Kawerau District Council has received several noise complaints this week related to a geothermal operation happening in the district.

Two separate geothermal operations are under way, with flow-testing of wells being carried out for Ngāti Tūwharetoa Geothermal Assets in the Spencer Avenue area and drilling being done for Mercury Energy further from town.

Both organisations had obtained the necessary resource consents from the district council and Bay of Plenty Regional Council to carry out the work.

On Monday, NGTAL started geothermal well testing works over five days. This flow-testing work is at a site located off Spencer Avenue and is being undertaken by Western Energy Services.

A flyer placed in letterboxes in the neighbourhood in advance of the work stated it would be carried out 24 hours a day, and no disruption to surrounding businesses or other activities was expected as the equipment being used was designed to muffle noise.

However, complaints about the work have been made to the council and on social media, with some saying they couldn’t sleep and saying it felt like earthquakes were happening. Many people thought the sound was coming from the drilling work being carried out by Mercury Energy.

Kawerau District Council says the Mercury Energy geothermal drilling operation set up outside town was not responsible for the noise that has affected some residents this week. Photo: Troy Baker.

The Beacon visited the area around Spencer Avenue during daylight hours yesterday and experienced a low-frequency, juddering vibration, which could be distinctly heard from residential properties in the Domett Street area.

One resident told the Beacon she found the sounds and the unusual amounts of steam worrying, especially in the context of the area being earthquake prone. However, she said living in a mill town, she often heard loud noises and usually kept her radio or television on at night to mask the sound.

Another felt the disruption was minimal and only for a short period, and that everyone in the neighbourhood had been well notified ahead of time.

“Some people just like to complain. Motorbikes and big V8 vehicles driving up and down the road make much more of a disturbance.”

Neither resident wanted to be identified.

The council said it received noise complaints from residents overnight on Monday and, after discussions with NTGAL, advised the public of new operating hours. It stated that work would not be carried out overnight after 8pm and they had contacted the residents who had made the noise complaints to advise them of the source, and of the revised hours.

The testing work was expected to be completed either this week. The vibrations were caused by the stream and water hitting the baffles inside the containers used to push steam through for the testing. While the containers were designed to muffle the noise, wind direction could also play a large part in noise levels.

A map of well drilling sites from Mercury Energy shows where drilling will take place from October to December (Well 1). While dates are approximate, drilling is likely to start on well two in December and well three in February. Image supplied.

Meanwhile, Mercury Energy is drilling three new wells for its power station and has brought a drilling rig from Iceland with a team of about 40 people, mostly New Zealanders to carry out the work. The three sites are all located off State Highway 34, east and north-east of the town.

The wells they are drilling will be between 2000 metres and 2500 metres deep.

A spokesperson said Mercury Energy’s Kawerau Geothermal Power Station has been operating since 2008.

“During that time, we’ve learned more about the geothermal reservoir deep within the earth. Mercury is drilling three new wells - two production wells, which take steam and fluid to run the power station, and one reinjection well, which puts fluid back into the ground, as part of our sustainable management of the field and to be able to continue to produce energy to the grid.”

The council said the work was far enough away from any residential areas not to cause any noise disturbance. However, some extra traffic could be expected at certain times.

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