A local story of pee, poo and paper: WTW visit, Jan 2024
I suspect most of us live more wastefully than our grandparents ever did. In one way or another it all adds to our carbon footprint, our negative impact on the world. One of our very first ERA members put his finger on it when he spoke to us about needing to think and live more frugally (thanks Roger!). Hence ERA’s motto of Buy Less, Use Less, Waste Less!
One aspect of our waste is, of course, what we send down the pipes to Southern Water – our domestic waste water, including what we flush down the toilet. So far ERA has had two talks from Southern Water as well as having had several questions that we sent them answered. When I attended the recent Rother Summit, organised by SDNPA, the Southern Water representative there offered us the opportunity of a visit to a local Wastewater Treatment Works (WTW), sewage works to you and I! This visit took place on a very chilly January morning, with 12 of us attending and asking SO many questions throughout.
A primary concern of ours, and others, remains the high amounts of untreated sewage ‘spills’ that end up in the River Rother, hence our river monitoring project. (Needless to say, there is more than just untreated sewage making the river’s life tricky.)
These spills should only occur following exceptional rain storms, but who defines ‘exceptional’? We know that the Harting WTW spills something like a third of the time. Many WTWs, especially older ones, receive a mixture of ground water together with waste water from domestic and commercial sources. Following heavy rain the flow into the WTWs can be more than it can keep up with, and some will be diverted into holding tanks, but when these are full the excess has to bypass the treatment works and will go straight into the rivers. New regulations have meant that all these Combined Sewage Overflows had to have monitors fitted by the end of last year to record how often this is happening and as more of these monitors were fitted during the years building up to this deadline the public became aware of more and more of these spills. Changes in weather patterns due to Climate Change have led to us getting dry periods and wet periods, our rain is coming in ever greater clumps. We were told on our visit that these holding tanks typically hold about 2 hours worth of heavy rain. A system that may have worked reasonably well once (although we will never know as the system was not monitored back then) is definitely not coping well with the current situation.
Creating more tanks is part of the solution but Southern Water is also looking into ways of holding back that rain water, so that it doesn’t all arrive at the WTW at one time, for example, Sustainable Drainage Systems (SuDS), swales, rain gardens, ‘leaky’ water butts. One suggestion to us was that when we know heavy rain is coming we could empty our plentiful water butts so that we ourselves can catch and hold back some of the new rain.
For years now ERA has been asking about ‘near real time’ spills data from the monitors mentioned above. We were told that the timescale for this was likely to be about 18 months. In the meantime we wait until April each year for that data to be made available on the Rivers Trust Sewage Map for the previous year. The data is then given for the year as a whole. So, data about spills associated with the storms we are currently experiencing in January 2024, will be within the data for 2024 as a whole, which we will have access to in April 2025. (That data is actually available in March each year on the Environment Agency website, but not in an easily accessible format.) The Beachbuoy website for coastal areas show near real time data for our beaches and, by comparison, Thames Water Authority is already releasing this near real time data, see their Storm Discharge Map.
As ever, I brought up the issue of micro-plastics in waste water (typically from us washing synthetic fabrics in our washing machines) and how many of them will be ending up in the sludge that is then sold to farmers to use as fertilisers, transferring the micro-plastics out into the environment from where we have no way of getting them back. Filters in our washing machines, and a system for safely processing what they collect, would seem to be ideal but I see no moves in that direction. One of our hosts wondered if we might end up burning sludge for energy recovery. So, artificial fertilisers are not without their issues, sewage sludge is better than artificial fertilisers in some ways but not without issues, burning for energy is not without its issues. Could current research into microbes that digest plastic be a better solution and would that leave a residue that could still be used as a farming fertiliser and be less damaging than artificial fertilisers?
Phosphates got discussed a lot. Too much phosphate in the river leads to eutrophication which leads to algal blooms, which leads to decreased oxygen levels which leads to stuff dying. We want our river to be ‘green’, but not algal bloom green! They use a ferrous based system to neutralise the phosphate and then monitor the resulting iron and phosphate levels. I knew that human waste contains some phosphate but had not realised that we add more from our washing powders, shampoos and even our cakes and confectionaries! We all need to look a little more carefully at what we are buying and using and to try to influence producers to use less, or no, phosphate. I think this is an area where ERA can do some research, spread the word and see if we can have an influence.
I photographed the initial tank that the waste water goes into as it had a considerable layer of fatty scum floating on the top – delightful! As ever we were reminded that only the 3Ps should go down the toilet – Pee, Poo and Paper and that fat from our cooking should be put in a safe container to cool and solidify before going into our rubbish bins. Alternatively, you could always make fat balls for the birds in your garden. Incorrect disposal of oil, fat and grease from restaurants, butcher’s outlets and similar is another issue that can occur.
Early in the whole system is a filtering system that takes out all the paper plus all the other things that should not be there such as, wet wipes (flushable only means capable of being flushed, but due to the plastic in them wet wipes should never be flushed), random bits of plastic and even cuddly toys and false teeth (although we didn’t see evidence of those last too on our visit!). This is collected in a skip and then goes to landfill. Given that we have been told previously that there are no active landfill sites in West Sussex, this does beg the question of exactly where this waste from all the West Sussex WTWs goes (and what the carbon footprint of its transport is)? Does some of this go for incineration, more potential energy recovery, and do we think that better or worse? In email conversation after the visit I was told it is handled by separate contractors and goes through a composting process.
We learnt in our previous Southern Water talks that spending plans have to be agreed by Ofwat on a 5-yearly cycle. In our discussion today about finances we learnt that Ofwat can cap how much charges to customers can be increased, effectively capping how much Southern Water can spend on improving the system. We were reminded that (taken from their website) ‘Southern Water group shareholders have not received any dividends since September 2017 and although Southern Water's gearing remains below 70%, the company does not anticipate paying a dividend for the remainder of this regulatory period to March 2025.’ But will they lose shareholders if they are getting a lower return on their investments than if they moved their money elsewhere?
The issue of road run-off came up. The Highways department is responsible for whatever the gully suckers extract. As this would surely be classified as hazardous waste it would be interesting to know from them what happens to this. The ‘spills’ discussed above happen due to Combined Sewer Overflows, that ‘combined’ referring to ground water as well as sewage. Increasingly ground water from rain landing on our houses etc. is going into soakaways, and we were told that systems that were previously combined are being separated. If SW is only responsible for treating that which enters their system, who has the overview of what else is entering our rivers, would that be the Environment Agency, Natural England or who? Maybe somebody from Highways could be invited to give us a talk and extend our understanding. One point that was made was that the first 2 hours of what arrives at the WTW following heavy rain will contain relatively more of the heavily contaminated road run-off and will be caught in the holding tanks, implying that subsequent ‘spills’ will contain relatively less.
The extended discussion was really useful but I felt the tour needed backing up either with some handouts or some explanatory online content. We saw that it is a multistage process involving 6mm screens for physical filtering, settlement tanks, filter beds in which bacteria process the waste, chemical processes and even a small reed bed. Some sort of flow chart (pun unintended) of the whole process with a brief explanation of each stage would have been very helpful, maybe something similar to the West Sussex Recycles videos, but not quite as oversimplified as they are!
As ever, the individuals that one meets who work for Southern Water, without exception, come across as sincere and very aware of environmental issues and the company’s responsibilities. We are certainly grateful for how generous with their time and their expertise the men who took us on our tour were. My personal opinion is that SW’s PR/Communications with the public on such issues has been very poor, but maybe the Clean Rivers and Seas Task Force team, which was the team that arranged our visit, are on the point of turning that around? We can but hope!