All projects

Bathing Waters

Natural Resource Wales (NRW) and the Environment Agency (EA) have a key roles ensure that bathing waters have good water quality in Wales and England respectively. Bathing Waters are designated beaches (or inland swimming spots) assessed by the EA and NRW in line with the relevant legislation and regulations. Water samples are taken at designated…

The Environment Agency (EA) and Natural Resource Wales (NRW) have a key roles ensure that bathing waters have good water quality in Wales and England respectively. Bathing Waters are designated beaches (or inland swimming spots) assessed by the EA and NRW in line with the relevant legislation and regulations.

Water samples are taken weekly at designated points, during the bathing water season (May to September). Historically the Environment Agency had focused on meeting legal requirements and not the needs of users. Data was published through many disconnected routes where information about the bathing waters (profiles) was only available in pdf form and updated rarely.

At the start of the project (2010) the Environment Agency was beginning its Open Data journey and wanted to meet an open data ambition and improve the user experience. They approached us initially, to help build a pilot service that used linked data to get information out in a timely, reliable and reusable way.

Client: National Resources Wales and Environment Agency

Our Role: Consultancy, data modelling, data publishing, app development

Sites: and

The challenge

Develop a flexible ecosystem around bathing water sample data (and related datasets), publish the data in a timely way and help the public to access relevant information


The Environment Agency monitors and reports on bathing water quality the 419 beaches and other bathing waters in England and NRW at 107 locations in Wales (as of 2022). From May to September, waters samples are taken on a weekly basis and a picture of bathing water quality is built up. Sampling visits at each location result in two measurements of bacterial concentration that are determined in laboratory analysis.

At the end of the season an annual assessment based upon statistical processing of the samples is used to classify each bathing water and produce the official statistics (England / Wales). Under the Legislation, possible values range from excellent to poor.


Starting in 2010, we developed a proof-of-concept service to convert the water quality data to linked data with the Environment Agency (EA). This included an initial data visualisation as a web application. This phase of project was important for building support for the approach among data users and internal EA staff.

Following the successful pilot phase, we developed the web application through an iterative improvement. Initially this was to better show the data and allow non-specialist users to understand the water quality information. The data model was extended to include a major new information source: the bathing water profile – which gives detailed information about the site

Critically this required little or no modification to the existing data store or API (Application Programming Interface).

More iterations have added extra data and features in response to user needs. For example:

  • the service added abnormal situation alerting
  • daily pollution-risk forecasts and
  • embeddable web widgets
  • and had to cope with the separation of Welsh bathing water data in 2014 when Natural Resources Wales became a separate organisation.

With all these extensions we extended the linked data model to encompass the required changes without a period of downtime.

The bathing water data site is as a cloud-based service, using our automation deployment and monitoring tools.

We also developed an interface to allow authorised users from the Environment Agency and NRW to update the data easily and quickly. In this way, we met a key performance goal of getting water quality information out to the public and to beach managers with the smallest delay.


A key need for both Environment Agency, and subsequently also NRW, was to also support other users of the data. In particular this was to enable developers to incorporate the data within their own applications. We built the Environment Agency’s data explorer on a rich API that we documented to provide easy use by others. A simple widget was also created to help those wanting to incorporate the data into their own websites with minimal effort.

Current status

Each of the additional data sets have been integrated and cross-linked with other relevant entities. This has happened without requiring any database redesign or system downtime. All while being directly available on the web.

Using linked data to share information gives greater flexibility between data and the applications that use it. Data publishers and third parties can create applications that combine information from multiple providers.

For example: local bathing water information from the Environment Agency and NRW can be combined with information about other local amenities. This could include car parking and local accommodation to create a richer and more valuable experience for the end user.

The profiles application is now a primary channel for communicating pollution forecasts to beach operators so that they can erect appropriate signage at a bathing water each morning.


At a strategic level we have helped the Environment Agency and NRW to build a deeper understanding of the potential of linked‐data in meeting their vision to “create a better place”. We provide ongoing support and maintenance for the deployed solution with NRW as a managed service.

Linked data has enabled the Environment Agency (EA) and Natural Resources Wales (NRW) to extend the reach of their data. The development of these services has shown how linked data enables the incremental extension and enrichment of an information system. Highlighting how we can flexibly adapt to changing needs without needing to start over and minimising costs.

Bathing Water Project image

Epimorphics have been working closely with us as an agile supplier, helping us to deliver our open data commitments and vision of changing the way that we provide information on the environment. As a result, our data is more open, richer, and better able to support innovative reuse.

Evidence Manager, Environment Agency