Sudden smell of rotten eggs at home?

The Wasserwerke Zug (WWZ) utility company is about to start its two-yearly checks on its supply of gas to households. To this end, it has introduced an extra strong odorant to the gas which will help in detecting any leaks.
 

The gas used to supply households is odourless but an odorant, which is totally harmless, is added to it for safety reasons.

This latest test using the extra strong odorant is to start on Monday 25 March in the city of Zug, Baar, Cham, Steinhausen, Hünenberg, Risch and Rotkreuz, in addition to Sins in the neighbouring canton of Argovia, as well as in the Knonaueramt region of the canton of Zurich.

If anyone does notice this smell, they should ring 0417 48 48 48, though they should also note it can take two or three days for the odorant to pervade the whole system.