The well water never smelled really bad before this spring. I would say it smells like sulphur. Could it be because of all the rain? The well is about 160 ft. deep.
Could be a number of things, including the rain. I would have my well checked for water quality if it was mine (and I wouldn't drink it in the meantime).
Don't have any idea what your 'well' is like, but it may have gotten some surface water in (depends on how much is cased), or some animal dropped in and is decaying, or other things too numerous to mention. But a change in taste or smell means something happened, and you probably should get an idea if the water is fit to drink.
Are you in an area that gets sulfur in the water in wells? Some areas are known for such water.
Check a cold Tap outside. The water heater anode is a good source of smell if bacteria has attacked it. If that has happened remove it and install a plug or buy a new heater. They say it voids the warrantee. Big deal. They don't replace them anyway.
My water smells like sulpher all the time. I have lots of volume, just smelly. When I bought the house, I knew I wouldn't be able to handle this for long, so chlorine is added in a holding tank to make the smell disappear, then other filters are in line to remove the chlorine. Sounds complicated, but in reality, it simple and works.
Mine does that when the water level gets low.
When you dig around my place you can bring up big bright yellow rocks from time to time. Its sulfur. Leaches into the water and creates the smell.
Bleach will solve it if its a short term problem.
If it continues to be a problem get a chorlinator. This will drop small amounts of chlorine (basically concentrated pellets of bleach) into the well when your pump runs.
Plus side is is will stop the problem and you will be sure that no bacteria will survive. Negative is it costs about $1K to install.
The chlorinator will not completely solve the problem if you have a very large amount of hydrogen sulfide (rotten egg smell) and do not use much water.
i've never seen a chorlinator that drops pellets into the well, but it sounds like a good idea..i use a small pump that runs when the pump does, and takes a bleach mixture out of a tank, then puts it into the water line..the pump cost about $250 retail, i bought mine off ebay for about half price and it was new. plus about twice a year, i pour bleach down my well..this seems to work.
heehaw
my well also does this some times, mostly when low consumption lets it build up. I drop in a few pool tabs every so often just to help keep oit clear durring off times when I'm not out there enough to keep it running. the boss, has his brother living out back and pumps water out of the pond to use for hole house, (not drinking) but runs it through a filter bank we built, on the outlet side is a small strainer which he puts in one of the 1" dia tablets which colorinates the water as it passes through. (same ones I drop in my well) also if it gets bad a gallon of bleach down does the trick, but my hot water did it really bad last fall under low use. so I drained and poured in 1 gallong of bleach dirrectly into tank then left it set for a week or two full of bleach water hasn't stunk since I ran all the bleach out...
warning don't wash cloths with it or else they will get much lighter... lol
also if the bleach is UPSTREAM of the bladder pressure tank it can make the bladder rot on the pressure tank best to bleach oafetr the pressure tank if possable like my boss's brother does.