Summary
The NSW Government maintains 20 air quality monitoring stations in the Hunter Valley:
- 3 government-funded stations in the Lower Hunter
- 3 industry-funded stations around the port of Newcastle
- 14 industry-funded stations in the Upper Hunter.
The government-operated, industry-funded Upper Hunter and Newcastle Local air quality monitoring networks were established in 2011 and 2014, respectively, to monitor local industrial and other pollution sources. Due to the proximity of industrial sources, the national ambient air quality standards do not apply directly to the data collected at these monitoring stations. However, the government recognises the community’s interest in knowing how air pollution levels at these stations compare against the standards. Therefore, this section refers to national standards as national benchmarks when evaluating air quality data throughout the Hunter Valley.
More information on these networks can be found on the government website, including seasonal newsletters.
Large population centres
Hunter large population centres:
- Upper Hunter – Aberdeen, Singleton and Muswellbrook
- Lower Hunter – Beresfield, Newcastle and Wallsend
- Newcastle Local – Carrington, Mayfield and Stockton.
Gaseous pollutants
Ozone, sulfur dioxide and nitrogen dioxide met the relevant hourly, daily and annual national benchmark in the Upper and Lower Hunter regions, including the Newcastle Local network, during 2020.
In comparison, in 2019, there were 5 days over the ozone benchmark in the Lower Hunter.
PM10 particles
Within the Hunter Valley, PM10 levels generally are highest at Stockton in the Newcastle port area, due to the influence of sea salt under onshore winds (Lower Hunter Particle Characterisation Study). (Refer to the Stockton tab for more information.) In the Upper Hunter region, PM10 levels generally are highest at stations closest to mining activity.
Annual averages
In 2020, annual average PM10 levels exceeded the 25 µg/m3 benchmark only at Stockton (one of 9 stations in larger population centres). Annual averages ranged from 17.7 µg/m3 at Wallsend to 34.5 µg/m3 at Stockton.
Daily averages
Daily average PM10 levels exceeded the benchmark on 17 days at one or more stations in large population centres (excluding Stockton). These occurred on:
- 1–8, 11–12, 20–21 and 23–24 January
- 19 February
- 19 August
- 29 November 2020.
At Stockton, the daily PM10 average was over the benchmark on 55 days, predominantly affected by sea salt under onshore air flows, bushfire smoke and long-range dust transport. Refer to the Stockton tab for more information.
The maximum daily PM10 averages recorded in the Hunter population centres occurred on 11 January 2020, due to a widespread dust storm through the Upper Hunter. The maximum PM10 levels in the Upper Hunter and Newcastle regions on this day were 267.7 µg/m3 at Aberdeen and 65.1 µg/m3 at Stockton, respectively.
PM2.5 particles
Annual averages
Annual average PM2.5 levels exceeded the 8 µg/m3 benchmark at Stockton, Muswellbrook and Singleton, 3 of 7 stations measuring PM2.5 in the Hunter’s large population centres (PM2.5 annual averages were not available at Newcastle in 2020 due to less than 75% of data available for the year). Annual averages ranged from 7.3 µg/m3 at Wallsend to 9.3 µg/m3 at Stockton and Muswellbrook.
Daily averages
Daily average PM2.5 levels exceeded the benchmark on 13 days at one or more large population centres. These occurred on:
- 1–5, 8–9 and 11–12 January and 24 January
- 6–8 June.
During January, the region was affected by smoke from extensive bushfires and dust storms. In June, the Hunter was affected by smoke, most likely from domestic wood heating during cold and calm overnight conditions. The Upper Hunter Fine Particle Characterisation Study found that woodsmoke was a major contributor to PM2.5 levels at Muswellbrook and Singleton in winter 2012.
The maximum daily average PM2.5 level occurred on 8 January 2020 at Newcastle in the Lower Hunter, due to bushfire smoke and long-range transport of windblown dust. On this day, PM2.5 levels in the Lower Hunter ranged from 49.7 to 78.5 µg/m3.
In the Upper Hunter, the maximum daily average PM2.5 level of 49.1 µg/m3 occurred at Muswellbrook on 5 January 2020, due to bushfire smoke and windblown dust transported into the region. On this day Camberwell and Singleton recorded PM2.5 daily averages of 36.6 and 37.2 µg/m3, respectively.
Upper Hunter air quality monitoring network
The Upper Hunter air quality monitoring network comprises 14 stations – 3 stations in larger population centres, 6 stations in smaller communities, 3 diagnostic stations close to mining operations and 2 background stations at the north-west and south-east extents of the region.
Annual averages
All monitoring stations in the Upper Hunter recorded annual average PM10 levels below the 25 µg/m3 benchmark. PM10 annual averages in the Upper Hunter ranged from 17.8 µg/m3 at Aberdeen to 24.3 µg/m3 at Camberwell.
The highest annual average PM10 levels occurred at stations closer to mines, Camberwell (24.3 µg/m3) and Warkworth (23.7 µg/m3), followed by the Muswellbrook population centre (22.5 µg/m3).
Two of 3 stations monitoring PM2.5 in the Upper Hunter, Muswellbrook and Singleton, recorded annual average PM2.5 levels exceeding the 8 µg/m3 benchmark, as noted above. PM2.5 annual averages ranged from 7.5 µg/m3 at Camberwell to 9.3 µg/m3 at Muswellbrook.
Daily averages
The Upper Hunter recorded 35 days with daily average PM10 levels over the benchmark at one or more stations, compared to 120 days in 2019.
Camberwell recorded the highest number of days over the PM10 daily benchmark in the region, with a total of 18 days, compared to 87 days at Camberwell in 2019.
All stations in the Upper Hunter, except Camberwell, recorded their highest daily average PM10 levels in January, during intense drought conditions, extensive bushfires and frequent widespread dust storms across New South Wales.
The highest daily average PM10 level of 620.7 µg/m3 occurred at the Merriwa background station on 11 January 2020, during a widespread dust storm under westerly to north-westerly winds. This was the highest daily PM10 average recorded throughout the State during 2020.
Summary of PM10 levels in the Upper Hunter 2020
# Days exceeding standard the benchmark have not been divided into exceptional and non-exceptional events, as the NEPM goals do not apply to these sites.