Scientists found a special chemical called TFA in many UK rivers; it's called a 'forever chemical' because it doesn't disappear easily.
They checked lots of rivers and found TFA in almost all of them, it's like a tiny little hidden secret in the water.
This TFA comes from other chemicals that were used a long time ago It slowly builds up in the environment.
Scientists are learning more about this chemical to keep our water safe, it's very important to protect our beautiful rivers.
