| #D001 | | Guideline Technical Documents | formerly known as Guideline Supporting Documents | high |
| #D002 | | Multi-Barrier Approach to Safe Drinking Water | This approach looks at each drinking water system from the source all the way to the consumer's tap to make sure all known and potential hazards are identified and addressed so water remains free of contaminants. | high |
| #D003 | | Aesthetic quality guidelines | address parameters which may affect consumer acceptance of drinking water, such as taste, odour and colour. | high |
| #D004 | | Operational guidelines | are set for parameters that may affect processes at a treatment plant or in the drinking water distribution system. | high |