Another option is to hire a specialist company that will paint your tile after acid etching so the paint adheres.  

It appears to be a caustic soda or acid. 

A combination HEPA/Acid gas may be more appropriate.

You went on with a physics soliloquy on why an island would not tip over based on a premise (an island tipping over) that can only be described as a congressional acid trip.

Around here, the acid test on a septic field is the hydraulic load test...they put a specified volume of water (based on BR count because systems are sized/designed based on BRs) and measure the water level in the field following the specified input. 

I was thinking perhaps use a light acid wash before painting or perhaps using a brillo pad to scratch the surface. 

I went to high school with STeve Jobs lived down the road from him.. and ended up living in the same hood as him in Palo Alto.. we were just west coast wanna be hippies smoking dope dropping acid etc etc. ( jobs more than most).. we had no clue as to how you folks live back there .. and its still that way today...

One cause could be electrolosis , dissimilar metals touching each other , another cause acidic water eating the copper from the inside out , third it could be bad pipe , in the early 1980's they built houses near me with copper pipe , after 15 years they were all having problems with leaks .Prepare yourself to replace the pipes in your house , its going to need to be done .

My main ingredients for weapons were simply a boric acid (borax) and sugar powder mix (about 1 to 10 borax to sugar).

When Chlorine reacts with water, it produces hydrochloric acid and atomic oxygen (For those of you following along, that's O not O+O, which is what we actually breathe.)