These installations are fondly talked about by so-called ''environmentalists'' who like to make everything ''natural'' and ''friendly'' and it is a shame that in general reed beds do not work efficiently enough to treat raw sewage. The idea is sound in principle. Clumps of common reeds are grown in contained beds, and sewage is directed through the bed. A combination of bacterial action, and absorption of nutrients by the reeds neutralises the waste material in the sewage. A withy (willow) bed is another variation to this. The problem is maintenance, or rather lack of it.  Prince Charles has a withy bed at Highgrove House, and is justly proud of it because it works, but it is maintained by a squad of groundsmen. A normal domestic bed is in most cases installed and then forgotten. The Environment Agency generally frown upon reed beds used for main treatment of raw sewage.

 I.H.S. Systems Ltd. can install reed beds as primary treatment where the Environment Agency agree, but more commonly we install reed beds for add-on tertiary treatment where existing sewage installations have problems maintaining the Environment Agency required level of purity. Reed beds ''polish'' up pre-treated sewage before final discharge to a watercourse. Reed beds are also used when the treated effluent is discharged to a pond or lake to further purify the final liquid.