Effective groundwater management is vital for helping in situ recovery (ISR) and other mining sites operate safely, efficiently and meet government regulations. It is also crucial for protecting the environment and local communities.
However, the current best-practice method for ISR operations relies upon a manual “pump and test” method that has significant challenges. These include high installation and labour costs, high maintenance requirements, and lengthy processing times that delay corrective actions and can put the environment at risk.
“To date, there is no embedded automated groundwater monitoring system that exists for ISR operations,” CSIRO industry trial project lead, Daniella Caruso, says.
World's first automated, real-time groundwater monitoring sensor system
Developed by CSIRO, SENSEI is the world’s first automated, real-time monitoring and reporting system that operates in remote and extreme conditions, including low pH conditions (acid) and groundwater pressures of at least 20 bar (i.e. to depths of around 200 metres below ground level).
The end-to-end sensor, hardware and software solution features robust, solid-state electrochemical sensors for measuring multiple chemical properties in embedded aqueous applications.
The small, proprietary button-sized sensors include a novel reference electrode, and measure oxidation-reduction potential and pH. Third party conductivity, pressure, depth and temperature sensors have also been integrated into the product.
The systems are currently hard-wired for data and power transfer between the local surface communication gateway and sensor pack. Data from the gateway can be transmitted to an online server using wireless options.
Measurements can be taken and transmitted as often as every few seconds, and sent to an online data server. This data can be viewed securely and live from anywhere in the world via a dashboard that makes it easy to interpret and make quick decisions.
Customisable sensor system being trialed with Heathgate Resources
SENSEI offers a solar-powered solution for off-the-grid applications, and can be integrated with existing third party systems or devices.
“We can customise the software and hardware, by adding or removing features so it suits our customer’s purpose and needs,” Ms Caruso says.
In partnership with Heathgate Resources, Boss Resources and National Energy Resources Australia (NERA), CSIRO is trialling 10 SENSEI sensor packs at Heathgate’s Four Mile West uranium mine, situated in far-north South Australia.
“The objective is to test the sensors in controlled conditions alongside current manual monitoring techniques,” Heathgate Resources HSSE regulatory and compliance superintendent, Kathryn Levingstone, says.
“And with government support – subject to it all going well – have it recognised it as an approved or best-practice technology.”
If the first trial phase is successful, 16 more sensor packs will be deployed in April 2019.
“It will be a 12-month trial that will give us a really good indication of how the sensors are working,” Ms Caruso says.
“We are already receiving measurements from the wells, so that’s given us confidence we’re measuring and collecting data, which is exciting.”
Because staff no longer need to manually take, transport and analyse samples, or enter and report data, SENSEI will reduce operational costs and help Australian mining companies be more globally competitive.
“The uranium market is in quite a tight place,” Ms Levingstone says.
“Some of our overseas counterparts can produce uranium via ISR methods at a much more competitive price, due to lower costs and less rigorous regulatory standards.”
SENSEI sensors are robust for harsh environments
SENSEI sensors are also easier and cheaper to maintain than their current counterparts.
“With a standard commercial pH electrode, you need to calibrate and do general maintenance – like cleaning and topping it up with solution – on a daily basis,” Ms Caruso says.
“Whereas, our solid state pH electrode is fine for months with no daily maintenance once calibrated.”
The sensors are more stable and have a significantly longer lifespan than other sensors in harsh environments, thanks to the unique solid-state electrodes, construction materials and specialised, Australian-designed casing and electronics.
According to SENSEI’s co-inventors, CSIRO scientists Miao Chen and Mikko Vepsalainen, a traditional pH electrode is not designed to be embedded inside wells at depths of 100 to 200 metres. But, SENSEI’s stable reference electrode allows its sensors to operate for extended periods with little signal drift. The cases are also highly acid resistant and can withstand the pressures at these well depths.
SENSEI’s real-time results improve safety for the environment and local communities. Mining companies get results on-the-spot – instead of waiting up to two months using manual systems – so they can respond immediately to changes in water conditions. This will also help improve all-round confidence in groundwater monitoring.
“By getting real-time results, you can ensure that you’re not having a negative impact, or that any impact, is contained immediately,” NERA project manager, Tim Duff, says.
Data to increase transparency and meet government regulations
It’s hoped that online access to real-time data will increase trust between industry and government regulators.
“We’d love to increase transparency with government agencies through use of this technology. The live, web-based monitoring portal enables review of the data at any location and at any time,” Ms Levingstone says.
“SENSEI is a great example of Australian-developed technology, local manufacturing and local employment combining to solve a national challenge,” CSIRO’s SENSEI portfolio leader, Kathie McGregor, says.
Through ON Accelerate, a national technology and innovation accelerator program powered by CSIRO, the team behind SENSEI received funding to make a viable product. The team commissioned an Australian electronics manufacturing company to make a prototype, and contacted Heathgate to see if it was of interest.
CSIRO’s team tailored SENSEI to Heathgate’s specific needs, including adding water pressure and depth sensors and solar-powered gateways.
Heathgate successfully applied to NERA for funding for the trial and brought Boss Resources on board as part of the funding agreement.
Mr Duff explains that NERA was happy to support the trial, seeing it as an opportunity for increased industry research collaboration with potential to commercialise Australian technology.
“Regulatory groundwater monitoring for recovery operations is a costly and resource-intensive activity,” Mr Duff says.
“We hope to show that this innovative Australian solution can be successfully and cost-effectively integrated into operational environments to reduce monitoring costs, and improve timeliness and environmental outcomes.”
Potential applications beyond mining
Dr McGregor explains that CSIRO is exploring opportunities to partner with other mining and METS companies to conduct more commercial field trials of SENSEI in a variety of applications.
As it needs little maintenance and is stable in acidic environments, SENSEI is ideal for monitoring areas with low pH and where current sensors aren’t effective, such as acid-mine drainage legacy sites, and remote or abandoned mining sites. It could also be used to monitor mine tailings, environmental toxicity, water quality at waste treatment plants or mineral leaching processes. It may even have applications in the pharmaceutical, food and beverage industries.
Australian technology an opportunity for international markets
SENSEI also offers a great opportunity to promote Australian technology overseas.
“One direct application within international in situ mining operations, is export into the United States and Kazakhstan markets, to improve global environmental outcomes in those areas,” Mr Duff says.
But, until the trial’s completion in 2019, the focus remains on the Australian mining industry.
“Nearly every mine has an impact on groundwater and needs to monitor and manage it,” Ms Levingstone says.
“Without any current commercially available technology to do that, the potential opportunities within the mining industry are tremendous.”
- As of July 2020, SENSEI technology has been re-named and is now known as Vesi™. Vesi is a Finnish word for water, reflecting the cultural heritage of one of the team members developing the technology and its application.