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When we joined the project, Surfers Against Sewage’s Safer Seas and Rivers Service (SSRS) was already a widely used and trusted service, with over 30 years building public trust around water safety. Our role wasn’t to reinvent the wheel, we came on board to strengthen it!The most important part of this project was to continue to put people before performance, clarity before complexity, and trust before trends.
What is Safer Seas and Rivers Service (SSRS)?
The Safer Seas and Rivers Service (SSRS) is an app from Surfers Against Sewage that sends real-time pollution alerts, helping people decide when it’s safe to swim, surf, or paddle.
But it’s more than a safety tool. SSRS also empowers communities to take action when water quality falls short, while supporting research into the real health impacts of polluted water.
The app is used across 650+ UK locations and is trusted by over 208,000 users, all of which are actual people using the app to make real safety decisions.
Most users are members of the public. Surfers, swimmers, paddlers, families, and communities who need clear answers in real time. They’re often on a windy beach, in poor weather, with a patchy signal, and little patience, so the app experience needs to be quick, calm, and reliable. Because If the app fails, it fails at the moment that matters most.
There’s also a second group of users. These people want deeper transparency as they care about pollution infrastructure and accountability, not just a simple status indicator.
Where data meets real-world safety
From the outset, there was a clear brief for this project with four key objectives:
Increase meaningful engagement with pollution data through the introduction of a dedicated Combined Sewer Overflow (CSO) location map
Improve visibility into how users interact with features such as alerts, notifications, and onboarding
Establish a reliable analytics foundation to support long-term prioritisation
Future-proof the service through roadmapping and targeted technical improvements
So how’d we actually make all this happen?
Balancing urgency with complexity
First, we focused on the users. Our strategy was simple, throughout the process, we had to meet the needs of both user groups without compromise. That meant delivering fast, scannable safety signals to support immediate decisions, while also offering deeper context for those who want to understand the bigger picture.
We focused on extending an already trusted public service while protecting what makes it work:
Live bathing water status remains quick and scannable.
Alert coverage was extended into Scotland, reflecting how widely the service is used in practice.
The new CSO map lives in a dedicated space, allowing users to explore locations without slowing or cluttering the core safety journey.
Environmental data is complex, but safety decisions need to be simple. On one hand, overloading users risks confusion, but on the other hand, oversimplifying risks losing trust! Our solution was to separate experiences based on intent, meaning users get fast answers when speed matters and deeper context when understanding matters.
Now, alert engagement has increased! The number of users receiving notifications rose from 9.8% to 10.8% and the number of users opening notifications also rose from 11% to 14.8%.
The differences between notifications received and notifications opened figures reflect platform behaviour across iOS and Android, but together they show a clear upward trend in timely engagement!
CSO Map Launch
Another technical challenge (the development kind, not the bake-off kind) was the introduction of the CSO map. The service went from handling data for around 600–700 locations to surfacing more than 17,000 assets in a mobile experience.
Performance was critical as the map gives users a broader pollution context.
We solved this through progressive data loading based on map location, alongside close collaboration with Surfers Against Sewage’s developers to design efficient API calls. For this feature, success wasn’t measured by clicks alone, but by how deeply people engaged with the information. Following the CSO map launch, engagement with pollution data increased! Average CSO page views rose from 2.2 to 4.78 per user, showing deeper exploration when data is presented clearly.
Improving visibility of interactions
Last but certainly not least, another challenge was the limited visibility into how the SSRS service was actually used.
Behind the scenes, we implemented PostHog analytics with custom events and reporting! For Surfers Against Sewage, this provides visibility into real user journeys, feature usage, and key drop-off points.
Using PostHog has allowed us to establish baseline consent metrics. These now show 60% analytics tracking acceptance and 36% notification acceptance. Now the foundations have been set for evidence-led iteration and optimisation in the future!
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Turning complex data into clear decisions
Why does all this matter?
The Safer Seas and Rivers Service (SSRS) project shows what responsible data use looks like when people’s safety is involved.It isn’t a one-off campaign launch, it’s a public service used by hundreds of thousands of people to decide whether to enter the water, often in challenging conditions.
Our work focused on making data work in the real world. We shaped complex environmental datasets into something people can act on quickly, without hiding uncertainty or overwhelming users. Transparency has increased without sacrificing clarity and insight has improved without reducing people to numbers!
Surfers Against Sewage and the 3 Sided Cube crew have put people before performance, clarity before complexity, and trust before trends.
Want to learn more?
Read the full project case study here,
Or shout us a Holla (we love to chat!).
Published on 12 March 2026, last updated on 12 March 2026