Net Zero and Beyond with Amanda Lake - Part 2

I am again with Amanda Lake to this interview, a Chartered Chemical engineer with 22 years of experience in the wastewater sector for a second part of our conversation – you’ll find the first part here! Join us as we explore the cutting-edge solutions and best practices being implemented in the wastewater sector with a focus on the UK and Europe – in order to move towards a more sustainable future.

5)How do you see the role of wastewater treatment plants evolving in the UK to achieve Net Zero emissions in the future?

We need to move towards zero emissions treatment works, towards circular economy – resource recovery where the net impact of wastewater treatment is positive (considering not just carbon but all planetary boundaries). Of course, this means we must rethink these as resource recovery facilities which is slowly happening – there is some five times the energy within wastewater than we currently expend to treat it.

I think a critical role for the wastewater sector is to engage more with true circular economy frameworks – the many and various Rs in circular economy. But this must start with reducing inputs – of water to the system (think stormwater separation, demand management), of energy into treatment, probably also of protein (here we could think eating a diet aligned with planetary boundaries, recommended national intakes and also source separation toilets).

It may not be easy, or align with our accounting frameworks to think upstream in catchments, but we must – fiduciary duties of our largely private UK companies aside, ethically, as chemical engineers, we are taught to think in systems to engineer for the betterment of society. We need to have a hard think about this – then change the system as required – to discharge our own ethical commitments that we sign up to as chartered professionals. ?

We put so much energy into treating wastewater to remove nutrients, we have industrial fertilizer production highly fossil fuel intensive within a food system which desperately needs to change. Changing diets will change the inputs of nitrogen and phosphorus to our WWTWs. Utilities have a role in catchment regeneration, helped by reformed, regenerative agriculture– with better drinking water sources as one obvious outcome of this, but so many others too! So as a sector we can focus upstream, reducing inputs through dietary and agricultural changes, which will make us all healthier. We can trial through living labs, and deliver household and community-level nutrient recovery and recycling. We do this in space, the technologies exist!

We can then look at ‘end of pipe’ – and recover the nitrogen at the WWTW – probably from liquor streams, possibly to fertilizer products like the recent EU-Refertilize project[1] has trialed, or to other chemical end products .

Right now, there is a driver in the UK towards total nitrogen (N) removal (we currently mostly just nitrify to meet ammonia consents, often stringent down to 1-2mg/l NH3-N on a 95%ile basis). This move towards Total Nitrogen (TN) is occurring to address a concept of ‘nutrient neutrality’ for all new development in selected catchments where N pollution is an issue for our waterways and ground water sources (in large part due to agricultural and wastewater inputs!). The solutions to meet TN reduction must be upstream too but at a site level, moving from nitrifying only to a TN reduction works brings potential benefits for N2O emissions – with latest work highlighting the emissions from full N removal sites likely to be at least 50% lower[1] than for nitrifying only works and possibly much lower[1]. The TN driver and the net zero implications offer huge potential for intervention and innovation.

I think our role is to evolve towards more systems thinking, collaboration, more open access sharing, and we are likely to see a stepwise evolution of WWTW from waste disposal to WRRFs (water resource recovery facilities), in addition to a key role as catchment stewards in a much bigger way. We need to recognize a role aligned with circular economy frameworks, with evidence from life cycle assessment and participatory decision making.

Beyond demand and source reduction, we could rethink decentralized treatment and centralized treatment. This must tend towards processes which are not just trying to ‘treat’ nutrients and contaminants, but are recovering these to their rightful role substituting fossil derived fertilizer, mined non-renewable phosphate fertilizer, and virgin sand. Given the desperate need to mitigate and draw down CO2 from the atmosphere, we have a critical role for carbon sequestration too. Here, I like less the techno-optimist (a form of climate delay[2]!) technology solutions. There are industries far more needy than ours for the carbon capture and storage technologies and infrastructure which don’t yet exist yet at scale anyway – and more the natural climate solutions (rewilding, afforestation, catchment restoration) – though at the rate we’re going, we may also need the biochar.

There are no golden bullets, and we must move beyond the end of pipe solutions in wastewater. As well as lower energy, anaerobic, abiotic, probably modular and very digital technology solutions, the best, most holistic solutions are likely to be messy, complex ones that involve a lot of people and cross sectors and markets, some new. The work of AquaMinerals[3] in the Netherlands is really inspiring here. Venturing upstream as a wastewater sector is key. If we can show what wastewater treatment within planetary boundaries needs to look like – whether considering nutrients like the above, or what we’re going to do about novel entities (PFAS, microplastics), or what we absolutely can do with nature-based solutions to support biodiversity and blue/green water – then we will have the advocates we need for the systemic change required. Connections, trust and relationships are so important. This is a huge issue for the UK water sector – with trust at an all-time low.

As professionals, we have a role not to lose sight of the system, which is complex, and we need to consider our role within this as the wastewater treatment sector, but also as the good ancestors most of us aspire to be for our children if not for wider humanity .

6)Can you discuss the potential challenges and obstacles that UK wastewater treatment plants may face as they work towards Net Zero emissions and how do you suggest overcoming them?

Key obstacles are a lack of drivers to fund net zero – we remain in a system where cost, often just capital cost, drives decision making despite what we say. And we have no means to assess projects, programs and policies in a way which factors in societal costs of carbon, nitrous oxide and methane. We could absolutely do this – so you could say the obstacle is a lack of will to make the changes required.

Lack of data is another key obstacle – for those robust assessments required - but as you can imagine, if there is no funding for this then this remains a struggle.

We lack diversity – there is still a huge gender gap, a huge ethnicity gap, and we are not good at the type of interdisciplinary and cross-sector working required. This hinders diversity of thought and imagination!

Other key challenges are risk appetite. We have an emerging and quite progressive Task Force on Climate Related Financial Disclosures being used by utilities to report their climate related financial risks, so this is a start (and there is a critical and interconnected Task Force on Nature Related Financial Disclosures on the way). But this is not being done in a way which really? informs us of true risks and costs. Yet anyone who has read the IPCC reports, produced in the most conservative scientific manner possible, absolutely understands that the risks of our current lack of action at the pace required will be SO much higher risk and at SO much greater cost! But these are challenging to bring down to a utility, a catchment, a facility scale – in addition to lacking key data – whether process emissions baselines, catchment scale human health impacts of rising temperatures and water scarcity, or (any scale) human health risks of PFAS and microplastics.?

The structure of the sector and underlying (global) economic framework is a key obstacle in all of this. We need wellbeing economies like Earth4All are now recognizing – the pursuit of infinite economic GDP growth in a finite biosphere with huge inequities will not get us close to a safe place for humanity to thrive.

We will overcome these challenges with incremental and structural change, and we need it both bottom up and top down. In addition to the systems thinking, we need new approaches to risk assessment and management, better use of existing (and future) data, cultural transformation as a sector and new thinking which is much more intergenerational. So just a few small things!?

7) In summary, what are the key takeaways or recommendations that you would like to leave with us regarding the state of the UK's wastewater sector and its progress towards achieving Net Zero emissions, and what are the most important steps that need to be taken to move forward in this regard?

In summary – there is some great progress being made towards net zero in the UK. Progressive carbon accounting and renewable energy production from sewage sludge has been done for decades. Recent progress is the 2020 Route Map and the collaborative work being done through UKWIR, through Ofwat innovation projects and by many companies together and individually in trying hard to bring net zero thinking into decision making for their next 5-year investment cycle and beyond. ?

However, we are nowhere near where we need to be – we have a lot to learn about emission baselines, we remain highly siloed, and we aren’t recognizing key opportunities at a system level to address emissions from the urban water cycle for greatest benefits. Some of what we do, despite well-intentioned policy, is not net zero aligned and there is recognition that the system needs to change. ?I’m proud that the UK is leading in some areas – but really, if it’s still leading to a 3 degrees warmed planet then we need to be clear that ?there are still many important steps remaining! ???

Given lessons to date and reflecting on some of the great work which is ongoing, I think the most important steps we can take in the UK wastewater sector to move forward are to:?

1. ?????Improve our diversity and work better together – there is no winner unless we all get to zero emissions; leading the way is great, but those leading need to be carrying a ladder to help the other ones up too. A good example of this is our GHG mitigation group within IWA (International Water Association) – whilst we’re doing well bringing best global practice to this, we are also in IWA collaborating with other groups like DANVA (Danish Water and Wastewater Association) and in the WEF (Water Environment Federation) – with some initiatives happening soon like our Nordic series starting on 2nd May and other ideas in planning, so we’re all sharing and learning together.
2. ???????Move out of our comfort zones and assess whole life costs, carbon and risk as if the future mattered. Apply societal costs of GHGs in decision making so even if regulators are not applying them, people start to see the implications. Apply life cycle assessment even if it’s hard and full of assumptions. Only by starting to talk about these assessments and learning by doing, will we be able to bring them into (participatory) decision making. This requires good quality data – we need to prioritize this and operate our WWTPs as if one of the most valuable materials on all of earth was running through them.
3. ?????Move out of our silos and spend more time in catchments (literally and on paper) and working with other sectors, to truly realize what is possible in a much more circular water sector – for example a more grounded approach with decision makers, communities, farmers, citizens assemblies, which becomes the norm not the exception.
4. ???????Inform ourselves enough to make decisions which really consider the GHG emissions, energy, nutrient and materials and water flows required for a future within planetary boundaries. This means applying circular economy principles that start with reducing system inputs – leaving more water in natural systems, which are far more efficient than we will ever be.
5. ??????In some ways we need to slow down and build less, and really ensure that what can be very reactive decisions taken today don’t lock future generations into a high-carbon future that no-one deserves. In other ways, we need to take much more rapid action and be activists for a future that we need – speak up about the challenges and the remedies. We have existing solutions; we need more for a truly zero emissions sector – but to support the funding required, we need the will to change things both within the sector and beyond. This requires trust and communication, and we all have a role. ?

Thank you so much for the chance to chat, George! I am very grateful for the work that you’re doing publicizing the science and sharing knowledge on such critical topics for us in water.?

Bibliography & Sources :

[19] https://webgate.ec.europa.eu/life/publicWebsite/project/details/5092

[20] https://www.sciencedirect.com/science/article/pii/S0048969722034192?dgcid=raven_sd_search_email

[21] https://www.bafu.admin.ch/dam/bafu/en/dokumente/klima/externe-studien-berichte/elaboration-of-a-data-basis-on-greenhouse-gas-emissions-from-wastewater-management-n2oklimara.pdf.download.pdf/Gruber_2021_-_Final_report_N2OklimARA.pdf

[22] https://www.cambridge.org/core/journals/global-sustainability/article/discourses-of-climate-delay/7B11B722E3E3454BB6212378E32985A7

[23] https://aquaminerals.com/home/