Rotten egg gas is hydrogen sulphide, while sulphur is a yellow solid which you can see at Gunung Ijen in East Java - they carry loads of 80 Kg down the steep slope. At Ijen when the mist over the lake drifts in your direction it is very acrid and what we may described as sulphurous - I think this is more sulphur dioxide.
You seem to be identifying hydgrogen sulphide in your water supply, and there is this Canadian web page
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex1160 that addresses the issue.
One thing it says is that water with hydgren sulphide in it will turn sterling silver black - so dig out your Sunday best silver and expose it to your water.
