Blenheim and Picton meet air quality goals

Annual air quality monitoring in Blenheim and Picton shows positive results, with both towns remaining within national standards.

Monitoring in Blenheim found no breaches of the National Environmental Standard (NES) for Particulate Matter, PM10, in 2025, according to a report presented to the Council’s Environment and Planning Committee.

The highest daily concentration recorded at 44 micrograms per cubic metre (µg/m3) was well below the NES limit of 50µg/m3. While daily peaks of PM10 and PM2.5 were slightly higher than in 2024, the number of days exceeding the proposed Ministry for the Environment (MfE) guideline for PM2.5 dropped to its lowest since monitoring began. The annual average for PM10 in Blenheim also remained below both the revised World Health Organisation (WHO) guideline and the MfE guideline.

Strategic Planner Sarah Pearson said the data showed air quality in Blenheim continued to trend positively. “Improvements in emissions likely exceeded those anticipated under the Proposed Marlborough Environment Plan,” she said. “However, should new standards for PM2.5 be introduced, further reductions would be needed to meet the stricter targets.”

In Picton, 2025 was the first full year of air quality monitoring. The highest daily PM10 level was just 23µg/m3, and the annual average was 9.6µg/m3, both well within national and international guidelines. While technical issues affected the reliability of PM2.5 data, overall air quality in Picton was assessed as high.

The monitoring results and full reports will be made available on the Air Quality Monitoring webpage
Go to the Air Quality Monitoring webpage