Friday, January 12, 2018

Wellwater smells of boiled egg

Q: I am from Lesotho, In my village, there is small river with a well in that river, water from this well has smell of boiled egg in it, NB. There are no swerage or any gas plan around, this well I am told has been there before that village. I want to know the possibility of mineral dispose that can be found there
- Tsepo K

A: The smell you describe is SO2. It can occur when volcanic gases broach a water table above it, and the natural volcanic H2S gas (which smells like a burnt match) is in effect "scrubbed" by the water and converted to SO2. SO2 can also form from rotting vegetation in a swamp in some circumstances, however, your location along the East African Rift strongly suggests a volcanic origin. 

This gas does not usually imply nearby mineralization, unless you are searching for sulfur deposits.