The dirty truth about E coli in the bathing waters at Portobello

Eight months of water quality tests by citizen scientists uncovers significant problems

This video, created by Dr Tom Scanlon, shows E.coli concentration levels calculated every 20 mins, shown as an animated series of E.coli density maps. These are the peak levels of pollution that recreational swimmers are likely to encounter after a sewage discharge.

The beach at Portobello is renowned for its windswept natural beauty.

Take a walk along the beach any day of the year, from an icy January morning to a busy summer’s afternoon, and you will find swimmers, rowers, paddleboarders and even the occasional surfer when the sea is wild enough to produce half-decent waves at Porty.

It recently ranked as the second-best coastal spot in the UK, behind Whitby in north England, in a survey based on visitor ratings and reviews.

But people using the beach rarely know if the water is safe or if they could be swimming in sewage.

There’s a growing movement of locals taking action over the poor state of the water quality, impacted by several unchecked sewage overflows bringing waste water downstream to the sea from the Figgate Burn, which runs into the sea close to the Tumbles gymnastics centre.

Following an e coli scare in the summer which saw the beach closed for two days, follow up tests by SEPA found the water quality was ‘satisfactory’.

The regulator assured it was a short-lived event, identifying pigeon or dog dirt as the likely cause, rather than human sewage.

However, local volunteers say the official testing regime provides only a snapshot that doesn’t capture the true scale of the ongoing problem.

The Porty Water Collective has found dangerously high levels of e coli after testing the water regularly for eight months.

The group believes the authorities are at best downplaying the scale of the problem and at worst ignoring it.

How bad is e coli at Portobello?

Local resident and surfer Stephen Cousins co-founded the Collective after becoming increasingly worried about the state of the water.

The group of individuals, organisations, community groups and charities is committed to protecting the blue spaces in and around Portobello.

“I’m a surfer and go in the water all the time. It’s my favourite thing to do in the whole world. But the scale of the poor quality has shocked me. It’s time to get a grip on this.”

Dedicated volunteers collected samples regularly between July 2023 and April 2024.

Alarmingly, 21 out of 26 tests found unsafe levels of e coli.

“That’s 82 per cent containing what are called faecal coliforms. E coli and enterococci were both found in summer when the beach was closed. Our tests have found high levels of e coli over a much longer period. It’s pretty staggering. We suspected it was bad but we never thought it would be this bad.”

Charity worker Stephen said: “The release of e coli into the water here has been way above safe levels – that’s by SEPA measures. The threshold for what’s safe is 400 per 1000mg of colony forming units (CFUs).

“We’ve regularly seen the levels top 1000 mg and above. Once it goes above 1000 the tests don’t give us the specific number. It’s alarming.”

Members have been out in all weathers with a pole and beaker attached to it and collected samples from one of the main sewage outflow points near the Figgate Bburn.

Stephen said: “At first I was essentially growing e coli in my kitchen sink. But since we got funding support from Surfers Against Sewage, we have been able to use proper testing kits and send off to a local lab.

“Based on results there is no doubt that there is a significant sewage problem. We do the tests because the system is failing. We need to raise awareness.”

Isn’t the water monitored by authorities?

Monitoring remains limited across Scotland compared to England and Wales.

It’s a busy spot year round but Portobello only has designated ‘bathing water’ status, meaning the water quality is only routinely tested by the regulator during May to September.

SEPA issued warnings against paddling and swimming at Portobello beach and nearby Fisherrow Sands, at Musselburgh, in July, after finding harmful levels of e coli and intestinal enterococci in the water – classic signs of pollution.

Both alerts were lifted after subsequent tests found pollutants had returned to “acceptable” levels.

Campaigners, local MPs and others say the system is inadequate. Stephen said: “Locals know not to use the water after heavy rainfall, you can almost guarantee e coli levels will be high. What about the rest of the time?”

The uncomfortable reality is that until recently a paltry 4 per cent of overflows were actually monitored across Scotland. Significant investment has seen that figure rise in recent months to around 30%, compared to almost blanket coverage in England and Wales. Portobello isn’t among them.

The data collected for those problem sewage overflows that are monitorited is limited. The official records only confirm if a monitored outfall is discharging, not the reason for the discharge, for example, or even whether there are telltale signs of human sewage in the overflow.

Sewage overflows in Scotland are entirely legal, with the drains designed to discharge into waterways in ‘exceptional circumstances’ such as during periods of unusually heavy rainfall. But there is evidence that it’s happening more regularly. In 2022, untreated sewage was discharged at least 14,008 times across Scotland for 113,230 hours.

Scottish Water told the Inquirer that the infrastructure in the Portobello area is working “as it should” and both bathing waters – Portobello Central and Portobello West – achieved ‘sufficient’ status this year.

But what does ‘sufficient’ really look like? And does it match the standards that we would expect to see before swimming or letting our children play in the sea?

‘It shouldn’t be left to volunteers’

Stephen Cousins, co-founder of Porty Water Collective at Portobello beach

Scottish Water’s assurances don’t wash, says the Collective. Visible signs of pollution are common around the three points along the shore at Portobello where rainwater and sewage is discharged onto the beach.

Stephen said: “We can regularly smell sewage by the swimming pool area and from Figgate Burn. We see wet wipes wash up on the shoreline. Combined with hardcore numbers from the tests it’s clear there’s a big problem. I don’t believe that the e coli in summer was caused by dog and gull poo.”

“The overflows are designed to be used in extreme weather events but tests point to them now being used as part of normal proceedings. We only focus on one area, one part of the system. We need an updated infrastructure. More houses are being built in the area. At the very least we need to see proper monitoring.”

There’s growing frustration around the lack of data, says Stephen.

“It seems to be an almost wilful strategy of keeping this issue in the dark. If there was data from compulsory, regular testing there would be nowhere to hide.

“The only way we know if sewage has been discharged into the water is if we happen to be doing a test that day. Surely, that’s the wrong way around. It shouldn’t be left up to volunteers.”

Science backs calls for robust data

Experts have also called on authorities and Scottish Government to take urgent action over sewage in the Forth.

Marine expert Dr Tom Scanlon has created a biological computer model of the Firth of Forth which captures a stark visual of what happens when raw sewage is released into the Forth.

Dr Scanlon says more testing and robust data is needed to help protect the public.

A striking heat density map of his model shows not only that e coli leaks out into a large area – but that it takes more than two days to decay.

The model shows that a swimmer on a 2 km path from Joppa Rocks to Craigentinny would come into contact with significant levels of e coli.

Virtual probes were placed off Joppa Rocks to measure e coli concentration at different times and it found “particles are widely dispersed across a large portion of the Firth of Forth.”

Dr Scanlon, an engineer with over 25 years’ experience in applied computational mechanics, said: “For the first time, we can see what really happens when raw sewage is released into the Forth. The presence of e coli is in indicator, it tells us that there are likely other pathogens present too.

“The model shows that e coli can take two and a half days to decay after release in and around Portobello.

Dr Scanlon, director at engineering consultancy firm MTS-CFD, said sewage discharges from combined sewer overflows (CSOs) are among the main sources of e. coli contamination in the Forth.

The team hopes to use the model to create an app for the public that would show spillages into the Forth.

He added: “Ideally the app would show what month a spillage occurred and for how long. We’d need Scottish Water to share information.

“What we’d appreciate is the actual date, time and durations of spillages of sewage and measurements of the concentration of e coli at the point of release. We can get an idea of this from the model and physical measurements locally, from groups like the Porty Water Collective. But it’d be better to have more robust data.

“Sewage can have hotspots but it disperses widely. Our model extends from Grangemouth round the coast to St Andrews. Imagine if ten CSOs all released sewage at the same time. The consequences would be dire.”