potted water can be anything...directly from a lake, or an old well...usually used to cool cutting devices you see alone the road, grinding up the pavement...or to water down the dust....
His car may have got blasted from an old well he was watering his yard with...it costs too much to use treated city water to water lawns around here, so many drill a small well for their sprinkler systems....or draw from the lake...don't want your car anywhere near them....