Mick Jennings, 55, a mechanical fitter for Yorkshire Water, was badly injured at the sewage treatment works on Oxton Lane on Monday.
A Yorkshire Water spokeswoman said: “Following the serious accident at Tadcaster waste water treatment works on Monday, it is with great sadness that we can confirm the death yesterday of our colleague Mick Jennings.
“Mick, 55, was a mechanical fitter in our Engineering Reliability team and had worked for Yorkshire Water for eight years.
“Our deepest thoughts and sympathies go out to his family, friends and work colleagues at this most difficult of times.
“We are working closely with the Police, Fire Service and the Health and Safety Executive to determine the cause of the accident. The family have asked for privacy during this time of grief”.