They are still studying as to why some areas tend to be hotbeds for mac. I have a feeling it has to do with the municipal water source. I had the water company test my water at my home here in Bluffton and it was negative for mac. I have not had mac since I moved here in 2012. The water here does have another bacteria in it that is not usually harmful to health that does not let mac live. I have the name written down somewhere. I know we had a discussion about that on this site. Will see if I can find it for you. Yes, I tested negative without the Big 3. Click on my photo icon and read how my Mayo doc treated it.

Dear Connect Members, @aerogirl

Remember the poll I started about who has the ‘pink slime’ AKA Methylobacterium in their bathrooms? I have been in contact with Joseph Falkinham, a NTM reseacher and professor at Virginia Tech. He is very interested in starting a data base for where this particular bacterium is located throughout the U.S. and Canada. I have noted the locales from those of you who have already responded. Am encouraging any others with the pinkish/orange bacteria to report it back here to me. I don’t know about you, but I am excited to be a part of important research.
Please include your state and county name when submitting. Thank you in advance for helping with this poll. See e-mail below from Dr. Falkinham – Terri M.

“Dear Terri:

The source of mycobacteria in homes and buildings is the municipal water from a utility. It enters the treatment plant from the source water, usually adhering to soil particulates. The mycobacteria are disinfectant-resistant and are the few survivors of disinfection (e.g., chlorine) and have no competitors that have been killed off.

When that water reaches our homes, the mycobacteria grow in the water heaters and then are circulated throughout the house. We are currently finishing up work showing the impact of the water heater on mycobacterial numbers. Thus, the critical control point for mycobacteria might be the water heater.

I would certainly appreaciate knowing where the “Connect” group has found pink slime. You have given me an idea….I can use the NTM Foundation data base to get an idea of pink slime across the US and Canada.

Best,
Joe”

aerogirl, You can scroll to the top of this thread and go click on the magnifying glass icon; type in 'pink slime' and you will see all kinds of comments about that and mac in plumbing pipes. That kind of search works for other topics too.