Monitoring air quality is part of Council’s consent compliance programmes, which check resource consent conditions for things such as industrial and agricultural emissions are being met.
We also conduct regular testing of air quality at ‘worst-case scenario’ checkpoints, such as high traffic intersections in urban centres or around industrial areas to be sure the region’s good air quality is being maintained.
How are we doing?
The Government has set a National Environmental Standard for air quality (NES)(external link), and requires regional councils to demonstrate that air meets the standard.
Taranaki is one of only two regions that has never exceeded the NES air quality guidelines, always falling into the Ministry for the Environment's categories of 'Acceptable' to 'Excellent'. Intensive ongoing air quality monitoring is therefore not required in Taranaki.
What do we look for?
Since 1991, the Council has gathered air quality data at up to 20 representative sites across the region including urban, industrial, rural, coastal and pristine areas.
Particulate matter (PM10 ), or tiny particles in the air (less than 10 micrometres in diameter per cubic metre of air), is potentially dangerous because it can penetrate deep into the lungs, causing illnesses such as cancer, and lung and heart disease leading to premature death.
There are many sources of PM10, including motor vehicles (particularly diesels), wood and oil-burning processes and coal-fired power generation, incineration and waste burning, and natural sources such as pollen, rock-dust and sea-spray.
Council scientists use filtering equipment to take air samples, then measure the concentrations of PM10 it contains. All results from surveys to date have been well within national standards.
We also measure finer PM2.5 concentrations around the region. Commonly derived from incomplete combustion, these particles pose a more particular public health risk than PM10. All PM2.5 monitoring results are also well within international guidelines.
Nitrogen oxides (NOx ) come from natural sources such as vegetation and soil. They also come from motor vehicles and indoor domestic appliances such as gas stoves, or unflued gas heaters. In poorly ventilated areas, these gases can accumulate and can aggravate asthma and reduce lung defences against bacteria.
We survey (NOx ) at seven sites throughout the region as part of state of the environment monitoring. We also monitor NOx at other sites in the region as part of consent compliance monitoring.
All results from Council monitoring to date have been consistently well below the NES, with 80% in the Excellent category of the environmental performance indicator and 20% within the Good category.
Volatile organic compounds
The Council also monitors air quality for gases that are classified as volatile organic compounds (VOCs). The four most common VOCs are benzene, toluene, ethylbenzene and xylenes—often found together and referred to as BTEX.
These volatile gases occur naturally and are also produced during the combustion of organic matter such as petroleum products. Other common sources are solvents (including paints and glues), and petrol and diesel fuels. Prolonged or chronic exposure to high levels of these compounds can affect the kidney, liver and blood systems.
Results of surveys for BTEX at four general sites in Taranaki are well within recommended National Ambient Air Quality guidelines(external link) (2002). Results of monitoring around significant potential sources, such as gas production stations, as part consent compliance programmes are also well within guideline values.
Carbon monoxide (CO) comes from motor vehicle emissions and from burning natural gas, wood or coal for home heating or industrial purposes. In high concentrations carbon monoxide can cause dizziness or aggravate heart conditions. It can be fatal.
Carbon monoxide concentrations in New Plymouth meet the NES, with monitoring results showing extremely low levels of CO.
We also routinely undertake consent compliance monitoring for carbon monoxide in Taranaki around significant potential sources such as gas production stations. Results have never reached more than a trivial level of either the National Ambient Air Quality guidelines or the NES guideline values.
Results of our monitoring
Results of all of our monitoring are published in our environmental monitoring technical reports and in the Air Quality chapter of the 2015 State of the Environment Report. There are links on this page. You'll also find links to consent monitoring reports relating to air emissions.
The New Plymouth District Council holds one consent relating to air emissions from the crematorium on Junction Rd, New Plymouth.NPDC Crematorium consent monitoring 2019-2020 (454 KB pdf) Earlier reports
Lower Waiwhakaiho air discharges (Glen Avon-The Valley industrial area)
Companies with consents allowing emissions to air in this urban New Plymouth area include Downer EDI Works Ltd, Fitzroy Engineering Group Ltd, Katere Surface Coatings Ltd, Ravensdown Fertiliser Co-op Ltd and Intergroup Ltd.Lower Waiwhakaiho air discharges consent monitoring 2018-2019 (1.9 MB pdf) Earlier reports