It is slick with grease and clacks and groans. There is no sign directing you to it. The forest preserve once erected a sign noting that usage of the pump was limited to 10 gallons, but that’s a losing game. Now there’s just a notice not to the feed wildlife that wander in from the surrounding meadows. The pump sits at the end of a long path, which is shoveled in the winter. During spring rains, pumpers hold umbrellas high for their fellow pumpers. The stream of customers feels endless. One car pulls away, two pull up. A grandmother with grandson fills six mayonnaise jars; a jogger fills a water bottle then jogs off. An old man wearing his work uniform pushes a hand truck stacked with large office water jugs; he fills each then loads them into his trunk. Chris Berndt, a University of Illinois at Chicago graduate student, rode up on a scooter and filled several small bottles. He told me he has been coming here for two years, partly because he doesn’t trust the fluoridation treatment in tap water.