Dumping at Campgrounds and Flushing Black Water Tank Too

That's good info. My family and I took our TT out for the first time and there was a long line of RVers at the dump site (Sunday late-morning of July 4th weekend)... I just dumped it, flushed the dump hose with the gray water and left. We have a years worth of free dumping at the place we bought our TT so I'll probably take it over there and do a proper flush.