"They include such substances as benzene, ethylbenzene, toluene, boric acid, monoethanolamine, xylene, diesel-range organics, methanol, formaldehyde, hydrochloric acid, ammonium bisulfite, 2-butoxyethanol, and 5-chloro-2-methyl-4-isothiazotin-3-one. (Recently, in congressional testimony, drilling companies have confirmed the presence of many of these chemicals.) According to Theo Colborn, a noted e" . . . .