The graph above illustrates the percentage of water in UK rivers that was counted as having good chemical properties between 1990 and 2002.
Overall, Wales and Northern Ireland mostly remained steady. Conversely, England faced a sudden sharp rise and then declined back to its starting point. Similarly, quality water in Scotland increased and decreased back.
Wales’ percentage of clean water was about 96 percent from 1990 till 1998. But it was reduced to 80 percent in 2002. Northern Ireland was nearly at 83 percent between 1990 and 1998. But in 1998, it transcended Wales and rose up approximately to 96 percent in 2002.
Rivers like England and Scotland had the worst chemical quality as England was at 45 percent while Scotland was at 22. But it soared to 69 percent in England, in the years 1990 and 1996. Later, it fluctuated back to 50 percent. Ultimately, it dipped to 50 percent in 2002. Scotland was practically ceaseless till 1996 and later experienced a surge in water classification reaching 40 percent in 2002.