This van (seen in Pittsburgh) wryly references the myriad, often toxic rainbow of chemicals found in the hydraulic shale fracturing (or “fracking”) method used in drilling and stimulating natural gas wells. Although it’s a hot issue in New York and Pennsylvania, these chemicals are making their way into groundwater all over the US – including the “over 32 million gallons of diesel fuel or hydraulic fracturing fluids containing diesel fuel (utilized without permits and despite denial by industry spokespeople) in wells in 19 states between 2005 and 2009. (source)“