JKB, great stuff! Where did you get your data (so I can save the link). I agree with your math, nicely done. I was unaware that so little chlorine could do that much damage.
The other think I was thinking about was the fact that there will be a lot of losses during the run down slope. As the water fans out, the surface area will be expanded and the interactions with plants, soils, and air should cause a lot of the chlorine to leave the solution.
Clearly you have thought about this more than the rest, so I will be interested in how much of the chlorine you think will be lost as the water runs downhill to his pond.
Darrell did you know how much chlorine was in your pool before it got pumped? The math would be interesting.
