Rotorua Lakes Council and Bay of Plenty Regional Council (BOPRC) are embarking on a free geothermal well maintenance audit in a joint project to ensure the safety of geothermal wells in Rotorua.
The audit will be jointly funded and coordinated by the two councils and will take place between September and November 2016.
Rotorua Lakes Council chief operating officer Dave Foster says it’s important to maintain geothermal wells to a safe standard and is also a requirement of the district council’s geothermal bylaw 2016 and BOPRC resource consents.
“It’s important because of the risks involved when using geothermal fluids, including uncontrolled discharge of hot water and steam, poisonous gasses such as H2S, and potential well blowouts,” Mr Foster says.
About 50 geothermal wells were audited in 2015 as the first part of the well audit project.
Many of the owners of these wells have since completed the required work to bring their wells up to standard, Mr Foster says. This next phase will followup on the previous audit as well as complete an audit of the remaining consented sites in the Rotorua city which number about 70.
“The response to the 2015 audit was generally positive and we expect that to continue. However, where wells have not been properly installed or maintained, well owners will have responsibility for these repairs.”
The audit will be undertaken by Kiwi Geothermal and well owners will be provided with a copy of the report and notified if any maintenance issues are found. Well maintenance audits will then be carried out every three years.
Group manager science and strategy Fiona McTavish, says the regional council is also working on a related project to trial safe and cheaper ways to measure use of geothermal fluid. This should help consent holders, who are required to provide this kind of information to council. The information is used to improve our understanding of the resource and to help ensure it is used efficiently and sustainably.
“We are trialing measurement techniques on about 12-15 wells and if successful, this approach may be rolled out to all wells in the future. The regional council is funding the trial and disruption to well owners should be minimal.”
An information session will be held for well owners on Thursday, 15 September 2016 at Rotorua Lakes Council, between 11-1pm and 4-6pm. Staff from both councils (supported by maintenance experts) will be available to talk to well owners.
The Rotorua geothermal system is managed primarily to protect surface features, but geothermal wells are also used to extract fluid and/or heat for bathing, heating etc. There are about 300 operating wells covered by about 140 consents in Rotorua city, as well as hundreds of abandoned or decommissioned wells.
Three agencies have roles in the management of geothermal wells. Bay of Plenty Regional Council (BOPRC) allocates geothermal fluid under the Resource Management Act 1991; Rotorua Lakes Council ensures public safety under its Geothermal Bylaw 2016; WorkSafe NZ has a role in ensuring safety in the workplace. Both regional resource consents and the Rotorua Lakes Council bylaw require that geothermal wells meet best practice standards for safety purposes (e.g. to avoid injury from H2S or hot fluid) and to allow monitoring of the resource.