There is no longer such a Nitrates Directive requirement, but a broader range of evidence must be considered in relation to wider obligations when considering water quality.
Nid oes gofyniad Cyfarwyddeb Nitradau o'r fath yn bodoli bellach, ond rhaid ystyried ystod ehangach o dystiolaeth mewn perthynas â rhwymedigaethau ehangach wrth ystyried ansawdd dŵr.