
is most commonly an issue during construction activities. The dust deposition
guideline in Table 9-1 is not defined in the EPP (Air), but has been
recommended by the EPA as a design goal for avoiding nuisance.
Table 9-1:
Air quality guidelines defined by the NEPM, EPP (Air) and
Victorian EPA
Standard
Averaging
period
Units
10,000
8 hour
g/m³
EPP(Air)
11,247
8 hour
g/m³
NEPM
320
1 hour
g/m³
EPP(Air)
246
1 hour
g/m³
NEPM
30
annual
g/m³
EPP(Air)
62
annual
g/m³
NEPM
570
1 hour
g/m³
EPP(Air), NEPM
100
24 hours
g/m³
EPP(Air)
228
24 hours
g/m³
NEPM
60
annual
g/m³
EPP(Air), NEPM
214
1 hour
g/m³
EPP(Air), NEPM
170
4 hour
g/m³
EPP(Air) , NEPM
Particulates
(PM10)
150
24 hour
g/m³
EPP(Air)
50
24 hour
g/m³
NEPM
Particulates
(TSP)
90
annual
g/m³
EPP(Air)
Particulates
(PM2.5)
25
24 hour
g/m³
8
annual
g/m³
NEPM (advisory
reporting
standard)
Pollutant
Carbon monoxide
Nitrogen dioxide
Sulfur dioxide
Ozone
Source
NEPM (advisory
reporting
standard)
2
Dust deposition
130
annual
1,3 Butadiene
73
3-minute
g/m³
Vic EPA
Benzene
100
3-minute
g/m³
Brisbane City
Council
53
mg/m /day
g/m³
Recommendation
from EPA
Vic EPA
Toluene
Page 96
10.5
Annual
g/m³
Air Toxics NEPM
650
3-minute
g/m³
Vic EPA/Brisbane
City Council
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
Pollutant
Xylene
9.3
Standard
Averaging
period
Units
Source
4,112
24-hour
g/m³
Air Toxics NEPM
411
Annual
g/m³
Air Toxics NEPM
350
3-minute
g/m³
Vic EPA
1,185
24-hour
g/m³
Air Toxics NEPM
984
Annual
g/m³
Air Toxics NEPM
Climate and local meteorology
On the regional scale the terrain surrounding the area of the Ipswich to
Springfield PTC is quite complex with ranges to the south and to the north-west
of Springfield, Redbank Plains and Ripley Valley, resulting in drainage flows from
these ranges influencing morning winds. While the Springfield, Redbank Plains
and Ripley Valley areas are located approximately 30 km from the coast, the sea
breeze can reach the region in the afternoon.
The nearest long-term record of climatic conditions is available from the Bureau
of Meteorology station at Amberley Airport. The Bureau of Meteorology has
conducted monitoring at Amberley for many years. An automatic weather station
capable of recording half-hourly average wind speed, wind direction,
temperature and relative humidity was installed in October 1995. Before this time
3-hourly observations were recorded. This data has been included in the climate
assessment covering the period from 1941 to 2004.
The typical climate for the region features mild to hot summers and cool winters.
Its inland position ensures a wider temperature range than coastal areas but
results in restricted rainfall.
9.3.1
Temperature, humidity and rainfall
The hottest 1-hour average temperature recorded between 1941 and 2004 was
42.6°C in January 1994. The coldest 1-hour average temperature recorded
between 1941 and 2004 was -5°C in August 1995. Figure 9-1 illustrates the
average maximum and minimum temperatures for each month.
PB
2134204A-RPT020-D:br
Page 97
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
Figure 9-1:
Mean maximum and minimum monthly temperatures (°C) at
Amberley Airport, Bureau of Meteorology, for the period 1941
to 2004
The mean 9:00 am relative humidity is highest in February averaging 54% and
the lowest in September averaging 38%. The mean 3:00 pm relative humidity is
highest in June averaging 77% and the lowest in November averaging 60%
(refer Figure 9-2).
Figure 9-2:
Page 98
Monthly mean 9:00 am and 3:00 pm relative humidity (%) at
Amberley Airport, Bureau of Meteorology, for the period 1941
to 2004
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
The mean annual average rainfall is 854 mm based on data collected by the
Bureau of Meteorology at Amberley Airport. Rainfall is the highest in the summer
months (averaging 120 mm) and the lowest in the winter months (averaging
35 mm) (refer Figure 9-3).
Figure 9-3:
9.3.2
Mean monthly rainfall (mm) at Amberley Airport, Bureau of
Meteorology, for the period 1941 to 2004
Wind speed and wind direction
Wind flows in the area are important for understanding the capacity of the air to
disperse air pollutants. For dispersion of pollutants, worst-case meteorological
conditions are generally light winds during the evening or early morning. Wind
speed is also important for dust emissions during the construction phase.
Exposed dust sources, such as stockpiles or exposed land will have higher dust
emissions during strong winds than during light winds. During strong winds, dust
particles are more likely to be lifted by the wind and carried further off-site than
during light winds.
Wind data collected by the Bureau of Meteorology at Amberley Airport and the
EPA at Flinders View are the nearest available set of high-quality meteorological
information to Springfield, Redbank Plains and the Ripley Valley area.
Figure 9-4 illustrates the distribution of winds during the period 1997 to 2004 at
Amberley Airport. Figure 9-5 shows the distribution of winds based on time of
day. Light south-westerly to southerly winds as well as north-westerly winds
dominate in the early morning with moderate to strong north-westerly winds
occurring in the afternoon due to the arrival of the sea breeze.
PB
2134204A-RPT020-D:br
Page 99
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
Page 100
Figure 9-4:
Wind rose for Amberley Airport, Bureau of Meteorology,
January 1997 to September 2004, all hours
Figure 9-5:
Wind rose for Amberley Airport, Bureau of Meteorology,
January 1997 to September 2004, based on time of day
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
Figure 9-6 illustrates the distribution of winds for 1997 to 2005 at Flinders View.
Figure 9-7 shows the distribution of winds based on time of day. The distribution
of wind direction is similar to that of Amberley but the winds at Flinders View are
lighter than at Amberley. Very light south-easterly and westerly winds dominate
in the early morning, with moderate to strong north-easterly winds occurring in
the afternoon due to the arrival of the sea breeze. In the morning, 45% of winds
are very light (less than 1 m/s) with winds typically from the west, north-west and
south-east due to drainage flows from the ranges.
PB
Figure 9-6:
Wind rose for Flinders View, Bureau of Meteorology, January
1997 to September 2004, all hours
Figure 9-7:
Wind rose for Flinders View, EPA, January 1997 to December
2005, based on time of day
2134204A-RPT020-D:br
Page 101
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
9.4
Existing ambient air quality
Key existing air polluting activities include the Swanbank Power Station, coal and
clay mining activities and a solid waste disposal facility. Emissions from these
operations are predominantly nitrogen dioxide, sulfur dioxide and PM10. Motor
vehicles travelling along the Cunningham Highway and Redbank Plains Road
are a source of carbon monoxide and nitrogen dioxide. All of these sources
contribute to the local air quality.
The local air quality is expected to be represented in the Flinders View
monitoring data, which measures PM10, sulfur dioxide, nitric oxide, nitrogen
dioxide and oxides of nitrogen. The 95th percentiles for various averaging periods
for each pollutant are presented in Table 9-2. For PM10, the 24-hour average is
exceeded seven times for a particular year. These are usually due to bushfires.
The nearest station that records benzene, toluene and xylene is located at
Springwood. There is no continuous monitoring data available for other volatile
organic compounds (VOCs) such as 1,3-butadiene in the Brisbane air shed. The
NSW Department of Environment and Conservation measure 1,3-butadiene and
benzene in the Sydney CBD where a ratio of 14.5 % (mass basis) is found
between these compounds. This ratio has been applied to calculate 1,3butadiene concentrations from the Springwood benzene levels.
Carbon monoxide is estimated from the EPA’s monitoring station at South
Brisbane. Background levels of various air pollutants assessed in this study are
summarised in Table 9-2.
Table 9-2:
Measured 95th percentile concentrations for various
pollutants across the monitoring network, EPA data,
1997 – 2004
Pollutant
Sulfur dioxide
Nitrogen dioxide
95th percentile
(g/m³)
1-hour
16
24-hour
12
annual
4
1-hour
50
annual
18.7
PM10
24 hour
30
Carbon monoxide
1-hour
1,925
8-hour
1,790
3-minute
9.1
Annual
2.4
1,3-butadiene
3-minute
1.3
Toluene
3-minute
30.8
Annual
7.0
3-minute
41.3
Annual
14.2
Benzene
Xylene
Page 102
Averaging period
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
9.5
Potential impacts and mitigation strategies
9.5.1
Health effects
In respect of electric trains air pollutant emissions will be minimal. Trace
amounts of ozone and nitrogen oxides may be emitted due to electrical arcing,
but these will be insignificant. Some dust may be raised from the track bed due
to air movement generated by trains, and small quantities of fine particles may
be generated by brake pads etc. Most of this material will fall within a few metres
of the railway track.
If the preferred mode of transport is selected as diesel burning buses, the main
pollutants will be carbon dioxide, carbon monoxide, traces of nitrogen oxides,
sulfur dioxide, particulate matter and unburned hydrocarbons. Uncontrolled
diesel emissions are similar but generally with lower carbon monoxide
emissions.
Carbon dioxide is usually not considered in terms of health impacts, but is
considered in terms of greenhouse impact. Lead and ultra fine particles form a
subset of particulate emissions. Ozone is generated by photochemical activity
involving hydrocarbon and nitrogen oxide emissions from vehicles and other
sources. Unburned hydrocarbons and particles can contribute to odour
emissions from vehicles. If, however, new generation compressed gas driven
buses are selected as the preferred transport mode, the above mentioned
pollutants no longer apply.
Carbon monoxide
Carbon monoxide is a colourless, odourless, toxic gas. It binds strongly to
haemoglobin in the bloodstream, to form carboxy-haemoglobin. Because the gas
has an affinity for haemoglobin 250 times that of oxygen, it interferes with the
capacity of the blood to transport oxygen to the tissues.
The World Health Organisation recommends that, to protect people from harmful
effects, ambient concentrations of carbon monoxide are kept below the 4% level.
The eight-hour goal noted by the EPA provides a significant margin for safety.
This is appropriate for this type of guideline, which is designed to protect a wide
range of people in the community, including the very young, the elderly and the
infirm.
Oxides of nitrogen
Nitric oxide constitutes the bulk of the emissions from a combustion process.
This compound is generally oxidised, within times in the order of minutes to
hours, to form nitrogen dioxide. Other compounds, such as nitrous oxide and
nitrogen tetroxide, could be formed in smaller quantities. The total of all oxidised
nitrogen species is referred to as ‘oxides of nitrogen’.
Nitric oxide is a colourless, odourless gas. It is slightly soluble in water and has a
strong affinity for blood haemoglobin, forming methaemoglobin. This results in a
reduction in the capacity to supply oxygen to the tissues. In the presence of
oxidising agents or solar radiation, nitric oxide is rapidly oxidised to nitrogen
dioxide.
PB
2134204A-RPT020-D:br
Page 103
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
Nitrogen dioxide is a reddish-brown gas with a pungent odour. It is irritating and
toxic, and is also a mutagen. It is almost insoluble, but combines with water in
the lungs to form nitrous and nitric acids. In combination with hydrocarbons and
sunlight, it is responsible for the formation of smog.
The EPA has set a one-hour goal and an annual average goal for nitrogen
dioxide.
Particulate matter
Particulate matter from vehicle exhausts can irritate mucous membranes lining
the respiratory tract and may give rise to breathing difficulties. Some constituents
(for example, polyaromatic hydrocarbons, derived from hydrocarbons in fuel)
may be carcinogenic.
The size of particles has an important bearing on their respiratory effects.
Particles with an aerodynamic diameter of 10 microns (PM10) are inhalable
(small enough to be breathed in). Thoracic particles are defined as those which
penetrate beyond the larynx, and those with a diameter of less than 2.5 microns
(often referred to as ‘respirable particles’) are small enough to penetrate to the
deep lung where they are retained. Particles may be amongst the most harmful
components of vehicle exhaust. Several international studies indicate a link
between mortality rate and high annual average concentrations of airborne
particles.
Ultra-fine particles
Ultra-fine particles are those of sub-micron size, generally considered as part of
fine particles, (those with a diameter of less than 2.5 microns). Ultra-fine particles
have recently been identified as a cause of respiratory problems for residents
near roads. Studies from the United Kingdom have reported that even small
concentrations of ultra-fine particles can cause alveolar inflammation and
exacerbation of lung disease in susceptible individuals (Seaton et al. 1995;
Donaldson and MacNee 1996).
High emissions of ultra-fine particles can be expected from poorly maintained
diesel vehicles under high load. Poorly maintained catalyst-equipped gasoline
engines can also be significant sources of ultra-fine particles.
Lead
Lead is a cumulative poison affecting the blood, nervous and reproductive
systems. It has been linked with mental retardation in babies and children. Tetraethyl lead was used as an additive to fuels to increase octane rating and reduce
valve-stem
friction.
Approximately
70–75% of lead in fuel is emitted from the exhaust, with 40% emitted in the form
of particles sufficiently small to remain airborne for extended periods of time.
Leaded and unleaded petrol contain 200 mg/L and 2.5 mg/L respectively
(Environment Australia 2000). Lead use in fuel is being progressively phased
out.
The National Health and Medical Research Council goal for lead is 1.5 Pg/m3
(90-day average). The National Environment Protection Measures draft standard
is 0.5 Pg/m3 on an annual basis. Since the introduction of unleaded petrol, there
Page 104
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
has been a steady and unambiguous decline in lead emissions and in the
concentration of lead in the air in urban environments, clearly demonstrating the
effectiveness of this strategy. It is expected that lead will no longer be a
significant emission from motor vehicles by 2010. These potential impacts will
only apply if the chosen mode of transport is diesel driven buses.
Sulfur dioxide
Sulfur dioxide is an acid gas, which can have harmful effects on the respiratory
system (but only at concentrations well above those experienced due to traffic)
as well as on vegetation and building materials. It is a minor component of motor
vehicle emissions, due to the low sulfur content of Australian petrol.
Ozone
There is evidence that high concentrations of ozone increase susceptibility to
infections, irritate mucous membranes and reduce lung function, resulting in
temporary respiratory difficulties in sensitive individuals and in those undertaking
vigorous exercise. USA studies have found that exposure to ozone
concentrations of 160–300 Pg/m3 for periods of an hour reduced lung function in
adults and children undertaking vigorous exercise. USA studies also found a
wide variation in ozone sensitivity. Although 5–10% of the population is sensitive,
asthmatics appear to be no more or less so than others. High concentrations of
ozone are intermittent and essentially a regional problem. Ozone levels near a
roadway are likely to be lower than those elsewhere in the area because of the
scavenging action of nitrogen oxides.
Odours
Odours associated with transport arise as a result of the volatile or gaseous
nature of fuels and their combustion products. There is, as with noise pollution, a
subjective element in the perception of odour as a nuisance. Some people object
to the smell of kerosene, petrol or diesel fuel, while others do not. Diesel vehicles
are generally less odorous than they were 10 or 20 years ago due to
improvements in engine technology, and many people are now more concerned
about the smell of hydrogen sulfide, released under certain driving conditions
from cars with new three-way catalysts. Significant traffic flows, freely moving
traffic and an open layout are conducive to rapid dispersion of odours.
Vehicle emissions and photochemical smog
Photochemical smog is a complex mixture of compounds produced by reactions
between nitrogen oxides and reactive hydrocarbons in the presence of sunlight.
Motor vehicle emissions are generally found to be major contributors to
photochemical smog in and near large cities. The improvement in traffic flow,
resulting in reduced levels of stopping and starting, should reduce the emission
of both nitrogen oxides and hydrocarbon compounds.
9.5.2
Vegetation impacts
The main pollutants implicated in plant damage, sulfur dioxide and ozone, have
little relevance to motor vehicle or railway emissions. There is a small quantity of
sulfur in fuel, but the concentrations of sulfur dioxide near roads are negligible.
Emissions of nitric oxide by vehicles will actually reduce ambient ozone
PB
2134204A-RPT020-D:br
Page 105
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
concentrations as they react to form nitrogen dioxide. Emissions from trains will
be minimal. Oxides of nitrogen generally only reduce plant growth if
concentrations of 1,000 Pg/m3 are applied for periods of three hours or more.
Visible injury requires approximately three times the concentration for this
exposure duration (Doley 1981; NAS 1977). Nitrogen dioxide generally
comprises 10 to 20% of total nitrogen oxides near roads. The Queensland
Environmental Protection (Air) Policy provides (as indicators for biological
integrity) nitrogen dioxide goals of 4.6 ppmh for 4 hours and 1 ppmh for one
year, based on European studies for sensitive species.
Particulates affect plants only if they have a pH greatly different from the neutral
or if they form a hard crust on plant leaves. Rates of deposition of alkaline dust
up to 1.5 g/m2/day have little harmful effect on plants (Lerman and Darley 1975).
Such deposition rates would only be encountered in the immediate vicinity of
unsealed construction roads. It is most unlikely that normal soils or road
construction materials would be highly acidic or alkaline.
9.5.3
Operational impacts
The area to the north of the Cunningham Highway is largely medium density
residential housing with the area to the south of the Cunningham Highway being
largely undeveloped rural land, although development of the area is likely in the
immediate future. It must be understood that this impact study does not consider
future development in the area and the receiving environment could substantially
change over the next 5-10 years. Air quality standards may also change over
this period. Therefore the issues pertaining to air quality will need to be
assessed in greater detail as part of a future Environmental Impact Assessment.
No significant impacts are anticipated since all sensitive receptors are located
outside of the critical zone of 20 m as identified in the REF. This however does
not preclude negative impacts from occurring and will need to be reconsidered
prior to construction as part of future environmental assessments undertaken for
approval of the project.
9.5.4
Construction impacts
Potential air quality impacts during construction include airborne dust and
exhaust pollutants from construction plant. Construction impacts are likely to
occur and will have a far greater impact than operational impacts. Airborne dust
would be generated from a number of sources:
ƒ
clearing of vegetation and topsoil
ƒ
excavation and transport of materials
ƒ
loading and unloading of trucks
ƒ
re-entrainment of deposited dust by vehicle movements
ƒ
wind erosion from stockpiles and unsealed roads.
The Queensland guidelines for dust deposition from construction activities are
equivalent to approximately 130 mg/m2/day monthly average of insoluble dust at
residences (EPA 1994). The appropriate goal for this project is a total dust
Page 106
Ipswich to Springfield Public Transport Corridor Study
Environmental Impact Study
deposition rate of 4 g/m2/month measured on an annual basis (equivalent to 130
mg/m2/day).
High wind conditions would increase the emission rates of airborne dust from
stockpiles and exposed areas, while reducing the concentration of vehicle
exhaust emissions. During high wind conditions, particular attention should be
paid to dust suppression.
Because the majority of the length of the preferred corridor is distant from
residences, fugitive dust should not be a major issue. Air quality management
planning should consider the following measures:
ƒ
applying water by truck sprays on all exposed areas as required to minimise
dust emissions
ƒ
restricting dust-generating activities such as blasting or topsoil removal
during high winds or during more stable conditions with winds blowing
toward nearby residences
ƒ
limiting the amount of cleared vegetation
ƒ
siting the construction compound away from residences
ƒ
avoiding spillages and prompt cleanup
ƒ
covering haul vehicles moving outside the construction site
ƒ
restricting speed of construction vehicles to below 30 km/hour
ƒ
visually checking particulate emissions from diesel vehicles and regular
maintenance
ƒ
monitoring odours and hydrocarbon emissions from pavement, spray sealing
work and line painting
ƒ
monitoring emissions from on-site concrete batching plants and bitumen
batching plants
ƒ
protect stockpile materials from high winds
ƒ
prohibiting burning or incineration on site
ƒ
monitoring dust near residences close to high activity areas identified during
the construction period using dust gauges, high volume sampling or other
ambient monitoring techniques to determine whether controls are being
applied appropriately. Dust gauges should be adequate for areas where
impact is likely to be low. If levels approaching air quality guidelines are
found, more frequent high-volume sampling is recommended.
These control methods will be formalised in the EMP prior to the commencement
of construction. The EMP should also identify any maintenance requirements of
the proposed air quality management measures. The extent of monitoring
including duration, number of locations and type of equipment to be used would
be determined in consultation with the appropriate government advisory bodies.
PB
2134204A-RPT020-D:br
Page 107