All Hail Dr Zessner!

This coming Wednesday at the Global Water Summit in London I will chair a 90 minute session on ‘How to halve the cost of wastewater treatment’. When Christopher Gasson, CEO for GWI (and organiser of the summit), proposed this title my initial reaction was Pah! Merely halving the cost is not nearly ambitious enough. Modern sewage is ripe with all sorts of goodies (nutrients, cellulose, precious metals, copious amounts of energy…). We should be shooting for how to make wastewater treatment facilities profit centres, I argued. Christopher responded by saying he wanted the session to include the sewage network, not just the treatment facilities. That raised the bar somewhat. Now we had a challenge…

Even if I say so myself, Wednesday is going to be awesome. It will be a multi-media, highly interactive session (think fireworks, sparkly lights, carefully choreographed dancers and you won’t be far wrong). We are even giving away some free samples which, bearing in mind the wastewater theme, will provide something uniquely different to add to the usual conference delegate swag. There will be 25 ‘lighting showcases’, a dozen on-the-floor interviews, a 2 person expert panel who, like Theresa May and Jeremy Corbyn tussling with Brexit, will argue and jostle despite them both essentially being on the same side. If they don’t, then I will channel Jean-Claude Juncker and generally stir things up from the safety of my Chairman’s podium.

Of course, to halve the cost of treatment requires having some knowledge of the actual costs to start with; you can’t halve something if you don’t know where you are starting from. My good friend Frank Rogalla (Head of Innovation for the Spanish utility Aqualia) sent me some interesting data: the costs for water and wastewater in the UK average around 3,5 €/m3 and this compares to just 1,8 €/m3 in Spain and 9 €/m3 in Denmark. [As an aside, it is worth noting that Frank would have been a much better choice of Chairman for this session. Through his inspiring work on the Horizon 2020 projects https://www.all-gas.eu and https://www.run4life-project.eu he has a far greater knowledge. However, Christopher met me first so boo-yah Frank]. The above bill costs are interesting, but are miss-leading (sorry Frank). Firstly they are for both water supply and wastewater treatment. Secondly this is the prices customers are charged, not the costs incurred. The figures are ‘confused’ by local government regulations and subsidies. I needed to do some more detailed research.

This is where Dr Zessner (and his colleagues Lampert, Kroiss and Lindtner) came to the rescue. I found a truly fascinating paper (no really) which they published back in 2010. Their work centred on the countries around the Danube/Black Sea area, with a particular focus on Austria. They concluded that in Austria the cost of treatment (including N and P removal) was around 30€ per person per year. This is a captivating figure, not least because a quick (but unscientific) poll completed with my non-water sector mates revealed an expectation that this cost would be 10 – 100x higher (ie 300 - 3000€/head/year). If nothing else, this confirms that Joe Public (or perhaps it is just my mates) simply hasn’t got a clue how much their water bill is. It also makes a mockery of the financial regulators who obsess about continually squeezing down water bills, despite survey after survey showing that most people would prefer to pay a bit more to their water utility in return for better environmental stewardship, but that’s a blog topic for another day.

Dr Zessner, and his marvellous team, didn’t stop there. They then looked at what happens if you include the cost of the sewer network. My Joe Public test group confidently predicted the increase would be between 5% and 50%. However according to Dr Zessner and his team, the actual cost (in Austria, in 2010) was 90€ per person per year, ie increasing the wastewater treatment cost by 200%. We are going to have such fun on Wednesday unwrapping this further.

All Hail Dr Zessner, you are my hero (at least for this month). I feel slightly saddened that your paper, published in Water Science and Technology (vol 62(2):223-30) had only been downloaded 36 times. As a measure of my shallowness I am pretty certain that if I had a paper published in WST I would have persuaded my family, and everyone in both my inner and outer circle of friends (ie all 3 of them) to log on at least twice and leave a slew of positive comments. Clearly you do not have my combination of insecurity and ego. Dr Zessner, perhaps, just perhaps, you will get a surge of interest now: https://www.researchgate.net/publication/45282491_Cost_comparison_of_wastewater_in_Danubian_countries