Translate the following English sentence to French:
"When the Drinking Water Directive was reviewed a couple of years ago, the European Parliament insisted on a tough limit for radioactive substances. Thanks to the European Parliament' s perseverance, this was also included in legislation."
Lors de la révision de la directive "eau potable", il y a quelques années, le Parlement européen avait insisté pour imposer une limite sévère en ce qui concerne les substances radioactives.