This is in response to the comments from Dr. Hans Brix of May 14

>(1) The plants used on and in the 'Living Machine' provide a marginal
>contribution to treatment and are not essential for realization of process
>treatment goals.  The plants do, however provide a pleasing aesthetic
>environment which can significantly enhance public acceptance as a
>waste treatment process.

With reference to the Vienna paper, you raise the issue of the efficacy of the contribution of plants to Living Machines.

We in Living Technologies believe that plants provide substantial surface areas in the water columns in Living Machines.  To some extent the game is one of surface area.  A water hyacinth is said to have 27 miles of root hairs in one mature plant.

There is also the issue of the surface area being provided by living tissue. We believe there are substantial exchanges in liquid and gaseous forms between the plants and the microorganisms in the water column that enhance the treatment process.

It has been shown in recent aquatic systems studies, which is also confirmed by Sherwood Reed, that more degradation of pathogen colonies is found in planted versus non-planted aquatic systems.

The statements in the Report, I believe, are highly politicized.  There was an underlying agenda, which we do not believe is corroborated by the data, to downplay the effectiveness of the application of ecological design principles to wastewater treatment.