Click on a marker on the map below to see recent data.
|Location||Number of exceedances|
|Nelson airshed A at St Vincent Street:||0|
|Nelson airshed B1 at Tahunanui:||2|
Since September 2016 the National Standards required that there be no more than three high pollution nights per year.
By 2020 there shall be no more than one high pollution night per year in order to meet the standard.
A High Pollution night is defined as when the daily PM10 reading is above 50 µg/m3.
Tasman District Council follows the national Good Practice Guide for Air Quality Monitoring and Data Management (Ministry for the Environment, 2000 or subsequent editions) and equipment manuals. Audits and calibrations have been undertaken with peer review by Air Quality Scientists and Technicians from both Nelson City Council and Watercare Services Ltd.
The equipment Tasman District Council uses was considered the best available on the market at the time of purchase and continues to be very commonly used in New Zealand, throughout Europe and the USA.
Please note that data is brought to our website via radio or cell phone. If communication problems occur, this site may not always be up-to-date.
There is currently no national or regional standard or guideline for hourly average PM10 concentrations as represented on the graph of hourly rolling averages shown above. Short term high hourly concentrations (even well over 50 ug/m3) are acceptable under the National Environmental Standard provided the 24-hour average values are below 50 ug/m3.
The plots of hourly rolling average PM10 over the past 48 hours and 24-hour average PM10 over the last week should be regarded as provisional as it has not been checked using Quality Assurance procedures. However, only very rarely do the provisional results vary from the validated results. This data are validated weekly.
Plots of the 24-hour average PM10 have been adjusted according to national protocols. The adjustment factor has been calculated using data obtained from a reference unit (Partisol) co-located with the continuous monitor (Beta Attenuation Monitor or BAM). Tasman District Council has confidence in the adjustment factor applied as its calculation has been subject to considerable peer review and the two instruments are highly correlated (r2=0.95).
We monitor air quality by measuring the amount of small particles in the air - the technical term is 'particulate matter smaller than 10 microns', or PM10. The National Environmental Standard for air quality requires that fine particles (finer than 10 micron; called PM10) must not average over 50 µg/m3 over a 24-hour period for more than one day each year.
We need to decrease the number of exceedences to no more than 1. This is because there is a very significant increase in risk to human health above this level.
Richmond has been the only place in Tasman where breaches of this standard are known to occur and this is the only designated airshed requiring improvement under this legislation.
We measure air quality in Richmond throughout the year to determine the volume of small particles in the air.
Nelson City measures smoke (PM10) at two sites, one on St Vincent St in Nelson (Airshed A), and the other on Blackwood St in Tahunanui (Airshed B).
We also measure the weather conditions in Richmond and Nelson, as wind direction, wind speed, rainfall, temperature and solar radiation may affect how air contaminants are dispersed, and where they build up. This is important in the process of managing Richmond’s air quality problem during winter. This will help us understand if air quality is improving for a certain meteorological condition.
To measure air quality in Richmond, we use a Beta Attenuated Monitor (BAM) to find out how much suspended particulate (PM10) is in the air. We also use a Partisol for specific investigations in Richmond and other towns.
A small pump in the instrument sucks air through a size-selective inlet and through a filter at a constant rate. A constant source of high energy electrons (beta particles) is beamed through the filter where the PM10 deposit is collected. The number of these electrons is reduced (attenuated) by the PM10 deposit on the filter at a rate directly related to particulate mass (weight) which is then calculated. Because the machine knows how much air was sucked through the filter the concentration of PM10 in outside (ambient) air can be calculated.
The information from the BAM is then automatically sent to Tasman District Council via the phone lines along with wind speed, wind direction and temperature data. Data you see on the website is raw data directly fed from the instrument.
The 1- minute or hourly PM10 readings are averaged into a daily reading, and are also displayed as daily averages for the past week and winter season.