I acid etched my floor two weeks ago and let the rinse water go down the driveway(asphalt) to the curb. No ill effects that I can see. By the time the acid gets to the driveway it is very diluted except from the slab right at the overhead doors. When I rinsed mine, I went outside and rinsed towards the back wall of the garage enough to really dilute the water so that I wouldn't ahve any problems.
A couple of other things to keep in mind:
- Keep the grass along the driveway wet with clean water to keep it from burning with the acidic rinse water.
- Park your vehicle(s) away from any area that may get splashed with the acid. I don't know what it would to the finish and I didn't really want to find out.
- Wear a respirator with Muriatic acid - the fumes will knock you on your azz if your not careful.
- Wear all of the protective gear listed on the bottle - goggles, rubber gloves (make sure they are specifically listed for acid contact - most aren't), rubber boots, long pants, and long sleeves.
- Keep everyone out of your work area that doesn't know exactly what you're doing. Anyone in the work area also needs to be using all of the protective gear you are.
