Determining the likelihood and cost of detecting reductions of nitrate‑nitrogen concentrations in groundwater across New Zealand

Congratulations to Matt Hanson Dumont and co-authors Zeb Etheridge and Rich McDowell on the publication of their paper on Determining the likelihood and cost of detecting reductions of nitrate‑nitrogen concentrations in groundwater across New Zealand in Science of The Total Environment. Have a read of the full paper here.

The paper summarises some of the key findings of our work on the two-year Monitoring Freshwater Improvements programme, funded by Our Land and Water and part of the National Science Challenge. The aim of the programme was to investigate how monitoring programmes can be designed to establish relationships between improvements actions and their effect; actions are being taken to improve freshwater quality, but how do we know if these actions are successful?


Main takeaways from the paper include:

  • Both the groundwater lag (the time it takes water to flow through the system) and the noise (the unexplained variation in NO3-N measurements) make it more difficult to confidently detect whether groundwater quality is improving due to national and regional policy and rules and on-the-ground actions.
  • Excluding either groundwater lag times or the impact of noise will significantly overestimate our ability to detect changes and can set unrealistic stakeholder expectations.The current monitoring network, which was predominantly designed for aquifer characterization, is not suitable for detecting NO3-N reductions of the magnitude and at the rates which are likely to be implemented. 
  • Policy-relevant changes will likely only  be detected by 40% of New Zealand’s network after 30 years.
  • Confidently detecting NO3-N reductions is a difficult task and will often require bespoke monitoring networks integrating surface and groundwater monitoring.
  • These new networks will require a significant increase in funding (100-300% increase) 

For more information on the Our Land and Water programme, see our website and the official website, where you can find all the incredible work that the wider team have put out throughout the challenge. 

Penguin fun!

At KSL, we love to dive into exciting projects, but this one really had us doing a Happy Feet dance! 🐧 Recently we’ve waddled our way into working with some rather cute and feathery clients. The Otago Peninsula Eco Restoration Alliance (OPERA) is a private eco reserve that focuses on conservation, reforestation, rehabilitation, and education. They are home to hoiho (yellow eyed penguin) and kororā (little blue penguin), as well as a whole host of other wonderful creatures. We were thrilled to carry out a catchment and water management study for the OPERA, and hope our work will help these penguins huddle happily ever after.

If you’re interested in supporting the OPERA and finding out more about what they do, check out their website: https://theopera.co.nz/

Image source: https://lnkd.in/gWDbBSQN

A Conversation with the Team: Patrick Durney

To celebrate Patrick Durney joining our team, we’ve asked him to share a little bit about himself!

Tell us a about your background:
I began my hydrogeology journey with a BSc in Geology & a Postgrad Diploma in Engineering Geology. Despite my initial preference for fieldwork, my career ironically shifted towards computational modelling and coding, shaped by diverse roles in engineering consulting and local government.
While working at the Canterbury Regional Council & later at DHI, I decided to further my education by pursuing an MSc part-time, to enhance my contributions to hydrogeology. Following this, I entered into a research role, focused on MBIE-funded projects. Although I thoroughly enjoyed the research aspect, I found my true calling in translating this research into practical, beneficial applications, aiming to solve tangible environmental problems.

What are you currently working on?
At KSL, I tackle contemporary hydrogeological challenges, notably contributing to the MBIE Future Coasts Aotearoa programme. Integrating groundwater science with computational advancements, the aim is to develop sustainable water management solutions and deepen our understanding of groundwater’s role in environmental systems.

What’s been your biggest challenge this year?

This past year has been marked by significant transitions, including the difficult decision to leave a role at LAL that I thoroughly enjoyed. Adapting to the rapidly evolving field of hydrogeology, especially keeping pace with the latest in modelling techniques & environmental policies, has been both challenging & invigorating. On a lighter note, having a  reviewer assigned for my Journal of Hydrology publication, which has only just occurred after 3 months, has been a peculiar saga in itself!

What’s been your biggest success this year?
Completing research commitments at LAL & contributing to 3 research papers (all in press) before transitioning roles has been fulfilling. Transitioning from coding in R to Python has been a highlight, along with embracing my new role at KSL.

What has caught your attention in the industry lately?
The potential impact of AI and automation on hydrology and hydrogeology has caught my attention. The industry’s focus on sustainable water management and advanced technologies suggests a future where computational models and AI-driven insights revolutionise groundwater resource management , heralding a new era of sustainability & environmental stewardship.

What do you love to do outside of work?
Outside of work, I prioritise family time, cherishing moments with my 4-year old daughter and 1-year old son. When possible, I escape to the tranquillity of nature, where I enjoy fishing. Whether it’s from a boat in the sea or more recently, fly fishing on a river, being close to water, ironically, is where I find my peace away from work.

Open loop Ground Source Energy

Decarbonisation of building heating is an important component of the UK’s commitment to major reductions in greenhouse gas emissions. Open loop Ground Source Energy (GSE) schemes use groundwater for heating and cooling, drawing water from abstraction wells and returning the water via injection wells at a warmer or cooler temperature. The constant temperature of groundwater provides significant heat pump efficiency improvements relative to air source units. GSE schemes, powered by electricity from a decarbonising national grid, can deliver a major reduction in greenhouse gas emissions compared to fossil fuel heating systems. 

Working with our partner in the UK, we have helped 10 hospitals and universities with their goal to replace fossil fuel boilers with GSE schemes over the last few years via desk-based feasibility and aquifer thermal energy modelling studies. 

Below is an animation of the modelling outputs from one of our recent projects which evaluated how much heat can be extracted from an aquifer without causing problematic temperature declines in the abstraction wells. Check out our projects page if you’re interested in finding out a bit more.

A Conversation with the Team: Jens Rekker

Happy New Year! 🎉 We hope everyone had a wonderful break. To kick off 2023 we’d like to share our “Conversation with the Team” with Jens Rekker, a principal hydrogeologist at KSL

𝗧𝗲𝗹𝗹 𝘂𝘀 𝗮 𝗯𝗶𝘁 𝗮𝗯𝗼𝘂𝘁 𝘆𝗼𝘂𝗿 𝗯𝗮𝗰𝗸𝗴𝗿𝗼𝘂𝗻𝗱?
I had always been fascinated with freshwater in my formative years. So, after four years working in South Island hydro-electricity schemes I enrolled in papers in aquatic biology, geography and geology. I rolled out of university as a geologist with specialisations in hydrogeology. I had to travel around the globe to get my first job and two years of experience, where my second nationality to the Netherlands came in handy. I landed back in New Zealand during the 1990s recession and went into survival mode to keep myself employed in hydrogeology. I have worked for myself, small consultancies, multinational consulting corporations, regional councils and a university over the last thirty years and loved most of it.

I have a strong affinity for regional authority work where most water management in NZ is actually carried out, plus the research that informs it. However, I keep coming back to consulting, which I consider is an important interface between the community and water environmental managers, and therefore an important role to fill.

𝗪𝗵𝗮𝘁 𝗮𝗿𝗲 𝘆𝗼𝘂 𝗰𝘂𝗿𝗿𝗲𝗻𝘁𝗹𝘆 𝘄𝗼𝗿𝗸𝗶𝗻𝗴 𝗼𝗻?
The new and emerging mineral sands industry has been a pre-occupation this past year, which looks like it will continue for a few years to come. My first mineral sands hydrological assessment was in 2018 and now I am contributing to investigations on three separate West Coast deposits. It’s always exciting working from the ground up with drilling, aquifer testing and instrumentation programmes to characterise unexplored groundwater systems.

𝗪𝗵𝗮𝘁’𝘀 𝘄𝗮𝘀 𝘆𝗼𝘂𝗿 𝗯𝗶𝗴𝗴𝗲𝘀𝘁 𝗰𝗵𝗮𝗹𝗹𝗲𝗻𝗴𝗲 𝗶𝗻 𝟮𝟬𝟮𝟮?
The usual consulting industry challenges of keeping all of the pots on the stovetop simmering without boiling over during a busy year for everyone.

𝗪𝗵𝗮𝘁 𝘄𝗮𝘀 𝘆𝗼𝘂𝗿 𝗯𝗶𝗴𝗴𝗲𝘀𝘁 𝘀𝘂𝗰𝗰𝗲𝘀𝘀 𝗶𝗻 𝟮𝟬𝟮𝟮?
Getting vehicles and rigs in and out of muddy paddocks in one of the wettest years and on our wettest Coast! Actually, that was mostly the drilling contractors’ success but I spent a lot of hours worrying about what to do if we remained stuck.

𝗪𝗵𝗮𝘁 𝗵𝗮𝘀 𝗰𝗮𝘂𝗴𝗵𝘁 𝘆𝗼𝘂𝗿 𝗮𝘁𝘁𝗲𝗻𝘁𝗶𝗼𝗻 𝗶𝗻 𝘁𝗵𝗲 𝗶𝗻𝗱𝘂𝘀𝘁𝗿𝘆?
I am noticing more collaboration and cooperation between hydrologists in different organisations working in the same patch. It’s something heartening to see.

𝗪𝗵𝗮𝘁 𝗱𝗼 𝘆𝗼𝘂 𝗹𝗼𝘃𝗲 𝘁𝗼 𝗱𝗼 𝗼𝘂𝘁𝘀𝗶𝗱𝗲 𝗼𝗳 𝘄𝗼𝗿𝗸?
I started canoeing on the Otago Harbour when I was barely 7 years old. In my teens, twenties and thirties, I loved nothing more than to kayak whitewater gorges all over the South Island. Nowadays I find myself canoeing on Otago Harbour again but in a much flasher, expensive new kayak!

Exciting groundwater research

At KSL we love to see advances in our field. We’d like to highlight this paper by Mao et al., in Nature Communications (https://lnkd.in/gZxFTqZE), which uses seismic data to monitor groundwater levels.

It’s a novel approach that doesn’t require a pin cushion of wells; they use changes in the velocity of seismic waves to infer information about the amount of saturated media and thus groundwater levels. Their analysis of the data showed seasonal trends, as well as trends related to groundwater policy.

This is such a neat method, and it will be exciting to see how it gets used! A great summary of the paper can be found here: https://lnkd.in/gMB38xyd

𝗦𝘂𝗺𝗺𝗮𝗿𝘆 𝗽𝗼𝗶𝗻𝘁𝘀:
• Monitoring GW is needed as more areas become reliant on it due to climate change related droughts
• Traditionally, this is difficult and expensive with drilling etc
• Study uses seismic data to monitor GW; analysing seismic wave velocities can be used to calculate how much water is stored underground
• Don’t need to wait for an earthquake – can use records of seismic ambient noise, as Earth is always vibrating – these are recorded by seismic stations and contain a huge amount of info
• Ability to use records mean they can back-date GW levels
• Trends found: seasonality, and depleted in the last 20 years (more taken from than can recover)
• Trends also reflect GW abstraction policies – shows that well-managed pumping strategies have a big impact
• Cost-effective

* note KSL was not involved in this research; we just think it’s really neat.