Given the limitations outlined above and in the absence of a single methodology it is difficult at this point to draw any conclusion on the direct impact of the regulations on water quality to date.
O ystyried y cyfyngiadau a amlinellir uchod a'r diffyg methodoleg benodol, ar hyn o bryd mae'n anodd dod i unrhyw gasgliad yn ymwneud ag effaith uniongyrchol y rheoliadau ar ansawdd dŵr hyd yma.