Home fires main source of Picton emissions

Domestic heating is the main source of daily emissions in Picton during the winter months, an emissions inventory study by Environet Limited has found.

Strategic Planner Sarah Brand told last month’s Environment and Planning Committee meeting that the purpose of an inventory is to estimate the contribution of different sources of emissions to air and evaluate changes over time.

“This is the first emission inventory for Picton,” she said.

In 2019-2020 an air quality screening study was undertaken by NIWA following concerns expressed by the community about Picton’s air quality.

Results indicated that elevated levels of some contaminants could exceed National Environmental Standards (NES) for air quality guidelines, triggering the need to install compliant monitoring. Two sites have recently been selected and monitoring equipment has been sourced.

The inventory evaluation focuses on particulate matter (PM10 and PM2.5) and other contaminants including carbon monoxide, nitrogen oxide, sulphur oxide, volatile organic compounds and carbon dioxide. PM10 is particulate matter of 10 microns or less which can be inhaled deep into the lungs.

Emission sources included in the inventory were domestic heating, motor vehicles, port activities, industrial and commercial activities and outdoor burning.

“Domestic heating was found to be the main source of daily winter PM10 emissions in Picton accounting for 75 per cent of the daily winter PM10,” Sarah said.

The next most significant contributors were outdoor burning at 12 per cent, industry at nine per cent with shipping and rail contributing six per cent.

Shipping emissions produced less than one tonne of PM10 per year - around six per cent of all emissions. The report estimated that PM10 emissions from ferries was around 0.31 tonnes, followed by recreational vessels at 0.28 tonnes.