Extending the reach of Bathing Water Quality information

Linked data has enabled the Environment Agency(EA) and more recently Natural Resources Wales (NRW) to extend the reach and impact of their open bathing water quality information while reducing their costs for publishing the data and responding to queries. The development of this service over a five year period is a case study in how linked data enables us to incrementally extend and enrich an information system, to flexibly adapt to changing needs without having to start over.

Start small and extend

Between them EA and NRW monitor and report on bathing water quality at around 500 beaches and other bathing waters in England and Wales. During the bathing water season, which runs from May to September, waters samples are taken on a weekly basis. The sample are processed in a lab, bacterial colonies grown over a couple of days are counted and recorded on an internal system. Over the period of a season the results of these weekly assessment build up a picture of bathing water quality at a location which is formally reported in November after the close of the season. These processes exist in order for the UK to meet its obligations to the EU under the relevant Bathing Water Directives. Perhaps more importantly these processes help "make a better place" because the quality of bathing water in a locale that depends on tourism can have a significant impact on the local economy in that place.


From an initial pilot that published just:

  • basic reference data about bathing-waters and sampling points
  • in-season sample assessment collected weekly during the bathing-water season
  • annual compliance assessments made at the end of the season based derived from the weekly sample data

Successive expansion projects have added:

  • live bathing-water profile pages that contain information of public interest about each bathing water as well as embedding up to the minute water quality information
  • notices of abnormal situations affecting water quality
  • short-term pollution risk forecasts which provide daily predictions of whether water quality is at increased risk generally due to weather situation.

Each of these additional data sets have been integrated and cross-linked with the other relevant entities, without requiring any database redesign or system downtime.

This data is all available directly from the web as simple web page retrieval using a Web API. The API also provides the data in machine readable JSON, XML, CSV and of course linked data formats such as RDF/XML and Turtle.

Reaching out

Building on top of the Web API we have developed an bathing water profile application that presents the data in a form that is more accessible to the general public. It also contains pages that provide overviews of multiple bathing waters that are of interest to beach operators and to local authorities. These pages are highly configurable with respect to the bathing waters that are presented. The profiles application benefits from considerable user research conducted with the general public, beach operators, local authorities, interest groups and NGOs and with water companies. The profiles application is now a primary channel for communicating pollution forecast to beach operators so that they can erect appropriate signage at a bathing water each morning.


Recognising that learning a Web API can still be an obstacle to the integration and reuse of data we undertook a project to develop an embeddable widget that enables authoritative bathing water quality information to be embedded into a 3rd party site simply by copying a small amount of markup into a web page. This has been enormously successful with the Marine Conservation Society embedding the widget for a given bathing water into the page it maintains about the corresponding bathing water. Widget variants are also targeted on local-authorities enabling them to easily provide up-to-date summary information about bathing waters on their patch.

Other third parties have taken the API and created their own presentations on top - including several mobile phone applications as well as beach information web sites.

What difference open access to data can make

EA and NRW have taken on the open-data idea. They are making data available as a matter of course and avoiding having to handle multiple, costly, freedom of information (FOI) requests. Instead they have opened the data and are providing facilities so that users can self-serve - whether a causal inquiry about the current state or a deeper inquiry into the longer-term trends at multiple locations.

They have thought creatively about how to make the data accessible to web developers, partners and the general public in ways that meet their needs through the provision of a developer centred Web API, a user centred rich web application and an embeddable widget that makes integrating water quality data into local web pages even easier.