Sulfur in water is not a defect...stinky, but not a defect! I have always told people about it if I was aware. It does not pose a health risk, or any other risk, again....other than being stinky.

Hi Sydario
In NY State an agent has a duty to disclose any material defects. Not only are we required to disclose defects we are aware of, but also defects we "should be aware of". That said, if you love everything else about the house, be aware that there are water treatment systems that can be retro-fit to the home to deal with this situation. Your Realtor should be able to put you in touch with professionals in your area who can give you an estimate on cost to install and maintain such systems. If the cost is over $1000, you can go back to the seller and try to renegotiate the sale price.
As to the seller, they are required to fill out a NYS Property Condition Disclosure form. If they don't fill out the form the Buyer gets an automatic $1000 credit. If they fill it out honestly and completely there is a question on that form regarding the water. The catch 22 here is they can also answer unknown or I don't know.
I don't know if the law is the same in AL, but if you contact a local Realtor, I'm sure you will get loads of help. I'd be happy to give you a recommendation for a great agent in your area if you need one.
I hope that helps you.
Laurie Stephenson
Associate Broker
Keller Williams
Saratoga Springs, NY
518-469-9000

States very, but generally if it is a known defect yes. Anything that the seller knows to be a defect, hazard or material fact must be disclosed.

Some states require disclosures about items that affect or could affect the property such as:

Earthquakes
Natural Hazards
Zoning Changes
Flood Zones
Fire Hazards
Noise Pollution
Ground Pollution
Air Pollution, among others