Water Runoff Toxicity from New Concrete

Jun 5, 2012
Anyone know what the effects are to plants (grass & young trees/shrubs) with regard to water running off of new concrete?
The water appears amber/green and is very "slimy" to the touch which means the pH is on the base side (probably 2 - 3 if I guessed). It is highly irritating to the skin.

Have approx 1000 sq ft of concrete pool patio that collects in the middle and runs off to one end into my grass right near a new tree.
The earth worms hate it and make a mad dash away from the area.

Any info is helpful, thanks!


Mod Squad
TFP Expert
Apr 4, 2007
SW Indiana
Low pH is acidic, but you are correct that concrete is basic. 12 or 13 if my memory serves me. Any effect is going to be very temporary.