SimplexHealth working with Earthwatch organised national WaterBlitz events.

Fighting for healthy freshwater habitats across the UK. Pollution, climate change, and over-exploitation have brought our fresh water systems to crisis point. Many rivers are no longer fit to swim in and our water supplies for drinking and growing food are threatened.

Working together with local communities and partners, Earthwatch have created a growing network of concerned local citizens who care about the health of their precious freshwater resources: FreshWater Watch. This involves training community groups across the UK to use our FreshWater Watch toolkit to detect nutrient pollution and fight for real change

How did SimplexHealth work with Earthwatch?

As part of the April 2025 WaterBlitz, SimplexHealth was asked to provide the Laboratory River Analysis for coliform bacteria.

FreshWater Watch UK at a glance

There are 58 community groups across the UK, monitoring the health of their local freshwater bodies. FreshWater Watch groups cover catchments across England, Wales, Scotland and Northern Ireland. Over 1,000 group members are actively collecting monthly data and sharing it on our open-access platform.

WaterBlitz events

Organised local, national and international WaterBlitz events, encouraging everyone to take water samples locally over one weekend.

A WaterBlitz is a FreshWater Watch activity for everyone. Over one weekend, members of the public can sign up to receive a water testing kit and become citizen scientists by testing their local waterbody. The data collected by thousands of people over this same time period allows us to compare freshwater health.

Spring Great UK WaterBlitz Report

During 25-28 April, Earthwatch received over 4,000 data points from nearly 8,000 citizen scientists across the UK.

They found that:

  • 66% of datapoints across the UK show poor water quality, with unacceptable levels of nutrient pollution
  • Over three WaterBlitzes, England has the worst water quality in the UK – this April, 74% of sites tested had unacceptable levels of nutrient pollution
  • The Thames and Anglian river basin districts have the worst water quality in the UK, with 86% of measurements showing unacceptable levels of nutrient pollution
  • The Neagh Bann river basin district in Northern Ireland has the best water quality in the UK
  • The Scottish counties of Roxburgh, Ettrick and Lauderdale, Ross and Cromarty, Kirkcudbrightshire and Inverness have the best water quality in the UK
  • The English counties of East Riding of Yorkshire and Rutland have the worst water quality in the UK, closely followed by Oxfordshire and Hertfordshire
  • 24% of datapoints across the UK show E. coli levels that would classify as poor (were the site to be given bathing water status) with significant regional variation

See the April 2025 results here

Earthwatch believe that we cannot truly understand what is going on in our rivers without collecting evidence to demonstrate how healthy, or unhealthy, they really are. They use data collected by the WaterBlitz volunteers to identify clean waters, to pinpoint pollution hotspots, and gain a snapshot of overall water quality.

In the UK, funding is enabling national WaterBlitz events to take place biannually across England, Wales, Scotland and Northern Ireland every spring and autumn. Wider WaterBlitz events have also been held by our research partners across Europe, in Ireland, France, Italy, Luxembourg, the Netherlands, Spain and Sweden.

Check out our WaterBlitz event listings here to see if there is one happening soon in your area!