FEBRUARY 2022, Seafield sewage treatment works, a vast construction of pools and pipes at the edge of the city, where Edinburgh meets the Firth of Forth. For a long while, I’ve been wanting to see what lies behind its fences, partly because it’s my local sewage treatment centre, but also because it’s the largest in Scotland, dealing with the wastewater equivalent of 800,000 people, 4 million flushes a day. It looks like a futuristic city, a colony for the processing of crap.

I peer into a skip, which contains what is left after the sewage is passed through a coarse screen. This filters out a grey mess the site operators call rag.

On average, there are one to two skips a day of it, which have been known to contain £5,£10 and £20 notes, a Winnie-the-Pooh toy and a wedding ring, though what’s mostly visible now is wet wipes, condoms and a Covid mask.

This is what, when sewage is not screened, ends up in our waters.

As I write, we are coming up to the start of Scottish bathing waters season, the summer months in which some of our beaches and waters are monitored for sewage-related bacteria that are harmful to human health.

It starts a few weeks later here than in England, though nowadays many of us involved in the ever-growing craze for wild-swimming, dip the whole year round.

A regular swimmer myself, one of the things that concerns me is what is in our waters – not just for the sake of my health but for the wellbeing of the life that makes those waters its home.

My concern also took me, recently, to a water quality workshop run by the South East of Scotland Surfer’s Against Sewage branch. One of the hosts was Charlie Allanson-Oddy, an SAS rep, who had done the hard slog last year of carrying out water tests at Portobello beach. His was the only Scottish contribution, amongst many from England and Wales, to a significant Surfers Against Sewage Water Quality report last year.

What he found was that, while the waters tested at Straiton Place, a stretch on Portobello beach,where many people swim, were good, those collected where the Figgate Burn emerges onto the sands, were poor – the worst in the entire SAS report.

“I chose the Figgate burn,” he told me, “because it runs through the nation’s capital. It was the worst of all the areas that were tested because every single test was dangerous and unsafe levels for E Coli. There was no other venue that had these levels with no break.”

The Herald: Charlie Allanson-Oddy (foreground) Surfers Against Sewage, day of action in Edinburgh, c Mike Guest

Whether our waters in Scotland are better or worse than those in England is a subject of much debate. Among the barriers to comparison is the fact that the sites at which spillovers happen, what are called combined sewer overflows are less monitored here. On this, Scotland is way behind England, where around 80 per cent of sewage overflows are monitored, with the remainder to be monitored by 2023. Here, only 10 per cent are monitored by Scottish Water.

Of course, you don’t need to be a swimmer or surfer to be bothered by this. All of us should be, and a movement is building across the UK, but also in Scotland, which is demanding greater controls over sewage release into our waters.

Last week, in advance of the start of bathing waters season in England and Wales, Hugo Tagholm of Surfers Against Sewage called for "more inland bathing waters, like our European neighbours, so people can have the cleanest and safest experience on our rivers and beaches".

In recent years, a movement has been building across the UK, but also in Scotland, which is demanding greater controls over sewage release.

In England, already, two stretches of river – the Thames at Oxford and Wharfe at Ilkley – have been given bathing waters status. In Scotland, as yet, no river has bathing waters status, though an application made for the River Almond was turned down.

Another difference is that, in Scotland, we have a single public water company, Scottish Water, not a series of private companies. Many of our sewage treatment works are operated through PFI deals with the international company Veolia.

Yet what’s striking is that we still have many of the same sewage problems that afflict waters south of the border. The problem is bigger than that. It’s about how we live, and how the systems we have set up to deal with our waste have not developed to cope, and are now straining.

The Herald: Seafield Sewage Treatment Works

Seafield treatment works


BACK to Seafield, and my tour of the Veolia-run site, as, on a cold February morning, I pitch up, marvelling at views out to snow-sprinkled Arthur’s Seat. I know this place well, though only from the outside. It’s where I run. It’s also where I swim, in the waters just below, a corner of the sea near which, I recently discovered, at least three combined sewer overflows (CSOs) release.

What are combined sewer overflows? Scottish Water describes them thus, “During heavy rainfall storms, more water is getting into our sewers than they have been designed to cope with. Combined sewer overflows have been included as a relief mechanism to safely relieve the pressure on the network which greatly reduces the risk of sewer flooding in streets and in customer homes.” They are the release valves that prevent our homes being flooded with sewage.

This is the first time I’ve been inside the works, and the trip is inspired by the popular tour they run during Doors Open Day – my guides for the morning Tracy Byford and Stuart Marsden from Veolia as well as Keith Sinclair from Scottish Water.

The first place, I am taken, is the smelliest, that aforementioned skip which gathers the waste of the first screening. During the first flood of a storm, waste that has built up inside sewers during dry days, comes through in the first flush as a giant slug of material. A large pipe with a low flow through can accumulate a mat of wipes, and that whole carpet can arrive in one big sloosh. Byford observes, “the first flush is like a river of rag.”

If all of us only put pee, poo and paper down our toilets, then this whole part of the site would barely be necessary. Many drain blockages would also be avoided. Scottish Water, according to Keith Sinclair, sends out what’s called “choke squads” which deal with around 36,000 blockages a year, at a cost of £7 million a year. 80 percent of these include wipes.

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One option is that the public stops putting these products down our pipes, the other is that the products themselves are banned, just as, for instance, plastic cotton wool buds were banned in 2019. “We used to see cotton buds all the time,” says Byford, “but we don’t see them now.” Hence, Scottish Water’s latest campaign, Nature Calls, asks the public to join forces to avoid sewer blockages, flooding, and pollution by consigning wipes to the bin. It also calls on governments north and south of the border to work together to ban wipes made with plastic.

At Seafield, they are always watching the weather. The rainfall and melt affect the flow through and allow them to predict when they will get a sudden flood both of water and plastic-contaminated waste. Heat impacts how much odour will be produced, wind, how much and in which direction it will drift. As Byford notes, “We avoid doing anything, where possible, that could be odorous during warm summer days.”

Odour is less of a problem than it used to be, since the installation in 2012 of an odour extraction system. A white pipe which runs the edge of one of the settling tanks is part of that system, in which the smelly air is sucked out by a pump, and then taken to tanks where it is “scrubbed”, using chlorine, or its smell. Since the system was fitted, Byford says, there has been a significant 90 percent reduction in complaints.

But there still are smellier days, and as a local, I am aware of some of them as I pass on my runs and swims. Eileen Simpson a community councillor in Leith who has been a key driver in a campaign around the smell, and helped set up a public complaints portal, observes, "They have promised to try to keep maintenance work to a minimum between April and September, but they have conspicuously failed to do so and there have been smells most days throughout April, ranging from mild to horribly gut-wrenchingly obnoxious."

Simpson points out that the works are "out of date". Among her concerns is that there is a "fast-growing increase in housing throughout this area, and of course an increasing number of extreme weather events." As a result of pressure from campaigners like herself, the Scottish Government committed in 2020 to spend £10 million between then and 2024, on short-term improvements.

Nevertheless, there’s a kind of elegance about the system, a beauty to the science of extracting water from waste, a process which involves water running at different speeds, then sitting in tanks, or being aerated. “Wastewater treatment,” says Byford, “is all about changing speed in different areas and, gravity, settling out solids.”

When I think about sewage, I have to remind myself of the significant progress that has been made. The wastewater system of the city in which I live, like many, is based on a Victorian infrastructure.

Once upon a time sewage from Edinburgh was discharged untreated into the Water of Leith, and it’s worth noting that only just two decades ago, this Seafield site was still sending its sludge out in a boat famously called the Gardyloo, to be dumped at sea in the Firth of Forth.

Things are better than they once were – but at the same time, we are living with a waste system that hasn’t caught up with the way we live today – wasn’t, for instance, designed with all this plastic in mind.

One of the most impressive pieces of progress, however, is that these days, the sludge that would once have been dumped in the firth is put to good use. To find out how, I am taken to a futuristic corner of the site. Inside towers, all the sludge produced onsite, and some from other plants, is processed to produce biogas which last calendar year yielded energy at a rate of 18,205 mwh of energy and which powers the plant and, when there is excess, feeds into the grid.

My guides describe the process through multiple domestic analogies. Here, the sludge, which is like a “porridge” in consistency is put through a series of machines, one which works like a mangle, another more like a tumble drier. From there it goes on to the thermal hydrolysis tanks, which, I am told, are like pressure cookers, preparing the material for the anaerobic digesters, which are themselves like “stomachs”.

The Herald: Seafield Sewage Treatment Works

The result is two end products. One, the biogas, the other a cake which is high in ammonia and looks almost like soil and which is spread by farmers on fields.

THIS tour of Seafield is an eye-opener and reminder of our own role in the problem. The grey rag filtered out should prompt all of us to avoid putting non-biodegradable products down our toilets. But will that entirely stop the overflow of sewage itself into our waterways?

The issue of what’s going wrong with our combined sewer overflows is one I’ve questioned Scottish Water about. Last year it was reported that discharges were up 40 percent on 2016.

When asked about this, Scottish Water provided summary figures on spills for the past six years. While the 2020 figure was higher, they noted that 2021 was in line with the average number of total spills. “We don’t have a singular reason for this. Changing weather patterns, rainfall patterns, the intensity of rainfall events and the localised nature of some events all have an impact.”

In December, Scottish Water released their Urban Waters Route map which set out how they would improve water quality by improving some CSOs, “increasing monitoring and reporting to cover all combined sewer overflows that discharge into the highest priority waters”, and “progressively introducing interventions which will reduce spills”.

READ MORE: What is Scottish Water doing to stop sewage entering rivers? 

However, worryingly, a recent article by investigative journalists at The Ferret website revealed that letters released under freedom of information law had shown that Scottish Water had agreed, due to the cost of living crisis, to keep prices in line with inflation, but, the article summarised, had said “this may impact its ability to meet agreed targets, including those on the long standing problem of overflowing sewers, polluting rivers, lochs and seas.”

This may be good news in a cost of living crisis – but what will it mean for our waters? What will it mean, for instance, for the Urban Waters Routemap and its ambition to install 1000 combined sewer outflow monitors at an estimated cost of between £50 million and £70 million?

THE Naysmith bridge, River Almond, April – a calm stretch, where the river widens and picnic benches line its banks, a place of beauty which is the subject of an application for bathing waters status. Ducks fly and skim the water. A dog paddles. Children, I’m told, sometimes wade and play there too. But measurements taken in this river suggest that sewage contaminants frequently flow through this watercourse.

I’m not alone in having a geekish interest in our sewage systems. Members of the River Almond Action Group are among those who share my fascination – and are keen to tell their stories of tours of sewage works, and their volunteer observations made on “Outfall safaris” which are now taking place on the River Almond and Leven.

The Herald: Alison Baker of the River Trust on the Almondell River by the proposed bathing pools. STY ALLAN..Pic Gordon Terris Herald & Times..25/4/22.

Alison Baker of Forth Rivers Trust

One such member, Ruth Plevin, takes me on a tour of the Almond as it wanders through the lush Almondell and Calderwood Country Park, pointing out the East Calder sewage treatment works and the seemingly idyllic spot in the river that is the subject of the first ever bathing waters application for a river stretch in Scotland. This month the application was turned down by a panel chaired by the Scottish Environmental Protection Agency (as was an application that I backed for bathing waters status at popular Edinburgh swimming spot Wardie Bay) on the basis that not enough people were swimming there.

Another  member of the group, guides me to a stretch of the river in which he used to swim as a teenager, between 2006 and 2010. He and his friends would jump off the rocks into the deep pool below.

The idea of pollution didn’t bother him much then. It does now. During lockdown, he found himself walking the Almond most days and was quite shocked by the amount of times he went by a CSO feeding untreated sewage into the river. “I’m a civil engineer,” he says, “and I know these are only meant to operate in extreme weather.”

Plevin talks about her shock  at sewage contamination – as well as  worry over other contaminants like pharmaceuticals, microplastics and agricultural run off. She describes a “toilet tinsel tree”, fallen in the water, covered with wipes and plastic waste.

I’VE seen some of the sewage they mention. A year ago I took a similar walk along the Almond in the company of Alison Baker director of Forth Rivers Trust, a key force behind the bathing waters bid.

“Do we really want this in a country park?” she said as we observed baby wipes clinging to the spindles of overhanging twigs downstream from an outfall pipe. “One of the things we’ve tried to say to Scottish Water is that people could be swimming here, paddling, fishing, and there is no notification that they are allowed to dump. Where’s the sign saying, it’s raining, we’re going to dump? Where’s the Twitter post?.”

Baker had proposed the bathing waters bid partly because, she felt, it would “kickstart a discussion about water quality”.

She described how she had put in a freedom of information request to find out what untreated sewage had been dumped into the river in 2020. Though SEPA’s data was incomplete, she was shocked to find there were at least 617 untreated sewage dumping events, in which 121 Olympic swimming pools of waste entered the water.

She said: “If a sewage overflow happened once a year in a big flood. I’d think, ‘Oh, okay. I don’t want people’s homes flooding. But if it’s happening every week and the river is not high, then that’s wrong.”

Over fourteen months later I talk to Baker again, and ask how she feels Scotland has progressed in terms of that conversation.

“There has been a change in the dialogue,” she says. “Scottish Water are calling for the banning of wet wipes. It’s encouraging that they’re being a bit more proactive, but it doesn’t take away from the fact that they are still discharging the sewage.”

So much seems to be working against solving this issue. Meanwhile, the Almond still swirls, regularly, with wipes and faecal matter. In recent years, 9000 new houses have been built in its vicinity. More people, more waste. We have come a long way since Victorian sewers, or the Gardyloo, but you only have to observe this river to see how far we have to go. When are we going to cut this crap?