Re: private water supply - manganese
The smell is from Hydrogen Sulphide. It is a fellow traveler with Iron and Manganese.
You should have your water tested by a reputable laboratory.
You should then show the results to a number of water treatment contractors (check them in the golden pages). Get a detailed description of the equipment they intend to install.
Search this site for "Manganese" and you will get plenty of hits. Beware of the many "cowboys" operating in the water treatment industry. Check if they belong to the WQA water quality association.
Make sure that they are in a position to conduct an annual check and adjust your filters if necessary.
Standard water softners will get rid of low to moderate amounts of Iron and Manganese but will not get rid of the H2S hydrogen sulphide smell.
To the best of my knoledge Iron, Manganese and Hydrogen Sulphide do not have an adverse effect on health.
You should test your well water annually for bacteria, chemistry and metals.
The bulbs in you UV filter need to be replaced very regularly.
...other filtering systems ...
What are these filters?