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The above photo shows the prefabricated grenhouse box at Britannia lodge, which shelters the blackwater module and ensures sufficient temperature conditions for the biological process inside.

SANBOX prototype at 3,000 meters - impressions and first results from the prototype at Britannia lodge 

November 25, 2010
The winter 2009/2010 was characterized by cold temperatures and extremely little snow. In April 2010 only half of the normal amount of snow was lying in the mountains around Saas Fee ( The low snow coverage of the glacier between Britannia lodge and Felskinn cable car resulted that it was not possible to access the lodge by snowmobiles, which normally can operate until July.

Swiss Air Force solves transport challenges

Transportation of the SANBOX components had to be reorganized by helicopter, which was possible thanks to the tremendous effort of the two SANBOX partners Swiss Alpine Club SAC and Gysi+Berglas AG and in addition the Swiss Air Force who did a great job for the project.

The Swiss Air Force supported the SANBOX project with
an AS332 Super Puma to transport components to Britannia lodge. Click on photo to enlarge.

The Swiss mountains offer a spectacular view for the installation teams doing trenching and pipe laying work. Click on photo to enlarge.


Building challenges

Building in the harsh environment on 3030 meters above sea level is challenging. However, thanks to the long experience of SAC and highly motivated construction companies the site preparation work could be accomplished without facing critical problems.

Ground preparation work between two glaciers at 3030 meters above sea level.

Prefabrication and installation

On July 16th the construction site was ready for the final installation of the greenhouse box which shelters the blackwater system from snow and cold temperatures. The box was prefabricated by Gysi+Berglas AG in Baar, from where it was transported to the final location at the south face of Britannia lodge. The long experience of Gysi+Berglas AG in greenhouse construction enabled a smooth positioning of the greenhouse box by helicopter.

The helicopter sets the greenhouse box down perfectly
onto its intended position at the south face of Britannia.
Click on photo to enlarge.

Staff from Gysi+Berglas AG conduct a final
check of position and pipe connections.
Click on photo to enlarge.

The greenhouse box being constructed at
Gysi+Berglas AG. Click on photo to enlarge.

The greenhouse box fully installed and ready for use.
Click on photo to enlarge.

Test results and treatment levels

Both the blackwater and greywater systems showed promising treatment results in the first period. The greywater module reached a good performance with 60%-70% reduction rate for COD (Chemical Oxygen Demand), despite of the extremely high inlet concentration, which was 5 times higher than in greywater used for initial tests. Due to this unexptedly high load, additional experiments are planned for the spring season to deal with this challenge.

The blackwater module reached a high performance of 80-85% COD reduction. More than 50% of the COD could be removed by the blackwater filter and collected in the composting module. Initial samples of the compost material indicate that the decomposition process results in a compost quality that can be used as fertilizer in local agriculture. However, it is still questionable if the treatment system at 3000 meters altitude can handle the composted extra from 8,000 – 10,000 accommodation guests per year. Additional tests are necessary to secure the final processing of blackwater solid fraction according to the project's goals.

The new Jets™ vacuum toilets installed at Britannia
are particularly appreciated by female guests.

The old urine diverting dry toilets were more difficult to keep clean.

The greywater module in the basement is challenged
by the extremely high organic load in the inflow.

More than 90% of the greywater is kitchen wastewater.

Initial test period conclusions

The first testing period strongly indicates a high potential for using SANBOX system in high alpine tourist facilities such as Britannia lodge. The SANBOX steering committee would like to thank all involved project partners for their great and professional efforts facilitating the system's operation in this highly challenging environment. A special thanks goes to the cabin team of Therese Andenmatten for her excellent hospitality provided to scientists and workers and the patience with all the inconveniences related to the construction work.

Solar based energy supply system on the roof of the greenhouse box. Click on photo to enlarge.

Solids being collected in the post-composting system.
Click on photo to enlarge. © 2011