Roadworthy- generally, “sulfur water” is “older” water from a deeper source. Often highly mineralized because it’s been in contact with rocks for a long time. Connotation is it’s also protected from contamination.
Oddly, that hard, stinky water is often good for you, because it does contribute to your dietary intake of minerals like calcium and iron. Unfortunately, it’s often objectionable for odor, plumbing fixture staining, laundry, and other aesthetic characteristics.
Some harmless anaerobic bacteria can produce hydrogen sulfide in that environment. Hence, the sulfur smell.
I’m not aware of coliforms producing hydrogen sulfide in that manner in groundwater, but certainly a raw sewage discharge can have that characteristic. At 440 feet to top of pump, I think you’re generally protected from that unless it seeped down an annular space along the casing.
Some folks have luck with a wellhead pellet chlorinator to control sulfur as well as oxidation of iron and manganese. As someone said, if there’s chlorine, there’s no sulfur.
Your case sounds simple enough and is behind you.
If you wanted, you could shock the well a couple times a year. Pour chlorine solution down well as noted above. Run water inside in a bunch of taps until you can smell bleach, then shut everything off and let sit for a couple hours. Then flush out an outside hose bib.
I had a friend with a deep well and a bunch of harmless iron/manganese bacteria. First time he did that process, he could have filled a couple buckets of disinfected bacterial mass…oozed out of the hose bib like thin black jelly….
Take care.