We got a new condensing boiler thanks to Superstorm Sandy. The condensate exits the house through a cinder block foundation wall and drips into flower bed. The drip pipe sticks out from the wall about 3 inches. I know the condensate is acidic and can corrode cast iron pipes but do I need to worry about damaging the cinder block over the long term? The “soil” is pretty much sand and drains rapidly. In the winter it drips maybe a gallon a day. Someone suggested digging a hole under the drip pipe and filling it with lime chips. Is this a non-issue or something to be concerned about?
Not sure it really is acidic. Theoretically it would be fairly neutral, but from my experience with such things, the pH will be hard to measure consistently as it isn’t buffered and any contaminants will have a great influence on it. CO2 dissolved in it will make it acidic, but not greatly so.
That being said, I accept as a probability that it will corrode iron as it will promote rust fairly easily.
To me, its a non-issue. But its pretty dang easy and a low cost, low risk situation to use lime to buffer the water. Heck I think cinder blocks are mostly lime (could be wrong) so you can just have it drip on some crushed up sacrificial cinderblocks.
My verdict if I were you: I wouldn’t worry about it, but put the lime or blocks under the drip anyway, because it won’t hurt and it might be fun to watch it and see how they dissolve over time.
You need to put limestone where the water exits so the water can grab from there, and return to normal state. You will be surprised how fast the limestone is eaten away.
The best way (and least expensive) would be to use some pH test paper as shown here: