(I am also curious but probably not all that important...... if anyone has any thoughts on type of PEX PEX-A - "Uponor" - more flexible more expensive, not a strong against high pressure; PEX-B "Viega", more rigid but harder to bend or curve, has higher pressure, oxidation, chlorination tolerance; PEX-C... ?

An air pressure test will help detect issues with the domestic water; however, the water lines will need to be disinfected/chlorinated.

There are many solutions that you can do yourself.There are some that you never want to do yourself.The EPA guidance on mold issues is here:  http://epa.gov/mold/moldguide.htmlThe digital copy of the same information is here: http://epa.gov/mold/pdfs/moldguide.pdfThis document does not help you estimate costs for repairs, but does help you see through the "smoke screen" that many remediation companies will put up when talking about mold in homes.In spite of what John D. recommended in his response above, the use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup.  

Smoking in the presence of these chemicals when they are free in the atmosphere in an enclosed space can cause death by phosgene poisoning if the refrigerant is formulated with chlorine (R-12, R-22, etc.)

Be careful, the bleach mixed with the ammonia in the pee and caused a mild chlorine gas ( which may have helped the smell but didn't do much for my lungs).

There's not a species of mold on this planet that won't be killed by chlorine bleach.  

I bought a property where the head of the well head had not been taken out since 1967, now that I did to chlorinate it, I realised it lies a few feet into neighbor's property.

I ran all the 240v electric to the hot tub & it's always set to 96degF with it being adjusted higher during use, yet the electrical consumption is not noticeable.We do not use anything other than Eco-one to treat the water, but I throw in a cup of chlorine after heavy use.

Some state environmental divisions are trying to shut down Wells for communities because of thee a safety factor and communities cant afford the chlorine and treatment that a community well needs..I'd forget this deal If I were you.

The fix for one problem (i.e. tannin) creates an entirely new pro lem (i.e. chlorine injectors), etc.I'll still buy a property with a well, but I'll greatly increase my capex and monthly expense calculations before I count cash flow.