spitting: dirty or am I foolishly fastidious

In an effort to swim closer to home I started going to a community pool nearby. Just as I was about to get in a lane, the young woman in it stopped at the end, hawked something up, and spit it in the gutter. Then she did it again. The lifeguard to whom I pointed this out said that the gutters empty into the sewer. I don't think so, and even if the water is sent through the filters, is spitting in the gutter now acceptable? Wasn't when I swam in college 35 years ago, isn't at the (expensive) club I was trying to substitute for. But is this dirty or am I being foolishly fastidious? Your honest comments please!