Monitoring Noise and Air Quality in Auckland’s CBD

Buckley is charged with delivering the Wai Horotiu Queen Street project and taking it through the various project lifecycle stages through to completion.

“Obviously, the Auckland city centre has a huge residential population. It’s got 40 thousand plus residents. So, we wanted to understand, initially, what the current status quo is with the number of daily traffic vehicle trips and how that’s potentially impacting the quality of the air and the quality of the noise levels in that environment.

“Through the work that we’re doing – basically reducing Queen Street’s vehicle capacity by half – we wanted to see if there were any correlations between the traffic volumes and any measurable improvements on the air quality and the environmental noise quality,” he said.

Project Overview

Buckley approached Spark looking for sensor solutions that could help monitor the impact of the project changes on the environmental quality.

The sensor scope Buckley required focused on monitoring key pollutant gases within traffic emissions and sound monitoring equipment to provide background noise level.

“We’re not looking at identifying what the specific noise generators are,” says Buckley. “We’re more interested in what the overall ambient impact is.

“So, as we reduce the traffic lanes and introduce a low emissions area, the hypothesis is that the air quality is going to improve and the ambient noise level is going to reduce – both of those then contributing to residents’ quality of life, and that of visitors, workers, or anybody who is using the area,” he says.

Being at the bottom of a valley, Queen Street feels the impact of industry, the port, and general traffic, part of which includes approximately 600 bus movements per day, many of which are diesel. Buckley says however, that there are some existing factors that will change in time, especially once the City Rail Link completes and AT metro limits buses on Queen Street to just the City Link.

The Adroit Solution

The environmental monitoring solution utilises three sensors measuring noise (dB), dust (particle matter) and nitrogen dioxide (NO2). Data is uploaded to the Adroit Platform for visualisation and reporting every 10 minutes via the Spark Cat M1 network. Measurements are taken within every 10 minute period as follows.

Dust – measured over a one-minute period, with the sensor taking multiple readings to create an average.

Noise – measured over a one-second period, multiple readings and averages into a one-minute reading.

Nitrogen dioxide – measured every one minute.

The data can be exported from the Platform and fed into other data sources such as vehicle counts (inc passenger numbers), bus journey times and pedestrian counts to provide different metrics on the project’s performance and overall benefits.

Baseline sampling data was collected in a pre-construction period (December 2021) for comparison.

“We started construction on the 10th of January 2022, and the construction period is expected to be fully complete by November. Then we’re scheduling a second sampling point in December ’22, which will give us the comparison data that we need.

There were three key factors that were important to Buckley: portability – the ability to potentially move the sensor to other locations in the future; affordability – the ability for the project to add multiple sensors to measure KPI’s; and self-sufficiency – the ability to use solar charging, avoiding the need for additional infrastructural costs.

Council has an existing air quality sensor array on Queen Street that is a very high-accuracy piece of equipment, but is very expensive. As a result, there’s only one and it’s in a static location.

Results

With live data now streaming in, Buckley says he’s already seeing some surprises.

“Two things have become quite apparent: Queen Street is a noisy environment, but the air quality is actually not bad.”

With regard to air quality, Buckley reports that sensors are reporting that Queen Street is well within the World Health Organization’s standards for healthy, livable streets.

“So that’s obviously a good story, the data that we’re seeing says it’s actually pretty good and with the changes that we’re making on the ground, it’s only going to improve.”

Noise levels however, present a not-so-rosy picture for Queen Street. The district plan noise levels in the Business – City Centre Zone between 7am – 11pm, states an equivalent continuous level of 65 dB LAeq and between 11pm – 7am its 60 dB LAeq

“So it is quite useful and quite usable data,” he says.

Buckley says that having a stream of live data reveals some interesting and surprising outcomes.

“I see some large spikes on the data and it just coincides with an antisocial motor vehicle, for example. It’s quite a common complaint from city centre residents. At two o’clock in the morning, you see a 90 dB spike in noise and can make these links.

“So, seeing things like that happening, means there’s evidence to support investment to improve the situation.

“The benefit of having these sensors installed is measurable and repeatable data.
“It’s quite a useful tool,” Buckley says.

Adroit Environmental Monitoring Solutions

As an end to end solution provider, Adroit supplied the device hardware, IoT connectivity, nationwide installation, maintenance, and ongoing support.

Adroit has proven solutions, not just for construction, but for all environmental monitoring applications, including waterway and water catchment monitoring, agriculture and aquaculture water quality monitoring, workplace environmental monitoring, and solutions for urban and regional environmental monitoring.