In East Anglia, many river reaches fail to achieve the RE targets set for them,consistently showing low levels of DO during the summer. However, since the RE system was derived from two schemes that were not rigorously defined statistically, the translation of old standards into the new RE targets resulted in many river stretches being assigned the highest targets, when in the past they were more likely to attain only lower standards, which were then deemed acceptable. This, together with the fact that the RE system was not adopted with reference to the ecology of specific rivers but rather was designed to apply to a wide range of rivers across the UK