Decentralized treatment and re-use of toilet wastewater in alpine areas
In the last century, the upper alpine region experienced a major
change in activities, from a pure agricultural land use toward an increased use
for tourism. The Swiss Alpine Club (SAC) alone operates 153 Alpine huts for
about 300`000 overnight stays each year and about 1`000`000 day visitors. In
addition, hundred thousands of winter sports tourists enjoy daily the high
mountain environment.
Because of the special location of these infrastructures (see picture above) the
problematic of water supply and wastewater disposal is particularly significant.
In many cases no supply with melt or spring water exists. Furthermore it turns
out to be especially difficult and complex to dispose the produced wastewater in
a conventional way. Due to its high contamination level wastewater cannot be
disposed off as such, posing a threat to environment and spring water quality
especially in karstic regions. The option of piping it down to a valley
wastewater treatment plant (WWTP) however generates high construction and
maintenance costs.
In this project the operation of Europe's highest biological WWTP
in the ski resort of Zermatt is investigated. The plant, based on Membrane
Bioreactor (MBR) is located in a cable car mountain station, 10'781 ft. above
sea level (see plant scheme). The negative impact on sensitive mountain environment is minimized by
using the treated wastewater again as flush water for the toilets. The project
deals with treatment, disposal and long term maintenance questions. In a global
view the project is of great importance, it covers problems existing hundredfold
in the Alps and furthermore re-use of treated wastewater (only urine) will
definitely be of great importance for arid regions all over the world. The
operation of the plant is a joint venture of Zermatt Bergbahnen, terraLink Gmbh
and of Eawag. The project is financially supported by the Swiss Federal Office
for the Environment (BAFU).
The Jury of the Mülheim Water Award, which was given
for the first time in 2006, was positively convinced by the project
results (more). The award is supported by the IWA (International Water
Association). [more...]
Detailed informations about the project are given in the paper.