아펜젤 지역 환경당국은 당초 외부에서 유입된 물질에 의해 호수가 오염된 것으로 보고 인근 지역을 조사했으나, 원인을 찾지 못했다.
The Appenzell Regional Environmental Authority initially suspected that the lake had been contaminated by substances introduced from outside, and they investigated the surrounding area but were unable to identify the source.