Well guys there have been a few threads on this subject and I have read them all and gained a lot of knowledge. It's my turn to pick a treatment plant and I think I have settled on the Vortex eco. http://www.wte-ltd.co.uk/vortex_sewage_treatment_plant.html. It appears to tick all my boxes and I particularly like the two sizes of air bubbles they develop ( or am I being baffled by science ?). It's also adjustable to make sure it's not under used, a feature I have not seen elsewhere. On one site t
This table might be useful.
Sewage Treatment Plant Selection - Which Sewage Plant is the BEST?
Comparision of EN12566-3 Test Results
Below is a comparison list of Performance Results during the EN12566-3 Test - taken from the EN12566-3 PIA Test Centre website.
The figures are the average of the 38 weeks testing - the lower the figures, the better the result. It is probably better to avoid plants which have figures in red that are at, or close to, the limit