Minimising watercourse pollution – First 5mm of rainfall requirement

  • Created:
  • Reference: KBCN1059

It may not be possible for the first 5mm of rainfall to be prevented from leaving a site completely. An appropriately qualified professional must explain comprehensively why this criterion cannot be fully met and design a system to meet the intent of this criterion as far as possible. Where this can be justified and all other relevant criteria have been achieved, the credit can still be awarded.