Dilution of polluting materials

When dealing with domestic quantities of polluting materials, it may be appropriate to dilute them with a sufficiently large volume of water if other control measures are unsuitable. High levels of dilution should ensure that pollutants have minimal impact on the environment. A risk assessment should be carried out before diluting polluting materials, which considers the pollutant type and quantity, and the nature of any receiving water system.

Approval should be obtained from the environmental agency or sewerage undertaker before diluting polluting materials, unless there is a threat to life. In such circumstances they should be informed as soon as is reasonably practicable.

Detergent or other cleaning products should not be added to polluting materials or spillages hosed to the drain without prior agreement by the appropriate environmental agency or sewerage undertaker.

Advice about dilution of polluting materials may need to be obtained from specialists, including a hazardous materials adviser (HMA), external specialist or the Chemsafe service provided by the National Chemical Emergency Centre (NCEC).

For more information refer to Foundation for environmental protection – Additional pollution control techniques.