I learned the embarrassing way by ribbing my neighbor when I thought I saw water from his sump spewing anti-freeze out that it isn't. The Sanitation Department dumped a green harmless chemical in water sources downtown Hamilton Park area to test sewage exit piping and put it in to household sump pump systems too. I've seen a couple green glowing puddles in back alley's or front of brownstones the last two weeks when walking my dog. It disappears fast and is apparently harmless. The good news is, I've also noticed Sanitation cleaning out our street sewage pipes. What, are my taxes going to good use?